Patent ID: 7608526

Claim:
A method of manufacturing a semiconductor workpiece, the method comprising: providing a substrate; depositing a relaxed buffer layer on the substrate; and during depositing the relaxed buffer layer, depositing at least one strained transitional layer wherein depositing the relaxed buffer layer comprises depositing silicon and germanium in an epitaxial deposition reactor, wherein depositing the relaxed buffer layer comprises: depositing a first portion of the relaxed buffer layer by flowing silicon and germanium precursors, a germanium concentration in the first portion of the relaxed buffer layer increasing as the first portion of the relaxed buffer layer is deposited; after depositing the first portion of the relaxed buffer layer, depositing a first strained transition layer by pausing flowing the germanium precursors; and after depositing the first strained transition layer, depositing a second portion of the relaxed buffer layer by resuming flowing the germanium precursors, a germanium concentration in the second portion of the relaxed buffer layer increasing as the second portion of the relaxed buffer layer is deposited.