Patent ID: 6410377
Filing Date: 2002-06-25
Classification: H01L

Abstract:
A method for integrating a CMOS sensor and a high voltage device, said method comprising:s providing a substrate of a first conductive type with a first region and a second region; forming a first well of a second conductive type in said substrate of said second region, wherein said second conductive type being opposite to said first conductive type; forming a plurality of field oxide regions on said substrate to define a first active region of said sensor in said first region and a second active region of said high voltage device in said second region, wherein said first well being in a lateral of said substrate of said second active region, and one of said field oxide regions being floating on said first well; forming a first doped region of said second conductive type in said substrate of said first active region of said sensor and in said substrate of said second active region of said first well, wherein said first doped region in said second region being capping said field oxide region in said first well; forming a second well of said first conductive type in said substrate, wherein said second well in said first region being under each one of said field oxide regions, and said second well in said second region being adjacent to said first well in said second active region; forming a gate oxide layer on said substrate except said field oxide regions; forming a polysilicon gate electrode covering a portion of said second well and a portion of said first well in said second active region, wherein said polysilicon gate electrode being covering a portion said field oxide region on said first well; and forming a source region and a drain region of said second conductive type in said substrate of said second active region, wherein said source region being in said substrate of said second well around said polysilicon gate electrode, and said drain region being in said substrate of said first well around a lateral of said field oxide region which is not covered by said polysilicon gate electrode.