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}}

Revision as of 13:03, 27 February 2010