JP2005347580A - Crystalline thin film, method of forming the same, semiconductor device thereof, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-quality crystalline thin film which does not include a crystal boundary in a desired area. <P>SOLUTION: Surrounding an amorphous silicon thin film 4 comprising a thin wire 5 patterned on a substrate 1, thin films are formed 6 which are in the state of an island separated from the amorphous silicon thin film 4 and which are made of the same material as the amorphous silicon thin film 4. The amorphous silicon thin film 4 is irradiated repeatedly with a pulse laser beam in the state of setting to make movement per once laser beam irradiation to be shorter than the length of the crystal growth in a horizontal direction of the amorphous silicon thin film 4 by once irradiation, and is irradiated repeatedly while moving the pulse laser beam nearly in parallel to the longitudinal direction of the thin wire 5. In this case, satisfactory melting condition is obtained to any pattern of various kinds of shapes and sizes on the same laser beam irradiation condition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a crystalline thin film forming method for crystallizing an amorphous thin film patterned on a substrate by applying energy, a crystalline thin film produced by using this crystalline thin film forming method, and the crystallinity thereof. The present invention relates to a crystalline thin film semiconductor device such as a crystalline thin film diode or a crystalline thin film transistor capable of exhibiting excellent performance using a thin film, and a display device including the crystalline thin film semiconductor device.

  2. Description of the Related Art Conventionally, a crystalline thin film forming method for crystallizing an amorphous thin film formed on a substrate by applying energy is known. In order to obtain a crystalline thin film with few crystal grain boundaries by using this method, it is important to control the generation of crystal grain boundaries by devising the energy application method and the sample structure.

  For example, in the third embodiment of Patent Document 1 and Non-Patent Document 1, in the excimer pulse laser light irradiation on the silicon film, the silicon film is laterally irradiated (one direction parallel to the substrate surface) by one excimer pulse laser light irradiation. In this method, the laser beam irradiation position is moved by a distance shorter than the crystal growth length, and the next excimer pulse laser beam irradiation is repeated to sequentially continue the crystal growth in the lateral direction. Yes.

  In Patent Document 2, a semiconductor thin film formed on a substrate is patterned to form a sub-island, and the sub-island is irradiated with a continuous wave laser beam while scanning, thereby forming the sub-island as a crystalline semiconductor film. The method is shown.

Further, Non-Patent Document 2 discloses a method of irradiating an excimer pulse laser beam to an amorphous silicon film patterned in a chevron (mountain shape) to form a single crystal region in the central part of the chevron shape. Yes.
Japanese Patent Laid-Open No. 2001-274088 (Third Example) JP 2003-289080 A Appl. Phys. Lett. Vol. 69, no. 19, pp. 2864-2866 Appl. Phys. Lett. Vol. 70, no. 25, pp. 3434-3436

  Conventionally, when crystallization is performed by irradiating an amorphous thin film with an energy beam, if the amorphous thin film is patterned and then irradiated with the energy beam, the amorphous thin film is formed in a region where the amorphous thin film is formed. The absorption state and heat dissipation state of the energy beam are different in the region where the thin film is not formed. For this reason, a large temperature difference is generated in the amorphous thin film due to the shape and size of the amorphous thin film pattern, and all the regions of the amorphous thin film are in a good molten state under a constant energy beam irradiation condition. Have difficulty.

  In addition, in order to manufacture a crystalline thin film semiconductor device having characteristics close to those obtained when a single crystal is used, a diode pn junction, a pin junction, or a transistor channel is used. It is necessary to form a crystalline semiconductor thin film having no crystal grain boundary in each region to be formed.

  Further, it is important for reducing the cost of the apparatus and improving the productivity that the energy beam can be scanned only by simple step feeding without requiring high-precision alignment for scanning the energy beam.

  However, as in Patent Document 1 and Non-Patent Document 1, the irradiation position of the laser light is moved by a distance shorter than the length of the crystal growth of the silicon film in the lateral direction by simple irradiation of the pulse laser light. Thus, in the method of repeatedly irradiating the next pulsed laser beam, the crystal growth proceeds in the moving direction of the laser beam by the next laser beam irradiation using the crystal formed by the previous laser beam irradiation as a seed. In this case, since crystal growth does not proceed in the direction perpendicular to the moving direction, a crystalline thin film composed of elongated crystal grains extending long in the moving direction of the laser beam is formed.

  When a thin film transistor is formed using such a crystalline thin film, when the channel length direction is parallel to the laser beam movement direction, the channel length is arranged in the direction in which the crystal grain boundary extends, so that the carrier movement is relatively A thin film transistor having a high degree of absoluteness and a threshold voltage having an absolute value (hereinafter simply referred to as | Vth (int) |) that is substantially equal between an n-type transistor and a p-type transistor can be manufactured in the absence of impurity doping. On the other hand, when the channel length direction is perpendicular to the moving direction of the laser beam, the crystal grain boundary crosses the channel width direction, so that the carrier mobility is low, and | Vth between the n-type transistor and the p-type transistor Thin film transistors with significantly different (int) | are produced.

  Further, although the crystal grain boundary extends long in the moving direction of the laser beam, it is not completely parallel to the moving direction of the laser beam, and there is a portion that merges with the adjacent crystal grain boundary or branches. For this reason, even when the channel length direction is parallel to the moving direction of the laser beam, the crystal grain boundary crossing in the channel width direction is not always 0, so that the carrier mobility is low and the n-type transistor and the p-type transistor Thin film transistors with greatly different | Vth (int) | are also produced, causing variations in characteristics.

