Milestone-Proposal:Thin Film Hall Elements
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Docket #:2025-19
This is a draft proposal, that has not yet been submitted. To submit this proposal, click on the edit button in toolbar above, indicated by an icon displaying a pencil on paper. At the bottom of the form, check the box that says "Submit this proposal to the IEEE History Committee for review. Only check this when the proposal is finished" and save the page.
To the proposer’s knowledge, is this achievement subject to litigation? No
Is the achievement you are proposing more than 25 years old? Yes
Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes
Did the achievement provide a meaningful benefit for humanity? Yes
Was it of at least regional importance? Yes
Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes
Has the IEEE Section(s) in which the plaque(s) will be located agreed to arrange the dedication ceremony? Yes
Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes
Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes
Year or range of years in which the achievement occurred:
1983
Title of the proposed milestone:
Commercialization of Thin Film Hall Elements, 1983
Plaque citation summarizing the achievement and its significance; if personal name(s) are included, such name(s) must follow the achievement itself in the citation wording: Text absolutely limited by plaque dimensions to 70 words; 60 is preferable for aesthetic reasons.
Milestoneの訴求点を「旭化成が1983薄膜ホール素子を量産化したこと」とすると、何処の章節に書いてある？
審査員にそれを納得して貰える証拠は何処にある？
Thin film Hall elements revolutionized magnetic sensing applications when they were first commercialized by Asahi Kasei in 1983. These magnetic sensors utilize the Hall effect and feature a structure that significantly enhances sensitivity, consisting of thin film InSb sandwiched between ferrites. Thanks to high performance, it quickly enabled a wide range of applications, establishing it as a crucial milestone in semiconductor thin film magnetic sensor technology. (66words)
200-250 word abstract describing the significance of the technical achievement being proposed, the person(s) involved, historical context, humanitarian and social impact, as well as any possible controversies the advocate might need to review.
Thin film Hall elements made its commercial debut in 1983, marking a revolutionary milestone in magnetic sensing technology. We focused on InSb, compound semiconductor that had previously been overlooked due to its difficulty in industrial mass production. By using thin film InSb vacuum-deposited on mica, its sensitivity and temperature characteristics were improved. Thin film InSb was then attached to magnetic ferrite material, and Hall elements were fabricated using photolithography process. Magnetic amplification structure was then formed on top of the ferrite chip, which was then packaged in plastic, creating a mass-production process. Unlike conventional Hall elements, these Hall elements can be applied to standard automated mounting processes, enabling a wide range of applications in both home and industrial equipment. These Hall elements became a fundamental component of DC brushless motors. Compared to brushed motors, DC brushless motors offer longer life, lower noise, and smaller, thinner components due to their non-contact nature. They were first used in VCRs, PC FDDs, CD-ROMs, and cooling fans, contributing significantly to the development of these components. Subsequently, These Hall elements were applied to cooling fans in servers and air conditioners, contributing to energy savings around the world, and to drive motors in power tools, making them significantly more compact. By 2025, a total of 40 billion Hall elements had been sold, and they have remained the foundation of magnetic sensing. Its enduring legacy reflects both the ingenuity of its commercialization in 1983 and the adaptability of sensor technology to evolving market and technological demands. (249words)
IEEE technical societies and technical councils within whose fields of interest the Milestone proposal resides.
IEEE Electron device
In what IEEE section(s) does it reside?
IEEE Fukuoka Section
IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:
IEEE Organizational Unit(s) paying for milestone plaque(s):
Unit: IEEE Fukuoka Section
Senior Officer Name: Tadashi Suetsugu
IEEE Organizational Unit(s) arranging the dedication ceremony:
Unit: IEEE Fukuoka Section
Senior Officer Name: Tadashi Suetsugu
IEEE section(s) monitoring the plaque(s):
IEEE Section: IEEE Fukuoka Section
IEEE Section Chair name: Tadashi Suetsugu
Milestone proposer(s):
Proposer name: Chiaki Ishikawa
Proposer email: Proposer's email masked to public
Proposer name: Ichiro Shibasaki
Proposer email: Proposer's email masked to public
Proposer name: Naofumi Uesugi
Proposer email: Proposer's email masked to public
Proposer name: Tsuyoshi Shiraki
Proposer email: Proposer's email masked to public
Proposer name: Takashi Yoshida
Proposer email: Proposer's email masked to public
Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.
Street address(es) and GPS coordinates in decimal form of the intended milestone plaque site(s):
Asahi Kasei Nobeoka Exhibition Center, 6-4100, Asahi-cho, Nobeoka-Shi, Miyazaki, 882-0847, Japan.
GPS coordinates: 32.5708047,131.6681052,16
Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.
Please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. The Asahi Kasei Nobeoka exhibition center is a corporate facility operated by Asahi Kasei corporation.
Are the original buildings extant?
No.
Details of the plaque mounting:
The milestone plaque is scheduled to be displayed inside the exhibition room, mounted on a display base.
How is the site protected/secured, and in what ways is it accessible to the public?
The exhibition center is open to the general public by making a reservation through the booking system. The exhibition is open from Monday to Friday, between 9:00 AM and 12:00 PM, and from 1:00 PM to 4:00 PM.
Who is the present owner of the site(s)?
Asahi-kasei corporation
What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include detailed support at the end of this section preceded by "Justification for Inclusion of Name(s)". (see section 6 of Milestone Guidelines)
Historical Significance
この章の目的は、1983年に、旭化成が薄膜ホール素子を量産化したことが、Milestone「歴史的な一里塚」であることを説明すること。つまり、(1) その薄膜ホール素子の製品化が、「その当時、画期的な出来事であった」ことと、 (2) それが今日振り返ると「歴史的にインパクトが大きい」ことを、審査員に知ってもらうこと。技術論文とは違う意味の新規性（新しい市場を作った）と、有効性（現代まで役に立った）を説明する。
薄膜ホール素子の知識は、Proposalを読んでもらうための最低限で良い。何度も言うが、審査員は文系の人が半分で、理系の人と雖も、こんな専門用語で長々と書かれても判らない。
技術の議論の中心は、4章（課題と解決策）と5章（他の方式との比較）である。
この章は、現状の半分の長さで良い。この章は10節に分かれているが、せいぜい5節程度（導入・技術的な説明、技術的な重要性、社会的なインパクト等々）に纏められるのではないか。
Introduction
Modern society relies heavily on compact and efficient electromechanical systems. At the heart of many of these systems lies the Hall effect sensor—a device capable of non-contact magnetic field detection. Among various implementations, the development of thin-film InSb (indium antimonide) Hall elements by Asahi Kasei in the 1980s–1990s represents a milestone in sensor technology. This proposal highlights the technical breakthroughs, commercialization journey, and societal impact of these detectors, arguing for their recognition as an IEEE Milestone.
