Patent ID: 7843016
Filing Date: 2010-11-30
Classification: H01L

Abstract:
1. A design structure embodied in a machine readable medium used in a design process, the design structure comprising a field effect transistor structure comprising: a source region having a first bottom surface, a first top surface opposite said first bottom surface, and a first predetermined height from said first bottom surface to said first top surface; a drain region having a second bottom surface, a second top surface opposite said second bottom surface and a second predetermined height from said second bottom surface to said second top surface, said second bottom surface and said first bottom surface being approximately level and said second predetermined height being less than said first predetermined height; and a channel region positioned laterally between said source region and said drain region and having a third top surface, said first top surface, said second top surface and said third top surface all being at different levels; isolation regions positioned laterally adjacent to said source region and said drain a gate electrode on said third top surface approximately equidistance between said isolation regions, said gate electrode being essentially rectangular in shape and having a first side and a second side opposite said first side; a first sidewall spacer on said third top surface adjacent to said first side of said gate electrode and having a first predetermined width, said source region being separated from said first side of said gate electrode by a first predetermined distance that is approximately equal to said first predetermined width; and a second sidewall spacer on said third top surface adjacent to said second side of said gate electrode and having a second predetermined width that is greater than said first predetermined width, said drain region being separated from said second side of said gate electrode by a second predetermined distance that is approximately equal to said second predetermined width and, thereby greater than said first predetermined distance such that said source region and said drain region have different lengths.