  In addition, a crystal grain boundary extending in the channel length direction does not cause a decrease in carrier mobility or a large difference in | Vth (int) | between an n-type transistor and a p-type transistor. When this occurs, a leakage current path is formed, which has the adverse effect of increasing the junction leakage current of the crystalline thin film diode and increasing the leakage current when the crystalline thin film transistor is turned off.

  Next, in the conventional non-patent document 2, a single crystal region can be formed in the central portion of the chevron shape by patterning the amorphous silicon film into a chevron shape and irradiating with an excimer pulse laser beam. In other parts, polycrystals are formed, and the region in which the semiconductor device can be manufactured is limited. In addition, when trying to melt chevron shapes of different sizes under the same excimer pulse laser light irradiation conditions, as described above, a large temperature difference occurs depending on the size of the chevron shapes, and all chevron shapes of various sizes It is difficult to obtain a good molten state. Furthermore, since the interval at which the single crystal can be formed is defined by the chevron-shaped interval, the single crystal region cannot be formed in the vicinity.

  Next, in the above-mentioned conventional patent document 2, a method for forming a sub-island by patterning a semiconductor thin film and irradiating the sub-island while scanning with a continuous wave laser beam is used. Then, it is necessary to scan the laser light so that the position of the sub island and the irradiation position of the laser light are matched with high accuracy. In addition, as described above, the laser light absorption state and the heat dissipation state are different between the narrow sub-island part and the wide part connected to the sub-island part. Therefore, a large temperature difference occurs, and both regions are affected by the same laser light irradiation condition. It is difficult to achieve a good molten state together. Furthermore, when an inexpensive material such as glass is used for the substrate because the continuous wave laser beam is irradiated, thermal damage to the substrate occurs unless the laser beam is scanned at high speed.

  Therefore, in Patent Document 2, it is necessary to scan a continuous wave laser beam at high speed and with high positional accuracy, and it is a problem to maintain its controllability and stability. In addition, since it is necessary to scan the laser light with high positional accuracy along the position of the sub-island, there is no problem when a circuit having a simple repetitive pattern is produced. However, TFTs in various shapes, sizes, and channel length directions In order to manufacture a circuit or the like provided with a complicated control system and a scanning system for scanning the laser beam based on a large amount of sub-island position information and data such as the scanning direction of the laser beam. Furthermore, it is difficult for the narrow sub-island part and the wide part connected to the sub-island part to be in a good molten state under the same laser light irradiation conditions.

  Furthermore, since it is difficult to obtain a large output with a continuous wave laser, a single laser tube cannot form a line laser beam with a large width.

  The present invention solves the above-described conventional problems, and requires high-precision alignment of an energy beam having a large output with respect to an amorphous thin film having various shapes and sizes on a substrate. Rather than simply step-feeding in one direction and irradiating repeatedly, the amorphous thin film is completely melted to form a high-quality crystalline thin film with no grain boundaries in the desired region. Crystalline thin film forming method, crystalline thin film formed by this crystalline thin film forming method, and crystalline thin film semiconductor device such as crystalline thin film diode and crystalline thin film transistor having excellent performance using the crystalline thin film And a display device including the crystalline thin film semiconductor device.

  The crystalline thin film forming method of the present invention is a crystalline thin film forming method in which an amorphous thin film on a substrate is crystallized to form a crystalline thin film. The crystalline thin film forming method includes one or a plurality of parallel thin line portions and at least the thin line. Patterning the amorphous thin film into a predetermined shape having a thin film portion made of the same material as the thin line portion, at least a predetermined distance from the thin line portion around the portion, and the patterned amorphous thin film And applying the energy to melt the amorphous thin film and then growing the crystal to form a crystalline thin film, whereby the above object is achieved.

  Preferably, energy is applied in the crystalline thin film forming method of the present invention by irradiation with an energy beam.

  Further preferably, the energy beam in the crystalline thin film forming method of the present invention uses a beam having an absorption coefficient larger than that of the substrate by the amorphous thin film.

  Further preferably, the energy beam in the crystalline thin film forming method of the present invention is a pulsed energy beam.

  Further preferably, the energy beam in the crystalline thin film forming method of the present invention is light.

  Further preferably, the light in the crystalline thin film forming method of the present invention is a laser beam.

  Further preferably, the light in the crystalline thin film forming method of the present invention is pulsed light.

  Further preferably, the pulsed light in the crystalline thin film forming method of the present invention is pulsed laser light.

  More preferably, the amount of movement of each irradiation of the energy beam in the crystalline thin film forming method of the present invention is such that the amorphous thin film grows in a direction parallel to the substrate surface by the single irradiation. Is also set to be shorter.

  Further preferably, the irradiation with the energy beam in the method for forming a crystalline thin film of the present invention is performed while moving in a direction parallel to the longitudinal direction of the thin wire portion.

  Further preferably, in the crystalline thin film forming method of the present invention, a distance between the amorphous thin film including the thin line portion and the thin film portion formed around the amorphous thin film is in a range of 100 nm to 10 μm. Is set in.

  Further preferably, the width of the thin line portion in the crystalline thin film forming method of the present invention is set within a range of 10 nm or more and 2 μm or less.

  Further, preferably, the width of the thin line portion in the crystalline thin film forming method of the present invention is set to a width at which no crystal grain boundary occurs.

  Further preferably, the thin line portion in the crystalline thin film forming method of the present invention is formed so as to connect two wide portions of the amorphous thin film with the amorphous thin film.

