Abstract: A process of lateral crystallization is provided for increasing the lateral growth length (LGL). A localized region of the substrate is heated for a short period of time. While the localized region of the substrate is still heated, a silicon film overlying the substrate is irradiated to anneal the silicon film to crystallize a portion of the silicon film in thermal contact with the heated substrate region. A CO2 laser may be used as a heat source to heat the substrate, while a UV laser or a visible spectrum laser is used to irradiate and crystallize the film.

Abstract: A single-crystal structure is grown using free-form fabrication through principles of directional solidification and direct-deposition techniques. The structure is formed from a metallic alloy by building from feedstock on top of and upward from a heated base element. The top of the structure is also heated with a scanning beam as it is built. The higher temperatures near the melting alloy tend to promote crystal growth rather than nucleation as the grain grows toward the heat of the scanning beam. This allows a two-dimensional thermal gradient to be formed in the build direction, which allows the solid crystal to maintain one orientation during the deposition process. As the material initially solidifies, it nucleates off of a desired grain that is designated by a grain selector. This method eliminates the need for expensive mold cavities and segmented furnaces that are typically required by prior art processes for producing some components.

Abstract: A method is provided for maintaining a planar surface as crystal grains are laterally grown in the fabrication of crystallized silicon films. The method comprises: forming a film of amorphous silicon with a surface and a plurality of areas; irradiating each adjacent areas of the silicon film with a first sequence of laser pulses; and, in response to the first sequence of laser pulses, controlling the planarization of the silicon film surface between adjacent areas of the silicon film as the crystal grains are laterally grown. By controlling the number of laser pulses in the sequence, the temporal separation between pulses, and the relative intensity of the pulses, the lateral growth length characteristics of the crystal grains can be traded against the silicon film flatness. A silicon film formed by a pulsed laser sequence crystallization process is also provided.

Abstract: A semiconductor substrate that prevents formation of particles from an edge part of the substrate. The substrate contains an on-substrate oxide film and an SOI layer stacked on the oxide film. A molten layer is formed on the edge part of the on-substrate oxide film and the SOI layer by mixing the SOI layer and the on-substrate oxide film to cover the edge part. An epitaxial layer may also be formed on the edge part of the on-substrate oxide film and the SOI layer to cover the edge part.

Abstract: Processing and systems to create, and resulting products related to, very small-dimension singular, or monolithically arrayed, semiconductor mechanical devices. Processing is laser performed on selected semiconductor material whose internal crystalline structure becomes appropriately changed to establish the desired mechanical properties for a created device.

Abstract: Amorphous or polycrystalline films have been recrystallized into single-crystal thin films (of micrometer thickness) by a zone melting technique, in which an electrically heated wire generated a narrow heated or molten zone (0.5-2 mm wide) on the substrate sandwiched between two pieces of glass or indium-tin-oxide-coated glass. The substrate can be either an organic or inorganic compound. When the molten zone was moved slowly (3-120 ?m/min) across the layer from one end of the cell to the other, a single-crystal film was produced after a single pass. This technique allows for thin film purification and an improvement in electronic, optical, and optoelectronic properties of the thin film. After this treatment, the steady-state short-circuit photocurrent can be improved by several orders of magnitude. These films are useful in the fields of optics and electronics for improving the performance in devices such as thin-film transistors and organic light-emitting diodes.

Abstract: A sequential lateral solidification mask having a first region with a plurality of first stripes that are separated by a plurality of first slits. The mask further includes a second region having a plurality of second stripes separated by a plurality of second slits. The second stripes are perpendicular to the first stripes. A third region having a plurality of third stripes separated by a plurality of third slits, with the third stripes being transversely arranged relative to the first stripes. A fourth region having a plurality of fourth stripes and a plurality of fourth slits between the fourth stripes, with the fourth stripes being transversely arranged relative to the second stripes. Sequential lateral solidification is performed using the mask by multiple movements of the mask and multiple, overlapping irradiations.

Abstract: At least one amorphous silicon island is formed on a substrate first. A first step and a second step laser crystallization processes are thereafter performed in sequence. The amorphous silicon island is irradiated with a laser pulse having a first energy density to re-crystallize an edge portion of the amorphous silicon island into a polysilicon structure. The amorphous silicon island is then irradiated with a laser pulse having a second energy density to re-crystallize a center portion of the amorphous silicon island into a polysilicon structure.

