Methods of forming epitaxial semiconductor material in trenches located above the source and drain regions of a semiconductor device

A method of forming a device comprised of a gate structure, a source region and a drain region that are positioned on opposite sides of said gate structure, wherein the method comprises:

• forming said gate structure above an active region of a semiconductor substrate, said gate structure having an axial length in a gate width direction of said device, wherein a first portion of said gate structure is positioned above said active region and second portions of said gate structure are positioned above an isolation region formed in said substrate;
• forming an etch stop layer on said gate structure, wherein said etch stop layer covers end surfaces and sidewall surfaces of said second portions of said gate structure but does not cover any sidewall surfaces of said first portion of said gate structure;
• forming a sidewall spacer adjacent opposite sides of said first portion of said gate structure so as to define first and second epi formation trenches comprising said spacer and extending continuously along said first portion of said gate structure for less than said axial length of said gate structure, wherein said first epi formation trench is positioned above at least a portion of said source region and said second epi formation trench is positioned above at least a portion of said drain region;
• and
• forming an epi semiconductor material on said active region within each of said first and second epi formation trenches.