Patent ID: 6372588
Filing Date: 2002-04-16
Classification: H01L

Abstract:
A method of making an IGFET, comprising the steps of:providing a device region of a first conductivity type in a semiconductor substrate; forming a gate insulator on the device region; forming a gate on the gate insulator; forming an insulating layer over the gate and the device region; forming a heavily doped diffusion source layer over the insulating layer; and diffusing a dopant of a second conductivity type from the diffusion source layer through the insulating layer into the device region and throughout the gate, without driving essentially any of the dopant through the gate into the device region, thereby heavily doping the gate and forming a heavily doped source and drain in the device region so that the diffusion provides essentially all the dopant of the second conductivity type, and substantially no dopant of the first conductivity type, in the gate, source and drain.