MANUFACTURE OF SEMICONDUCTOR DEVICE

PURPOSE:To facilitate forming a source region and a drain region symmetrically about a gate electrode by a method wherein ions are implanted vertically to the direction of a channel width with a gate electrode as a mask and implanted with inclinations to the direction of a channel length so as to implantations in the source and drain regions uniformly from both sides of the gate electrode. CONSTITUTION:With a gate electrode formed on the surface of a semiconductor substrate 1 as a mask, ions are implanted vertically to the direction of a channel width into the substrate 1 surface and implanted with an inclination to the direction of a channel length so as to be implanted into a source region or a drain region (arrows A) and then with an inclination so as to be implanted into the other source region or drain region (arrows B) to achieve required quantity of impurity ion implantation. Finally, a heat treatment is carried out to form a source region 4a and a drain region 4d which are symmetrical about the gate electrode. 2: gate insulating film, 3: polycrystalline Si.