The dual-sensing-latch circuit proposed here can solve the synchronization problem of the conventional wave-pipelined SRAM, and the proposed source-biased self-resetting circuit reduces both the cycle and access time of cache SRAM's. A 16-kb SRAM using these circuit techniques was designed, and was fabricated with 0.25-µm CMOS technology. Simulation results indicate that this SRAM has a typical clock access time of 2.6 ns at 2.5-V supply voltage and a worst minimum cycle time of 2.6 ns.

A high-performance microprocessor-compatible small size full CMOS SRAM cell technology for under 1.8-V operation has been developed. Less than 1-µm spacing between the n and pMOSFETs is achieved by using a retrograde well combined with SSS-OSELO technology. To connect the gates of a driver nMOSFET and a load pMOSFET directly, a 0.3-µm n-gate load pMOSFET, formed by amorphous-Si-film through-channel implantation, is merged with a 0.25-µm p-gate pMOSFET for the peripheral circuits. The memory cell area is reduced by using a mask-free contact process for the local interconnect, which includes titanium-nitride wet-etching using a plasma-TEOS silicone-dioxide mask. The newly developed memory cell was demonstrated using 0.25-µm CMOS process technology. A 6.93-µm2 and 1-V operation full CMOS SRAM cell with a high-performance circuit was achieved by a simple fabrication process.

A 4-Mb CMOS SRAM with 3.84 µm2 TFT load cells is fabricated using 0.25-µm CMOS technology and achieves an address access time of 6 ns at a supply voltage of 2.7 V. The use of a current sense amplifier that is insensitive to its offset voltage enables the fast access time. A boosted cell array architecture allows low voltage operation of fast SRAM's using TFT load cells.

A 16-Mb CMOS SRAM using 0.4-µm CMOS technology has been developed. This SRAM features common-centroid-geometry (CCG) layout sense amplifiers which shorten the access time by 2.4 ns. A flexible redundancy technique achieves high efficiency without any access penalty. A memory cell with stacked capacitors is fabricated for high soft-error immunity. A 16-Mb SRAM with a chip size of 215 mm2 is fabricated and an address access time of 12.5 ns has been achieved.

An all-CMOS output buffer has been developed. The output buffer is composed of a voltage-follower and a source-follower circuit. The performance of the output buffer is characterized by a low-voltage operation of 1.7 V, a short delay of 1 ns, availability for the wired-OR connection, and adjustability to TTL, ECL, and a reduced swing level (RSL). The output buffer is incorporated into a 64-kb CMOS SRAM. This SRAM has achieved an access time of 4.3 ns at a supply voltage of -3.6 V.