  Further preferably, in the crystalline thin film forming method of the present invention, the thin line portion is patterned from one wide portion to the other wide portion, and the thin film portion is spaced apart from the thin line portion by a predetermined distance. Each of the portions up to both ends in the width direction of the portion is patterned with a width dimension.

  Further preferably, in the method for forming a crystalline thin film of the present invention, a plurality of thin line portions are patterned in parallel from one wide portion to the other wide portion, and the thin film portion is formed of the plurality of thin line portions. Patterning is performed with the width dimension between the outermost thin line portions and the widthwise ends of the wide portion at a predetermined interval.

  Further preferably, in the method for forming a crystalline thin film according to the present invention, the thin line portion is patterned from one wide portion to the other wide portion, and the thin film portion has a width that is wider on the outer peripheral side than the wide portion. Thus, the outer peripheral other side is patterned in a rectangular shape in plan view longer than the length between both wide portions, and the inner peripheral portion is patterned with a predetermined interval from the outer peripheral portions of the thin line portion and both wide portions.

  Further preferably, in the method for forming a crystalline thin film of the present invention, a plurality of thin line portions are patterned in parallel from one wide portion to the other wide portion, and the thin film portion has an outer peripheral side that is the width of the wide portion. The outer periphery is patterned in a rectangular shape in plan view with the outer periphery on the other side longer than the length between the two wide portions, and the inner peripheral portion is spaced apart from the outermost thin wire portions and the outer peripheral portions of both wide portions. Patterning.

  Further, preferably, the thin film portions are patterned between the thin wire portions only when the distance between the thin wire portions exceeds 10 μm in the crystalline thin film forming method of the present invention.

  Further preferably, the amorphous thin film in the crystalline thin film forming method of the present invention is an amorphous semiconductor thin film.

  Further preferably, the amorphous semiconductor thin film in the crystalline thin film forming method of the present invention is made of a silicon material.

The crystalline thin film of the present invention is produced by the crystalline thin film forming method according to any one of claims 1 to 21, and thereby the above-described object is achieved.
Preferably, in the crystalline thin film semiconductor device of the present invention, a crystalline thin film produced by the crystalline thin film forming method according to claim 20 or 21 is used.

  Further preferably, in the crystalline thin film semiconductor device of the present invention, a crystalline thin film diode having a pn junction or a pin junction is provided in the crystalline thin film of the thin line portion.

  Preferably, the crystalline thin film semiconductor device of the present invention further comprises a crystalline thin film transistor having a channel region in the crystalline thin film in the thin line portion.

  Further preferably, in the crystalline thin film semiconductor device of the present invention, a crystalline thin film diode having a pn junction or a pin junction is provided in the crystalline thin film of one of the thin wire portions, and the other of the above A crystalline thin film transistor having a channel region is provided in the crystalline thin film in the thin line portion.

  The display device of the present invention is provided with a crystalline thin film semiconductor device using a crystalline semiconductor thin film produced by the crystalline thin film forming method according to claim 20 or 21, whereby the above object is achieved. The

  With the above configuration, the operation of the present invention will be described below.

  In the present invention, a thin film portion made of the same material as that of the amorphous thin film is formed around the amorphous thin film including the patterned thin line portion and separated from the amorphous thin film. Depending on the shape and size of the amorphous thin film, the energy absorption state and heat dissipation state differ. Depending on the pattern shape, a large temperature difference occurs in the amorphous thin film, but the energy is also absorbed by the surrounding thin film part. Thus, it is possible to prevent the heat from escaping to the surroundings, to make the amorphous thin film into a good molten state, and to obtain a high-quality crystalline thin film free from crystal grain boundaries.

  More specifically, when the amorphous thin film patterned in a predetermined shape on the substrate is crystallized after being melted by applying energy, the amorphous thin film is formed around at least the thin line portion of the amorphous thin film. A thin film portion made of the same material as the amorphous thin film is formed in an island state separated from the thin film at an interval of, for example, 100 nm or more and 10 μm or less, and the thin film portion and the amorphous thin film are crystallized by applying energy. As a result, energy is absorbed in the pattern of the amorphous thin film of various shapes and sizes and the thin film portion around the amorphous thin film, so that a good molten state is obtained. A high-quality crystalline thin film can be formed regardless of the shape and size.

  In addition, when an energy beam, for example, a pulsed energy beam or a pulsed laser beam is repeatedly irradiated, the amount of movement for each irradiation is determined by the length of crystal growth of the amorphous thin film in the lateral direction by one irradiation. If it is set to be shorter, as shown in Patent Document 1 and Non-Patent Document 1, a crystalline thin film composed of crystal grains elongated in the moving direction of the pulsed energy beam or pulse laser beam is obtained.

  Further, this amorphous thin film is patterned into a shape having a thin line portion with a width of 10 nm or more and 2 μm or less, and the amount of movement for each irradiation of, for example, a pulsed energy beam or a pulsed laser beam as an energy beam is set once. When the irradiation is repeated while moving in a direction substantially parallel to the longitudinal direction of the fine line portion, the length of the amorphous thin film is set to be shorter than the length in which the amorphous thin film grows laterally by irradiation of It is possible to form a high-quality crystalline thin film without any defects. The thin line portion can be in a plurality of states in which the thin line portions are closely arranged in parallel.