Abstract: A mask and its application in sequential lateral solidification (SLS) crystallization of amorphous silicon are provided. The mask includes a light absorptive portion for blocking a laser beam and a plurality of stripe-shaped light transmitting portions for passing the laser beam. Each stripe-shaped light transmitting portion is rectangular-shaped, and each light-transmitting portion includes triangular-shaped or semicircular-shaped edges on both sides. The distance between the adjacent light transmitting portions is less than the width of the light transmitting portion. The width of the light transmitting portions is less than or equal to twice the maximum length of lateral grain growth that is to be grown by sequential lateral solidification (SLS).

Abstract: A mask and its application in sequential lateral solidification (SLS) crystallization of amorphous silicon. The mask includes a light absorptive portion that blocks a laser beam and a plurality of tier-shaped light-transmitting portions that pass a laser beam. Each light-transmitting portion has a plurality of adjacent rectangular sub-portions. Adjacent rectangular sub-portions form a step. In operation, the mask moves transversely relative to a amorphous silicon film while a laser performs SLS crystallization. The light portions control grain growth such that high quality polycrystalline silicon is formed.

Abstract: The present invention relates to a method of fabricating a liquid crystal display panel that involves patterning a silicon film crystallized by sequential lateral solidification. The method comprises the steps of preparing a silicon film, crystallizing the silicon film by growing silicon grains on a slant with respect to a horizontal direction of the silicon film, and forming a driver and a pixel part using the crystallized silicon film wherein the driver and pixel part comprise devices having channels arranged in horizontal and perpendicular directions relative to the silicon film. The crystallized silicon film has uniform grain boundaries in the channels of the devices, thereby improving the products by providing uniform electrical characteristics of devices that comprise a driver and a pixel part of an LCD panel.

Abstract: A first layer made of polysilicon is formed on the surface of an underlying substrate. The surface of the first layer is exposed to an environment which etches silicon oxide. If the surface of the first layer is covered with a silicon oxide film, the silicon oxide film is removed. An energy is supplied to the first layer, the energy allowing silicon crystal to re-grow. Solid phase growth of silicon occurs in the first layer to planarize the surface thereof. A polysilicon film having small root mean square of roughness can be formed.

Abstract: A method of crystallizing an amorphous silicon layer includes the steps of generating an excimer laser beam having a first energy density and a second energy density, irradiating an amorphous silicon layer with at least one exposure of the excimer, wherein the first energy density melts the amorphous silicon layer to a first depth from a surface of the amorphous silicon layer equal to the first thickness and the second energy density melts the amorphous silicon layer to a second depth from the surface of the amorphous silicon layer less than the first thickness.

Abstract: A method is provided for maintaining a planar surface as crystal grains are laterally grown in the fabrication of crystallized silicon films. The method comprises: forming a film of amorphous silicon with a surface and a plurality of areas; irradiating each adjacent areas of the silicon film with a first sequence of laser pulses; and, in response to the first sequence of laser pulses, controlling the planarization of the silicon film surface between adjacent areas of the silicon film as the crystal grains are laterally grown. By controlling the number of laser pulses in the sequence, the temporal separation between pulses, and the relative intensity of the pulses, the lateral growth length characteristics of the crystal grains can be traded against the silicon film flatness. A silicon film formed by a pulsed laser sequence crystallization process is also provided.

Abstract: A method is provided to produce thin polycrystalline films having a single predominant crystal orientation. The method is well suited to the production of films for use in production of thin film transistors (TFTs). A layer of amorphous silicon is deposited over a substrate to a thickness suitable for producing a desired crystal orientation. Lateral-seeded excimer laser annealing (LS-ELA) is used to crystallize the amorphous silicon to form a film with a preferred crystal orientation. The crystallized film is then polished to a desired thickness for subsequent processing.

Abstract: A method of forming a single crystal semiconductor film on a non-crystalline surface is described. In accordance with this method, a template layer incorporating an ordered array of nucleation sites is deposited on the non-crystalline surface, and the single crystal semiconductor film is formed on the non-crystalline surface from the ordered array of nucleation sites. An integrated circuit incorporating one or more single crystal semiconductor layers formed by this method also is described.

