Abstract: A thin film semiconductor device which includes an insulating substrate, a semiconductor polycrystal thin film formed over the substrate and a transistor with the thin film as a channel. The polycrystal includes a plurality of crystal grains, with grain boundaries between the crystal grains being recessed. The grain boundaries with the recessed surfaces are the most predominant of all grain boundaries within the channel. With this structure, the polycrystal can be a low temperature polycrystal that can be formed at a temperature of 150° C. or less, thereby achieving a low-cost device with high carrier mobility.

Abstract: An image display device capable of high-resolution and smooth moving image display, equipped with TFTs in an n-type (or p-type) semiconductor layer with a high on-off ratio and a low resistance. In polysilicon crystallization by laser annealing, an n-type (or p-type) semiconductor layer with a low resistance is produced by performing the following processes in order: implanting nitrogen (N) ions into an amorphous silicon precursor semiconductor film; laser crystallization; implanting n-type (or p-type) dopant ions; and annealing for dopant activation. When fabricating TFTs, this low-resistance semiconductor layer is used to form a source and a drain. Since C, N, and O impurities decrease the mobility of the TFTs, polysilicon is used in which the contaminants concentrations meet the following conditions: carbon concentration ?3×1019 cm?3, nitrogen concentration ?5×1017 cm?3, and oxygen concentration ?3×1019 cm?3.

Abstract: A semiconductor thin film is manufactured by scanning laser light or a substrate onto an arbitrary region of the semiconductor thin film and irradiating a laser thereon. The semiconductor thin film is formed by the substantially belt-shaped crystal being crystallized such that crystalline grains grow in the scanning direction, on the substrate, on XY coordinates where value x of beam size W (?m) of the laser light measured in substantially the same direction as the scanning direction is defined as X axis, and where value y of scanning velocity Vs (m/s) is defined as Y axis, the crystallization processing is performed within a region where all of the following conditions hold: condition 1: the beam size W is larger than wavelength of the laser beam, condition 2: the scanning velocity Vs is smaller than upper-limit of crystal growth speed, and condition 3: x×(1/y)<25 ?s.

Abstract: There is provided a method for fabricating an image display device having an active matrix substrate including high-performance transistor circuits operating with high mobility as drive circuits for driving pixel portions which are arranged as a matrix. The portion of a polysilicon film formed in a drive circuit region DAR1 provided on the periphery of the pixel region PAR of the active matrix substrate SUB1 composing the image display device is irradiated and scanned with a pulse modulated laser beam or a pseudo CW laser beam to be reformed into a quasi-strip-like-crystal silicon film having a crystal boundary continuous in the scanning direction so that discrete reformed regions each composed of the quasi-strip-like-crystal silicon film are formed.

Abstract: A semiconductor thin film is manufactured by scanning laser light or a substrate onto an arbitrary region of the semiconductor thin film and irradiating a laser thereon. The semiconductor thin film is formed by the substantially belt-shaped crystal being crystallized such that crystalline grains grow in the scanning direction, on the substrate, on XY coordinates where value x of beam size W (?m) of the laser light measured in substantially the same direction as the scanning direction is defined as X axis, and where value y of scanning velocity Vs (m/s) is defined as Y axis, the crystallization processing is performed within a region where all of the following conditions hold: condition 1: the beam size W is larger than wavelength of the laser beam, condition 2: the scanning velocity Vs is smaller than upper-limit of crystal growth speed, and condition 3: x×(1/y)<25 ?s.

Abstract: There is provided a method for fabricating an image display device having an active matrix substrate including high-performance transistor circuits operating with high mobility as drive circuits for driving pixel portions which are arranged as a matrix. The portion of a polysilicon film formed in a drive circuit region DAR1 provided on the periphery of the pixel region PAR of the active matrix substrate SUB1 composing the image display device is irradiated and scanned with a pulse modulated laser beam or a pseudo CW laser beam to be reformed into a quasi-strip-like-crystal silicon film having a crystal boundary continuous in the scanning direction so that discrete reformed regions each composed of the quasi-strip-like-crystal silicon film are formed.

Abstract: Only a region where TFTs constituting a high-performance circuit will be disposed in a precursor semiconductor film PCS on an insulating substrate GLS with an insulating layer UCL serving as an undercoat is irradiated with a first energy beam LSR so as to be poly-crystallized while growing crystal grains laterally. Further a second rapid thermal treatment is performed all over the panel so as to reduce defects in the crystal grains in a region PSI poly-crystallized by the aforementioned energy beam. Thus, a high-quality polycrystalline semiconductor thin film serving as TFTs for a high-performance circuit and having a high on-current, a low threshold value, a low variation and a sharp leading edge characteristic is obtained.

Abstract: Agglomeration of a polycrystalline silicon film is eliminated at the time of obtaining a high quality polycrystalline silicon film by forming a silicon layer on an insulating film substrate and conducting long-term melting and re-crystallization. For this purpose, a layer or a plurality of layers of an underlayer UCL are provided on an insulating substrate GLS, the area near the surface in contact with a precursory silicon film PCF provided on this underlayer UCL is formed as an insulating film UCLP showing a film composition to improve the wettability of the melted silicon layer, and thereafter a high quality polycrystalline silicon film PSI is formed through elimination of agglomeration by melting of the precursory silicon film PCF using a laser beam LSR.