  In addition, the width | variety of a thin wire | line part is a width | variety shown by the arrow W in Fig.7 (a) and FIG.7 (b). Further, the longitudinal direction of the thin line portion is a direction indicated by an arrow 30 in FIGS. 7 (a) and 7 (b). In FIG. 7A, an amorphous thin film 4 having a thin line portion 5 is provided on a silicon dioxide film 3 formed on a substrate, and the amorphous thin film 4 is separated from the amorphous thin film 4 around the amorphous thin film 4. A thin film portion 6 made of the same material as the thin film 4 is formed. Moreover, in FIG.7 (b), the several thin wire | line part 5 is provided along with the parallel direction on the silicon dioxide film 3 formed on the board | substrate.

  The amorphous semiconductor thin film is a crystalline semiconductor thin film, and a high-quality thin line portion having no grain boundary is formed on a pn junction or a pin junction of a crystalline thin film diode, or a channel region of a crystalline thin film transistor. Thus, it is possible to manufacture a crystalline thin film diode or a crystalline thin film transistor having characteristics close to those using a single crystal and uniform characteristics.

  In addition, the thin line portion can be formed in a pattern at an arbitrary place where a semiconductor device such as a crystalline thin film diode or a crystalline thin film transistor is to be formed. Moreover, it is possible to arbitrarily set the number of fine line portions and the interval between the fine line portions.

  Since the pulsed energy beam or the pulsed laser beam may be irradiated while scanning in the longitudinal direction of the fine line portion regardless of the position of the fine line portion, conventional high-precision alignment is unnecessary.

  In addition, the number of thin wire portions connected in parallel in the thin wire portion can be determined as appropriate depending on the amount of current desired to flow through the crystalline thin film diode, the crystalline thin film transistor, or the like.

  As described above, according to the present invention, energy such as a pulsed laser beam having a large output is simply stepped and repeatedly irradiated without requiring high-precision alignment on the substrate. It is possible to obtain a crystalline thin film having a good crystalline state in which the entire region of the pattern having various shapes and sizes is in a good molten state and there is no crystal grain boundary in the thin line portion.

  If a pn junction or a pin junction of a crystalline thin film diode or a channel region of a crystalline thin film transistor is formed in this thin line portion, the characteristics are similar to those when a single crystal is used and the characteristics are uniform. A high-performance crystalline thin film semiconductor device such as a crystalline thin film diode or a crystalline thin film transistor can be manufactured.

Embodiments 1 to 3 of the crystalline thin film forming method of the present invention and the crystalline thin film produced thereby, Embodiments 4 and 5 of the crystalline thin film semiconductor device of the present invention using the same, and the following Embodiment 6 of the display device according to the present invention will be described with reference to the drawings.
(Embodiment 1)
In the first embodiment, an amorphous silicon film as a thin film formed on a glass substrate is separated from the thin wire portion of the amorphous thin film and the amorphous portion provided around the thin wire portion in a state separated from the thin wire portion. A method for forming a crystalline thin film in which an amorphous silicon film including a thin line portion is crystallized by patterning into a shape having a thin film portion of the same material as the thin film and applying energy thereto will be described.

  FIG. 1A and FIG. 1B are a cross-sectional view and a plan view of a main part for explaining the crystalline thin film forming method according to Embodiment 1 of the present invention.

As shown in FIG. 1A, first, the silicon nitride film 2 is formed on the entire surface of the glass substrate 1 by plasma CVD (chemical vapor deposition) using, for example, SiH ₄ gas, NH ₃ gas, and N ₂ gas. The film is uniformly formed to a thickness of 200 nm.

Next, the silicon dioxide film 3 is formed to a thickness of 100 nm over the entire surface of the silicon nitride film 2 by plasma CVD using TEOS (tetraethoxysilane) gas and O ₃ gas.

Subsequently, an amorphous silicon film 4 is formed to a thickness of 50 nm over the entire surface of the silicon dioxide film 3 by plasma CVD using Si ₂ H ₆ gas and H ₂ gas.

Further, by the photolithography process and the RIE (reactive ion etching) method using CF ₄ gas and O ₂ gas, as shown in FIG. 1B, both wide portions and one wide portion to the other wide portion. In a range of 10 nm to 2 μm in width provided in the part, no crystal grain boundary is generated, for example, a range surrounded by the fine line part 5 having a width of 500 nm, the fine line part 5 and both wide parts, and on both sides of the fine line part 5 In a state of being separated from the thin line portion 5 within a range of 100 nm to 10 μm, for example, at an interval of 2 μm, a shape having an amorphous silicon film portion 6 as an amorphous thin film portion in the width of both wide portions The crystalline silicon film 4 is patterned.

  Thereafter, a line-shaped excimer pulse laser beam 7 having a length of 5 μm in the scanning direction and a length of 30 cm in a direction perpendicular thereto is irradiated while moving in the scanning direction 8 substantially parallel to the longitudinal direction of the thin line portion 5. The amorphous silicon film 4 is melted and recrystallized to form a crystalline silicon film.

  At this time, the laser beam 7 having an absorption coefficient by the amorphous silicon film 4 larger than that by the glass substrate 1 is used, and the amount of movement for each irradiation is one pulse laser beam. 7 is set to be shorter than the length of crystal growth of the amorphous silicon film 4 in the direction parallel to the substrate surface, and the laser beam is repeatedly irradiated at a pitch of 0.5 μm, for example.

  As in the first embodiment, when the amorphous silicon film 4 patterned into a shape having the fine line portion 5 between both wide portions is applied with energy for melting the amorphous silicon film 4 and crystallized, An amorphous silicon film portion 6 made of the same material as the amorphous silicon film 4 is formed around the fine wire portion 5 in an island state separated from the fine wire portion 5 and irradiated with a line-shaped excimer pulse laser beam 7. To do. As a result, energy is also absorbed by the amorphous silicon film portion 6 provided around the thin wire portion 5, so that a good molten state is obtained in the thin wire portion 5 as well as both wide portions. A quality crystalline silicon film can be formed.

