Abstract: A thin film semiconductor device formed as integrated circuits on an insulating substrate with bottom gate type thin film transistors stacked with gate electrodes, a gate insulating film and a semiconductor thin film in the order from below upward. The gate electrodes comprise metallic materials with thickness less than 100 nm. The gate insulating film has a thickness thicker than the gate electrodes. The semiconductor thin film comprises polycrystalline silicon crystallized by a laser beam. By reducing thickness of metallic gate electrodes, thermal capacity becomes small and difference in thermal condition on the metallic gate electrodes and on the insulating substrate made of glass or the like becomes small. This invention relates to the task of uniforming and optimizing recrystallization by a laser anneal treatment provided for the semiconductor thin film which works as an active layer of the bottom gate type thin film transistors.

Abstract: A thin film semiconductor device formed as integrated circuits on an insulating substrate with bottom gate type thin film transistors stacked with gate electrodes, a gate insulating film and a semiconductor thin film in the order from below upward. The gate electrodes comprise metallic materials with thickness less than 100 nm. The gate insulating film has a thickness thicker than the gate electrodes. The semiconductor thin film comprises polycrystalline silicon crystallized by a laser beam. By reducing thickness of metallic gate electrodes, thermal capacity becomes small and difference in thermal condition on the metallic gate electrodes and on the insulating substrate made of glass or the like becomes small. This invention relates to the task of uniforming and optimizing recrystallization by a laser anneal treatment provided for the semiconductor thin film which works as an active layer of the bottom gate type thin film transistors.

Abstract: A thin film semiconductor device formed as integrated circuits on an insulating substrate with bottom gate type thin film transistors stacked with gate electrodes, a gate insulating film and a semiconductor thin film in the order from below upward. The gate electrodes comprise metallic materials with thickness less than 100 nm. The gate insulating film has a thickness thicker than the gate electrodes. The semiconductor thin film comprises polycrystalline silicon crystallized by a laser beam. By reducing thickness of metallic gate electrodes, thermal capacity becomes small and difference in thermal condition on the metallic gate electrodes and on the insulating substrate made of glass or the like becomes small. This invention relates to the task of uniforming and optimizing recrystallization by a laser anneal treatment provided for the semiconductor thin film which works as an active layer of the bottom gate type thin film transistors.

Abstract: A thin film semiconductor device formed as integrated circuits on an insulating substrate with bottom gate type thin film transistors stacked with gate electrodes, a gate insulating film and a semiconductor thin film in the order from below upward. The gate electrodes comprise metallic materials with thickness less than 100 nm. The gate insulating film has a thickness thicker than the gate electrodes. The semiconductor thin film comprises polycrystalline silicon crystallized by a laser beam. By reducing thickness of metallic gate electrodes, thermal capacity becomes small and difference in thermal condition on the metallic gate electrodes and on the insulating substrate made of glass or the like becomes small. This invention relates to the task of uniforming and optimizing recrystallization by a laser anneal treatment provided for the semiconductor thin film which works as an active layer of the bottom gate type thin film transistors.

Abstract: A thin film semiconductor device formed as integrated circuits on an insulating substrate with bottom gate type thin film transistors stacked with gate electrodes, a gate insulating film and a semiconductor thin film in the order from below upward. The gate electrodes comprise metallic materials with thickness less than 100 nm. The gate insulating film has a thickness thicker than the gate electrodes. The semiconductor thin film comprises polycrystalline silicon crystallized by a laser beam. By reducing thickness of metallic gate electrodes, thermal capacity becomes small and difference in thermal condition on the metallic gate electrodes and on the insulating substrate made of glass or the like becomes small. This invention relates to the task of uniforming and optimizing recrystallization by a laser anneal treatment provided for the semiconductor thin film which works as an active layer of the bottom gate type thin film transistors.

Abstract: For manufacturing a thin film semiconductor device, first conducted is a film-making step to make a non-single-crystalline semiconductor thin film (4) on an insulating substrate (1). Next conducted is an annealing step to irradiate laser light (50) for once heating and melting the non-single-crystalline semiconductor thin film (4) and then changing it into a polycrystal in its cooling process. Thereafter, a processing step is conducted to form thin film transistors in an integrated form, which includes the polycrystalline semiconductor thin film (4) as their active layer. For the purpose of ensuring uniform crystallization and enlargement of grain sizes, in the annealing step, by using a laser oscillator (51) including an excimer laser source, the laser light (50) having a pulse width not shorter than 50 ns is shaped by an optical system (53) to form a rectangular cross-sectional area whose sides are not shorter than 10 mm to sequentially irradiate the semiconductor thin film (4).