Abstract: The present invention relates to a method of fabricating a liquid crystal display panel that involves patterning a silicon film crystallized by sequential lateral solidification. The method comprises the steps of preparing a silicon film, crystallizing the silicon film by growing silicon grains on a slant with respect to a horizontal direction of the silicon film, and forming a driver and a pixel part using the crystallized silicon film wherein the driver and pixel part comprise devices having channels arranged in horizontal and perpendicular directions relative to the silicon film. The crystallized silicon film has uniform grain boundaries in the channels of the devices, thereby improving the products by providing uniform electrical characteristics of devices that comprise a driver and a pixel part of an LCD panel.

Abstract: A mask and its application in sequential lateral solidification (SLS) crystallization of amorphous silicon are provided. The mask includes a light absorptive portion for blocking a laser beam and a plurality of stripe-shaped light transmitting portions for passing the laser beam. Each stripe-shaped light transmitting portion is rectangular-shaped, and each light-transmitting portion includes triangular-shaped or semicircular-shaped edges on both sides. The distance between the adjacent light transmitting portions is less than the width of the light transmitting portion. The width of the light transmitting portions is less than or equal to twice the maximum length of lateral grain growth that is to be grown by sequential lateral solidification (SLS).

Abstract: Disclosed is a method of producing fluoride crystal, wherein the method includes a dehydrating step for dehydrating a raw material of fluoride by heating a crucible being adapted to accommodate a raw material of fluoride therein and having an exhaust mechanism for exhausting an inside gas of the crucible, and a exhausting step for exhausting, in the dehydrating step, an inside gas of the crucible by use of the exhaust mechanism.

Abstract: A single crystal producing method for growing a single crystal, comprises the steps of: placing a material at one focal point in a light-condensing and heating furnace having an ellipse in section; placing a heat light source at another focal point; and emitting a laser beam has a wavelength of not less than about 160 nm and not greater than about 1,000 nm, on or near the one focal point to form a melt zone; and moving the melt zone to grow a single crystal.

Abstract: Semiconductor integrated devices such as transistors are formed in a film of semiconductor material formed on a substrate. For improved device characteristics, the semiconductor material has regular, quasi-regular or single-crystal structure. Such a structure is made by a technique involving localized irradiation of the film with one or several pulses of a beam of laser radiation, locally to melt the film through its entire thickness. The molten material then solidifies laterally from a seed area of the film. The semiconductor devices can be included as pixel controllers and drivers in liquid-crystal display devices, and in image sensors, static random-access memories (SRAM), silicon-on-insulator (SOI) devices, and three-dimensional integrated circuit devices.

Abstract: The present invention relates to a method of producing a recrystallized-material-member by melting a given zone of a crystalline-material-member and moving the molten zone continuously along the crystalline-material-member to recrystallize a desired region of the crystalline-material-member, wherein dimension of the molten zone of the crystalline-material-member is controlled to be constant and/or quality of crystal of the recrystallized-material-member is controlled to be uniform.

Abstract: A method of crystallizing an amorphous silicon layer on a substrate includes the steps of irradiating the amorphous silicon layer by a laser beam positioned over the amorphous silicon layer and having a predetermined repeat rate, while simultaneously partially heating the laser-irradiated part of the amorphous silicon layer upwardly with an RTP, thus crystallizing the amorphous silicon by a laser without damaging the glass substrate by a high temperature.

Abstract: An improved method for growing a first layer on a second layer in which the first and second layers have different thermal indices of expansion and/or a mismatch of the lattice constants and the deposition being carried out at a temperature above ambient. The first layer includes a material that decomposes upon beating above a decomposition temperature. One of the first and second layers absorbs light in a first frequency range and the other of the first and second layers is transparent to the light in the first frequency range. In the method of the present invention, the one of the first and second layers that absorbs light in the first frequency range is exposed to light in the first frequency range by passing the light through the other of the first and second layers. This exposure heats the first layer to a temperature above the decomposition temperature at the interface of the first and second layers after the first layer has been deposited on the second layer.