  Further, when the pulsed excimer pulse laser beam 7 is repeatedly irradiated, the amount of movement for each irradiation of the laser beam is changed so that the amorphous silicon film 4 is crystallized in the lateral direction by the irradiation of the pulse laser beam 7 once. By setting the length to be shorter than the growing length, a crystalline silicon film composed of crystal grains grown elongated in the moving direction 8 of the pulse laser beam 7 can be obtained.

  Further, the width of the thin line portion 5 is set to 10 nm or more and 2 μm or less, and the amount of movement for each irradiation of the line-shaped excimer pulse laser beam 7 is changed by the irradiation of the pulse laser beam 7 once. High quality with no crystal grain boundaries in the fine wire portion 5 when the irradiation is repeated while moving in the direction substantially parallel to the longitudinal direction of the fine wire portion 5 by setting the length 4 to be shorter than the length of crystal growth in the lateral direction. The crystalline silicon film can be formed.

Furthermore, since the line-shaped excimer pulse laser beam 6 may be irradiated while scanning in the longitudinal direction of the fine line portion 5 regardless of the position of the fine line portion 5, highly accurate alignment is not necessary.
(Embodiment 2)
In Embodiment 2, a plurality of thin line portions arranged in parallel to each other are connected between two wide portions, and the width of the wide portion is such that an amorphous thin film portion is formed in an island shape around the thin line portion. A method for forming a crystalline thin film in which an amorphous silicon film including a thin line portion is crystallized by patterning and applying energy thereto will be described.

  2 (a) and 2 (b) are plan views for explaining two examples in the second embodiment of the crystalline thin film forming method of the present invention.

  As in the case of the first embodiment, for example, a silicon nitride film 2 and a silicon dioxide film 3 are formed in this order on a glass substrate 1, and as shown in FIGS. 2 (a) and 2 (b), An amorphous silicon film 4 is formed on the silicon film 3; both wide portions; a plurality of thin wire portions 5 having a width of 500 nm provided in parallel from one wide portion to the other wide portion; The amorphous silicon film 4 is patterned into a shape having the island-like amorphous silicon film portions 6A or 6B separated from the thin wire portions 5 at intervals of 2 μm around the plurality of thin wire portions 5. That is, the amorphous silicon film 4 is patterned to form two wide portions, a plurality of thin line portions 5 between them, and an amorphous silicon film portion 6A or 6B in an island state around the thin line portions 5. Form. The amorphous silicon film portion 6A or 6B is made of the same material as the amorphous silicon film 4.

  For example, when the interval between adjacent thin wire portions 5 is 10 μm or less, as shown in FIG. 2A, the outermost thin wire portions 5 are separated from the thin wire portions 5 at intervals of 2 μm, respectively. The amorphous silicon film 4 is patterned into a shape having the island-like amorphous silicon film portions 6A.

  When the interval between adjacent thin line portions 5 exceeds 10 μm, as shown in FIG. 2 (b), the distance between adjacent thin line portions 5 is within a range of 100 nm to 10 μm from the thin line portions 5, for example, 2 μm. The amorphous silicon film 4 is patterned into a shape having the island-shaped amorphous silicon film portions 6B separated at intervals of.

  Thereafter, in the same manner as in the first embodiment, the line-shaped excimer pulsed laser light 7 is moved in the longitudinal direction 8 of the thin wire portion 5 and the amount of movement of the pulsed laser light 7 per one laser light irradiation is one. While the amorphous silicon film 4 is moved so as to be shorter than the length of crystal growth in the direction parallel to the substrate surface by irradiation, the amorphous silicon film 4 is melted by repeatedly irradiating laser light at a pitch of 0.5 μm, for example. Crystallization forms a crystalline silicon film.

Even when a plurality of thin line portions 5 arranged substantially parallel to each other are formed as in the second embodiment, the same as the amorphous silicon film 4 in the island state separated from the thin line portions 5 around the thin line portions 5 An amorphous silicon film portion 6A or 6B made of a material is formed and irradiated with a line-shaped excimer pulse laser beam 7, whereby the amorphous silicon film portion 6A or 6B around the thin wire portion 5 and between the thin wire portions 5 is formed. Since the energy is absorbed in the thin wire portion 5 as well, a good molten state is obtained in the same manner as the wide portion, and a high-quality crystalline silicon film having no crystal grain boundaries is formed in the plurality of thin wire portions 5. Can do.
(Embodiment 3)
In the third embodiment, not only the periphery of the thin line portion as in the first and second embodiments, but also the entire periphery of the amorphous silicon film including the region other than the thin line portion is separated from the amorphous silicon film. A method for forming a crystalline thin film, in which an amorphous silicon film including a thin line portion is crystallized by patterning the amorphous thin film portion into a shape and applying energy thereto, will be described.

  FIG. 3A to FIG. 3C are plan views for explaining three examples in Embodiment 3 of the crystalline thin film forming method of the present invention.

