Semiconductor structure comprising field effect transistors with stressed channel regions and method of forming the same

A method of forming a semiconductor structure, comprising:

• forming a first gate electrode structure and a second gate electrode structure above a semiconductor substrate;
• forming an extended source region and an extended drain region in said semiconductor substrate adjacent said second gate electrode structure;
• depositing a stressed material layer over said first and second gate electrode structures;
• forming sidewall spacers adjacent said second gate electrode structure, wherein forming said sidewall spacers comprises performing an etching process adapted to remove portions of said stressed material layer over said second gate electrode structure;
• forming a first cavity in said extended source region adjacent said second gate electrode structure and a second cavity in said extended drain region adjacent said second gate electrode structure;
• and
• forming a first stress-creating element in said first cavity and a second stress-creating element in said second cavity.