Milestone-Proposal:First Practical Field Emission Electron Microscope, 1972-1984: Difference between revisions
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However, the instability of the FE emission current was an essential difficulty in the development of a practical FE electron microscope. After many years of fundamental research and development of FE electron source stability technology, Hitachi finally achieved a commercial FE-SEM featuring a stable and reliable FE electron source.|a6=For FE emission current stability, a steady-state ultra-high vacuum of 10^−8 Pa was necessary since residual gas molecules cause the FE emission current to fluctuate. This is a much higher vacuum than that of a conventional thermionic emission electron source (order of magnitude of 10^−4 Pa). Moreover, maintaining an ultra high vacuum under electron beam emission conditions is quite a challenge because the electron beam stimulates outgassing from the anode, which degrades the vacuum. | However, the instability of the FE emission current was an essential difficulty in the development of a practical FE electron microscope. After many years of fundamental research and development of FE electron source stability technology, Hitachi finally achieved a commercial FE-SEM featuring a stable and reliable FE electron source.|a6=For FE emission current stability, a steady-state ultra-high vacuum of 10^−8 Pa was necessary since residual gas molecules cause the FE emission current to fluctuate. This is a much higher vacuum than that of a conventional thermionic emission electron source (order of magnitude of 10^−4 Pa). Moreover, maintaining an ultra high vacuum under electron beam emission conditions is quite a challenge because the electron beam stimulates outgassing from the anode, which degrades the vacuum. | ||
Hitachi succeeded in establishing an ultra-high vacuum technology for the FE electron source. Patented "innerbake” technology, i.e., heating and degassing of a heater built into the anode, was the breakthrough. A “flashing" technique, i.e., short-duration heating of the cathode to remove the gas molecules, produced a stable, clean state of the cathode surface. This low outgas material and surface treatment technology were integrated and used to reduce the effect of the residual gas molecules. As a result, the FE emission current was fundamentally stabilized, enabling development of a stable and reliable FE electron source, which realized the development of practical high-resolution electron microscopes.|a7=The plaque will be installed outside the main building at the sites where FE technology and electron microscopes were developed. | Hitachi succeeded in establishing an ultra-high vacuum technology for the FE electron source. Patented "innerbake” technology, i.e., heating and degassing of a heater built into the anode, was the breakthrough. A “flashing" technique, i.e., short-duration heating of the cathode to remove the gas molecules, produced a stable, clean state of the cathode surface. This low outgas material and surface treatment technology were integrated and used to reduce the effect of the residual gas molecules. As a result, the FE emission current was fundamentally stabilized, enabling development of a stable and reliable FE electron source, which realized the development of practical high-resolution electron microscopes.|a7=The plaque will be installed outside the main building at the sites where FE technology and electron microscopes were developed. | ||
(1) Naka Division, Hitachi High Technologies Corporation (formerly Naka Works, Hitachi Ltd.) and (2) Central Research Laboratory, Hitachi Ltd.|a8=Yes|a9=The site is guarded by security officers at the entrance of the site. The entrance lobby of the building is open to visitors by registering at the security gate.|a10=The sites are owned by (1) Hitachi High Technologies Corporation and (2) Hitachi, Ltd.|a11=Yes|a12=Dr. Hideki Imai, Chair of the IEEE Tokyo Section, has agreed to sponsor the milestone nomination. Dr. Imai's e-mail address is imai@imailab.jp|a13name=Prof. Hideki Imai|a13section=Tokyo|a13position=Chair|a13email=tokyosec@ieee-jp.org|a14name=Prof. Ryuji Kohno|a14ou=Tokyo Section|a14position=Treasurer|a14email=treasurer@ieee-jp.org|a15Aname=Hidehito Obayashi|a15Aemail=obayashi-hidehito@nst.hitachi-hitec.com|a15Aname2=Toshio Masuda|a15Aemail2=masuda-toshio@naka.hitachi-hitec.com|a15Bname=Makoto Hanawa|a15Bemail=secretary@ieee-jp.org|a15Bname2=Toshio Masuda|a15Bemail2=masuda-toshio@naka.hitachi-hitec.com|a15Cname=Hidehito Obayashi, Ph.D.|a15Ctitle=President, Chief Executive Officer and Director|a15Corg=Hitachi High-Technologies Corporation|a15Caddress=24-14, Nishi-Shimbashi 1-chome, Minato-ku, Tokyo 105-8717, Japan|a15Cphone=81-3-3504-7111|a15Cemail=obayashi-hidehito@nst.hitachi-hitec.com}} | (1) Naka Division, Hitachi High Technologies Corporation (formerly Naka Works, Hitachi Ltd.) and (2) Central Research Laboratory, Hitachi Ltd.|a8=Yes|a9=The site is guarded by security officers at the entrance of the site. The entrance lobby of the building is open to visitors by registering at the security gate.|a10=The sites are owned by (1) Hitachi High Technologies Corporation and (2) Hitachi, Ltd.|a11=Yes|a12=Dr. Hideki Imai, Chair of the IEEE Tokyo Section, has agreed to sponsor the milestone nomination. Dr. Imai's e-mail address is imai@imailab.jp|a13name=Prof. Hideki Imai|a13section=Tokyo|a13position=Chair|a13email=tokyosec@ieee-jp.org|a14name=Prof. Ryuji Kohno|a14ou=Tokyo Section|a14position=Treasurer|a14email=treasurer@ieee-jp.org|a15Aname=Hidehito Obayashi|a15Aemail=obayashi-hidehito@nst.hitachi-hitec.com|a15Aname2=Toshio Masuda|a15Aemail2=masuda-toshio@naka.hitachi-hitec.com|a15Bname=Makoto Hanawa|a15Bemail=secretary@ieee-jp.org|a15Bname2=Toshio Masuda|a15Bemail2=masuda-toshio@naka.hitachi-hitec.com|a15Cname=Hidehito Obayashi, Ph.D.|a15Ctitle=President, Chief Executive Officer and Director|a15Corg=Hitachi High-Technologies Corporation|a15Caddress=24-14, Nishi-Shimbashi 1-chome, Minato-ku, Tokyo 105-8717, Japan|a15Cphone=81-3-3504-7111|a15Cemail=obayashi-hidehito@nst.hitachi-hitec.com}} |