Method for manufacturing a semiconductor device including top gate thin film transistor and method for manufacturing an active matrix device including top gate thin film transistor

A method for manufacturing a semiconductor device comprising the steps of:

• forming an insulating film comprising silicon oxide nitride over a substrate by a plasma CVD process;
• forming a first semiconductor film comprising silicon having an amorphous structure over the insulating film;
• providing the first semiconductor film with a metal element for promoting crystallization;
• performing a heating process on the first semiconductor film to form a second semiconductor film;
• irradiating laser light to the second semiconductor film to form a third semiconductor film having a plurality of convexes;
• irradiating intense light to the third semiconductor film to form a fourth semiconductor film;
• patterning the fourth semiconductor film to form at least one semiconductor layer;
• forming a gate dielectric film over the fourth semiconductor film;
• forming a gate electrode over the fourth semiconductor film;
• forming a first concentration impurity region by doping the fourth semiconductor film;
• forming a second concentration impurity region having a region that overlaps the gate electrode by doping the fourth semiconductor film;
• and
• performing a heating process in a nitrogen atmosphere to getter a metal element into the first concentration impurity region and the second concentration impurity region.

A method for manufacturing a semiconductor device comprising the steps of:

• forming an insulating film comprising silicon oxide nitride over a substrate by a plasma CVD process;
• forming a semiconductor film comprising silicon and having an amorphous structure over said insulating film;
• crystallizing said semiconductor film by an irradiation of laser light wherein a plurality of convexes are formed on a surface of the crystallized semiconductor film;
• irradiating the crystallized semiconductor film with intense light to reduce said convexes;
• patterning the crystallized semiconductor film to form at least one semiconductor layer after the irradiating of intense light;
• forming a gate dielectric film over the crystallized semiconductor film;
• forming a gate electrode over the crystallized semiconductor film;
• forming a first concentration impurity region by doping the fourth semiconductor film with an n type impurity element;
• forming a second concentration impurity region having a region that overlaps the gate electrode by doping the fourth semiconductor film with an n type impurity element;
• and
• performing a heating process in a nitrogen atmosphere to activate the n type impurity element added to the first concentration impurity region and the second concentration impurity region.

A method for manufacturing a semiconductor device comprising the steps of:

• forming an insulating film comprising silicon oxide nitride over a substrate by a plasma CVD process;
• forming a semiconductor film comprising silicon and germanium and having an amorphous structure over said insulating film;
• crystallizing said semiconductor film by an irradiation of laser light wherein a plurality of convexes are formed on a surface of the crystallized semiconductor film;
• irradiating the crystallized semiconductor film with intense light to reduce said convexes;
• patterning the crystallized semiconductor film to form at least one semiconductor layer after the irradiating of intense light;
• forming a gate dielectric film over the crystallized semiconductor film;
• forming a gate electrode over the crystallized semiconductor film;
• forming a first concentration impurity region by doping the fourth semiconductor film with an n type impurity element;
• forming a second concentration impurity region having a region that overlaps the gate electrode by doping the fourth semiconductor film with an n type impurity element;
• and
• performing a heating process in a nitrogen atmosphere to activate the n type impurity element.

A method for manufacturing an active matrix device comprising the steps of:

• forming an insulating film comprising silicon oxide nitride over a substrate by a plasma CVD process;
• forming a semiconductor film comprising silicon having an amorphous structure over said insulating film;
• crystallizing said semiconductor film by an irradiation of laser light wherein a plurality of convexes are formed on a surface of the crystallized semiconductor film;
• irradiating the crystallized semiconductor film with intense light to reduce said convexes;
• patterning the crystallized semiconductor film to form at least one semiconductor layer;
• forming a gate dielectric film on the semiconductor layer;
• forming a gate electrode over a channel region of said semiconductor layer with said gate dielectric film interposed therebetween;
• forming a first concentration impurity region by doping the fourth semiconductor film with an n type impurity element;
• forming a second concentration impurity region having a region that overlaps the gate electrode by doping the fourth semiconductor film with an n type impurity element;
• and
• performing a heating process in a nitrogen atmosphere to activate the n type impurity element added to the first concentration impurity region and the second concentration impurity region.