Method of manufacturing image sensors

Claim 1

A method of manufacturing image sensors in which photo detect elements and thin film transistor switching elements are formed on a substrate, the method comprising the steps of: forming a metal electrode as a gate electrode of each said thin film transistor switching element on said substrate; forming a gate insulating layer covering said metal electrode; providing a semiconductor active layer on said gate insulating layer so as to correspond in location to said metal electrode; forming a semiconductor layer as an ohmic contact layer on said semiconductor active layer; dividing said semiconductor layer to form a part of a drain electrode and a part of a source electrode; covering said parts to e used as said drain electrode and said source electrode respectively with chromium layers as barrier metal; forming a lower electrode for the photo detect elements from said chromium layer simultaneously with the formation of said barrier metal; forming a photoconductive layer and an upper electrode of said photo detect element on said lower electrode; forming an insulating layer on said upper electrode; forming contact holes on said insulating layer at said upper electrode and said drain electrode; and forming a metal wiring layer connecting said upper electrode and said drain electrode part through said contact holes.

Claim 2

A method of manufacturing image sensors in which photo detect elements and thin film transistor switching elements are formed on a substrate, the method comprising the steps of: forming a metal electrode as a gate electrode of each said thin film transistor switching element on said substrate; forming a gate insulating layer covering said metal electrode; providing a semiconductor active layer on said gate insulating layer so as to correspond in location to said metal electrode; forming a semiconductor layer as an ohmic contact layer on said semiconductor active layer; dividing said semiconductor layer to form a part of a drain electrode and a part of a source electrode; covering said parts to e used as said drain electrode and said source electrode respectively with chromium layers as barrier metal; forming a lower electrode for the photo detect elements from said chromium layer simultaneously with the formation of said barrier metal; forming a photoconductive layer and an upper electrode of said photo detect element on said lower electrode; forming an insulating layer on said upper electrode; forming contact holes on said insulating layer at said upper electrode and said drain electrode; and forming a metal wiring layer connecting said upper electrode and said drain electrode part through said contact holes.

Claim 3

A method of manufacturing image sensors in which photo detect elements and thin film transistor switching elements are formed on a substrate, the method comprising the steps of: forming a metal electrode as a gate electrode of each said thin film transistor switching element on said substrate; forming a gate insulating layer covering said metal electrode; providing a semiconductor active layer on said gate insulating layer so as to correspond in location to said metal electrode; forming a semiconductor layer as an ohmic contact layer on said semiconductor active layer; dividing said semiconductor layer to form a part of a drain electrode and a part of a source electrode; covering said parts to be used as said drain electrode and said source electrode respectively with tantalum layers as barrier metal; forming a lower electrode of each said photo detect element from said tantalum layer simultaneously with the formation of said barrier metal; forming a photoconductive layer and an upper electrode of said photo detect element on said lower electrode; forming an insulating layer on said upper electrode; forming contact holes on said insulating layer at said upper electrode and said drain electrode; and forming a metal wiring layer connecting said upper electrode and said drain electrode part through said contact holes.

Claim 4

A method of manufacturing image sensors in which photo detect elements and thin film transistor switching elements are formed on a substrate, the method comprising the steps of: forming a metal electrode as a gate electrode of each said thin film transistor switching element on said substrate; forming a gate insulating layer covering said metal electrode; providing a semiconductor active layer on said gate insulating layer so as to correspond in location to said metal electrode; forming a semiconductor layer as an ohmic contact layer on said semiconductor active layer; dividing said semiconductor layer to form a part of a drain electrode and a part of a source electrode; covering said parts to be used as said drain electrode and said source electrode respectively with tantalum layers as barrier metal; forming a lower electrode of each said photo detect element from said tantalum layer simultaneously with the formation of said barrier metal; forming a photoconductive layer and an upper electrode of said photo detect element on said lower electrode; forming an insulating layer on said upper electrode; forming contact holes on said insulating layer at said upper electrode and said drain electrode; and forming a metal wiring layer connecting said upper electrode and said drain electrode part through said contact holes.