Abstract: A semiconductor film deposited on a substrate has regions of different thermal conductivity. A pulsed laser radiation is applied to the semiconductor film to melt the semiconductor film. When the melted semiconductor film is cooled and solidified, localized low-temperature regions are developed in the respective regions of different thermal conductivity. Crystal nuclei are produced in the respective localized low-temperature regions and grown into a single semiconductor crystal. The regions of different thermal conductivity are formed in the semiconductor film by high-thermal-conductivity members deposited on the semiconductor film in thermally coupled relationship thereto. A semiconductor device is fabricated using the semiconductor film and has channels disposed in the vicinity of the crystal nuclei.

Abstract: There is provided a single crystal growth method which allows single crystal of an incongruent melting compound to be grown stable while controlling its growth orientation. The single crystal growth method comprises the steps of: holding polycrystal and seed crystal within a heating furnace; joining the polycrystal with the seed crystal; heating the polycrystal on the side opposite from the side where the polycrystal is joined with the seed crystal to form a melt zone; moving the melt zone to the side where the polycrystal is joined with the seed crystal so that the melt zone is in contact with the seed crystal to allow seeding; and growing single crystal by moving the melt zone which has been in contact with the seed crystal and been seeded to the opposite side from the side where the polycrystal is joined with the seed crystal.

Abstract: The present invention provides a cerium-containing magnetic garnet single crystal having a size large enough to use as a material for optical communication of an isolator and for an electronic device, and a production method therefor. The cerium-containing magnetic garnet single crystal of the present invention is obtained by melting a cerium-containing magnetic garnet polycrystal while applying a sharp, large temperature gradient to the solid-liquid interface of the melt and the solid, and then solidifying the melted polycrystal. The polycrystal is preferably heated by using an optical heating device, for example, a combination of a main heating device using a laser beam, and an auxiliary heating device using reflected light from a halogen lamp.

Abstract: The invention provides a method for forming a plurality of single silicon crystals over a substrate. The method forms a plurality of nucleation sites over the substrate. An amorphous silicon layer is formed over the substrate covering the plurality of silicon nucleation sites. The amorphous silicon layer is melted by using a laser beam and then crystallized to form the plurality of single silicon crystals. Each of the plurality of single silicon crystals correspond to one of the plurality of nucleation sites.

Abstract: The present invention provides a process for preparing SOI wafer, more specifically, a process for preparing a large-sized SOI wafer of high quality of crystallization employing an apparatus for the manufacture of the SOI wafer in a simple and efficient manner. The apparatus for the manufacture of SOI wafer of the invention comprises electric furnace for heating polycrystalline silicon filled in a heat-resistant container; means for moving up and down of an insulating substrate whose one side is accompanied with silicon single crystalline seed, and immersing the substrate in the molten silicon filled in the heat-resistant container to form a thin single crystalline film on the substrate; and, shapers to keep a constant thickness of the thin single crystalline film which is formed on the insulating substrate by the moving means.

Abstract: The present invention is directed to methods for crystallizing macrophage colony stimulating factor (M-CSF) and to a crystalline M-CSF produced thereby. The present invention is also directed to methods for designing and producing M-CSF agonists and antagonists using information derived from the crystallographic structure of M-CSF. The invention is also directed to methods for screening M-CSF agonists and antagonists. In addition, the present invention is directed to an isolated, purified, soluble and functional M-CSF receptor.

Abstract: A glass substrate is positioned between a chamber with a reduced pressure and a chamber filled with a heated helium, and the glass substrate is forcibly bent by the pressure difference and the heated helium gas into a uniform shape. The irradiation of laser light is carried out in this state to compensate the difference of annealing effects due to fine difference of deformation of the respective glass substrates.

Abstract: There is provided a high quality epitaxial water on which the density of microscopic defects in the epitaxial layer is reduced to keep the GOI thereof sufficiently high and to reduce a leakage current at the P-N junction thereof when devices are incorporated, to thereby improve the yield of such devices. In an epitaxial wafer obtained by forming an epitaxial layer on a substrate, the density of IR laser scatterers is 5.times.10.sup.5 pieces/cm.sup.3 or less throughout the epitaxial layer.

