Method of fabricating a semiconductor device with protection means

摘要

The invention provides for a method of fabricating a semiconductor device in a substrate (100). Active regions are defined within the substrate (100) using a thin oxide layer (102) and a silicon nitride layer (104) with portions of the silicon nitride layer being etched away to expose the thin oxide layer (102). Field oxide regions (106) are formed over regions other than the defined active regions. These field oxide regions (106) are located between the active regions. The remaining portions of the silicon nitride layer and the thin oxide layer are removed and a sacrificial oxide layer (108) is then grown on the surfaces of the active regions. A first mask (110), a N-well mask, is formed for implanting N-type dopants. A buried layer implanted using P-type dopants with the first mask (110) in place. Thereafter, the N-well regions are implanted. The first mask is removed and a second mask (116) is formed to define regions for implanting P-well regions using P-type dopants. The P-well regions are implanted using P-type dopants.