Historical Context & Emerging Societal Needs
Following the oil crises of the 1970s, Japan's electronics manufacturers shifted focus toward compact consumer devices—portable audio players, VCRs, and personal computers—driven by the ethos of “light, thin, short, small.” Key to this transformation were required a reliable, miniaturized motors with noiseless and precise rotation(=anguler velocity) control. Traditional brushed motors proved inadequate due to size, noise, and wear. The technological bottleneck was the development of a high-sensitivity, compact, and cost-effective magnetic sensor to enable non-contact permanent magnet rotor detection. It may be well understand from Fig.1. showing the large monotonic increase of application(=salese) of the Asahikasei Electronics Hall elements start from 1983, reflecting the market trends in consumer electronics i.e. world demand for miniaturized electronic systems during the early 1980s to 1990s. Thin-film InSb Hall elements provided the critical solution to this challenge. After the oil shocks of the 1970s, Japanese electronics manufacturers began focusing on compact consumer devices such as portable audio players, VCRs (video cassette recorders), and personal computers. This trend responded to market demands for products that were “light, thin, short, and small,” and its realization required improvements in the reliability of compact motors with high precision and controllability. Conventional brushed motors were unsuitable due to limitations in size, noise, and wear, leading to a demand for brushless motors. To implement brushless motors, it was necessary to mass-produce high-sensitivity, compact, and cost-effective magnetic sensors capable of non-contact rotor position detection. An important technology that helped overcome this challenge was the development of thin-film InSb Hall sensors. Since the start of mass production of thin-film Hall elements in 1983, shipments of Hall sensors by Asahi Kasei have increased rapidly (see Figure 1), showing the large monotonic increase of application(=sales) of the Asahi Kasei Electronics Hall elements start from 1983, reflecting the market trends in consumer electronics i.e. world demand for miniaturized electronic systems during the early 1980s to 1990s. Thin-film InSb Hall elements provided the critical solution to this challenge.
この図は、吹き出しが黒く潰れ、字が小さいので読めない。
Figure 1 Growth in application of high-sensitivity InSb thin-film Hall elements with ferrite sandwich structure.
Principles and Importance of Thin-Film InSb Hall Elements
Fundamental Principle of the Hall Effect
Hall effect was discovered as a magnet-electric phenomena in 1879 by Edwin H. Hall and named Hall effect later.
Hall effect produces a voltage or Hall voltage VH proportional to the magnetic field when current flows through a conductor or semiconductor under a perpendicular magnetic field. Next, expression of Hall voltage VH under 2 driving methods are shown. Hall element is a magnetic sensor used Hall effect made from conducting plate with 2 input(driving) electrodes(1,3) and 2 output(Hall) electrodes(2,4).
Schematic diagram of a thin-film Hall element based on n-type semiconductor, showing terminal layout and Hall voltage generation, shown in Figure 2.
Figure 2 Hall element principal and Hall element with input electrodes 1, 3 and output electrodes 2,4.
Arrow means applied magnetic field with magnetic flux density B
1)Driving of Hall element
Practically Hall elements or sensors are operated in either constant current or constant voltage modes, with the latter offering lower thermal drift when used with high-mobility semiconductor such like InSb. The temperature characteristics parameters vary depending on which method is used.
-Constant Current Drive:
When a constant current (Ic) is applied to terminals 1 and 3, the output voltage VH at terminals 2 and 4 can be expressed by the following equation:
VH = RH × (1 / d) × Ic × B ----- (1)
Here, RH is the Hall coefficient, and d is the thickness of the semiconductor film in the direction perpendicular to the terminal surface. The Hall coefficient RH is defined using the electron charge e and the carrier concentration n as follows:
RH = 1 / (e × n) --------------------(2)
The temperature characteristic of the output voltage in constant current drive is determined by the temperature dependence of RH.
-Constant Voltage Drive:
When a constant voltage (Vc) is applied to terminals 1 and 3, the output voltage at terminals 2 and 4 can be expressed by the following equation:
VH = μH × (W / L) × Vc × B ------(3)
Here, μH is the electron mobility, and W and L are the lengths in the directions of terminals 2-4 and 1-3, respectively. The temperature characteristic of the output voltage VH in constant voltage drive is determined by the temperature dependence of μH. Temperature coefficient of electron mobility of InSb thin film deposited on mica substrate was measured as ±0.1~0.2%/ ℃.
2)The two problems to be solved
この説明が、1983年当時の課題と解決策を述べているなら、4章に移す。但し、専門外の人が、こんな技術の話を長々読まされても判らない。
-Temperature dependence of Hall voltage VH
Constant voltage driving produced over current damage to InSb Hall elements made from crystal thin plate with low input resistance. At the age of before 1980, Hall elements must be driven by constant current. Thus, the temperature coefficient of Hall voltage was -2%/ ℃. This large value limited practical application of Hall elements and a big problem for practical application. However, there was no solution for long time. Reduction of the temperature dependence are most urgent problem to be solved at that time.
-The magnetic field sensitivity
Practical application of Hall elements, large Hall voltage or high magnetic field sensitivity was strongly required Magnetic field sensitivity of old InSb Hall element was very low and Hall element application was limited. This low sensitivity was big problem to be solved at the time.
