JP5004838B2 - A method for forming a semiconductor film, and a semiconductor device and a display device using the semiconductor film. - Google Patents

Description

  The present invention relates to a method for forming a polycrystalline semiconductor film, a semiconductor device manufactured using the method, and a display device, and more particularly, to an amorphous formed on a non-single crystal insulating film or a non-single crystal insulating substrate. A method for forming a polycrystalline semiconductor film and a method for forming the same by applying thermal energy and light energy by intense light irradiation to the semiconductor film to crystallize the amorphous semiconductor film into a polycrystalline semiconductor film with few crystal defects The present invention relates to a semiconductor device such as a liquid crystal driver, a semiconductor memory, and a semiconductor logic circuit using a polycrystalline semiconductor film formed by using the semiconductor device, and a display device using these semiconductor devices.

  Conventionally, a non-single crystal insulating substrate is formed by forming an amorphous semiconductor film on a non-single crystal insulating film or a non-single crystal insulating substrate formed on a substrate and applying energy to the amorphous semiconductor film. A method for crystallizing the amorphous semiconductor film formed thereon is known.

For example, IEICE technical report, IEICE technical report, Vol. 100, no. 2, ED2000-14 (April 2000) pp. 27-32 (hereinafter referred to as Conventional Example 1) (see Non-Patent Document 1), PE-CVD (Plasma Enhanced Chemical Vapor Deposition) is used to form an amorphous silicon film on a glass substrate at 45-50 nm. It is described that the amorphous silicon film is crystallized into a polycrystalline silicon film having a crystal grain size of 700 nm by irradiating the amorphous silicon film with an excimer laser beam after the film thickness is formed. Further, this conventional example 1 describes that when a thin film transistor (TFT) is formed using a polycrystalline silicon film obtained by this method, the mobility is improved to 320 cm ² / V · sec. .

  Japanese Patent Application Laid-Open No. 2000-150381 (hereinafter referred to as Conventional Example 2) describes a method in which crystallization is advanced by heat treatment in a state where a catalytic element is introduced into the surface of an amorphous silicon film, and then laser A crystallization method is described in which a crystalline silicon film with further improved crystallinity is obtained by irradiation with light (see Patent Document 1).

  FIG. 7 is a schematic diagram for explaining the crystallization method described in Conventional Example 2.

  In the method of Conventional Example 2, first, an amorphous silicon film 2 having a thickness of 100 nm is formed on the glass substrate 1 by using a PE-CVD method, and then the thickness is about 2 nm in order to improve wettability. A silicon oxide film 3 is formed.

  Next, a solution containing nickel, which is a catalyst element that promotes crystallization, is applied and then spin-dried to form a solution film 4 on the silicon oxide film 3.

  Next, in this state, the amorphous silicon film 2 is crystallized by annealing for 4 hours under a temperature condition of 550.degree.

Next, in order to further improve the crystallinity of the crystallized silicon film 2, KrF excimer laser light with a wavelength of 248 nm is irradiated at an energy density of 200 to 350 mJ / cm ² .

  In such a crystallization method of Conventional Example 2, crystallization is promoted using a catalyst element, and thus a crystalline silicon film can be obtained at a low temperature and within a short time.

IEICE Technical Report, Vol. 100, no. 2, ED2000-14 (April 2000) pp. 27-32

JP 2000-150381 A

  However, in the method of the conventional example 1, the laser irradiation condition of the laser beam applied to the amorphous silicon film is not optimized, and a crystal grain having a small crystal grain size of about several μm is obtained. There is a possibility that a polycrystalline silicon film including the crystal grain boundary is obtained. Since the crystal grain boundary has a recombination center and functions as a carrier trap level, mobility is lowered when a TFT is formed using a polycrystal including many crystal grain boundaries.

  Further, in the method of Conventional Example 1, it is not easy to uniformly irradiate the entire surface of a large-area substrate with laser light having sufficient stability. Therefore, it is not possible to form a silicon film having uniform crystallinity. There is also the problem that it is difficult.

