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: 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: 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 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: 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 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: Protrusions called ridges are formed on the surface of a crystalline semiconductor film formed by a laser crystallization method or the like. A heat absorbing layer are formed below a semiconductor film. When the semiconductor film is crystallized by laser, a temperature difference is produced between a semiconductor film 1010 positioned above a heat absorbing layer 1011 and a semiconductor film 1013 of the other region to produce a difference in thermal expansion at the boundary of the outside end 1015 of the heat absorbing layer. This difference produces a strain to form a surface wave. The surface wave starting at the outer periphery of the heat absorbing layer is formed in the vicinity of the heat absorbing layer. When the semiconductor layer is solidified after it is melted, the protrusions of the surface wave remain as protrusions after the semiconductor film is solidified.

Abstract: To provide a TFT that can operate at a high speed by forming a crystalline semiconductor film while controlling the position and the size of a crystal grain in the film to use the crystalline semiconductor film for a channel forming region of the TFT. Instead of a metal or a highly heat conductive insulating film, only a conventional insulating film is used as a base film to introduce a temperature gradient. A level difference of the base insulating film is provided in a desired location to generate the temperature distribution in the semiconductor film in accordance with the arrangement of the level difference. The starting point and the direction of lateral growth are controlled utilizing the temperature distribution.

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: 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: 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 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: To form a polycrystalline silicon film having a grain size of 1 ?m or greater by means of laser annealing. A beam emitted from a laser apparatus (101) is split in two by a half mirror. The split beams are processed into linear shapes by cylindrical lenses (102) to (105), and (207), then simultaneously irradiate an irradiation surface (209). If an amorphous silicon film formed on a glass substrate is disposed on the irradiation surface (209), an area will be irradiated by both a linear shape beam entering from a front surface and a linear shape beam that has transmitted through the glass surface. Both linear shape beams irradiate the same area to thereby crystallize the amorphous silicon film.

Abstract: To form a polycrystalline silicon film having a grain size of 1 ?m or greater by means of laser annealing. A beam emitted from a laser apparatus (101) is split in two by a half mirror. The split beams are processed into linear shapes by cylindrical lenses (102) to (105), and (207), then simultaneously irradiate an irradiation surface (209). If an amorphous silicon film formed on a glass substrate is disposed on the irradiation surface (209), an area will be irradiated by both a linear shape beam entering from a front surface and a linear shape beam that has transmitted through the glass surface. Both linear shape beams irradiate the same area to thereby crystallize the amorphous silicon film.

Abstract: This invention improves TFT characteristics by making an interface between an active layer, especially a region forming a channel formation region and an insulating film excellent, and provides a semiconductor device provided with a semiconductor circuit made of a semiconductor element having uniform characteristics and a method of fabricating the same. In order to achieve the object, a gate wiring line is formed on a substrate or an under film, a gate insulating film, an initial semiconductor film, and an insulating film are formed into a laminate without exposing them to the atmosphere, and after the initial semiconductor film is crystallized by irradiation of infrared light or ultraviolet light (laser light) through the insulating film, patterning is carried out to obtain an active layer and a protection film each having a desired shape, and then, a resist mask is used to fabricate the semiconductor device provided with an LDD structure.

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: 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: This invention improves TFT characteristics by making an interface between an active layer, especially a region forming a channel formation region and an insulating film excellent, and provides a semiconductor device provided with a semiconductor circuit made of a semiconductor element having uniform characteristics and a method of fabricating the same. In order to achieve the object, a gate wiring line is formed on a substrate or an under film, a gate insulating film, an initial semiconductor film, and an insulating film are formed into a laminate without exposing them to the atmosphere, and after the initial semiconductor film is crystallized by irradiation of infrared light or ultraviolet light (laser light) through the insulating film, patterning is carried out to obtain an active layer and a protection film each having a desired shape, and then, a resist mask is used to fabricate the semiconductor device provided with an LDD structure.

Abstract: To provide a TFT that can operate at a high speed by forming a crystalline semiconductor film while controlling the position and the size of a crystal grain in the film to use the crystalline semiconductor film for a channel forming region of the TFT. Instead of a metal or a highly heat conductive insulating film, only a conventional insulating film is used as a base film to introduce a temperature gradient. A level difference of the base insulating film is provided in a desired location to generate the temperature distribution in the semiconductor film in accordance with the arrangement of the level difference. The starting point and the direction of lateral growth are controlled utilizing the temperature distribution.