3) The solution of the 2 problems
この説明が、1983年当時の課題と解決策を述べているなら、4章に移す。但し、専門外の人が、こんな技術の話を長々読まされても判らない。
-Reduction of temperature dependence of Hall voltage
Asahi-kasei research group found a solution and developed Hall elements which could be driven and no avalanche damage by constant voltage. To realize constant voltage driving, Hall elements must have high input resistance.Thus,the Hall elements must be made from InSb vacuum deposited thin film with high sheet resistance ~150Ω. Table 1 shows a typical characteristics of the InSb thin films made by the unique 2-temperature multi-source evaporation method developed by Asahi-kasei research group.
By use of the thin films temperature dependence of Hall voltage VH is reduced as follows －2.0%/ ℃ at constant current driving→±0.1~0.2%/℃ at constant voltage driving This new technology Hall elements HW-series drivable at constant voltage were open a road to new innovation.
-The solution to get high sensitivity
By using high electron mobility InSb thin films by unique vacuum deposition method and new technology of magnetic field amplification by Ferrites, the world highest magnetic field sensitivity Hall elements HW-series(HW-300A,
HW-101A, etc.) Hall elements was developed. This Hall elements have a high sensitivity at low magnetic field. Less than 0.1T. The sensitivity was about 20~30 times than old Hall elements H-300A.
Thin-Film Advantages
Thin-film embodiments, especially submicron InSb layers, bring significant advantages
1）High sensitivity due to electron mobility of ~20,000–30,000 cm²/V·s.This value is 4~6 time larger than before.
2）Reduced temperature dependence, particularly under constant-voltage drive
-2.0%/ ℃ at constant current driving→±0.1~0.2%/℃ at constant voltage driving
3) By this structure, Hall voltage is amplified 3~6 times larger than the voltage with no ferrites.
4) Fabrication process compatibility with photolithography and packaging of IC processes.
Thin InSb film on ferrite substrate is easily processed to make Hall elements on the wafer for mass production.
5) Enabling fine control over performance parameters through material tuning.
InSb Thin Film and Ferrite Sandwich Structure
この節は要るのか？専門外の人に読んでもらう必要はあるのか？
The special structure to get ultra-high sensitivity by the structur InSb thin film sandwiched ina gap between ferrite substrate and ferrite chip as shown in Fig.5.(a).
In the structure, high electron mobility InSb thin films, particularly the 0.8 µm vacuum-deposited thin layer on mica substrates developed via unique 2 temperatyre multisource vacuum deposition method with programed substrate temperature control., combined with ferrite flux concentrators, amplified magnetic field response several-fold. This structure resulted in Hall elements with sensitivity far above that of old devices. The calculated ferrite gap magnetic flux density is proportional to applied magnetic field and approximately B/ L, where B is magnetic flux density of the applied magnetic field and L is demagnetization coefficient .The value of L is smaller than 1 and is only depend on ferrite geometrical structure. Magnetic flux density at ferrite gap B/ L is designed 3 to 6 times larger than original applied magnetic field B for practical Hall element. In the case of HW series Hall elements, amplification rate 1/ L is 3~6. Amplification of magnetic flux density by ferrite sandwich structure is often explained as collimation or concentration effect of magnetic flux lines of applied magnetic field by ferrites.［1］［2］
The cross-sectional structure (a), the concentration image of magnetic flux (b) and the InSb thin-film "sandwich" Hall element with the ferrite flux concentrators on both sides (c), respectively, are shown in Figure 3.
Cross-sectional diagram of InSb thin-film "sandwich" Hall element with ferrite flux concentrators on both sides, shown in Figure 4.
Figure 4 Ferrite sandwich structure of high-sensitivity InSb thin-film Hall element:
(a) cross-sectional structure of ferrite substrate/InSb thin film/ferrite chip, (b) collimation of magnetic flux at gap between ferrite chip and substrate, (c) photograph of wired Hall element sandwich with ferrite substrate and ferrite chip bonded to center of Hall element pattern. Table 2 shows the typical characteristics of HW-300A Hall Elements.
File:HW300A.jpg
This Hall elements have a high sensitivity at low magnetic field Less than 0.1T. The sensitivity was about 20~30 times than old Hall elements. The magnetic field property is shown in Figure 5.
Figure 5 A relation of Hall voltage VH and magnetic flux density B of the applied magnetic field.
Broader Integration and Applications
These Hall elements or sensors were integrated or used extensively into consumer and industrial products:
- Brushless motors in VCRs, FDD ,CD-ROM and CPU cooling FAN drive motors of computers
- Energy-efficient, quiet operation, and long life of washing machines, and miniaturizing of power tools
- Cooling FAN motors, such as air conditioner
- Application for contactless sensors and switch and, so on
Societal Impact
この節は、何を言いたいのか判らない。
The sensors enabled quieter, more efficient, and smaller devices. Their resulting improvements in consumer electronics reliability and energy efficiency contributed significantly to technological progress across industries, and influenced subsequent generations of Hall ICs and sensor systems.
Development, Commercialization, and Market Expansion
Research and Early Technological Breakthroughs
Asahi Kasei began dedicated R&D on thin-film InSb Hall elements in 1974. Innovations over the following decade included 0.8 µm thin-film deposition, ferrite sandwich structures for flux amplification, constant-voltage drive circuitry, and the first photolithographic patterning process for Hall elements.
Production Challenges and the HW Series Breakthrough
Early 1980s production struggled with yield and stability. These hurdles were overcome with the 1983 release of the HW Series(HW-300A,HW-101A, and etc.). With enhanced sensitivity, thermal stability, semiconductor-style wafer fabrication, and resilient resin packaging, the HW Series marked a breakthrough in both performance and manufacturability.Figure 5 shows Fabrication process of Thin-film InSb Hall elements.
Figure 5 Fabrication process of InSb Hall elements
Mass Production and Market Leadership
Mass production of HW-series at the Nobeoka factory began in June 1983. By October, output reached 3 million units monthly, increasing to 7 million shortly thereafter. These sensors captured over 70% of the global Hall element market, driven by broad adoption in motors for electronics and appliances.
