Patent ID: 6057186
Filing Date: 2000-05-02
Classification: H01L,Y10S

Abstract:
A method of forming a butted contact in an SRAM memory device comprising:providing said SRAM memory device with a butted contact exposing the following,a) a contact region on the surface of a doped semiconductor substrate,b) a conductor stack above a field oxide region on the surface of said substrate;forming an interpolysilicon silicon oxide dielectric layer on the surface of said device with an opening framing said contact region and the butt end of said conductor stack adjacent to said contact region,forming an undoped upper polysilicon layer on the surface of said SRAM device covering said interpolysilicon silicon oxide dielectric layer, said contact region, and the butt end of said conductor stack,forming a Vcc mask on the surface of said undoped upper polysilicon layer with a window framing said interpolysilicon silicon oxide dielectric layer, said contact region, andthe butt end of said conductor stack, leaving an exposed region of said polysilicon layer,ion implanting a first dose of Vcc dopant through said window into said upper polysilicon layer at a first energy level, andion implanting a second dose of Vcc dopant through said window into said buried contact region and said butt end of said conductor stack layer at a higher energy level than said first energy level.