Progress in WSI SRAM development

Inova has developed a one megabit monolithic static RAM which contains over five million transistors and occupies a die area of approximately 320 square mm. This product has been in production since March, 1988, is fully 883C compliant, is the largest monolithic production memory in the world today, and has demonstrated wafer yields as high as 100%. The product exists in both *8 and *16 organizations, and is fabricated on a 1.2 mu P-well CMOS process. Current delivery rates are tens of thousands of devices per month. This paper reviews Inroute technology, the present state of the existing product, the Inroute yield model, current yield information on the Inova 1 M SRAM and an experimental monolithic eight megabit SRAM being developed jointly by INOVA and Westinghouse to explore the yield and packaging aspects of large area devices for use in military systems. The design combines the INOVA commercial one megabit SRAM, and the Westinghouse volumetrically efficient dual composite packaging approach.<>