Patent ID: 6291284
Filing Date: 2001-09-18
Classification: H01L

Abstract:
A method of fabricating a semiconductor device comprising:a step of forming a field oxide film having a bird's beak at an inner peripheral portion to surround a device region of a semiconductor substrate,a step of forming a gate insulating film on a surface of the semiconductor substrate within the device region,a step of forming a gate on the gate insulating film,a step of forming main doped layers by adding to regions of the semiconductor substrate between the gate and the field oxide film impurity for forming a source and a drain,a step of forming sub-doped layers by selectively adding impurity to regions of the semiconductor substrate at boundaries between the device region and the field oxide film, anda step of forming main active layers constituting the source and the drain and forming sub-active layers so as to cover an overlap between the bird's beak of the field oxide film and the main active layers by, after forming the whole surface of the semiconductor substrate with an insulating film, effecting annealing to activate the main doped layers and activate the sub-doped layers.