US 4,897,368 A · Method of fabricating a polycidegate employing nitrogen/oxygen implantation

Abstract

Disclosed is a method of fabricating a polycidegate in semiconductor device which has a step of forming a conductor film of polysilicon on a substrate, a step of forming an ion implanted layer by implanting nitrogen ions into the polysilicon conductor film, and a step of forming a low resistance conductor film of titanium on the non-monocyrstalline conductor film. When a field effect transistor is formed by this method, using titanium nitride and/or TiSi.sub.2 alloy of the polysilicon conductor and low resistance conductor of titanium by heat treatment as a gate electrode material, the thickness of the alloyed layer is uniform, and breakdown of the gate insulating film due to local diffusion of low resistance conductor is not induced. In other embodiments, oxygen ions and silicon ions are also employed to form thin layers of tunnel oxide and amorphous silicon, respectively.

Claims21

Dependent claims

A method of fabricating a semiconductor device comprising:

(a) forming an insulating film on a surface of a semiconductor substrate;
(b) forming a polycrystalline conductor film on said insulating film;
(c) forming an ion implanted layer within the body of said polycrystalline conductor film by ion-implantation;
(d) forming a low resistance conductor film on said polycrystalline conductor film in which said ion implanted layer is formed;
(e) annealing said low resistance conductor film and said polycrystalline conductor film by heat treatment to at least partially mix the films as to form an alloy layer on top of the polycrystalline conductor film;
and
(f) patterning said alloy layer film and said polycrystalline conductor film into a low resistance wiring pattern;
whereby the ion implanted layer serves to prevent the atoms composing the low resistance conductor film from diffusing by said heat treatment into the lower part of said polycrystalline conductor film through the ion implanted layer and reaching to said insulating film.

5 more elements

The method of fabricating a semiconductor device comprising:

(a) forming an insulating film on a surface of a semiconductor substrate;
(b) forming a polycrystalline conductor film on said insulating film;
(c) forming a first ion implanted layer within the body of said polycrystalline conductor film by ion-implantation;
(d) forming a second ion implanted layer in said polycrystalline conductor film by ion-implantation at a smaller depth than the said first ion implanted layer;
(e) forming a low resistance conductor film on said polycrystalline conductor film in which said two ion implanted layers are formed;
(f) annealing said low resistance conductor film and said polycrystalline conductor film by heat treatment to at least partially mix these films so as to form an alloy layer on top of the polycrystalline conductor film;
and
(g) patterning said alloy layer and said polycrystalline conductor film into a low resistance wiring pattern;
whereby the ion implanted layers are used for preventing the atoms composing the low resistance conductor film from diffusing by the heat treatment into the lower part of said polycrystalline conductor film through the second ion implanted layer and reaching into said insulating film.

6 more elements

The method of fabricating a semiconductor device comprising:

(a) forming an insulating film on a surface of a semiconductor substrate;
(b) forming a polycrystalline conductor film on said insulating film;
(c) forming a first ion implanted layer within the body of said polycrystalline conductor film by ion-implantation;
(d) forming a low resistance conductor film on said polycrystalline conductor film in which said first ion-implantation layer is formed;
(e) forming a second ion implanted layer in said low resistance conductor film by ion-implantation;
(f) annealing said low resistance conductor film and said polycrystalline conductor film by heat treatment to at least partially mix these films so as to form an alloy layer on top of the polycrystalline conductor film;
and
(g) patterning said alloy layer and said polycrystalline conductor film into a low resistance wiring pattern;
whereby the ion implanted layers are used for preventing the atoms composing the low resistance conductor film from diffusing by the heat treatment into the lower part of said polycrystalline conductor film through the second ion implanted layer and reaching into said insulating film.

6 more elements

The method of fabricating a semiconductor device comprising:

(a) forming an insulating film on a surface of a semiconductor substrate;
(b) forming a low resistance polycrystalline silicon film on said insulating film;
(c) forming a nitrogen ion implanted layer within the body of said low resistance polycrystalline silicon film by ion-implantation;
(d) forming a metal-silicide film on said low resistance polycrystalline silicon film in which said nitrogen ion implanted layer is formed;
(e) annealing said metal-silicide film and said low resistance polycrystalline silicon film by heat treatment to at least partially mix these films and form an alloy layer;
and
(f) patterning said low resistance polycrystalline silicon film and said metal-silicide film into a low resistance wiring pattern;
whereby the ion implanted layer is used for preventing the atoms composing the low resistance conductor film from diffusing by the heat treatment into the lower part of said polycrystalline conductor film through the ion implanted layer and reaching to said insulating film, and
wherein said nitrogen ion implanted layer is used for preventing the atoms composing the metal-silicide film from diffusing by the heat treatment into the lower part of said low resistance polycrystalline silicon film through the nitrogen ion implanted layer and reaching into to said insulating film.

6 more elements

Dependencies are inferred from the claim text.

Method of fabricating a polycidegate employing nitrogen/oxygen implantation

Life of this patent

Method of fabricating a polycidegate employing nitrogen/oxygen implantation

Life of this patent

Abstract

Claims21