DSA 4K static RAM

A high-performance diffusion self-aligned (DSA) 4K static RAM, which operates on a single power supply of 5 V without any clock input, has been fabricated. The RAM, composed of DSA MOSTs, depletion MOSTs, and high-impedance polysilicon load resistors, was designed using nonclocked static circuit techniques. The memory cell size and the chip size are 45/spl times/40 /spl mu/m and 3.88/spl times/3.45 mm, respectively. A typical access and cycle time of 76 ns is realized at a power dissipation of 500 mW. The RAM can retain data in a standby mode with a reduced supply voltage of 1.5 V, thereby decreasing the power dissipation to 60 mW. The active power dissipation can be decreased in a RAM fabricated with a lower ion-implantation dose to the depletion load MOSTs; thus the RAM may also be useful for memory applications where low power dissipation is of primary importance.