MANUFACTURE OF AL GATE CMOS IC

摘要

PURPOSE:To equalize threshold voltage and thus to minimize substrate bias effect and junction capacity by doping a P-type impurity on both channel portions of P-channel MOSFET and N-channel MOSFET and changing flat-band voltage (VFB) in the positive direction. CONSTITUTION:An oxidized film 2 is formed on an N-type Si substrate, an opening is arranged by means of a photoresist film pattern 3 and boron ion is dirven therein with the film 3 working as a mask, a low density P-type diffusion is carried out in an oxidized atmosphere to obtain a high density P-type diffusion layer 5, and a phosphorus diffusion is carried out successively in the oxidized atmosphere to obtain a high density V-type diffusion layer 6. Then, an SiO2 gate oxidized film is formed by carrying out photoetching on a portion 8 through which to arrange a contact hole on a channel area 7 of an N-channel MOSFET and also on both layers 5, 6, the boron ion is driven concurrently in both MOSFET's to change VFB of the area 7 in the positive direction, thereby forming an Al electrode 9.