A two-phase shift register using Si tunnel MIS switching diodes

A novel monolithic shift register consisting of tunnel MIS switching diode arrays is proposed, in which gold and molybdenum electrodes overlapping in part are arranged in close vicinity on thin oxides formed on an n on p⁺silicon epitaxial wafer. Directional shift with two-phase clocks is achieved by making use of unsymmetric electrode configurations and current coupling effects between adjacent elements together with the difference in the sustain voltages of ON states between the two metals. Both ten and twenty-bit devices have functioned as designed. The margins in the driving conditions depend on the unsymmetry in the electrodes. The maximum operation frequency of 3 MHz has been attained which is limited by the CR time constant. The proposed register can be realized with very simple fabrication processes which involve no impurity diffusion.