  As in the first and second embodiments, for example, a silicon nitride film 2 and a silicon dioxide film 3 are formed in this order on the glass substrate 1, and the silicon dioxide film 3 is formed on the silicon dioxide film 3 as shown in FIG. An amorphous silicon film 4 is formed. Next, both wide portions, one thin wire portion 5 having a width of 500 nm provided by being connected from one wide portion to the other wide portion, and the thin wire portion 5 and the entire periphery of both wide portions 5 and the amorphous silicon film 4 are patterned into the shape of an island-like amorphous silicon film portion 6C separated from the wide portions by an interval of 2 μm. At this time, not only the periphery of the thin wire portion 5 but also the periphery of the patterned amorphous silicon film 4 other than the thin wire portion 5 (the periphery of both wide portions) in a state separated at an interval of 2 μm. A film portion 6C is formed.

  When the interval between the plurality of thin line portions 5 arranged in parallel to each other is 10 μm or less, as shown in FIG. 3B, an island-shaped amorphous silicon film is formed between adjacent thin line portions 5. The part 6 is not formed. In this case, as in the case of FIG. 3A, not only the outside of the outermost thin wire portions 5 but also the periphery of the patterned amorphous silicon film 4 other than the thin wire portions 5 (the periphery of both wide portions). In addition, the amorphous silicon film portion 6D is formed in a state separated at intervals of 2 μm.

  Further, when the interval between the plurality of thin wire portions 5 arranged in parallel with each other exceeds 10 μm, as shown in FIG. 3C, the adjacent thin wire portions 5 are also separated from the thin wire portions 5 at an interval of 2 μm. An amorphous silicon film 6B is formed in the island state. Similarly to the cases of FIGS. 3A and 3B, not only the outside of the outermost thin wire portions 5 but also the periphery of the patterned amorphous silicon film 4 other than the thin wire portions 5 (both The amorphous silicon film portion 6E is also formed in the state of being separated at an interval of 2 μm also around the wide portion). Note that the outer peripheral shapes of these amorphous silicon film portions 6C to 6E are rectangular.

  Thereafter, in the same manner as in the first and second embodiments, the line-shaped excimer pulsed laser light 7 is moved in the longitudinal direction 8 of the thin wire portion 5 by the irradiation of the pulsed laser light 7 with one movement amount per irradiation. While moving the crystalline silicon film 4 so as to be shorter than the length of crystal growth in the direction parallel to the substrate surface, the amorphous silicon film 4 is melted and crystallized by repeatedly irradiating with a pitch of 0.5 μm, for example. A crystalline silicon film is formed.

As in the third embodiment, an amorphous silicon film portion 6 made of the same material as the amorphous silicon film 4 is formed on the entire periphery of the amorphous silicon film 4 including the fine line portion 5 and the region other than the fine wire portion 5. By doing so, it is possible to align the heating state of the region that is irradiated with and absorbed by the line-shaped excimer pulse laser beam 7, so that the same line-shaped excimer pulse laser can be applied to patterns of various shapes and sizes. Depending on the irradiation condition of the light 7, the amorphous silicon film 4 can be melted and crystallized in a good state, and a high-quality crystalline silicon film having no crystal grain boundary in the thin line portion 5 can be formed. .
(Embodiment 4)
In the fourth embodiment, in a crystalline semiconductor thin film manufactured by the crystalline thin film forming method of the present invention, a crystalline thin film diode in which a pn junction or a pin junction is formed in the thin wire portion 5, and the same A manufacturing method will be described.

  4A (a) to 4A (c) are plan views of respective steps (No. 1) for explaining a method of manufacturing a crystalline thin film diode as the crystalline thin film semiconductor device of Embodiment 4 of the present invention. 4B (d) and FIG. 4B (e) are planes of respective steps (No. 2) for explaining a method of manufacturing a crystalline thin film diode as the crystalline thin film semiconductor device of Embodiment 4 of the present invention. FIG.

  First, in the same manner as in the first embodiment, a silicon nitride film 2 and a silicon dioxide film 3 are formed in this order on a glass substrate 1, and both wide portions and one wide portion are formed on the silicon dioxide film 3. After forming an amorphous silicon film 4 having a thin line portion 5 connected to the other wide portion and an island-like amorphous silicon film portion 6 around the thin line portion with the width of the wide portion, A linear excimer pulse laser beam 7 is irradiated to form a crystalline silicon film 9 as shown in FIG. 4A (a). 4A shows a configuration in which an amorphous silicon film portion 6 is provided around the thin wire portion 5 as in the case of the first embodiment, but a line-shaped excimer pulse laser beam is shown as an example. 7, the amorphous silicon film 4 including the thin line portion 5 is melt-crystallized to form the crystalline silicon film 9, and the amorphous silicon film portion 6 is also melt-crystallized to form the crystalline silicon film 9. To do.

Next, phosphorus (P) is implanted into the entire surface by ion doping so that the average concentration of the crystalline silicon film 9 in the film thickness direction is 1 × 10 ¹⁷ / cm ³ .

Further, as shown in FIG. 4A (b), a silicon dioxide film 10 having a thickness of 200 nm is formed on the entire surface by plasma CVD using TEOS gas and O ₃ gas. Next, a resist 11 is formed thereon, and the resist 11 is patterned by a photolithography process, so that one side of the fine line portion 5 is included so as to include a part of the fine line portion 5 (the left half in FIG. 4A (b)). The upper silicon dioxide film 10 is exposed. Using this resist 11 as a mask, boron (B) is implanted into the crystalline silicon film 9 through the silicon dioxide film 10 by ion doping so that the average concentration in the film thickness direction is 1 × 10 ²⁰ / cm ^3. 11 is removed.