  In the method of Conventional Example 2 described above, the laser beam is irradiated to further improve the crystallinity of the silicon film 2 crystallized by introducing the catalyst element. The optimum conditions for the laser beam irradiation conditions are as follows. Is not described, and the silicon film formed by this method may have many crystal defects.

  When a semiconductor device (transistor) such as a liquid crystal driver, a semiconductor memory, or a semiconductor logic circuit is manufactured using a semiconductor film formed by such a crystallization method including many crystal defects, the carrier mobility is small and the threshold voltage is low. In addition, there is a problem that variations in carrier mobility and threshold voltage of each semiconductor device (transistor) formed in large numbers in a liquid crystal driver or the like increase.

  The present invention has been made to solve the above problems, and provides a method for forming a semiconductor film having good crystallinity with reduced crystal defects, and a semiconductor device and a display device manufactured using the method. The purpose is to do.

The method for forming a semiconductor film of the present invention includes a step of forming an amorphous semiconductor film on a substrate having an insulating surface, and a step of introducing a catalyst substance that promotes crystallization into the surface of the amorphous semiconductor film. Applying a first energy to the amorphous semiconductor film to crystallize the amorphous semiconductor film into a crystalline semiconductor film; and the crystalline semiconductor film further has a crystallinity of the crystalline semiconductor film. By applying the second energy to improve the crystalline semiconductor film, the ratio of the crystal orientation angle difference between adjacent crystal grains is approximately 10 ° or less or 58 ° to 62 ° is 0.8 . And a step of forming a polycrystalline semiconductor film.

The first energy is preferably thermal energy, and the second energy is preferably intense light.
The intense light is preferably excimer laser light.

  The semiconductor film is preferably made of a silicon material.

The catalyst material is at least one metal selected from Fe, Co, Ni, Cu, Ge, Pd, Au, a compound containing at least one of these metals, or at least selected from these metals one and is preferably a combination of a compound containing at least one of these metals.

The surface concentration of the catalyst substance on the amorphous semiconductor film is preferably in the range of 1 × 10 ¹¹ atoms / cm ^{2 to} 1 × 10 ¹⁶ atoms / cm ² .

  The semiconductor device of the present invention is formed by the method for forming a semiconductor film.

  The display device of the present invention includes the semiconductor device.

  As described above, in the semiconductor film of the present invention, a step of forming an amorphous semiconductor film over a substrate having an insulating surface and a catalyst substance for promoting crystallization are introduced into the surface of the amorphous semiconductor film. A step of crystallizing the amorphous semiconductor film into a crystalline semiconductor film by applying first energy to the amorphous semiconductor film, and a crystal of each crystal grain adjacent to the crystalline semiconductor film. The steps of sequentially improving the crystallinity of the crystalline semiconductor film by applying a second energy having an azimuth angle difference of approximately 10 ° or less or 58 ° to 62 ° to form a polycrystalline semiconductor film sequentially. In practice, the crystal orientation angle difference between adjacent crystal grains is maintained at about 10 ° or less or 58 ° to 62 °, and a polycrystalline semiconductor with few defects is formed. By using such a semiconductor film with improved crystallinity for a semiconductor device such as a TFT, the performance of the semiconductor device can be improved.

  In the present invention, an excimer laser is used to improve the crystallinity of a crystalline silicon film crystallized by introducing and heating a catalyst substance that promotes crystallization into an amorphous silicon film. When irradiating, it pays attention that there is an appropriate condition in the irradiation condition of the excimer laser. Under this proper condition, when an excimer laser is irradiated onto the crystalline silicon film crystallized by the heat treatment after the introduction of the catalyst substance, the crystal orientation difference between adjacent crystal grains of the polycrystalline silicon film is approximately 10 ° or less. Or it became 58 degrees-62 degrees, and it became clear by experiment of this inventor that the favorable crystallinity by which the crystal defect was reduced was obtained.

  Hereinafter, the experiment which obtained such a result is demonstrated in detail.

First, an amorphous silicon film was formed to a thickness of 50 nm on a glass substrate by PE-CVD using SiH ₄ gas at a film formation temperature of 300 ° C.