Abstract: In a film semiconductor device according to the present invention, a continuous oscillating light beam from a solid laser or the like is modulated on time axis and spatially, thereby realizing crystal growth that is nearly optimum for a crystal structure and growth speed of crystals in a Si thin film. Crystal grains with a large diameter, flatness with no projections at their grain boundaries, and controlled surface orientations are thereby formed. By forming channels with these crystal grains, high mobility semiconductor devices and an image display device using these semiconductor devices are realized.

Abstract: In a thin film semiconductor device according to the present invention, a continuous oscillating light beam from a solid laser or the like is modulated on time axis and spatially, thereby realizing crystal growth that is nearly optimum for a crystal structure and a growth speed of crystals in a Si thin film. Crystal grains with a large diameter, flatness with no projections at their grain boundaries, and controlled surface orientations are thereby formed. By forming channels with these crystal grains, high-mobility semiconductor devices and an image display device using these semiconductor devices are realized.

Abstract: There is provided a method for fabricating an image display device having an active matrix substrate including high-performance transistor circuits operating with high mobility as drive circuits for driving pixel portions which are arranged as a matrix. The portion of a polysilicon film formed in a drive circuit region DAR1 provided on the periphery of the pixel region PAR of the active matrix substrate SUB1 composing the image display device is irradiated and scanned with a pulse modulated laser beam or a pseudo CW laser beam to be reformed into a quasi-strip-like-crystal silicon film having a crystal boundary continuous in the scanning direction so that discrete reformed regions each composed of the quasi-strip-like-crystal silicon film are formed.

Abstract: There is provided a method for fabricating an image display device having an active matrix substrate including high-performance transistor circuits operating with high mobility as drive circuits for driving pixel portions which are arranged as a matrix. The portion of a polysilicon film formed in a drive circuit region DAR1 provided on the periphery of the pixel region PAR of the active matrix substrate SUB1 composing the image display device is irradiated and scanned with a pulse modulated laser beam or a pseudo CW laser beam to be reformed into a quasi-strip-like-crystal silicon film having a crystal boundary continuous in the scanning direction so that discrete reformed regions each composed of the quasi-strip-like-crystal silicon film are formed.

Abstract: A semiconductor thin film is manufactured by scanning laser light or a substrate onto an arbitrary region of the semiconductor thin film and irradiating a laser thereon. The semiconductor thin film is formed by the substantially belt-shaped crystal being crystallized such that crystalline grains grow in the scanning direction, on the substrate, on XY coordinates where value x of beam size W (?m) of the laser light measured in substantially the same direction as the scanning direction is defined as X axis, and where value y of scanning velocity Vs (m/s) is defined as Y axis, the crystallization processing is performed within a region where all of the following conditions hold: condition 1: the beam size W is larger than wavelength of the laser beam, condition 2: the scanning velocity Vs is smaller than upper-limit of crystal growth speed, and condition 3: x×(1/y)<25 ?s.

Abstract: A large number of pixels PXL are arranged in a matrix fashion in a display region DSP on an insulating substrate. Disposed around the display region DSP are a drain-side pixel-driving circuit including a drain shift register DSR, a digital-to-analog converter circuit DAC, a drain level shifter DLS, a buffer BF and sampling switches SSW; and a gate-side pixel-driving circuit including a gate shift register GSR and a gate level shifter GLS, and various kinds of circuits. Current mobility of thin film transistors constituting a circuit region SX requiring high-speed operation of these pixel-driving circuits is improved by optimizing a combination of plural layouts, arrangements and configurations for the respective circuits to meet the specifications special for the respective circuits.

Abstract: There is provided a method for fabricating an image display device having an active matrix substrate including high-performance transistor circuits operating with high mobility as drive circuits for driving pixel portions which are arranged as a matrix. The portion of a polysilicon film formed in a drive circuit region DAR1 provided on the periphery of the pixel region PAR of the active matrix substrate SUB1 composing the image display device is irradiated and scanned with a pulse modulated laser beam or a pseudo CW laser beam to be reformed into a quasi-strip-like-crystal silicon film having a crystal boundary continuous in the scanning direction so that discrete reformed regions each composed of the quasi-strip-like-crystal silicon film are formed.

Abstract: An image display device has an active matrix substrate provided with a drive circuit formed of high-performance active elements such as thin film transistors which operate with high mobility for driving pixel sections arranged in a matrix configuration. The image display device has discontinuous converted regions (virtual tiles) TL formed of roughly-band-shaped-crystal silicon films in circuit sections constituting a drive circuit DDR disposed around a pixel region PAR on the active matrix substrate SUB1, and has the drive circuit DDR formed of active elements such as thin film transistors fabricated in the discontinuous converted regions TL with their channel direction in a direction of growth direction of the roughly-band-shaped-crystal silicon films.

Abstract: In a thin film semiconductor device according to the present invention, a continuous oscillating light beam from a solid laser or the like is modulated on time axis and spatially, thereby realizing crystal growth that is nearly optimum for a crystal structure and a growth speed of crystals in a Sin thin film. Crystal grains with a large diameter, flatness with no projections at their grain boundaries, and controlled surface orientations are thereby formed. By forming channels with these crystal grains, high-mobility semiconductor devices and an image display device using these semiconductor devices are realized.