Abstract: An apparatus for zone-melting recrystallization of a semiconductor layer includes a first heater, on which a semiconductor wafer including the semiconductor layer and upper and lower insulating films sandwiching the semiconductor layer is mounted, for radiantly heating a rear surface of the semiconductor wafer to a temperature at which the semiconductor layer and the insulating layers are not melted; and a second heater disposed above the semiconductor wafer and radiantly heating a front surface of the semiconductor wafer. The second heater has a heat generating point that produces a heated spot in the semiconductor layer and moves spirally while maintaining a fixed distance from the semiconductor wafer, thereby producing a large-area monocrystalline region in the semiconductor layer. In this zone-melting recrystallization, a single crystalline nucleus is produced in the semiconductor layer, and the entire semiconductor layer is recrystallized with the crystalline nucleus as a seed crystal.

Abstract: The invention provides a buffered substrate that includes a substrate, a buffer layer and a silicon layer. The buffer layer is disposed between the substrate and the silicon layer. The buffer layer has a melting point higher than a melting point of the substrate. A polycrystalline silicon layer is formed by crystallizing the silicon layer using a laser beam.

Abstract: In order to improve a process for growing crystals from a molten zone which is heated and to which a source material is supplied which is melted and deposited in crystalline form on a substrate from the molten zone, such that dimensions of the substrate along an interface between the substrate and the molten zone are dependent to a lesser extent on dimensions of the source material supplied to the molten zone, it is suggested that the molten zone be mechanically stabilized by a wall member which forms a boundary of the molten zone and is essentially immovable relative to the molten zone, a base member which forms a lower boundary of the molten zone and is movable relative to the wall member and a meniscus arranged between the base member and the wall member.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A semiconductor film deposited on a substrate has regions of different thermal conductivity. A pulsed laser radiation is applied to the semiconductor film to melt the semiconductor film. When the melted semiconductor film is cooled and solidified, localized low-temperature regions are developed in the respective regions of different thermal conductivity. Crystal nuclei are produced in the respective localized low-temperature regions and grown into a single semiconductor crystal. The regions of different thermal conductivity are formed in the semiconductor film by high-thermal-conductivity members deposited on the semiconductor film in thermally coupled relationship thereto. A semiconductor device is fabricated using the semiconductor film and has channels disposed in the vicinity of the crystal nuclei.

Abstract: The present invention provides a method for producing single crystals of a group II-IV-V.sub.2 and group I-III-VI.sub.2 compounds by synthesizing compound material from its constituents and separately melting and refreezing the material in a transparent furnace while observing crystal growth.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of forming a polycrystalline silicon thin film improved in crystallinity and a channel of a transistor superior in electrical characteristics by the use of such a polycrystalline silicon thin film. An amorphous silicon layer of a thickness preferably of 30 nm to 50 nm is formed on a substrate. Next, substrate heating is performed to set the amorphous silicon layer to preferably 350.degree. C. to 500.degree. C., more preferably 350.degree. C. to 450.degree. C. Then, at least the amorphous silicon layer is irradiated with laser light of an excimer laser energy density of 100 mJ/cm.sup.2 to 500 mJ/cm.sup.2, preferably 280 mJ/cm.sup.2 to 330 mJ/cm.sup.2, and a pulse width of 80 ns to 200 ns, preferably 140 ns to 200 ns, so as to directly anneal the amorphous silicon layer and form a polycrystalline silicon thin film. The total energy of the laser used for the irradiation of excimer laser light is at least 5 J, preferably at least 10 J.

Abstract: High purity semiconductor foils, such as silicon foils useful in solar energy cells, are produced by treating an impure semiconductor foil with at least one reactive gas while in the crystallizing state.

Abstract: A display panel is formed using a single crystal thin-film transistors that are transferred to substrates for display fabrication. Pixel arrays form light valves or switches that can be fabricated with control electronics in the thin-film material prior to transfer. The resulting circuit panel is then incorporated into a projection display system with a light emitting or liquid crystal material to provide the desired light valve.

