A 1-µm Mo—poly 64-kbit MOS RAM

This paper describes a 1-µm 64-kbit MOS RAM using Mopoly technology. New 1-µm double-gate technology using molybdenum and polysilicon (Mo-poly technology) is proposed. In this technology, molybdenum and polysilicon are used for word lines and storage capacitor electrodes in the memory cell, respectively. Therefore, the propagation delay in a word line becomes extremely small and memory cell size is reduced. New two step annealing was developed for stabilizing an Mo-gate MOS structure. Design is optimized for 1-µm Si-gate FET's in peripheral circuitry. A 1-µm Mo-poly 64-kbit MOS RAM was experimentally fabricated by using 1-µm process technologies. The cell size and die size were 8 µm × 8 µm and 3 mm µ 3 mm, respectively. Access time was less than 100 ns.