Method for fabricating a semiconductor device

摘要

A method for fabricating a semiconductor device is disclosed. The method includes forming a gate stack over a substrate, forming spacers adjoining opposite sidewalls of the gate stack, forming a sacrificial layer adjoining the spacers, removing a portion of the sacrificial layer, removing a portion of the spacers to form a recess cavity below the left spacers. Then, a strain feature is formed in the recess cavity. The disclosed method provides an improved method by providing a space between the spacer and the substrate for forming the strained feature, therefor, to enhance carrier mobility and upgrade the device performance.

主权项

1. A method, comprising:
forming a gate stack over a substrate; forming a spacer adjoining a sidewall of the gate stack; forming a first recess in the substrate adjacent to an edge of the gate stack; thereafter, forming a sacrificial layer adjoining the spacer; removing a portion of the sacrificial layer to expose a lower portion of the spacer; removing at least a portion of the exposed spacer to form a second recess in the exposed lower portion of the spacer; and forming a strain feature in the second recess.