Manufacturing Scale-Up via Miyazaki Electronics
Establishment of Miyazaki Electronics as a dedicated manufacturing arm under Asahi Kasei ensured stable, high-volume sensor production. This capability fueled Japan’s 1980s consumer electronics revolution and supported trends in motor miniaturization and electrical control of power. [D7], [D8]
Technological Ripple Effects & Cross-Disciplinary Synthesis
The HW Series exemplified multidisciplinary integration: thin-film physics, quantum device, magnetic materials, LSI motor control, and industrial packaging. This cross-functional approach not only met immediate sensor needs but also created an ecosystem of ferrite and rare earth magnets, photolithographic processes, and automated packaging—driving innovation across adjacent domains.
Enabling Broader Applications and Efficiency Gains
Integration of Hall sensors in motors led to tangible benefits:
- Improved energy efficiency (e.g. inverter-based compressors, ~10% gains)
- Increased system reliability and lifetime
Broader adoption in consumer and industrial appliances
These improvements were amplified at scale: in Japan circa 2000, motors consumed over 50% of electricity; even small efficiency improvements translated into effective new power-generation capacity.
Legacy and Continued Evolution
By 2011, Asahi Kasei had produced over 200 billion sensor units, supporting infrastructure and supply chains worldwide. The thin-film Hall sensor’s legacy continues through its derivatives: integrated Hall ICs, current sensors, and hybrid sensor systems. The intellectual contributions to high-mobility semiconductor research remain influential in modern device engineering.
Social & Industrial Impact
Thin-film InSb Hall sensors helped make electronics quieter, energy-efficient, and reliable. They bolstered Japan’s industrial competitiveness in the 1980s–1990s. Globally, the sensors democratized access to high-value mechatronic technology—from household appliances to early robotics—driving environmental and economic benefits. Typical systems powered motors by HW-series Hall sensors and Hybrid Hall IC with InSb Hall element chip as magnetic sensor were shown in Figure 6.
図６は図13と何が違う？
Figure 6 Typical systems with brushless DC motors powered by HW Series Hall elements and hybrid Hall IC with Hall element chip as magnetic sensor same as HW-series.
Why It Merits IEEE Milestone Recognition
Milestoneの条件に合致しているということを言いたいなら、この書き方ではおかしい。
This technology meets key IEEE Milestone criteria:
- Pioneering innovation: first large-scale, high‑mobility thin-film Hall devices with flux amplification
- Commercial impact: over 200 billion units produced, >70% market share
- Interdisciplinary achievement: spanning materials, magnetics, electronics, and manufacturing
Enduring influence: direct lineage to modern sensor systems
Recognition would honor not only the device itself but the technological paradigm it enabled.
Conclusion
Asahi Kasei’s thin-film InSb Hall elements stand as a cornerstone of modern sensor technology. Their technical ingenuity, market penetration, and societal impact have been profound. By enabling the era of compact, electronically controlled motors and efficient systems, they have touched billions of lives. Granting IEEE Milestone status would aptly honor this deceptively simple yet transformative innovation.
What obstacles (technical, political, geographic) needed to be overcome?
Obstacles to Overcome
この章では、1983年に薄膜ホール素子の量産化にこぎつけるために、「こんな課題があって、それをこのように解決した」と説明することを問われている。
つまり課題（Obstacles, Challenge)と、その解決策（Overcome, Solution) の組み合わせ対比させて明確に書く。
Technological Challenges
In the 1970s and early 1980s, the Asahi Kasei team faced four major technical hurdles:
- Industrial-scale vacuum deposition: Conventional polished InSb crystals (mm-scale) were too fragile and expensive, and not adequate for mass production. Asahi Kasei invented a two-temperature, multi-source vacuum evaporation process—co-depositing indium and antimony on mica—to produce uniform ~0.8 μm films (36 wafers per batch) with high electron mobility (20,000–30,000 cm²/V·s).
- Magnetic sensitivity shortfall: High-mobility films still lacked sufficient sensitivity. To address this, the team developed a ferrite-sandwich structure that amplified sensitivity by 20–30× while halving offset signals.
- Thermal drift control: Early InSb sensors suffered temperature coefficients of –2%/°C. The innovation of combining thin-film high-resistance material with constant-voltage driving reduced drift to ±0.1–0.2%/°C.
- Sensor packaging: Bare chips were impractical for mass production. Asahi Kasei designed resin-molded packages capable of surviving SMT reflow at 260 °C, the first such implementation for compound-semiconductor sensors.
Each of these technical breakthroughs was essential for transitioning from lab prototypes to mass-producible components, enabling industrial scalability.
Organizational & Interdisciplinary Hurdles
Asahi Kasei’s move into compound-semiconductor technology challenged its own corporate structure:
- Domain shift: A chemical company embracing semiconductor electronics required new expertise and organizational models.
- Cross-disciplinary friction: Engineers, chemists, and physicists collaborated intensively to bridge knowledge gaps.
- External skepticism: Many dismissed the project as academically biased. Credibility was built only after rollout of the HW Series that met rigorous industrial specs.
These organizational efforts underpinned the successful technical implementations that followed.
Infrastructure & Supply-Chain Barriers
Building a semiconductor-capable plant in rural Nobeoka posed logistical challenges:
- Facilities: Specialized vacuum chambers, cleanrooms, and advanced thermal control systems were designed from scratch.
- Human resources: Remote location necessitated relocating and training staff lacking semiconductor experience.
- Materials sourcing: Ultra-pure In and Sb were hard to procure domestically—chemistry expertise enabled internal refining and supply-chain development.
These infrastructure solutions ensured stable, high-quality production outside existing industrial hubs.
Market Adoption & Distribution
Entering a competitive component market required more than better sensors:
- Sales channels: Asahi Kasei created dedicated teams to engage OEM motor manufacturers.
- Technical support: Design-in assistance became essential for adoption in VTRs, drives, and appliances.
