David S Koh

US Patent:

60491043, Apr 11, 2000

Filed:

Nov 28, 1997

Appl. No.:

8/980460

Inventors:

Fwu-Iuan Hshieh - Saratoga CA
Shang-Lin Weng - Cupertino CA
David Haksung Koh - Sunnyvale CA
Chanh Ly - Concord CA

Assignee:

MagePower Semiconductor Corp. - San Jose CA

International Classification:

H01L 2976
H01L 2994
H01L 31062
H01L 31113
H01L 31119

US Classification:

257328

Abstract:

The present invention discloses a method for fabricating a MOSFET device supported on a substrate. The method includes the steps of (a) growing an oxide layer on the substrate followed by depositing a polysilicon layer and applying a gate mask for performing an undercutting dry etch for patterning a plurality of polysilicon gates with a gate width narrower than a width of the gate mask; (b) applying the gate mask as body implant blocking mask for implanting a body dopant followed by removing the gate mask and carrying out a body diffusion for forming body regions; (c) applying a source blocking mask for implanting a source dopant to form a plurality of source regions; (d) forming an overlying insulation layer covering the MOSFET device followed by applying a dry oxide etch with a contact mask as a second mask to open a plurality of contact openings there through then removing the contact mask; (e) performing a high temperature reflow process for the overlying insulation layer and for driving the source regions into designed junction depths; (f) depositing a metal layer followed by applying a metal mask for patterning the metal layer to define a plurality of metal segments.