Abstract: A laser annealing method for obtaining a crystalline semiconductor film having a large grain size is provided. Laser light is irradiated to the top surface and the bottom surface of an amorphous semiconductor film when crystallizing the amorphous semiconductor film by laser light irradiation. Furthermore, a relationship of 0<(I0′/I0)<1, or 1<(I0′/I0) is achieved for the ratio (I0/I0′) between the effective energy strength of the laser light when irradiated to the top surface (I0) and the effective energy strength of the laser light when irradiated to the bottom surface (I0′).

Abstract: The invention relates to a method for manufacturing a semiconductor device, and it is an object of the invention to form a semiconductor area formed in island-like patterns as a single crystal or an area which can be regarded as a single crystal, and to simultaneously achieve a laminated structure by which various characteristics of TFTs can be stabilized, wherein an insulation film is formed on a glass substrate, and island-like semiconductor layer is formed thereon. A laser beam passed through a cylindrical lens is made into a linear laser beam and irradiated onto the island-like semiconductor layer by an optical system.

Abstract: To improve the operation characteristic and reliability of a semiconductor device by optimizing the structure of bottom gate type or inverted stagger type TFTs arranged in circuits of the semiconductor device in accordance with the function of the respective circuits. At least LDD regions that overlap with a gate electrode are formed in an N channel type TFT of a driving circuit, and LDD regions that do not overlap with the gate electrode are formed in an N channel type TFT of a pixel matrix circuit. The concentration of the two kinds of LDD regions is differently set from each other, to thereby obtain the optimal circuit operation.

Abstract: A crystalline semiconductor film in which the position and size of a crystal grain is controlled is fabricated, and the crystalline semiconductor film is used for a channel formation region of a TFT, so that a high performance TFT is realized. An island-like semiconductor layer is made to have a temperature distribution, and a region where temperature change is gentle is provided to control the nucleus generation speed and nucleus generation density, so that the crystal grain is enlarged. In a region where an island-like semiconductor layer 1003 overlaps with a base film 1002, a thick portion is formed in the base film 1002. The volume of this portion increases and heat capacity becomes large, so that a cycle of temperature change by irradiation of a pulse laser beam to the island-like semiconductor layer becomes gentle (as compared with other thin portion).

Abstract: A strip-like first insulating layer is formed on a glass substrate, and a second insulating layer is formed on the first insulating layer. Furthermore, an island-like semiconductor layer is formed on the second insulating layer. The island-like semiconductor layer is crystallized by irradiation with laser light through both surfaces of the glass substrate.

Abstract: A laser annealing method for obtaining a crystalline semiconductor film having a large grain size is provided. Laser light is irradiated to the top surface and the bottom surface of an amorphous semiconductor film when crystallizing the amorphous semiconductor film by laser light irradiation.

Abstract: In a semiconductor device including a laminate of a first insulating layer, a crystalline semiconductor layer, and a second insulating layer, characteristics of the device are improved by determining its structure in view of stress balance. In the semiconductor device including an active layer of the crystalline semiconductor layer having tensile stress on a substrate, tensile stress is given to the first insulating layer formed to be in close contact with a surface of the semiconductor layer at a substrate side, and compressive stress is given to the second insulating layer formed to be in close contact with a surface of the semiconductor layer at a side opposite to the substrate side.

Abstract: In a semiconductor device employing a glass substrate, the object of the present invention is to provide a high performance semiconductor device with a large screen at low cost, which prevents the semiconductor device from being contaminated by impurities from the glass substrate. In a semiconductor device comprising a blocking film provided in contact with a glass substrate and TFTs provided on the blocking film, the blocking film is characterized by being made of a tantalum oxide film.

Abstract: The invention relates to a method for manufacturing a semiconductor device, and it is an object of the invention to form a semiconductor area formed in island-like patterns as a single crystal or an area which can be regarded as a single crystal, and to simultaneously achieve a laminated structure by which various characteristics of TFTs can be stabilized, wherein an insulation film is formed on a glass substrate, and island-like semiconductor layer is formed thereon. A laser beam passed through a cylindrical lens is made into a linear laser beam and irradiated onto the island-like semiconductor layer by an optical system.

Abstract: A strip-like first insulating layer is formed on a glass substrate, and a second insulating layer is formed on the first insulating layer. Furthermore, an island-like semiconductor layer is formed on the second insulating layer. The island-like semiconductor layer is crystallized by irradiation with laser light through both surfaces of the glass substrate.

Abstract: The invention relates to a method for manufacturing a semiconductor device, and it is an object of the invention to form a semiconductor area formed in island-like patterns as a single crystal or an area which can be regarded as a single crystal, and to simultaneously achieve a laminated structure by which various characteristics of TFTs can be stabilized, wherein an insulation film is formed on a glass substrate, and island-like semiconductor layer is formed thereon. A laser beam passed through a cylindrical lens is made into a linear laser beam and irradiated onto the island-like semiconductor layer by an optical system.