Next, a nickel thin film is formed on the amorphous silicon film by sputtering. The nickel surface atomic concentration of the nickel thin film was 1 × 10 ^{13 to} 5 × 10 ¹³ atoms / cm ² .

  Next, heat treatment at 550 ° C. was performed for 4 hours using an electric furnace. By this heat treatment, the introduced nickel reacts with the silicon in the amorphous silicon film, and nickel silicide is randomly formed on the entire surface of the amorphous silicon film. Further, the nickel silicide serves as a crystal nucleus to promote crystallization of the amorphous silicon film. Nickel silicide moves laterally while crystallizing amorphous silicon, and after the nickel silicide has passed, a crystalline silicon film is formed.

  Subsequently, in order to further improve the crystallinity of the crystalline silicon film that has been crystallized by nickel silicide, XeCl excimer laser irradiation is performed, and a polycrystalline silicon film (in the following description, for convenience in the following description) The silicon film after the heat treatment is described as a crystalline silicon film, and the silicon film after the excimer laser irradiation is described as a polycrystalline silicon film).

For such heat treatment after the crystalline silicon film, the energy density of the excimer laser is irradiated to improve the ^{crystallinity,} while varying in a range of ^{280mJ / cm 2 ~380mJ / cm 2} , excimer The appropriate condition of laser energy density was investigated.

  The crystal orientation of the crystalline silicon film obtained by the heat treatment and the polycrystalline silicon film obtained by the excimer laser irradiation is measured by an EBSP (Electron Backscatter Diffraction Pattern) method. The EBSP method is a method in which a crystal orientation is measured with an angle accuracy of ± 1 ° or less using a chrysanthemum map represented by an electron beam scattered by the sample by irradiating the sample to be crystallized with an electron beam.

  Using this EBSP method, a silicon film having an area of 4 μm × 12 μm was irradiated with an electron beam at a measurement pitch of 0.05 μm, and the angle difference between crystal orientations between adjacent measurement points, that is, misorientation, was measured.

  FIG. 6 is a graph showing the number of occurrences of misorientation with respect to the crystal orientation of the crystalline silicon film obtained by performing the heat treatment in terms of length.

  Referring to FIG. 6, the misorientation length appears from 1 ° which is a lower limit value of the measurement accuracy, and is distributed up to about 65 °. The misorientio length is longer in the range of 1 ° to 10 ° and in the range of 58 ° to 62 °.

  The result that the misorientation length becomes long in the range of 1 to 10 ° is considered as follows.

  When heat treatment is performed in a state where nickel is added to the amorphous silicon film, nickel and silicon react first, and nickel silicide is randomly formed on the entire surface of the amorphous silicon film. The nickel silicide thus formed serves as a crystal nucleus for crystallization of the amorphous silicon film, and crystallization proceeds from the crystal nucleus in the lateral direction of the substrate.

  In the crystallization using nickel silicide as a crystal nucleus, the crystal grows in an amorphous silicon film so that the crystal extends in a needle shape or a column shape, and the crystal orientation gradually changes during the crystal growth. However, this change in crystal orientation is considered to change so as to relieve the stress in the film. The smaller the misorientation angle, the more stable the stress is, and therefore the misorientation length of 1 ° to 10 °. Seems to have grown.

  Moreover, the result that the misorientation length becomes long in the range of 58 to 62 ° is considered as follows.

  In order to further improve the crystallinity of the crystallized crystalline silicon, heat treatment is performed with nickel added to the amorphous silicon film, and excimer laser irradiation is performed.

  When the energy density of the excimer laser is increased, a part of the crystalline silicon film is locally melted to form small crystal grains when recrystallized. This small crystal grain is considered to form a misorientation of 58 ° to 62 °. As a result of examining the crystal structure of misorientation at 58 ° to 62 °, it was a twin structure. This twin structure is a structure formed by a crystal with a crystal orientation rotated from 58 ° to 62 ° with the <111> orientation as the rotation axis, and a crystal with a crystal orientation before the rotation, and there is a recombination center at the boundary. No.

