90 nm 32 × 32 bit tunneling SRAM memory array with 0.5 ns write access time, 1 ns read access time and 0.5 v operation

Functional robustness is one of the primary challenges for embedded memories as voltage levels are scaled below 1 V. A low-power high-speed tunneling SRAM (TSRAM) memory array including sense amplifiers and pre-charge circuit blocks operating at 0.5 V is designed and simulated using available MOSIS CMOS 90 nm product design kit coupled with VerilogA models developed from this group's Si/SiGe resonant interband tunnel diode experimental data. 1 T and 3 T-2 tunnel diode memory cell configurations were evaluated. The memory array assigns 0.5 V as a logic 1 and 0 V as a logic 0. Dual supply voltages of 1 and 0.5 V and dual threshold voltage design are used to ensure high sensing speed concurrently with low operating and standby power. Read access time of 1 ns and write access time of 2 ns is achieved for the 3 T memory cell. Write access time can be reduced to 0.5 ns for 32 bit write operations not requiring a preceding read operation. Standby power dissipation of 6× 10^-5mW per cell and dynamic power dissipation of &1.8× 10^-7mW/MHz per cell is obtained from the TSRAM memory array. This is the first report of TSRAM performance at the array level.