Method of making semiconductor device having thin film transistor

Claim 1

A method of manufacturing a semiconductor device including a thin film transistor including a pair of impurity regions in a thin film silicon layer, comprising the steps of: forming a first insulating layer on the surface of a semiconductor substrate; forming a conductive layer on the surface of said first insulating layer and patterning said conductive layer to form a gate electrode; forming a second insulating layer on the surface of said gate electrode; forming a silicon thin film layer on the surface of said second insulating layer; forming a pair of impurity regions in said silicon layer; and forming an oxidation preventing film on the surface of said silicon layer; wherein said step of forming said pair of impurity regions in said silicon layer includes the steps of: forming a third insulating layer on a portion of the surface of said silicon layer; and implanting impurity ions into said silicon layer using said third insulating layer as a mask to form said pair of impurity regions, and wherein said oxidation preventing film is formed on the surface of said silicon layer and on the surface of said third insulating layer.

Claim 2

A method of manufacturing a semiconductor device including a thin film transistor including a pair of impurity regions in a thin film silicon layer, comprising the steps of: forming a first insulating layer on the surface of a semiconductor substrate; forming a conductive layer on the surface of said first insulating layer and patterning said conductive layer to form a gate electrode; forming a second insulating layer on the surface of said gate electrode; forming a silicon thin film layer on the surface of said second insulating layer; forming a pair of impurity regions in said silicon layer; and forming an oxidation preventing film on the surface of said silicon layer; wherein said step of forming said pair of impurity regions in said silicon layer includes the steps of: forming a third insulating layer on a portion of the surface of said silicon layer; and implanting impurity ions into said silicon layer using said third insulating layer as a mask to form said pair of impurity regions, and wherein said oxidation preventing film is formed on the surface of said silicon layer and on the surface of said third insulating layer.

Claim 6

A method of manufacturing a semiconductor device including a thin film transistor including a pair of impurity regions in a thin film silicon layer, comprising the steps of: forming a first insulating layer on the surface of a semiconductor substrate; forming a conductive layer on the surface of said first insulating layer and patterning said conductive layer to form a gate electrode; forming a second insulating layer on the surface of said gate electrode; forming a thin film silicon layer on the surface of said second insulating layer; forming a pair of impurity regions in said silicon layer; forming a third insulating layer on the surface of said silicon layer; and forming an oxidation preventing film on the surface of said third insulating layer so that said third insulating layer is between said silicon layer and said oxidation preventing film and further so that said oxidation prevention film is positioned on a thin film transistor portion of said semiconductor device and is below a device passivation film.

Claim 7

A method of manufacturing a semiconductor device including a thin film transistor including a pair of impurity regions in a thin film silicon layer, comprising the steps of: forming a first insulating layer on the surface of a semiconductor substrate; forming a conductive layer on the surface of said first insulating layer and patterning said conductive layer to form a gate electrode; forming a second insulating layer on the surface of said gate electrode; forming a thin film silicon layer on the surface of said second insulating layer; forming a pair of impurity regions in said silicon layer; forming a third insulating layer on the surface of said silicon layer; and forming an oxidation preventing film on the surface of said third insulating layer so that said third insulating layer is between said silicon layer and said oxidation preventing film and further so that said oxidation prevention film is positioned on a thin film transistor portion of said semiconductor device and is below a device passivation film.

Claim 11

A method of manufacturing a semiconductor device including a thin film transistor including a pair of impurity regions in a thin film silicon layer, comprising the steps of: forming a first insulating layer on the surface of a semiconductor substrate; forming a conductive layer on the surface of said first insulating layer and patterning said conductive layer to form a gate electrode; forming a second insulating layer on the surface of said gate electrode; forming a silicon thin film layer on the surface of said second insulating layer; forming a pair of impurity regions in said silicon layer; and forming an oxidation preventing silicon nitride film on the surface of said silicon layer, wherein the oxidation preventing silicon nitride film is in contact with the whole surface of the silicon layer.

Claim 12

A method of manufacturing a semiconductor device including a thin film transistor including a pair of impurity regions in a thin film silicon layer, comprising the steps of: forming a first insulating layer on the surface of a semiconductor substrate; forming a conductive layer on the surface of said first insulating layer and patterning said conductive layer to form a gate electrode; forming a second insulating layer on the surface of said gate electrode; forming a silicon thin film layer on the surface of said second insulating layer; forming a pair of impurity regions in said silicon layer; and forming an oxidation preventing silicon nitride film on the surface of said silicon layer, wherein the oxidation preventing silicon nitride film is in contact with the whole surface of the silicon layer.