Raised source/drain using recess etch of polysilicon

Claim 1

A process for forming a structure in a semiconductor substrate, said structure including raised source/drain junctions and a salicide gate conductor, said process comprising: a. providing a semiconductor substrate containing (i) at least two shallow trench isolation (STI) elements formed by filling trenches in said substrate with an insulator material, (ii) a pad oxide layer on said semiconductor substrate between said STI elements, and (iii) a nitride layer overlying said pad oxide layer between said STI element; b. etching a portion of said nitride layer to expose a portion of said pad oxide layer, thereby forming a gate conductor trench between two of said STI elements; c. replacing said exposed pad oxide with a gate insulator; d. depositing polysilicon over the gate insulator in said gate conductor trench to form a gate conductor; e. removing said nitride layer from between said gate conductor and said two STI elements to expose sidewalls of said gate conductor and said STI elements; f. forming insulation spacers on said exposed sidewalls, said spacers defining two source/drain trenches on opposite sides of said gate conductor; g. blanket-depositing intrinsic polysilicon to fill said source/drain trenches and to cover said spacers and said two STI elements with said blanket-deposited intrinsic polysilicon; h. chemical mechanical polishing the polysilicon deposited in step (g) to expose at least a portion of each of said spacers and to planarize said polysilicon in said source-drain and gate conductor trenches; i. recessing said planarized polysilicon in said source/drain and gate conductor trenches to form recesses in said source/drain and gate conductor trenches, each recess being defined by two of said spacers and a recessed polysilicon surface; j. doping the recessed polysilicon in said source/drain and gate conductor trenches; and k. forming a salicide in said recesses on the doped polysilicon to form said salicide gate conductor and raised source/drain junctions.