Table 1 below shows the misorientation length of the polycrystalline silicon film obtained when various changes are made in the energy density range of 280 mJ / cm ^{2 to} 380 mJ / cm ² of the excimer laser irradiated to the crystalline silicon film after the heat treatment. The result of having measured is shown. In Table 1, the misorientation angle range is shown for each of the three regions of 1 ° to 10 °, 58 ° to 62 °, and 1 ° to 62 °.

  In the column (d) of Table 1, an N-channel TFT was manufactured using a polycrystalline silicon film obtained by irradiating an excimer laser with each energy density, and the mobility of the TFT was measured. Is shown.

表１を参照すると、エキシマレーザーのエネルギー密度が２８０ｍＪ／ｃｍ^２〜３２０ｍＪ／ｃｍ^２の範囲である場合、Ｍｉｓｏｒｉｅｎｔａｔｉｏｎの多くは１°〜１０°の範囲にある。Ｍｉｓｏｒｉｅｎｔａｔｉｏｎ角度が低いことは、格子欠陥が少なく、移動度も高くなると考える。エキシマレーザーのエネルギー密度が２８０ｍＪ／ｃｍ^２から３２０ｍＪ／ｃｍ^２に上がるに伴ってＭｉｓｏｒｉｅｎｔａｔｉｏｎ長さが短くなり、結晶性がよくなっている。さらに、結晶性の向上に伴って、移動度も高くなる傾向がある。

Referring to Table 1, when the energy density of the excimer laser is in the range of 280 mJ / cm ^{2 to} 320 mJ / cm ² , most of the misorientation is in the range of 1 ° to 10 °. A low misorientation angle is considered to have few lattice defects and high mobility. As the energy density of the excimer laser increases from 280 mJ / cm ² to 320 mJ / cm ² , the misorientation length is shortened and the crystallinity is improved. Furthermore, the mobility tends to increase with the improvement of crystallinity.

Further, the portion raising the energy density from 320 mJ / cm ² to 330mJ / cm ^2, Misorientation of 58 ° through 62 ° rapidly increases. This result is considered to be due to the phenomenon that the crystalline silicon film locally melted completely from the surface to the substrate interface and recrystallized by giving an energy density of 330 mJ / cm ² .

When the energy density of the excimer laser is 330 mJ / cm ^{2 to} 360 mJ / cm ² , most of the misorientation is in the range of 1 ° to 10 ° or 58 ° to 62 °. Both of them have a crystal structure with few recombination centers and do not lower the electrical characteristics, so the mobility is also high.

A slightly lower laser energy density than the crystalline silicon film starts to melt completely from the surface to the substrate interface. In the case of Table 1, a polycrystalline silicon film irradiated with a laser of 320 mJ / cm ² has the shortest misorientation length. The quality is considered high. The mobility is also the highest value.

When the energy density exceeds 370 mJ / cm ² , the misorientation lengths of 1 ° to 10 ° and 58 ° to 62 ° of the misorientation angles are increased even though the misorientation length of the misorientation angle of 1 ° to 62 ° is increased. It is almost the same. As a result, it is considered that after crystalline silicon is completely melted, it is precipitated as microcrystals during cooling. In this case, there are many misorientations other than misorientation angles of 1 ° to 10 ° and 58 ° to 62 °, so there are many recombination centers. The recombination centers act as carrier trap levels, and the mobility of the TFT is reduced. It is thought that.

In order to obtain the mobility 200cm ² / V · sec of the TFT, from Table 1, the energy density of the excimer laser in the range of 300mJ / cm ² ~350mJ / cm ² is in the proper. The misorientation of a polycrystalline silicon film crystallized by irradiating an excimer laser under such conditions has many angles of 1 to 10 ° or 58 ° to 62 °.

  The ratio of the crystal orientation difference between adjacent crystal grains is expressed by the following formula (1), and the ratio is shown in Table 1 above.

The energy density of the excimer laser, if the range of ^{300mJ / cm 2 ~350mJ / cm 2} , the ratio of the misorientation 1 ° of adjacent crystal grains to 10 ° or 58 ° through 62 ° is 0.5 or more It has become. Therefore, 0.5 to 1 is an appropriate value.

