Abstract:
A method for fabricating a semiconductor device, and a semiconductor device made with the method are described. In the method, a cavity is formed in a substrate, a first epitaxy process is performed under a pressure higher than 65 torr to form a buffer layer in the cavity, and a second epitaxy process is performed to form a semiconductor compound layer on the buffer layer in the cavity. In the semiconductor device, the ratio (S/Y) of the thickness S of the buffer layer on a lower sidewall of the cavity to the thickness Y of the buffer layer at the bottom of the cavity ranges from 0.6 to 0.8.
Abstract:
A method of forming a semiconductor device is disclosed. At least one gate structure is provided on a substrate, wherein the gate structure includes a first spacer formed on a sidewall of a gate. A first disposable spacer material layer is deposited on the substrate covering the gate structure. The first disposable spacer material layer is etched to form a first disposable spacer on the first spacer. A second disposable spacer material layer is deposited on the substrate covering the gate structure. The second disposable spacer material layer is etched to form a second disposable spacer on the first disposable spacer. A portion of the substrate is removed, by using the first and second disposable spacers as a mask, so as to form two recesses in the substrate beside the gate structure. A stress-inducing layer is formed in the recesses.