Patent ID: 7824846

Claim:
A method, comprising: forming a photoresist layer on a substrate; exposing a first annular region of said photoresist layer immediately adjacent to a perimeter of said substrate to actinic radiation, said first annular region having a first outer perimeter proximate to a perimeter of said substrate and a first inner perimeter away from said perimeter of said substrate, said actinic radiation gradually decreasing in intensity from said first outer perimeter to said first inner perimeter; developing said exposed first annular region of said photoresist layer to form a tapered profile in a second annular region of said photoresist layer, said second annular region having a second outer perimeter proximate to said perimeter of said substrate and a second inner perimeter away from said perimeter of said substrate, said profile gradually increasing in thickness from said second outer perimeter to said second inner perimeter; and after said developing, no portion of said photoresist layer is remaining on said substrate between said second outer perimeter and said perimeter of said substrate.