Ping Fong Ko

US Patent:

45326975, Aug 6, 1985

Filed:

Dec 2, 1983

Appl. No.:

6/557638

Inventors:

Ping K. Ko - Ocean NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

H01L 21225
H01L 21425

US Classification:

29571

Abstract:

In a metal-oxide-semiconductor device process, parasitic capacitance is significantly reduced by differentially oxidizing a substrate and a gate mesa thereon prior to ion implantation and "drive-in" of the drain and source regions. This results in a channel region being formed in the substrate beneath and substantially coextensive with the gate mesa. The conductivity of the channel region is different from the conductivity of the adjacent source and drain regions. In one embodiment, the source and drain regions each extend to a greater depth into the substrate with increasing distance from the channel region.