A Silicon and Aluminum Dynamic Memory Technology

Abstract

The Silicon and Aluminum Metal Oxide Semiconductor (SAMOS) technology is presented as a high-yield, low-cost process to make one-device-cell random access memories. The characteristics of the process are a multilayer dielectric gate insulator (oxide-nitride), a p-type polysilicon field shield, and a doped oxide diffusion source. Added yield-enhancing features are backside ion implant gettering, dual dielectric insulators between metal layers, and circuit redundancy. A family of chips is produced using SAMOS, ranging from 18K bits to 64K bits. System features such as on-chip data registers are designed on some chips. The chip technology is merged with “flip-chip” packaging to provide one-inch-square modules from 72K bits through 512K bits, with typical access times from 90 ns to 300 ns.