After that, a resist 12 is formed on the silicon dioxide film 10, and the resist 12 is again patterned into a predetermined shape by a photolithography process, and is arranged on one side of the thin line portion 5 as shown in FIG. 4A (c). An opening 13 having a predetermined size is formed on a wide crystalline silicon film region (wide portion), and phosphorus (P) is added to the region of the opening 13 in the thickness direction of the crystalline silicon film 9. Is implanted by an ion doping method so as to be 1 × 10 ²⁰ pieces / cm ³ . After removing the resist 12, heat treatment is performed at 550 ° C. for 1 hour in a furnace to activate the implanted impurities.

Further, a part of the silicon dioxide film 10 is etched by the photolithography process and the RIE method using CF ₄ gas and CHF ₃ gas, so that the contact holes 14 are formed in the wide portions as shown in FIG. 4B (d). Formed in each region.

Further, as shown in FIG. 4B (e), an Al (aluminum) material is formed on the entire surface to a thickness of 600 nm by a sputtering method, and a photolithography process and an RIE method using BCl ₃ gas and Cl ₂ gas. By patterning into a predetermined shape, electrodes 15 are formed on the crystalline silicon films 9 in both wide portions via the contact holes 14 to fabricate a crystalline thin film diode. Thereafter, if necessary, a multilayer wiring or a protective film is formed to manufacture a crystalline thin film semiconductor device.

  Using the crystalline silicon film 9 produced by the crystalline thin film forming method of the present invention as in the fourth embodiment, a pn junction or a pin junction is formed on the crystalline silicon film 9 in the thin line portion 5. By forming a high-quality crystalline thin-film diode having similar characteristics and uniform characteristics when a single crystal is used can be manufactured.

  In the fourth embodiment, a high-quality crystalline thin-film diode is manufactured by forming a pn junction or a pin junction in the crystalline silicon film 9 of the thin line portion 5 of the first embodiment. However, the present invention is not limited to this, and a pn junction or a pin junction is formed in each of the crystalline silicon films 9 of the plurality of thin line portions 5 in the second and third embodiments, thereby achieving high quality with high current capacity. A crystalline thin film diode may be fabricated. In this case, the amount of current flowing through the crystalline thin film diode of each thin line portion 5 can be reduced.

(Embodiment 5)
In the fifth embodiment, a crystalline thin film transistor in which a channel region is formed in a thin line portion 5 in a crystalline semiconductor thin film produced by the crystalline thin film forming method of the present invention and a method for manufacturing the same will be described.

  FIG. 5A to FIG. 5D are plan views of respective steps for explaining a method of manufacturing a crystalline thin film transistor as the crystalline thin film semiconductor device according to the fifth embodiment of the present invention.

  First, in the same manner as in the first embodiment, a silicon nitride film 2 and a silicon dioxide film 3 are formed in this order on a glass substrate 1, and both wide portions and one wide portion are formed on the silicon dioxide film 3. After forming an amorphous silicon film 4 having a thin line portion 5 connected to the other wide portion and an island-like amorphous silicon film portion 6 around the thin line portion with the width of the wide portion, A line-shaped excimer pulse laser beam 7 is irradiated to form a crystalline silicon film 9 as shown in FIG. FIG. 5A shows an example in which the amorphous silicon film portion 6 is provided around the thin wire portion 5 as in the case of the first embodiment, but a line-shaped excimer pulse laser beam is shown. 7, the amorphous silicon film 4 including the thin line portion 5 is melt-crystallized to form the crystalline silicon film 9, and the amorphous silicon film portion 6 is also melt-crystallized to form the crystalline silicon film 9. To do.

Next, as shown in FIG. 5B, a gate insulating film 16 made of a silicon dioxide film is formed on the entire surface by a plasma CVD method using TEOS gas and O ₃ gas, and sputtering is performed thereon. A laminated film of a polycrystalline silicon film having a thickness of 100 nm and a WSi ₂ film having a thickness of 400 nm is formed by the method. This laminated film is etched by a photolithography process and an RIE method using CF ₄ gas and O ₂ gas, thereby forming a gate electrode 17 that intersects the fine line portion 5 at a right angle. Using this gate electrode 17 as a mask, the average concentration of phosphorus P (in the case of an n-type transistor) or boron B (in the case of a p-type transistor) in the thickness direction of the crystalline silicon film 9 is 1 × 10 ²⁰ by ion doping. Ion implantation is performed so that the number of ions / cm ³ is reached.

Further, as shown in FIG. 5C, the silicon dioxide film 18 (not shown in FIG. 5C but shown in FIG. 6A) is formed by plasma CVD using TEOS gas and O ₃ gas. ) Is formed to a thickness of 100 nm, and a silicon nitride film 19 is formed to a thickness of 500 nm on the silicon dioxide film 18 by plasma CVD using SiH ₄ gas, NH ₃ gas, and N ₂ gas. A heat treatment is performed at 550 ° C. for 1 hour in the furnace to activate the implanted impurities.

Thereafter, partial regions of the silicon nitride film 19, the silicon dioxide film 18 and the gate insulating film 16 are etched by a photolithography process and an RIE method using CF ₄ gas and CHF ₃ gas. Each contact hole 20 is formed on the region of the wide crystalline silicon film 9 (both wide portions) disposed.

Further, as shown in FIG. 5 (d), a wiring metal material aluminum Al is formed on the entire surface to a thickness of 600 nm by sputtering, and a photolithography process and RIE using BCl ₃ gas and Cl ₂ gas. To form a source electrode 21 and a drain electrode 22 by patterning into a predetermined shape, thereby producing a crystalline thin film transistor. After that, if necessary, a multilayer wiring is formed, or a protective film is formed thereon to manufacture a crystalline thin film semiconductor device.