  Further, under the optimum conditions with the highest mobility, the ratios of the crystal orientation differences of 1 ° to 10 ° and 58 ° to 62 ° between adjacent crystal grains are the highest.

以下、本発明の多結晶半導体膜の形成方法の具体的な形態について、図面に基づいて説明する。なお、本発明の多結晶半導体膜の形成方法は、以下の実施の形態１〜４に限定されるものではない。

Hereinafter, specific embodiments of the method for forming a polycrystalline semiconductor film of the present invention will be described with reference to the drawings. The method for forming a polycrystalline semiconductor film of the present invention is not limited to the following first to fourth embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view illustrating a method for forming a crystalline semiconductor film according to the first embodiment.

First, an amorphous silicon film 12 is formed to a thickness of 50 nm over the entire surface of the glass substrate 11 by PE-CVD. As a material gas used for film formation, SiH ₄ gas is used, and the substrate temperature is set to 300 ° C.

Next, using a sputtering method, nickel (Ni) is deposited over the entire surface to form the nickel thin film 13. In the first embodiment, the surface atomic concentration of nickel in the nickel thin film 13 is 1 × 10 ¹³ atoms / cm ² .

  Next, heat treatment is performed using an electric furnace. The conditions for this heat treatment are, for example, 550 ° C. and 4 hours. By this heat treatment, nickel in the nickel thin film 13 and silicon in the amorphous silicon film 12 first react to form nickel silicide, and crystallization proceeds with the nickel silicide as a crystal nucleus.

Next, XeCl excimer laser is irradiated to further improve the crystallinity of the silicon film crystallized by heating. The energy density of the excimer laser in this excimer laser irradiation is set within a range of 300 to 350 mJ / cm ² .

  Through the above steps, a polycrystalline silicon film in which the crystal orientation angle difference between adjacent crystal grains is controlled to be approximately 10 ° or less or 58 ° to 62 ° is formed.

(Embodiment 2)
FIG. 2 is a cross-sectional view illustrating a method for forming a crystalline semiconductor film according to the second embodiment.

First, as shown in FIG. 2A, an amorphous silicon film 12 is formed to a thickness of 50 nm over the entire surface of the glass substrate 11 by PE-CVD using SiH ₄ gas.

Next, after the SiO ₂ film 14 is formed to a thickness of 100 nm over the entire surface of the amorphous silicon film 12, a predetermined portion of the SiO ₂ film 14 is removed by etching by the RIE method. To do. The catalyst material introduction region 15 is formed in a linear shape having a width of 10 μm, for example.

Next, a nickel thin film 13 is formed on the SiO ₂ film 14 by sputtering as shown in FIG. In the second embodiment, the surface atomic concentration of nickel in the nickel thin film 13 is 5 × 10 ¹³ atoms / cm ² .

  Next, heat treatment is performed using an electric furnace. The conditions for this heat treatment are 550 ° C. and 4 hours. By this heat treatment, nickel and silicon in the catalyst material introduction region 15 react to form nickel silicide, and crystallization proceeds with the nickel silicide as a crystal nucleus. The nickel silicide moves in the lateral direction with respect to the substrate surface while crystallizing the silicon of the amorphous silicon film 12, and forms a crystalline silicon film on the rear side in the moving direction.

Next, the SiO ₂ film 14 formed on the silicon film 12 made crystalline silicon by heat treatment is removed by etching.

Next, XeCl excimer laser is irradiated to further improve the crystallinity of the silicon film 12 crystallized by heating. The energy density of the excimer laser in this excimer laser irradiation is set within a range of 300 to 350 mJ / cm ² .

  Through the above steps, a polycrystalline silicon film in which the crystal orientation angle difference between adjacent crystal grains is controlled to approximately 10 ° or less or 58 ° to 62 ° is formed.

(Embodiment 3)
FIG. 3 is a cross-sectional view illustrating a method for forming a crystalline semiconductor film according to the third embodiment.

