Method for fabricating thin film transistor device
First Claim
1. A method for fabricating a thin film semiconductor device, comprising the steps of:
- forming a thin film transistor composed of an amorphous semiconductor thin film and a metallic gate electrode laminated on the opposite side from each other via a gate insulating film on a transparent substrate;
applying heat rays from the side of said gate electrode to heat said gate electrode which auxiliary heats a region of said amorphous semiconductor thin film which is opposed to said gate electrode;
applying energy beams from the side of said amorphous semiconductor thin film on the opposite side from said gate electrode to transform said amorphous semiconductor thin film in the region auxiliary heated by the gate electrode into a polycrystalline semiconductor thin film to form an active layer of said thin film transistor; and
thenintroducing impurities into parts of said semiconductor thin film adjoining said active layer to form a source region and a drain region of said thin film transistor.
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Accused Products
Abstract
A method for crystallizing a portion of a semiconductor thin film while forming a semiconductor device comprises providing a transparent substrate supporting a metallic gate electrode and an amorphous semiconductor thin film which are separated from each other by a gate insulating film, heating the gate electrode by subjecting it to light rays, and applying a laser beam to the amorphous semiconductor thin film so that the portion of the semiconductor thin film adjacent the metallic gate electrode is heated by both the laser beam and the heat of the gate electrode to cause a crystallization of a portion of the amorphous thin film and then processing the remaining amorphous portions of the thin film to form the transistor structure.
161 Citations
10 Claims
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1. A method for fabricating a thin film semiconductor device, comprising the steps of:
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forming a thin film transistor composed of an amorphous semiconductor thin film and a metallic gate electrode laminated on the opposite side from each other via a gate insulating film on a transparent substrate; applying heat rays from the side of said gate electrode to heat said gate electrode which auxiliary heats a region of said amorphous semiconductor thin film which is opposed to said gate electrode; applying energy beams from the side of said amorphous semiconductor thin film on the opposite side from said gate electrode to transform said amorphous semiconductor thin film in the region auxiliary heated by the gate electrode into a polycrystalline semiconductor thin film to form an active layer of said thin film transistor; and
thenintroducing impurities into parts of said semiconductor thin film adjoining said active layer to form a source region and a drain region of said thin film transistor. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for fabricating a thin film semiconductor device, said method comprising the steps of providing a transparent substrate, forming on said substrate a thin film transistor composed of an amorphous semiconductor thin film and a metallic gate electrode laminated on opposite sides of a gate insulating film, crystallizing a portion of the amorphous semiconductor material into a polycrystalline semiconductor thin film while maintaining adjacent portions of the semiconductor thin film amorphous by applying heat rays from a side of said gate electrode to heat the gate electrode, which auxiliary heats a region of the amorphous semiconductor thin film which is opposed to said gate electrode and applying energy beams from the side of the amorphous semiconductor thin film on the opposite side from the gate electrode to transform said amorphous semiconductor thin film in said region into a polycrystalline semiconductor thin film;
- and then introducing impurities to the parts of the amorphous semiconductor film adjoining an active layer to form source regions and a drain region for said film transistor.
- View Dependent Claims (8, 9, 10)
Specification