Method for fabricating semiconductor photodetector

Claim 1

A method for fabricating a photodetector comprising at least one vertical type static induction transistor, comprising the steps of: a. forming an oxide layer and a nonoxidizing layer on a first main surface of a silicon wafer; b. removing portions of at least said nonoxidizing layer from predetermined regions of said first main surface where a control gate region, a shielding gate region surrounding said control gate region and a first main electrode region between said gate regions are to be formed; c. selectively oxidizing said predetermined regions to form a field oxide layer; d. removing at least portions of said nonoxidizing layer from regions where said control gate region and said shielding gate region are to be formed to form said control gate region and said shielding gate region, each comprising an oxide layer on said first main surface; e. removing portions of said nonoxidizing layer and said oxide layer from the area on said first main surface where said first main electrode region is to be formed; f. forming an electrode of a first conductive material in said area where said first main electrode region is to be formed; g. covering the entirety of said first main surface of said silicon wafer with a first insulating layer; h. removing portions of said first insulating layer and said oxide layer on said control gate region; i. covering the entirety of said first main surface of said silicon wafer with a second insulating layer; j. forming an electrode of a second conductive material on said second insulating material layer on said control gate region; k. removing portions of said second insulating layer, said first insulating layer and said oxide layer on said shielding gate region to form at least one contact hole; l. covering the entirety of the first main surface of the silicon wafer with a metal layer; m. removing at least a portion of said metal layer on said control gate region; and n. forming an electrode for said second main electrode region on said main surface of said silicon wafer.

Claim 2

A method for fabricating a photodetector comprising at least one vertical type static induction transistor, comprising the steps of: a. forming an oxide layer and a nonoxidizing layer on a first main surface of a silicon wafer; b. removing portions of at least said nonoxidizing layer from predetermined regions of said first main surface where a control gate region, a shielding gate region surrounding said control gate region and a first main electrode region between said gate regions are to be formed; c. selectively oxidizing said predetermined regions to form a field oxide layer; d. removing at least portions of said nonoxidizing layer from regions where said control gate region and said shielding gate region are to be formed to form said control gate region and said shielding gate region, each comprising an oxide layer on said first main surface; e. removing portions of said nonoxidizing layer and said oxide layer from the area on said first main surface where said first main electrode region is to be formed; f. forming an electrode of a first conductive material in said area where said first main electrode region is to be formed; g. covering the entirety of said first main surface of said silicon wafer with a first insulating layer; h. removing portions of said first insulating layer and said oxide layer on said control gate region; i. covering the entirety of said first main surface of said silicon wafer with a second insulating layer; j. forming an electrode of a second conductive material on said second insulating material layer on said control gate region; k. removing portions of said second insulating layer, said first insulating layer and said oxide layer on said shielding gate region to form at least one contact hole; l. covering the entirety of the first main surface of the silicon wafer with a metal layer; m. removing at least a portion of said metal layer on said control gate region; and n. forming an electrode for said second main electrode region on said main surface of said silicon wafer.