An Mo gate 4K static MOS RAM

Performance of a 4K static RAM was improved significantly with utilization of low resistance molybdenum gate process instead of conventional poly-silicon gate process. A typical access time of 26 ns was achieved with a low power consumption of 250 mW when the RAM was operated at 5 V-supply voltage and TTL compatible I/O levels. A signal propagation delay along the word line of the RAM was quite small as a result of reduction in interconnection resistance. Several disadvantages of molybdenum gate process such as, heavy mobile ion contamination, large interface charges, high contact resistance between molybdenum and silicon were overcame by improving the fabrication technologies such as, forming gas annealing, protection film coating, and ion implantation.