Method for fabricating thin film transistor using anodic oxidation

A method of producing a semiconductor device comprising the steps of:

• forming an island semiconductor film having crystallinity on a substrate;
• forming an insulating film on the island semiconductor film;
• forming a gate electrode on the insulating film;
• anodically oxidizing the gate electrode, to form a first anodic oxide film on both sides of the gate electrode;
• anodically oxidizing the gate electrode, to form a second anodic oxide film between the gate electrode and the first anodic oxide film and on the gate electrode;
• etching the insulating film, to form a gate insulating film;
• removing the first anodic oxide film;
• introducing an element including at least one of oxygen, nitrogen and carbon into the semiconductor film;
• and
• introducing an impurity for providing one conductivity type into the semiconductor film.

A method of producing a semiconductor device comprising the steps of:

• forming an island silicon film having crystallinity on a substrate;
• forming an insulating film on the silicon film;
• forming an anodically oxidizable film on the insulating film;
• forming a mask film on the anodically oxidizable film;
• etching the anodically oxidizable film using the mask film, to form a gate electrode;
• anodically oxidizing the gate electrode, to form a first anodic oxide film on both sides of the gate electrode;
• removing the mask film;
• anodically oxidizing the gate electrode, to form a second anodic oxide film between the gate electrode and the first anodic oxide film and on the gate electrode;
• etching the insulating film, to form a gate insulating film;
• removing the first anodic oxide film;
• introducing an element including at least one of oxygen, nitrogen and carbon into the silicon film through the gate insulating film;
• and
• introducing an impurity for providing one conductivity type into the silicon film without passing through the gate insulating film.

A method of producing a semiconductor device comprising the steps of:

• forming an island silicon film having crystallinity on a substrate;
• forming an insulating film on the silicon film;
• forming an anodically oxidizable film on the insulating film;
• selectively forming a mask film on the anodically oxidizable film;
• etching the anodically oxidizable film using the mask film, to form a gate electrode;
• anodically oxidizing the gate electrode, to form a first anodic oxide film on both sides of the gate electrode;
• removing the mask film;
• anodically oxidizing the gate electrode, to form a second anodic oxide film between the gate electrode and the first anodic oxide film and on the gate electrode;
• selectively etching the insulating film, to form a gate insulating film;
• removing the first anodic oxide film;
• introducing an element including at least one of oxygen, nitrogen and carbon into the silicon film through the gate insulating film;
• selectively etching the insulating film using the gate electrode and the second anodic oxide film;
• and
• introducing an impurity for providing one conductivity type into the silicon film without passing through the gate insulating film.

A method of producing a semiconductor device comprising the steps of:

• forming an island silicon film having crystallinity on a substrate having an insulating surface;
• forming an insulating film on the silicon film;
• forming an anodically oxidizable film on the insulating film;
• selectively forming a mask film on the anodically oxidizable film;
• etching the anodically oxidizable film using the mask film, to form a gate electrode;
• anodically oxidizing the gate electrode, to form a first anodic oxide film on both sides of the gate electrode;
• removing the mask film;
• anodically oxidizing the gate electrode, to form a second anodic oxide film between the gate electrode and the first anodic oxide film and on the gate electrode;
• selectively etching the insulating film, to form a gate insulating film;
• removing the first anodic oxide film;
• introducing an element including at least one of oxygen, nitrogen and carbon into the silicon film through the gate insulating film;
• introducing an impurity for providing one conductivity type into the silicon film without passing through the gate insulating film;
• forming a metal film on a region of the silicon film on which the gate insulating film is not formed;
• and
• reacting the metal with the region by laser radiation, to form a metal silicide region.

A method of producing a semiconductor device comprising the steps of:

• forming an island silicon film having crystallinity on a substrate having an insulating surface;
• forming an insulating film on the silicon film;
• forming an anodically oxidizable film on the insulating film;
• selectively forming a mask film on the anodically oxidizable film;
• etching the anodically oxidizable film using the mask film, to form a gate electrode;
• anodically oxidizing the gate electrode, to form a first anodic oxide film on both sides of the gate electrode;
• removing the mask film;
• anodically oxidizing the gate electrode, to form a second anodic oxide film between the gate electrode and the first anodic oxide film and on the gate electrode;
• selectively etching the insulating film, to form a gate insulating film;
• removing the first anodic oxide film;
• forming a metal film on a region of the silicon film on which the gate insulating film is not formed;
• introducing an element including at least one of oxygen, nitrogen and carbon into the silicon film through the gate insulating film;
• introducing an impurity for providing one conductivity type into the silicon film without passing through the gate insulating film;
• and
• reacting the metal with the region by laser radiation, to form a metal silicide region.

A method of producing a semiconductor device comprising the steps of:

• forming an island silicon film having crystallinity on a substrate having an insulating surface;
• forming an insulating film on the silicon film;
• forming an anodically oxidizable film on the insulating film;
• selectively forming a mask film on the anodically oxidizable film;
• etching the anodically oxidizable film using the mask film, to form a gate electrode;
• removing the mask film;
• anodically oxidizing the gate electrode, to form a first anodic oxide film on both sides of the gate electrode and on the gate electrode;
• anodically oxidizing the gate electrode, to form a second anodic oxide film between the gate electrode and the first anodic oxide film;
• selectively etching the insulating film using the first anodic oxide film as a mask, to form a gate insulating film;
• removing the first anodic oxide film;
• introducing an element including at least one of oxygen, nitrogen and carbon into the silicon film through the gate insulating film;
• introducing an impurity for providing one conductivity type into the silicon film without passing through the gate insulating film;
• and
• forming a silicon nitride film on at least the gate insulating film.