- Quality assurance: Rigorous protocols ensured sensor performance under diverse environmental and client conditions.
These efforts accelerated the HW Series transition from lab success to global industrial deployment.
Overcoming the Obstacles
Collectively, the team transformed these challenges into strengths:
- New deposition method → reproducible thin-film production
- Ferrite amplification → highly sensitive detection
- Voltage-driving + packaging → robust sensors for SMT
- Organizational learning + external collaboration → agile development
- Rural manufacturing + supply-chain → cost-effective scalability
- Market infrastructure investments → global adoption
This multi-front strategy exemplifies the persistence, ingenuity, and systems thinking that characterize IEEE Milestone-level innovation.
What features set this work apart from similar achievements?
What Features Set This Work Apart from Similar Achievements?
この章で問われているのは、当時（1980年代）の、他の方式（素子）、他社の製品との、項目ごとの「比較」である。
現状を読む限り、この問いに答えていない。
In the late 1970s and early 1980s, thin film Hall elements were being explored in laboratories around the world. However, while many remained in the experimental or prototype stage, Ichiro Shibasaki and his team at Asahi Kasei succeeded in achieving the world’s first practical and mass-producible thin film Hall element based on indium antimonide (InSb), launching it as a commercial product. Their achievement was not merely a technological advance—it was a pioneering integration of materials science, semiconductor process innovation, and magnetic sensor design that laid the foundation for an entirely new generation of electronic motion control systems.
What set Shibasaki’s Hall element apart was not just its high sensitivity, but the holistic approach taken to address the full spectrum of challenges that stood between laboratory feasibility and industrial viability. At the time, existing Hall sensors were typically built from mechanically polished single-crystal InSb and designed primarily for use in laboratory Gaussmeters. These devices suffered from several limitations: they were bulky, expensive (often costing thousands of yen per unit), poorly packaged, fragile, and highly susceptible to environmental conditions such as temperature and mechanical stress. Above all, they lacked the mass manufacturability required for integration into consumer electronic products.
Shibasaki’s work addressed these limitations with a novel thin-film-based solution that combined several key innovations:
First Large-Scale Production of Thin-Film InSb:
One of the most significant breakthroughs was the development of a scalable vacuum deposition process to fabricate high-quality InSb thin films. The challenge lay in controlling the deposition of two elements, indium and antimony, which differ in vapor pressure by five orders of magnitude. Shibasaki’s team developed the “two-temperature multi-boat evaporation method,” which enabled precise control of the stoichometric composition and uniformity of the InSb thin film across large substrates. Using this method, they could simultaneously deposit uniform 0.8 μm thick films on up to 36 mica substrates on a single 2-inch wafer. This level of uniformity and throughput was unprecedented, establishing a viable production process for thin-film magnetic sensors. The electron mobility of 36 InSb thin films were shown in Figure 7.
Figure 7 Electron mobility of 36 InSb thin films by 2-temperature multiboat vacuum deposition method .
Magnetic Amplification Structure Using Soft Ferrite:
Another key innovation was the introduction of a magnetic flux concentrator structure. By sandwiching the InSb thin film between two soft ferrite layers (Ni-Zn and Mn-Zn ferrite types, respectively), they achieved magnetic field amplification of 3 to 6 times at the sensing point. This structural enhancement allowed the Hall element to detect magnetic fields with 20 to 30 times higher sensitivity than conventional sensors at the time—something not possible by material improvements alone. This structure also significantly reduced output offset, improving signal-to-noise ratio and operational stability.
A brief explanation of theoretical base of magnetic amplification must be important. The exact calculation of the flux density Bg in the gap or demagnetization coefficient L is tedious but simple approximation of the ferrite structure by cylindrical geometry is easy for calculation of the magnetization coefficient L, The graphical image of cylindrical model approximation of ferrite structure is shown in Figure 8. By using the height h and diameter R of the ferrite cylinder. demagnetization coefficient L is expressed as
L=1－h/(h2+R2)1/2＜1 (4)
The magnetic flux density Bg in Gap is given by
Bg≒B/L at χ≫1 (5)
Where χ=ferrite permeability and B is magnetic flux density of the applied magnetic field. The calculated L is plotted in Figure 9. This approximation was sufficient information for practical ferrite design.
Figure 8 (a) cylindrical approximation image(left) and (b) image of magnetic flux lines concentrated in ferrite substrate and chip(right).
Figure 9. Demagnetization coefficient L is plotted to h/R where h is the height and R is diameter of the ferrite cylinder.
Temperature Stability Through Thin-Film Engineering:
One longstanding issue with InSb Hall sensors was their high temperature coefficient of Hall voltage VH ,i.e. sensitivity.
Shibasaki’s thin-film approach, coupled with high input resistance design and constant-voltage drive methodology, reduced the temperature coefficient of the Hall voltage from −2%/°C (typical of conventional devices) to an unprecedented ±0.1–0.2%/°C—an improvement by a factor of 10 to 20. The temperature dependence of Hall voltage VH to HW-300A are shown in Figure 10 for the constant voltage driving (a) and the constant current driving (b),respectively. This performance was critical for applications in consumer electronics where temperature fluctuations are inevitable and tight control of motor speed and position is required.
Figure 10 Temperature dependence of Hall voltage for constant voltage and constant current drive, respectively
Packaging and Integration with Modern Manufacturing Processes:
Recognizing that sensor performance alone was insufficient for adoption, the team designed and made the device in a compact, plastic-encapsulated form that was compatible with automatic mounting process. This Hall elements are just HW-300A shown in Figure 11. The transformation image of the commercial devices from old H-300A to new HW-300A (HW-series) Hall element with Au wire connection and heat resistive package in1983 is shown in Figure 11. For Au wire connection between Hall element electrodes and reads, Asahi Chemical research group developed new electrode technology made from Au/Ni/Cu three thin layers. By this electrode technology, Au wire connection to 0.8 μm thickness InSb thin film on ferrite substrate could be possible. This patented electrode technology was final barrier for mass production and excellent 260℃ heat resistance of HW-series Hall elements. This important invention was patented[P3].
