AN ALPHA-IMMUNE, 2-V SUPPLY VOLTAGE SRAM USING A POLYSILICON PMOS LOAD CELL

- A SRAM for a supply voltage of as low as 2 V is investigated for realizing high-density SRAM’s using deep submicrometer devices. The key technology for achieving the low-voltage operation is shown to be a polysilicon PMOS load (PPL) cell. The polysilicon PMOS device is successfully stacked on the bulk MOSFET, using 0.5-μm CMOS technology. The investigation emphasizes the soft error rate (SER) and the stability of the cell. The SER of the PPL cell at a supply voltage of 2 V is comparable to that of the conventional high-resistivity polysilicon load cell at a supply voltage of 5 V. The cell stability is also improved using a PPL cell, so that the low-voltage operation is assured. © 1990 IEEE