Strained semiconductor device and method of making the same

A method of fabricating a semiconductor device, the method comprising:

• forming a first gate electrode and an adjacent second gate electrode over a semiconductor body, the first and second gate electrodes being electrically insulated from the semiconductor body;
• forming a first sidewall spacer along a first sidewall of the first gate electrode;
• forming a second sidewall spacer along a second sidewall of the second gate electrode;
• forming a masking layer over the semiconductor body including over the first and second gate electrodes and the first and second sidewall spacers;
• forming first and second sacrificial sidewall spacers over the masking layer adjacent the first and second sidewall spacers, the first and second sacrificial sidewall spacers and the first and second sidewall spacers overlying the semiconductor body;
• forming a planarization layer between the first and second sacrificial sidewall spacers;
• removing the first and second sacrificial sidewall spacers;
• etching first and second recesses in the semiconductor body, wherein the first and second recesses are separated by a region of the semiconductor body, and wherein the first and second recesses have substantially the same dimension;
• removing the planarization layer;
• and
• forming a first semiconductor material in the first recess and second semiconductor material in the second recess using the masking layer as a deposition mask.

A method of forming a semiconductor device, the method comprising:

• providing a semiconductor body formed from a first semiconductor material;
• forming a first gate electrode over an upper surface of the semiconductor body;
• forming a first sidewall spacer along a first sidewall of the first gate electrode;
• forming an opening in the semiconductor body by selectively removing a sacrificial sidewall spacer formed over the first sidewall spacer and exposing an underlying portion of the semiconductor body;
• embedding a first region of a second semiconductor material within the opening in the semiconductor body, the first region of the second semiconductor material being adjacent the first sidewall spacer and laterally spaced from an isolation region by a first distance;
• forming a second gate electrode over the upper surface of the semiconductor body;
• forming a second sidewall spacer along a second sidewall of the second gate electrode;
• and
• embedding a second region of a third semiconductor material within the semiconductor body, wherein the second region of the third semiconductor material is adjacent the second sidewall spacer and laterally spaced from the isolation region by a second distance, and wherein the first distance and the second distance are different.