Figure 11, The transform of the commercial devices from old H-300A to new HW-300A (HW-series) Hall element with Au wire connection and 260℃ heat resistive package in1983.
This made it possible to integrate the Hall sensor into printed circuit boards in a fully automated fashion, reducing assembly costs and increasing reliability. This packaging strategy enabled the device to be used widely in high-volume manufacturing environments, including VTRs, CD players, floppy disk drives.
Figure 12 HW-series (HW-300A, HW-101A, and etc.) Hall elements
Industrial and Social Impact:
問われている事と違うが、この節は必要か？
The introduction of this Hall sensor enabled the widespread adoption of brushless DC motors—commonly known as Hall motors—which offered precise speed and position control, low electrical noise, and high durability. This was especially crucial at a time when Japanese manufacturers were seeking noise-free, compact, and efficient motors to drive the emerging generation of consumer electronics. The sensor’s robustness, size, and cost-effectiveness made it a key component in the success of products like the Sony Walkman, VTRs, and personal computers, which defined the electronics boom of the 1980s and 1990s.
Long-Term Production and Market Leadership:
問われている事と違うが、この節は必要か？
図13は小さすぎて読めない。そもそも、図６と何が違うのか？
From the mid-1980s to the early 2000s, over 21 billion of these sensors were produced, with annual output exceeding 1 billion units for more than a decade. By the early 2000s, sensors using this magnetic amplification structure had achieved more than 70% global market share in certain applications. This is a testament not only to the technical excellence of the original design but also to its adaptability and relevance across multiple generations of electronics.
Figure 13 Application of high sensitivity InSb Hall elements from 1990 to 2017
Paving the Way for Hybrid Hall ICs:
問われている事と違うが、この節は必要か？
Shibasaki’s sensor technology also served as the basis for later innovations such as Hybrid Hall ICs—devices that combined high-sensitivity Hall sensors with integrated signal amplification. These hybrid devices offered digital outputs with low offset and high signal reliability, enabling a new class of smart sensors for switching and control in both consumer and industrial environments. Figure 14 shows a photographs of Hybrid Hall IC.
Figure 14 Photographs of Hybrid Hall Ics (digital magnetic sensor: 1986)
In summary, while many researchers in the 1970s and early 1980s explored thin film Hall technologies, Shibasaki’s work stands out for having crossed the crucial threshold from lab-scale experimentation to industrial production and widespread adoption. His work was not just about improving sensitivity; it was about delivering a solution that met the full demands of the electronics industry: high performance, mass manufacturability, environmental robustness, and seamless integration into emerging technologies. The InSb thin film Hall element developed under his leadership thus represents a landmark achievement in the history of semiconductor sensors, enabling the rise of intelligent motion control in modern electronics and leaving an enduring legacy in both technology and industry.
Why was the achievement successful and impactful?
Why was the achievement successful and impactful?
この章では、特に定量的な技術の話は要らない。
質問の内容は、何故、これが成功したのか、そして歴史的の重要なのか（インパクトがあるのか）、という「Proposerの考え・自己評価？」を聞いている。上の章と同じ技術的な議論を繰り返して答える必要はない。
Breakthrough in Magnetic Sensor Technology
The development of thin-film InSb Hall elements by Ichiro Shibasaki and his team at Asahi Kasei in the early 1980s marked a major breakthrough in magnetic sensor technology. At the time, existing Hall sensors were based on bulk InSb crystals, which were expensive, unreliable, and too large for mass-market consumer electronics. Shibasaki’s innovation—using a thin-film vacuum deposition method to mass-produce high-sensitivity InSb Hall elements—was unprecedented and paved the way for practical, low-cost, high-performance magnetic sensors. His "two-temperature multi-boat evaporation" technique enabled uniform and large-area deposition of thin InSb films, achieving electron mobilities over 20,000 cm²/Vs and allowing mass production with high yield and reliability.
Enabling the Brushless DC Motor Revolution
The new thin-film Hall elements met an urgent industrial demand: compact, high-precision, non-contact angular velocity detection for brushless DC motors. These motors were critical for emerging devices like video cassette recorders (VCRs), CD players, and personal computers, which required precise motor control without the noise, size, and reliability issues of traditional brush-type motors. Shibasaki’s Hall elements, when combined with permanent magnet rotors and newly developed motor control ICs, enabled the commercialization of ultra-compact, low-noise brushless motors. These motors powered devices like VCR capstan motors, and floppy disk drives, becoming essential components of 1980s and 1990s consumer electronics.
Magnetic Amplification for Unprecedented Sensitivity
A key innovation in Shibasaki’s design was the use of soft ferrite magnetic materials to sandwich the InSb thin film. This structure amplified the magnetic flux density detected by the Hall element by a factor of 3–6, resulting in sensitivity levels 20–30 times greater than conventional sensors. Furthermore, the low offset voltage and high output signal made the device uniquely suitable for integration with bipolar IC-based motor drivers. The result was not only higher sensitivity but also enhanced signal stability and robustness against temperature variation—less than ±0.2%/°C in Hall voltage drift—addressing a longstanding problem of InSb sensors
.
Seamless Integration into Mass Production
Shibasaki’s Hall elements were designed for full compatibility with modern manufacturing and packaging. Their small resin-molded packages supported automated surface-mount assembly, enabling high-volume deployment in consumer electronics. This compatibility with both application circuits and production processes played a crucial role in their rapid adoption. By 1997, production surpassed 1 billion units per year, peaking at over 1.5 billion in 2003, with a cumulative production exceeding 21 billion units by 2011.
Widespread Industrial and Societal Impact
The success of Shibasaki’s thin-film Hall elements catalyzed the widespread use of brushless motors in a range of industries and supported the global expansion of consumer electronics. They became foundational components in devices that defined the late 20th century: VCRs, CD-ROMs, and more. Furthermore, the hybrid integration of these sensors with ICs led to the development of digital magnetic switches and current sensors, extending their impact into industrial power control and home appliances. This achievement not only solved a key technical bottleneck but also exemplified the successful fusion of materials science, semiconductor engineering, and magnetics.
Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.
Bibliography
Reference
20件以上も論文を並べているが、何のために並べているのか？
審査員はProposalの内容の事実確認のために、1件ごとにPDFをダウンロードしないと確認をして貰うのか？ およそ現実的ではない
[R2] I. Shibasaki, "High sensitivity InSb Hall elements and their development for practical use", Monthly Report J. Chemical Industory Association, vol41, May 1988 Media:R2 JCIA.pdf, (US Transrated) Media:R2 JCIA E.pdf
[R3] I. Shibasaki, "High-Sensitivity InSb Thin-Film Hall Elements with Ferrite Sandwich Structure and Their Extensive Commercial Application
（Invited paper）", J. Jpn. Soc. Powder Powder Metallurgy Vbl. 61 Supplement, No. SI, PP. S335-S339, March 2014 Media:R3 JJSPM.pdf
[R4] I.Shibasaki, "Mass Production of High-Sensitivity InSb Hall Elements", Okochi Prize commemorative report,1987 Media:R4 Mass Production.pdf
[R5] I.Shibasaki, "High Sensitive Hall Elements by vacuum deposition", Technical Digest of 8th Sensor sympsium, pp.211-214,1989Media:R5 Sensor Sympsium.pdf
[R11] I. Shibasaki, "Mass production of InAs Hall elements by MBE", J. Cryst. Growth 175/176, 13,1997 Media:R11.pdf
[R13] I. Shibasaki and N.Kuze,"Mass Production of Sensors Grown by Molecular Beam Epitaxy", MOLECULAR BEAM EPITAXY from research to mass production Second edition Chapter 31 PP.693-719,2018 Media:R13.pdf
The following should be considered for publication
[R7]I.Shibasaki, "The practical Hall Elements as magnetic sensors by thin film technology", IEEE Lasers and Electro Optical Society,1995Media:R7 IEEE Lasers.pdf
[R9]I.Shibasaki, "High-Sensitive Thin-film Hall Element", Foundation of electricity pp.8-9,2014Media:R9 Foudation.pdf
[R15]I. Shibasaki, "Properties of narrow-gap semiconductors and their applications to magnetic sensors",Magnetics Japan ,2013 Media:R15.pdf
[R16] I. Shibasaki,"Current status and applications of semiconductor magnetic sensors", The Magnetics Society of Japan,2003Media:R16.pdf
[R17]I. Shibasaki,"InSb and InAs Hall Elements from Asahi Chemical", Compound Semiconductor ,September/October,1996 Media:R17.pdf
[R18]I. Shibasaki, "Development of compound semiconductor thin film Hall elements", Applied physics,1998 Media:R18.pdf
[R19]I. Shibasaki,"Physical properties of InSb single crystal thin films and their application to magnetic sensors", Transactions of the Institute of Electrical Engineers of Japan,2003 Media:R19.pdf
[R22] "High Sensitive Hall Effect ICs with Thin film Hall Elements", Sensors and Materials vol14 No.5 pp.253-261,2002 Media:R22.pdf
[R1]I. Shibasaki "Properties of Hall Elements by Vacuum Deposition", the Correction of Advanced Technology of
Semiconductor Devices, Keiei System Kenkyusyo, Chapter 3, Sec. 11, p. 373,1984 Media:R1 Advanced Technology.pdf,
[R6]I.Shibasaki et al., "Hall Effect Magnetic Sensors", Magnetic Sensors and Magnetometors, Ripka、Artec House Publishers, Chapter 5 Section 5.2 pp.184-201,2001 Media:R6 magnetic sensors.pdf
[R8]I.Shibasaki , "Hall Element", Cutting edge intelligent motion Mechatronics Editorial Department, pp.101-106,1995Media:R8 Mechatronics.pdf
[R12] I. Shibasaki, "Development of thin-film Hall elements and their sensor applications", T. IEEE Japan Vol 199-E No.8/9,1999 Media:R12.pdf
[R14]I.Shibasaki, "Magnetic Sensors," Next Generation Sensor Handbook 1. Basics, Chapter 5,2008 Media:R14.pdf
Documents
これは、何のために並べているのか？Proposerの意図は何か？
審査員はProposalの内容の事実確認のために、1件ごとにPDFをダウンロードしないと確認をして貰うのか？ およそ現実的ではない
[D7] "Rapid Development Electronics-Related Industry", The Yomiuri Shimbun Article, February 12,1982 Media:D7 Yomiuri Shimbun Article 19820212.pdf,
[D8] Asahi Kasei Electronics The biographical sketch, September 1995 Media:D8 AKE15 199509.pdf,
[D12] Hall Element Catalog 1983 Media:D12 Hall Element Catalog 1983.pdf,
[D13] Hall Element Catalog 1993 Media:D13 Hall Element Catalog 1993.pdf,
Patents
[P1] Patent related to Thin film Hall Element of Ferrite Sandwich Magnetic Amplification structure and manufacturing method of this Hall element, December 12. 1973, (JP)Tokko No.51-45234, Media:JPB 1976045234.pdf, (US transrated)Media:US Trans 1976045234.pdf
[Abstract]
Thin film Hall Element of Ferrite Sandwich Magnetic Amplification structure and manufacturing method of this Hall element
[P2] Patent related to Manufacturing method of ferrite sandwich thin film Hall Element, April 28 ,1975(JP)Tokko No.53-46675, Media:JPB 1978046675.pdf, (US transrated)Media:US Trans 1978046675.pdf
[Abstract]
Manufacturing method of ferrite sandwich thin film Hall element formed on a magnetic substrate overlaying an organic insulating layer with a step of forming a thin film by vapor deposition and mechanically peeling the magnetic material and adhering a second magnetic material on a magnetic substrate.
