Method for manufacturing semiconductor devices using double-charged implantation

摘要

The invention provides an isolation technique using fewer process steps and a double charged implantation step (141) for defining a well region (139) of a CMOS integrated circuit device. The invention provides steps of providing a semiconductor substrate comprising an multiple layer of films (105, 107, 109). These films include an oxide layer (105) overlying the substrate, a polysilicon layer (107) overlying the oxide layer, and a nitride layer (109) overlying the polysilicon layer. The invention also uses a step of removing a first portion of the nitride layer and a first portion of the polysilicon layer defined underlying the first portion of the nitride layer and removing a second portion of the nitride layer and a second portion of the polysilicon layer defined underlying the second portion of the nitride layer. This sequence of steps provides a partially completed semiconductor structure that defines isolation regions before forming well regions for active devices.