Photosensitive semiconductor device and a method of manufacturing such a device

Claim 1

A method for manufacturing a photosensitive semiconductor device comprising: (a) depositing a first dielectric layer on a semiconductor substrate formed of a material selected from the group consisting of silicon, polycrystalline silicon, microcrystalline silicon, amorphous silicon, monocrystalline silicon, and silicon layer of an SOS structure, said first dielectric layer comprising a material selected from the group consisting of an oxide layer, a nitride layer, and a superimposition of an oxide layer and a nitride layer; (b) depositing a first silicon layer on a portion of said first dielectric layer; (c) depositing a second dielectric layer on said silicon layer; (d) etching the first silicon layer covered by the second dielectric layer by photolithography to expose sides of said first silicon layer with a top surface of said first silicon layer remaining covered by said second dielectric layer; (e) depositing a metal layer which may give a silicide by thermal combination with silicon on the sides of the etched first silicon layer and on the second dielectric layer; (f) transforming by heat treatment the metal layer and a small thickness of the first silicon layer with which the metal layer is in contact into silicide; (g) removing the metal layer which has not been transformed into silicide; after step (g), depositing a second silicon layer on the first and second dielectric layers; depositing a third dielectric layer on said second silicon layer; etching the second silicon layer covered by the third dielectric layer by photolithography to expose sides of said second silicon layer with a top surface of said second silicon layer remaining covered by said third dielectric layer; depositing a metal layer which may given a silicide by thermal combination with silicon on the sides of the etched second silicon layer and on the third dielectric layer; transforming by heat treatment the second metal layer and a small thickness of the second silicon layer with which it is in contact into silicide; and removing the metal layer which has not been transformed into silicide.

Claim 2

A method for manufacturing a photosensitive semiconductor device comprising: (a) depositing a first dielectric layer on a semiconductor substrate formed of a material selected from the group consisting of silicon, polycrystalline silicon, microcrystalline silicon, amorphous silicon, monocrystalline silicon, and silicon layer of an SOS structure, said first dielectric layer comprising a material selected from the group consisting of an oxide layer, a nitride layer, and a superimposition of an oxide layer and a nitride layer; (b) depositing a first silicon layer on a portion of said first dielectric layer; (c) depositing a second dielectric layer on said silicon layer; (d) etching the first silicon layer covered by the second dielectric layer by photolithography to expose sides of said first silicon layer with a top surface of said first silicon layer remaining covered by said second dielectric layer; (e) depositing a metal layer which may give a silicide by thermal combination with silicon on the sides of the etched first silicon layer and on the second dielectric layer; (f) transforming by heat treatment the metal layer and a small thickness of the first silicon layer with which the metal layer is in contact into silicide; (g) removing the metal layer which has not been transformed into silicide; after step (g), depositing a second silicon layer on the first and second dielectric layers; depositing a third dielectric layer on said second silicon layer; etching the second silicon layer covered by the third dielectric layer by photolithography to expose sides of said second silicon layer with a top surface of said second silicon layer remaining covered by said third dielectric layer; depositing a metal layer which may given a silicide by thermal combination with silicon on the sides of the etched second silicon layer and on the third dielectric layer; transforming by heat treatment the second metal layer and a small thickness of the second silicon layer with which it is in contact into silicide; and removing the metal layer which has not been transformed into silicide.