Gate Current Injection in Submicron EPROM Cells

Hot electron generation is enhanced by controlling impurity profiles in deeper region from the surface. Reduction of gate oxide thickness, also increases the gate current even under the constant substrate current. It should be noted that the increase of deep channel concentration causes worse influence to long term instability in submicron MOSFET´s, therefore separately optimized peripheral devices were combined with EPROM cell. As a result, EPROM cell with 0.9 ¿m gate length, 180Ã… 1st gate oxide thickness and 2x1017 cm-3 deep boron concentration is designed and 100 ¿sec programming speed under 5V of drain voltage is successfully demonstrated.