A 1.2-NS HEMT 64-KB SRAM

A 1.2-ns ECL-compatible 64-kb static RAM using 0.60-mu-m-gate high electron mobility transistor (HEMT) technology has been developed. To achieve fast access time, the memory cell array is divided into sixteen 4-kb memory planes and a data-line equalization technique is adopted. The chip power consumption is suppressed to 5.9 W by using three power supply voltages (- 1.0, - 2.0, and - 3.6 V) and a normally-off (E/D) source-follower buffer for the word driver circuit. A new device fabrication technique, called the HEMT double-etch-stop process, enables the RAM to be fabricated in simple and fewer processing steps and reduces the chip dimensions to 7.4 x 6.5 mm.