Hidehito Obayashi’s development and implementation of the critical dimension scanning electron microscope (SEM) provided an indispensible tool for semiconductor manufacturing that has enabled the continued miniaturization of silicon wafers. The ability to characterize the fine layers and structures of silicon wafers is an important component of VLSI semiconductor manufacturing. As optical techniques became incapable of measuring critical dimensions on shrinking silicon wafers, during the 1980s, Dr. Obayashi converted the electron microscope, traditionally used to examine samples with high resolution using accelerated electrons, from a laboratory instrument into the critical dimension SEM for use in semiconductor production.
The use of a nondestructive electron gun instead of a thermal electron gun as a source of electrons was crucial to the success of Dr. Obayashi’s device. His field emission electron gun provided a low energy electron beam with little radiation damage to the semiconductor material during measuring and monitoring. This enabled high-speed measurement capabilities during continuous use on production lines. Modifications were also needed to make conventional SEMs robust to challenging environments encountered in semiconductor manufacturing including floor vibration, magnetic field variations and clean room noise.
Dr. Obayashi’s leadership was critical in incorporating electrical engineers and computer scientists in the development process to address these challenges. The result was a fully automated tool with modular redesign capabilities that was easy to operate. An IEEE Fellow, Dr. Obayashi began his career with Hitachi in 1969 and is currently president, chief executive officer and director at Hitachi High-Technologies Corporation, Tokyo, Japan.