[P3] Patent related to the structure of mold Hall element , May 10,1985.(JP)TokkoNo4-62474 Media:JPB 1992062474.pdf , (US)Pat.4908685 Media:USA1004908685.pdf
[P4] Patent related to Manufacturing method of mold Hall element , May 10,1985.(JP)TokkoNo4-62475 Media:JPB 1992062475.pdf , (US)Pat.4908685 Media:USA1004908685.pdf
[Abstract]
A magnetoelectoric transducer complying a group Ⅲ-Ⅴ compound semiconductor thin film formed as a magnetic field sensing portion on a substrate overlaying an organic insulating layer and a multilayer wirebonding electrode. And a bonding wire is connected directly to the wirebonding electrode.
Award
Milestoneは個人の表彰（Award）ではない。ここで書くべきものは、柴崎さんの「個人的な」業績の表彰の羅列ではない。
薄膜ホール素子自体の表彰。
世の中には、数えきれないほどの賞や認定があるのは知っての通り。誰から、誰に、何に対して貰えるものか、重要性も示さないと、審査員は判らない。
[A1] Ōkouchi Memorial Production Prize,1987 Media:A1 Ōkōchi Prize 1987.pdf
[Remarks]
-Development and Mass Production of High-Sensitivity InSb Hall Elements
-Awarding Organization: Ōkochi Memorial Foundation
-Recipient: Asahi Chemical Industry Co., Ltd.
-Citation: Asahi Chemical Industry Co., Ltd.'s high-sensitivity InSb thin-film Hall element of the HW series, which is based on the vacuum deposition method, was the first in the world to have an annual production volume of more than 150 million units, and its excellent mass production technology was awarded.
-Purpose: The Ōkouchi Memorial Production Prize was established to honor individuals or organizations that have made significant contributions to the field of production engineering and industrial technology, aiming to promote the advancement of Japan’s industrial capabilities.
-Value of the Prize: It is one of Japan’s most prestigious awards in the field of industrial technology. Receiving this prize signifies high recognition of technological excellence and innovation.
[A2] Invention Encouragement Award,1992, Media:A2_Invention Encouragement Award 1992.pdf
[Remarks]
-Awarding Organization: Japan Institute of Invention and Innovation (JIII)
-Recipients: Ichiro Shibasaki, Kohei Nonaka, Tsuyoshi Shimizu, (Asahi Chemical Industry Co., Ltd.)
-Citation: Patent award for [P2] patent
-Purpose: Contribute to scientific and technological advancement. Encourage inventive and creative activities.
-Value of the Award: Established in 1921, the Regional Commendation for Invention aims to promote local industry and encourage technological innovation across Japan’s regions.
[A4] Invention Encouragement Award,1999,Media:A4_Invention Encouragement Award 1999.pdf
[Remarks]
-Recipients: Ichiro Shibasaki , Takashi Kajino,(Asahi Chemical Industry Co., Ltd.)
-Citation: Patent award for [P3] patent
Others are the same as [A3]
[A7］The foundation of electricity 2013, Media:A7_The foundation of electricity.pdf
[Remarks]
-Awarding Organization: The Institute of Electrical Engineers of Japan (IEEJ)
-Recipient: Asahi Kasei Corporation
-Citation: Asahi Kasei was awarded for its development and commercialization of Thin-Film Indium Antimonide (InSb) Hall Elements in 1983. This innovation revolutionized magnetic sensing technology, enabling the widespread adoption of brushless DC motors and laying the foundation for electronic control in consumer electronics, computing .
-Purpose: The "One Step on Electro-Technology" honors the achievements of electrical technology that have made a great contribution to social life, and the achievements of electrical technology that has either historical technical value, social value, or academic and educational value for more than 25 years with the aim of widely disseminating its value to the world, making many people aware of the wonders and interests of electrical technology, and contributing to the development of electrical technology in the future.
-Value of the Award: The award signifies official recognition by a global technical organization of a This award is given to achievements with technical and social impact that can be recognized as milestones in electrical technology by the Institute of Electrical Engineers of Japan, that is an official recognition by Japan's leading academic organizations.
[A9] The Yamazaki-Teiichi Prise 2018, Media:A9 The Yamazaki-Teiichi Prise 2018.pdf
[Remarks]
-Recipient: Ichiro Shibasaki, (Asahi Kasei Corporation)
-Presenter: The Foundation for Promotion of Material Science and Technology of Japan (MST Foundation)
-Award Category: Semiconductor and Semiconductor Devices
-Citation: Ichiro Shibasaki was awarded for his pioneering work in the development and commercialization of high-sensitivity thin-film Hall sensors using III-V compound semiconductors such as InSb and InAs. His innovations included: Fabrication of monocrystalline and polycrystalline thin films and quantum wells. Mass production of ultra-thin, high-sensitivity Hall elements.
-Practical applications in VCRs, PC cooling fans, HDDs, CD-ROMs, air conditioners, contactless current sensors.
-These sensors achieved 20–30 times higher magnetic sensitivity and significantly reduced temperature dependence, leading to cumulative production exceeding 30 billion units.
-Purpose of the Award: The Yamazaki-Teiichi Prize honors individuals who have made outstanding contributions to the advancement of science and technology in Japan, particularly in the fields of materials, semiconductors, and devices. It aims to promote innovation and recognize achievements that have had a significant impact on industry and society. This award commemorates Dr. Teiichi Yamazaki’s legacy and encourages pioneering research and development that leads to practical applications and industrial progress.
-Value of the Award: The Yamazaki-Teiichi Prize is one of Japan’s most prestigious honors in applied science and engineering. It signifies national recognition of technological excellence and societal impact. The award enhances the visibility of the recipient’s work and promotes further innovation in the field. Winning this prize places the recipient among Japan’s top innovators and validates the long-term industrial and academic significance of their contribution.
Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to ieee-history@ieee.org. Please see the Milestone Program Guidelines for more information. Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to ieee-history@ieee.org with the subject line "Attention: Milestone Administrator." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s). Please recommend reviewers by emailing their names and email addresses to ieee-history@ieee.org. Please include the docket number and brief title of your proposal in the subject line of all emails.