First, an amorphous silicon film 12 is formed to a thickness of 50 nm over the entire surface of the quartz substrate 11 by PE-CVD. As a material gas used for film formation, SiH ₄ gas is used, and the substrate temperature is set to 300 ° C.

Next, using a sputtering method, nickel (Ni) is deposited over the entire surface to form the nickel thin film 13. In the third embodiment, the nickel surface atomic concentration in the nickel thin film 13 is 1 × 10 ¹³ atoms / cm ² .

  Next, heat treatment is performed. The conditions for this heat treatment are, for example, 550 ° C. and 4 hours. By this heat treatment, nickel and silicon first react to form nickel silicide, and crystallization proceeds using this nickel silicide as a crystal nucleus.

Subsequently, high-temperature heat treatment at 900 to 1000 ° C. is performed to further improve the crystallinity of the crystalline silicon film 12. The high-temperature heat treatment is a process for improving crystallinity by applying thermal energy instead of laser energy. The high temperature heat treatment, Si is not melted, the same Misorientation distribution as polycrystalline silicon was irradiated with an excimer laser of the laser energy density ^{300mJ / cm 2 ~320mJ / cm 2} .

  Through the above steps, a polycrystalline silicon film in which the crystal orientation angle difference between adjacent crystal grains is controlled to approximately 10 ° or less or 58 ° to 62 ° is formed.

(Embodiment 4)
FIG. 4 is a cross-sectional view showing a method for manufacturing the semiconductor device of the fourth embodiment.

  In the fourth embodiment, a method for manufacturing a semiconductor device such as a thin film transistor using the crystalline silicon film described in any of the first to third embodiments will be described. The semiconductor device manufactured by the manufacturing method of the fourth embodiment can be used for a liquid crystal driver, a semiconductor memory, a semiconductor logic circuit, and the like.

  Hereinafter, a specific description will be given with reference to FIG.

First, a polycrystalline silicon film is formed on the glass substrate 21 by the method for forming a crystalline semiconductor film according to any of the first to third embodiments described above, and then this polycrystalline silicon film is CF _4. An island-shaped polycrystalline silicon film 22 is formed by patterning into a predetermined shape by RIE using gas and O ₂ gas. Thereafter, a gate SiO ₂ film 23 is formed by plasma CVD using TEOS (tetraethoxysilane) gas and O ₃ gas over the entire substrate surface on which the polycrystalline silicon film 22 is formed.

Next, after forming a WSi ₂ layer over the entire surface of the glass substrate 21 on which the gate SiO ₂ film 23 is formed by sputtering, the crystalline silicon film 22 is formed by RIE using CF ₄ gas and O ₂ gas. Etching is performed so as to leave the WSi ₂ layer only in the substantially central portion above, thereby forming the WSi ₂ polycrystalline gate electrode 24.

Next, impurities are introduced onto the crystalline silicon film 22 by ion doping to form source / drain regions of the thin film transistor. In the case of the fourth embodiment, the WSi ₂ polycrystalline gate electrode 24 serves as a mask when introducing impurities, and impurities are not contained in the crystalline silicon film 22 other than the portion where the WSi ₂ polycrystalline gate electrode 24 is provided. Is introduced. In the case of forming an n-type transistor, the introduced impurity is phosphorus (P), and in the case of forming a p-type transistor, the introduced impurity is boron (B).

Next, after a SiO ₂ film 25 is formed over the entire surface of the glass substrate 21 by plasma CVD using TEOS gas and O ₃ gas, the source is formed by RIE using CF ₄ gas and CHF ₃ gas. A contact hole 26 is formed on the crystalline silicon film 22 used as the drain region.

Next, after depositing Al on the entire surface of the substrate by sputtering, crystallinity is obtained through a contact hole 26 formed in the SiO ₂ film 25 by RIE using BCl ₃ gas and Cl ₂ gas. An Al wiring 27 that is electrically connected to the silicon film 22 is used.

Next, the SiN protective film 28 is formed over the entire substrate surface by plasma CVD using SiH ₄ gas and NH ₃ gas or N ₂ gas, and finally a part of the SiN protective film 28 is CF ₄ gas. Through holes 29 are formed so as to be conductive to the Al wiring 27 by etching using and CHF ₃ gas, thereby completing a semiconductor device such as a semiconductor transistor, a resistor, and a capacitor.

