Length Measurement SEMs that Revolutionized Inspection in the VLSI Age

The 1980s brought the age of “submicron” VLSI devices with process line widths of less than 1μm. Optical testing equipment was reaching the limits of its usefulness in the inspection of such ultrafine semiconductor devices.

The Naka Works of Hitachi, Ltd. (as it was then known) possessed many years of experience in the field of scanning electron microscopes, and it embarked on the development of a length measurement SEM specifically for use in semiconductor testing. The S-6000 was commercialized in 1984. The first unit produced was delivered to the Device Development Center, which develops and manufactures computer elements for Hitachi, Ltd. Starting the next year a large number of units were delivered to the production line of the Musashi Works.

The overwhelming performance advantages of the length measurement SEM were widely acknowledged, and orders streamed in from semiconductor fabs in Japan and overseas. Soon this product line had captured over 80% of the world market. Today Hitachi High-Technologies continues to be the top manufacturer of length measurement SEM systems.

S-6000 length measurement SEM