Patent ID: 9257557
Filing Date: 2016-02-09
CPC Classification: H01L

Claim Text:
1. A method of forming a semiconductor structure, comprising: forming an n-doped, stress relaxed epitaxial first silicon germanium layer having a first germanium concentration onto a semiconductor substrate; depositing a compressively strained epitaxial second silicon germanium layer having a second germanium concentration onto the first silicon germanium layer, wherein the second germanium concentration is higher than the first germanium concentration; removing a portion of the second silicon germanium layer over a first region to create exposed regions of the first silicon germanium layer, thereby forming a preserved portion of the second silicon germanium layer over a second region; counterdoping to p-type the exposed regions of the first silicon germanium layer that are not covered by the second silicon germanium layer; selectively depositing a tensile strained, epitaxial silicon layer in the first region; and forming a plurality of shallow trench isolation regions in the first region and the second region of the second silicon germanium layer.