Abstract: A thin film semiconductor device having improved operating characteristics and reliability of a thin film transistor formed on a glass substrate. The thin film semiconductor device has a thin film transistor 3 formed on a glass substrate 1 containing alkali metal. The surface of the glass substrate 1 is covered by a buffer layer 2. The thin film transistor 3 formed on this buffer layer 2 has a polycrystalline semiconductor thin film 4 as an active layer. The buffer layer 2 includes at least a silicon nitride film and protects the thin film transistor 3 from contamination by alkali metals such as Na and has a thickness such that it can shield the thin film transistor 3 from an electric field created by localized alkali metal ions (Na+).

Abstract: A thin film semiconductor device having improved operating characteristics and reliability of a thin film transistor formed on a glass substrate. The thin film semiconductor device has a thin film transistor 3 formed on a glass substrate 1 containing alkali metal. The surface of the glass substrate 1 is covered by a buffer layer 2. The thin film transistor 3 formed on this buffer layer 2 has a polycrystalline semiconductor thin film 4 as an active layer. The buffer layer 2 includes at least a silicon nitride film and protects the thin film transistor 3 from contamination by alkali metals such as Na and has a thickness such that it can shield the thin film transistor 3 from an electric field created by localized alkali metal ions (Na+).

Abstract: A thin film semiconductor device formed as integrated circuits on an insulating substrate with bottom gate type thin film transistors stacked with gate electrodes, a gate insulating film and a semiconductor thin film in the order from below upward. The gate electrodes comprise metallic materials with thickness less than 100 nm. The gate insulating film has a thickness thicker than the gate electrodes. The semiconductor thin film comprises polycrystalline silicon crystallized by a laser beam. By reducing thickness of metallic gate electrodes, thermal capacity becomes small and difference in thermal condition on the metallic gate electrodes and on the insulating substrate made of glass or the like becomes small. This invention relates to the task of uiforming and optimizing recrystallization by a laser anneal treatment provided for the semiconductor thin film which works as an active layer of the bottom gate type thin film transistors.

Abstract: A thin film transistor (TFT) which may be used as a pixel drive element in an active matrix LCD display includes a pair of side wall spacers adjacent to the opposing side walls of its gate electrode. The side wall spacers provide the gate electrode with a substantially rectangular cross section, such that the gate electrode has a substantially constant thermal conductivity over its area. The TFT has a uniform device characteristic.

Abstract: A thin film transistor (TFT) which may be used as a pixel drive element in an active matrix LCD display includes a pair of side wall spacers adjacent to the opposing side walls of its gate electrode. The side wall spacers provide the gate electrode with a substantially rectangular cross section, such that the gate electrode has a substantially constant thermal conductivity over its area. The TFT has a uniform device characteristic.

Abstract: A thin film transistor (TFT) which may be used as a pixel drive element in an active matrix LCD display includes a pair of side wall spacers adjacent to the opposing side walls of its gate electrode. The side wall spacers provide the gate electrode with a substantially rectangular cross section, such that the gate electrode has a substantially constant thermal conductivity over its area. The TFT has a uniform device characteristic.

Abstract: In production of a thin film transistor, a gate electrode is formed on an insulating substrate. A gate nitride film and a gate oxide film are formed on the gate electrode. A semiconductor thin film is formed on the gate oxide film. The semiconductor thin film is irradiated with laser light for crystallization. The growth of the crystal grains in a first section of the semiconductor thin film lying just above the gate electrode is more significant than that of the crystal grains in a second section of the semiconductor thin film lying in a position other than just above the gate electrode. An impurity is selectively doped into the second section of the semiconductor thin film to form a source region and a drain region, while the first section of the semiconductor thin film is left without modification as a channel-forming region.

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.

Abstract: A semiconductor device includes an insulating substrate; a plurality of pixel electrodes arranged in a matrix on the insulating substrate; first thin film transistors for individually driving the pixel electrodes; and driving circuits composed of second thin film transistors formed on the insulating substrate. In this semiconductor device, each of the first and second thin film transistors has a bottom-gate structure comprising a gate electrode patterned on the insulating substrate; a gate insulating film covering the gate electrode; and a semiconducting thin film having a channel region and a source/drain region, which is formed on the gate insulating film. Each of the second thin film transistors has a lightly doped region at least between a drain side highly doped region and the channel region.

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.