(Embodiment 5)
FIG. 5 is a cross-sectional view showing a method for manufacturing a display device using the semiconductor device of the fourth embodiment.

  In the fifth embodiment, a method for manufacturing a display device such as a liquid crystal display device using a semiconductor device manufactured by the same method as in the fourth embodiment will be described.

  The fifth embodiment will be described below with reference to FIGS. 5 (a) and 5 (b).

  First, a semiconductor device is manufactured on an insulating substrate 21 such as a glass substrate by the manufacturing method of the fourth embodiment. In addition, about each structure of the semiconductor device formed on this insulating substrate 21, the code | symbol same as Embodiment 4 is attached | subjected, and detailed description is abbreviate | omitted.

Next, an ITO film was formed over the entire surface of the substrate on which the SiN protective film 28 was formed. Subsequently, etching was performed using HCl gas and FeCl ₃ gas and patterning was performed to form the SiN protective film 28. A pixel electrode 30 that is electrically connected to the Al wiring 27 of the semiconductor device through the through hole 29 is formed.

Next, the SiN film 31 is formed over the entire surface of the substrate by plasma CVD using SiH ₄ gas and NH ₃ gas or N ₂ gas. Further, a polyimide film 32 serving as an alignment film is formed on the SiN film 31 by using an offset printing method, and a rubbing process is performed.

  On the other hand, as shown in FIG. 5B, a film having R (red), G (green), and B (blue) photosensitive resin films on another glass substrate 41 is transferred by thermocompression bonding. Then, patterning is performed by a photolithography process, and a black matrix portion having a light shielding property is formed between portions where the photosensitive resins of R, G, and B are transferred, and the color filter 42 is manufactured. .

  On the color filter 42, an ITO film is formed over the entire surface of the substrate by a sputtering method to form the counter electrode 43. Further, a polyimide film 44 as an alignment film is formed on the counter electrode 43 by an offset printing method, and a rubbing process is performed.

  The glass substrate 41 formed with the color filter 42 shown in FIG. 5B and the glass substrate 21 formed with the semiconductor device shown in FIG. 5A are rubbed. It arrange | positions so that the provided surface may mutually oppose, and it bonds together by sealing resin. At this time, spherical silica is sprayed between the glass substrates so that the space between the two glass substrates is constant. Then, after injecting liquid crystal serving as a display medium between both substrates, a polarizing plate is attached to both outer sides of both glass substrates, and a driver IC or the like is mounted on the periphery thereof to complete a liquid crystal display.

  Next, the scope of application of the present invention will be described.

In the first to third embodiments, a glass substrate or a quartz substrate is used as a substrate on which a semiconductor film is formed. However, a substrate obtained by forming a SiO ₂ film or a SiN film on a Si wafer may be used.

  In the first to third embodiments, a method for forming a silicon film is shown as a specific example of a semiconductor film to be manufactured. However, the method for forming a crystalline semiconductor film of the present invention forms a silicon film. The present invention is not limited to this case, and the present invention can also be applied when forming a SiGe film or the like.

In the first to third embodiments, the PE-CVD method using SiH ₄ gas is used as the method for forming the amorphous silicon film, but the low pressure CVD method using Si ₂ H ₆ gas, Other methods such as sputtering may be used.

  In the first to third embodiments, the film thickness of the formed semiconductor is 50 nm. However, the method for forming a semiconductor film of the present invention can be applied as long as it is in the range of 50 to 150 nm.

  In the first to third embodiments, nickel, which is a catalyst material, is introduced by a vapor deposition method using a sputtering method, but a vacuum vapor deposition method, a plating method, an ion doping method, a CVD method, a spin coat method, and the like. Other methods such as a method may be used. When the catalyst material is introduced using the spin coating method, it is preferable that the solution containing the catalyst material contains at least one solvent selected from the group consisting of water, methanol, ethanol, n-propanol, and acetone. . When nickel is used as the catalyst substance, nickel can be applied to the insulating substrate or the amorphous silicon film by dissolving nickel acetate in the solvent.