Abstract: In a semiconductor device employing a glass substrate, the object of the present invention is to provide a high performance semiconductor device with a large screen at low cost, which prevents the semiconductor device from being contaminated by impurities from the glass substrate. In a semiconductor device comprising a blocking film provided in contact with a glass substrate and TFTs provided on the blocking film, the blocking film is characterized by being made of a tantalum oxide film.

Abstract: A strip-like first insulating layer is formed on a glass substrate, and a second insulating layer is formed on the first insulating layer. Furthermore, an island-like semiconductor layer is formed on the second insulating layer. The island-like semiconductor layer is crystallized by irradiation with laser light through both surfaces of the glass substrate.

Abstract: The present invention provides a semiconductor device in which a bottom-gate TFT or an inverted stagger TFT arranged in each circuit is suitably constructed in conformity with the functionality of the respective circuits, thereby attaining an improvement in the operating efficiency and reliability of the semiconductor device. In the structure, LDD regions in a pixel TFT are arranged so as not to overlap with a channel protection insulating film and to overlap with a gate electrode by at least a portion thereof. LDD regions in an N-channel TFT of a drive circuit is arranged so as not to overlap with a channel protection insulating film and to overlap with a gate electrode by at least a portion thereof. LDD regions in a P-channel TFT of the drive circuit is arranged so as to overlap with a channel protection insulating film and to overlap with the gate electrode.

Abstract: To provide a technique required for purifying the interface between an active layer and an insulating film. On a substrate (101), a gate wiring (103) is formed and the surface thereof is covered with a gate oxide film (104). Then, a first insulating film (105a), a second insulating film (105b), a semiconductor film (106) and a protective film (107) are sequentially formed and layered without exposing them to the air. Further, the semiconductor film (106) is irradiated with laser light through the protective film (107). In this way, a TFT may be given good characteristics by completely purifying the interface of the semiconductor film.

Abstract: In a semiconductor device including a laminate of a first insulating layer, a crystalline semiconductor layer, and a second insulating layer, characteristics of the device are improved by determining its structure in view of stress balance. In the semiconductor device including an active layer of the crystalline semiconductor layer having tensile stress on a substrate, tensile stress is given to the first insulating layer formed to be in close contact with a surface of the semiconductor layer at a substrate side, and compressive stress is given to the second insulating layer formed to be in close contact with a surface of the semiconductor layer at a side opposite to the substrate side.

Abstract: To provide a laser apparatus and a laser annealing method with which a crystalline semiconductor film with a larger crystal grain size is obtained and which are low in their running cost. A solid state laser easy to maintenance and high in durability is used as a laser, and laser light emitted therefrom is linearized to increase the throughput and to reduce the production cost as a whole. Further, both the front side and the back side of an amorphous semiconductor film is irradiated with such laser light to obtain the crystalline semiconductor film with a larger crystal grain size.

Abstract: An object of the present invention is to improve the reliability and the operation performance of a semiconductor device comprising a driver circuit and a pixel pixel section by optimizing the TFT structure disposed in each circuit in accordance with the function of the circuit. The optimized circuit operation can be obtained by providing a LDD region that overlaps with at least the gate electrode in the driver circuit n-channel TFT, and a LDD region in the pixel section n-channel TFT in which the impurity concentration of the both LDD regions are differed.

Abstract: To realize TFT enabling high-speed operation by fabricating a crystalline semiconductor film in which positions and sizes of crystal grains are controlled and using the crystalline semiconductor film in a channel forming region of TFT, a film thickness is stepped by providing a stepped difference in at least one layer of a matrix insulating film among a plurality of matrix insulating films having refractive indices different from each other. By irradiating laser beam from a rear face side of a substrate (or both sides of a surface side and the rear face side of the substrate), there is formed an effective intensity distribution of laser beam with regard to a semiconductor film and there is produced a temperature gradient in correspondence with a shape of the stepped difference and a distribution of the film thickness of the matrix insulating film in the semiconductor film.

Abstract: The present invention provides a semiconductor device in which a bottom-gate TFT or an inverted stagger TFT arranged in each circuit is suitably constructed in conformity with the functionality of the respective circuits, thereby attaining an improvement in the operating efficiency and reliability of the semiconductor device. In the structure, LDD regions in a pixel TFT are arranged so as not to overlap with a channel protection insulating film and to overlap with a gate electrode by at least a portion thereof. LDD regions in an N-channel TFT of a drive circuit is arranged so as not to overlap with a channel protection insulating film and to overlap with a gate electrode by at least a portion thereof. LDD regions in a P-channel TFT of the drive circuit is arranged so as to overlap with a channel protection insulating film and to overlap with the gate electrode.