Patent ID: 6097064
Filing Date: 2000-08-01
Classification: H01L

Abstract:
A semiconductor device including an N-channel MOS transistor, the N-channel MOS transistor comprising: a semiconductor substrate having a first conductivity type; source and drain regions having a second conductivity type formed in the semiconductor substrate; a gate electrode formed over the semiconductor substrate between the source and drain regions, the gate electrode having a portion disposed directly over a portion of the drain region; and a gate insulating film formed between the semiconductor substrate and the gate electrode; wherein the drain region has a first impurity region formed laterally spaced from the gate electrode and extending slightly under the gate electrode due to lateral diffusion, and a second impurity region formed substantially and directly under the gate electrode but not formed by lateral diffusion, the second impurity region having an impurity concentration of at least 5.times.10.sup.18 cm.sup.-3 and having an impurity concentration which monotonically decreases without a kink in the direction towards the source region under the gate electrode.