Abstract: A method for producing a semiconductor structure including a semiconductor film formed on a semiconductor substrate body via an insulating film includes: laminating a first insulating film, a first semiconductor film, and a second insulating film on the semiconductor substrate successively; forming stripe-shaped second semiconductor films of predetermined width on the second insulating film arranged periodically at a predetermined interval and covering these second semiconductor films with a third insulating film; performing zone melting recrystallization of the first semiconductor film from one end of the substrate to the opposite end along the stripe direction of the stripe-shaped second semiconductor film; etching the third insulating film and portions of the second insulating film not sandwiched by the first and second semiconductor films; oxidizing portions of the second semiconductor film and the first semiconductor film exposed in the etching step and etching and removing the second insulating film rem

Abstract: A process for producing a crystal comprises the step of applying crystal forming treatment on a light-transmissive substrate having a non-nucleation surface (S.sub.NDS) of a small nucleation density and a nucleation surface (S.sub.NDL) of a nucleation density (ND.sub.L) greater than the nucleation density (N.sub.DS) of said non-nucleation surface (S.sub.NDS) and formed of an amorphous material (M.sub.L) different from the material (M.sub.S) forming the non-nucleation surface (S.sub.NDS) at a small area sufficient to effect crystal growth from only a single nucleus to form a single crystal nucleus on the nucleation surface (S.sub.NDL), thereby growing a single crystal from the single nucleus, and the step of reducing the crystal defects of the crystal in the vicinity of the interface with the substrate by irradiation of light from the side of the substrate.

Abstract: A invention provides a method for production of diamond particles. The solvent metallic disk of a starting material specimen used in this diamond synthesis is divided into two layers. An intermediate layer is interposed between the two solvent metallic layers, so that the diamond crystals, formed on the two solvent metallic surfaces in contact with graphite disks and influenced by gravity, are not floated on the upper surface of the solvent metallic disk but grown at their positions in the individual solvent metallic layers at which they were nucleated. Hence, the method of this invention results in formation of the same number of diamond products, having the same size and desired good quality, on opposed surfaces or the upper and lower surfaces of the solvent metallic disk. The intermediate layer is a thin disk made of tungsten or molybdenum and having a thickness ranged from 10 .mu.m to 100 .mu.m.

Abstract: A thin semiconductor film having at least one an edge is formed on a base whose material is different from the material of the thin semiconductor film. A laser beam, for example, is applied to the semiconductor film thereby to melt the semiconductor film including the edge for thereby beading the edge upwardly. The melted semiconductor film including the edge is solidified and hence recrystallized into a semiconductor crystal. A plurality of spaced reflecting films may be formed on the thin semiconductor film before the laser beam is applied. Various semiconductor devices including a thin-film transistor, a solar cell, and a bipolar transistor may be fabricated of the semiconductor crystal.

Abstract: An epitaxially grown layer having a large area and an uniform thickness is formed on an insulating layer. The surface of a silicon substrate (2) is oxidized to form a silicon dioxide layer (4) acting as insulating layer. The silicon dioxide layer (4) is then provided with an opening (10) by etching with the aid of resist (6). After removing the resist (6), a silicon seed crystal layer (11) is selectively grown in the opening (10). Next, the silicon dioxide layer (4) is subjected to etchback using hydrofluoric acid, so that the side face (14) of the seed crystal layer (11) is emerged. The following epitaxial growth on the basis of the seed crystal layer (11) is allowed sufficient growth in the lateral direction. As a result, an epitaxially grown layer having (16) a large area and an uniform thickness is realized.

Abstract: The invention relates to the formation of arrays of thin film transistors (TFT's) on silicon substrates and the dicing and tiling of such substrates for transfer to a common module body. TFT's activate display electrodes formed adjacent the transistors after the tiles have been transferred. The invention can be used in a liquid crystal display and may include one or more light shielding layers.

Abstract: A method for making a polycrystalline silicon thin film by crystallizing an amorphous silicon thin film at a low temperature of 500.degree. C. to 600.degree. C. Over a glass substrate is deposited a microcrystalline silicon seed layer having a thickness of 100 .ANG. to 500 .ANG., using the chemical vapor deposition method. Over the microcrystalline silicon seed layer, a hydrogen-containing amorphous silicon layer is formed by chemical vapor deposition, at a temperature of 180.degree. C. to 270.degree. C., which is then crystallized to form a polycrystalline silicon thin film. A hydrogen-containing amorphous silicon layer having a thickness of 300 .ANG. to 500 .ANG. may be formed over the glass substrate. In this case, the hydrogen-containing amorphous silicon layer is crystallized at a temperature of 600.degree. C., to form a polycrystaline seed layer.