  In the first to third embodiments, nickel is used as a catalyst material for promoting crystallization. However, at least one metal selected from Fe, Co, Ni, Cu, Ge, Pd, and Au, or A compound containing at least one of these metals or a combination of at least one selected from these metals and a compound containing at least one of these metals can be used.

  In addition, as lasers for irradiating the semiconductor film, there are an excimer laser having an ultraviolet wavelength range and a YAG laser having a visible / ultraviolet wavelength range, which are selectively used depending on the type and thickness of the semiconductor film. For example, since the absorption coefficient of ultraviolet light is higher than that of silicon, an excimer laser having an ultraviolet light wavelength region is suitable for melting a thin silicon film. Further, since the absorption coefficient of visible / ultraviolet light is low, a YAG laser having a visible / ultraviolet light wavelength range is suitable for melting a thick silicon film. In the first to third embodiments, since the silicon film is a thin film of 50 nm, an excimer laser is suitable.

7 is a cross-sectional view illustrating a method for forming a crystalline semiconductor film in Embodiment 1. FIG. (A) And (b) is sectional drawing explaining the formation method of the crystalline semiconductor film of Embodiment 2, respectively. 10 is a cross-sectional view illustrating a method for forming a crystalline semiconductor film in Embodiment 3. FIG. FIG. 10 is a cross-sectional view showing the method for manufacturing the semiconductor device of the fourth embodiment. (A) And (b) is sectional drawing which shows the manufacturing method of the display apparatus using the semiconductor device of Embodiment 4, respectively. It is a graph which shows the misorientation length about the crystal orientation of the crystalline silicon film obtained by performing heat processing. It is the schematic explaining the crystallization method described in the prior art example 2.

Explanation of symbols

11 Glass substrate 12 Amorphous silicon film 13 Nickel thin film 14 SiO ₂ film 15 Catalyst material introduction region 16 Quartz substrate 21 Glass substrate 22 Polycrystalline silicon film 23 Gate SiO ₂ film 24 WSi ₂ polycrystalline gate electrode 25 SiO ₂ film 26 Contact Hole 27 Al wiring 28 SiN protective film 29 Through hole 30 Pixel electrode 31 SiN film 32 Polyimide film 41 Glass substrate 42 Color filter 43 Counter electrode 44 Polyimide film

Claims (8)

Forming an amorphous semiconductor film over a substrate having an insulating film surface;
Introducing a catalyst substance that promotes crystallization into the surface of the amorphous semiconductor film;
Crystallization of the amorphous semiconductor film into a crystalline semiconductor film by applying first energy to the amorphous semiconductor film;
By applying a second energy to the crystalline semiconductor film to further improve the crystallinity of the crystalline semiconductor film, the crystalline semiconductor film has a crystal orientation angle difference between adjacent crystal grains of approximately 10 A step of forming a polycrystalline semiconductor film having a ratio of 0.8 or less or 58 ° to 62 ° of 0.8 ,
A method for forming a semiconductor film, comprising:   The method of forming a semiconductor film according to claim 1, wherein the first energy is thermal energy and the second energy is intense light. The method of forming a semiconductor film according to claim 2 , wherein the intense light is excimer laser light . The semiconductor film is formed of a silicon material, method of forming a semiconductor film according to any one of claims 1-3. The catalyst material is at least one metal selected from Fe, Co, Ni, Cu, Ge, Pd, Au, a compound containing at least one of these metals, or at least selected from these metals one is a combination of a compound containing at least one of these metals, the method of forming the semiconductor film according to any of claims 1-4. The surface concentration of the amorphous semiconductor film on the catalytic material, 1 × a ¹⁰ 11 atoms / cm ² or more 1 × ¹⁰ 16 atoms / cm ² or less in the range, according to any of claims 1 to 5 A method for forming a semiconductor film.   A semiconductor device formed by the method for forming a semiconductor film according to claim 1. A display device comprising the semiconductor device according to claim 7.

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