Patent ID: 7354848

Claim:
A method of depositing an Î±-Si layer on a substrate, comprising: placing the substrate in a chamber; depositing an Î±-Si nucleation layer on said substrate using a first Si-containing source gas provided into the chamber; stopping flow of the first Si-containing source after the Î±-Si nucleation layer has been formed; depositing Î±-Si on the Î±-Si nucleation layer using a second Si-containing source gas to form an Î±-Si layer of less than about 50 â„« thickness; depositing a poly-SiGe layer on the Î±-Si layer; and thermally annealing the Î±-Si nucleation layer, the Î±-Si nucleation layer and the Î±-Si layer to convert the Î±-Si nucleation layer and the Î±-Si layer into poly-SiGe layers.