Patent ID: 6037222
Filing Date: 2000-03-14
Classification: H01L

Abstract:
A method for fabricating a semiconductor device having transistors with two different thickness gate oxide layers; comprising the steps of:(a) forming isolation areas on a substrate surrounding and electrically isolating device areas, said device areas composed of a logic area and Memory area;(b) sequentially forming a first gate oxide layer, a first polysilicon layer, and a first gate cap layer over said logic area;(c) sequentially forming a second gate oxide layer, a second polysilicon layer, a second polycide layer, a second gate cap layer, and hard mask layer at least over said memory cell area;(d) patterning said second gate oxide layer, said second polysilicon layer, said second polycide layer, said second gate cap layer, and said hard mask layer forming memory gate structures in memory area, and removing said second gate oxide layer, said second polysilicon layer, said second polycide layer, and said second gate cap layer from over said logic area;(e) forming memory LDD regions adjacent to said memory gate structures in said memory area;(f) patterning said first gate oxide layer, said first polysilicon layer and said first gate cap layer over said logic area forming logic gate structures;(g) forming LDD regions adjacent to said logic gate structures;(h) removing said first gate cap layer;(i) forming spacers on the sidewalls of said logic gate structures, said logic gate structures and said memory gate structures;(j) ion implanting n type ions forming Source/drain regions adjacent said logic gate structures and doping said logic gate structures in said logic area;(k) forming a resist protection oxide layer over said logic gate structure and said memory gate structures and said substrate;(l) removing said resist protection oxide layer from over said logic area;(m) using a salicide process to form self-aligned silicide logic S/D contacts to said Source/drain regions, and to form self-aligned silicide logic gate contacts to said logic gate structures; and(n) forming self aligned polycide contacts to said source/drain regions in said memory area.