  As in the fifth embodiment, by using the crystalline silicon film 9 produced by the crystalline thin film forming method of the present invention, a channel region is formed in the crystalline silicon film 9 in the thin line portion 5, thereby forming a single crystal. When used, a high-quality crystalline thin film transistor having characteristics close to each other and uniform characteristics can be manufactured.

In the fifth embodiment, a high-quality crystalline thin film transistor is manufactured by forming a channel region in the crystalline silicon film 9 of the single thin line portion 5 of the first embodiment. However, the present invention is not limited to this. A high-quality crystalline thin film transistor with a high current capacity may be produced by forming each channel region in the crystalline silicon film 9 of the plurality of thin wire portions 5 of the second and third embodiments.
(Embodiment 6)
In the sixth embodiment, a liquid crystal display device using the crystalline thin film semiconductor device of the present invention manufactured in the fourth or fifth embodiment and a manufacturing method thereof will be described.

  FIGS. 6A and 6B are diagrams for explaining a method of manufacturing a liquid crystal display device as a display device according to Embodiment 6 of the present invention. FIGS. 6A and 6B are a pair of opposingly arranged liquid crystal layers. It is principal part sectional drawing which shows the board | substrate part (element side board | substrate and opposing board | substrate).

  As shown in FIG. 6A, in one substrate portion (element-side substrate), a silicon nitride film 2 and a silicon dioxide film 3 are provided in this order on a glass substrate 1, and a crystalline silicon film 9 is formed thereon. A crystalline thin film transistor having a channel region as a channel region is manufactured.

  In this crystalline thin film transistor, a gate electrode 17 is provided on a crystalline silicon film 9 via a gate insulating film 16, and a silicon dioxide film 18 and a silicon nitride film 19 are sequentially laminated so as to cover the gate electrode 17.

  A source electrode 21 and a drain electrode 22 are provided on the silicon dioxide film 18 and the silicon nitride film 19, and the source electrode 21 and the drain electrode 22 are contact holes provided in the silicon dioxide film 18 and the silicon nitride film 19, respectively. 20 are respectively connected to both ends of the crystalline silicon film 9.

  A resin film 23 is provided so as to cover the source electrode 21 and the drain electrode 22, and an ITO film 24 is provided thereon. The ITO film 24 is provided on the resin film 23 and connected to the drain electrode 22 through a through hole. A polyimide film 25 serving as an alignment film is provided so as to cover the ITO film 24.

  On the other hand, as shown in FIG. 6B, in the other substrate portion (counter substrate), a color filter 27, an ITO film 28, and a polyimide film 29 are provided in this order on a glass substrate 26. Both substrate parts (element-side substrate and counter substrate) are arranged facing each other with a predetermined gap between them with the polyimide films 25 and 29 serving as alignment films facing inward, and the outer peripheral edges are pasted with a sealing material or the like. In addition, a liquid crystal material (liquid crystal layer) (not shown) serving as a display medium is sealed in the gap between the two substrate portions.

  The liquid crystal display device of Embodiment 6 is manufactured as follows, for example.

First, a crystalline thin film semiconductor device is fabricated on the glass substrate 1 by the method of any of Embodiments 4 and 5. In the example of FIG. 6A, a crystalline thin film transistor is manufactured. A resin film 23 is formed on the entire surface of the substrate portion so as to cover the source electrode 21 and the drain electrode 22, and a through hole is formed in the resin film 23. An ITO film 24 is formed by sputtering so as to be connected to the drain electrode 22 through the through hole, and the ITO film 24 is patterned by a photolithography process and etching using HCL and FeCl ₃ . A polyimide film 25 serving as an alignment film is formed on the ITO film 24 by using an offset printing method, and a rubbing process is performed thereon.

  On the other hand, as shown in FIG.6 (b), the film which attached | subjected each photosensitive resin film | membrane of R (red), G (green), and B (blue) was transferred by thermocompression bonding on another glass substrate 26. Thereafter, 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 27 is manufactured. On the color filter 27, an ITO film 28 is formed over the entire surface of the substrate by a sputtering method to form a counter electrode. Further, a polyimide film 29 serving as an alignment film is formed on the ITO film 28 by an offset printing method, and this is rubbed.

  The other substrate portion on the side of the glass substrate 26 on which the color filter 27 and the like shown in FIG. 6B are formed as described above, and a crystalline thin film semiconductor such as the crystalline thin film transistor shown in FIG. One substrate portion on the glass substrate 1 side where the apparatus is formed is arranged so that the surfaces of the polyimide films 25 and 29 subjected to the rubbing process are opposed to each other, and these both substrate portions are bonded with a sealing resin. Match.

  At this time, spherical silica is sprayed between the substrate portions so that the distance between the two substrate portions is constant. Further, after a liquid crystal material serving as a display medium is sealed between the two substrate portions, a polarizing plate or the like is attached to both outer sides of the two glass substrates 1 and 26 to complete the liquid crystal display device.

  According to the liquid crystal display device of the sixth embodiment, the current driving capability of the transistors provided in each pixel unit can be set to a value close to that of a transistor using a single crystal. The aperture ratio of the liquid crystal display device can be improved. In addition to the gate driver and the source driver, various circuits using the crystalline silicon film can be simultaneously formed on the glass substrate as the peripheral circuit.

  As described above, according to the first to sixth embodiments, the same material as the amorphous silicon thin film 4 is formed around the amorphous silicon thin film 4 patterned on the substrate in an island state separated from the amorphous silicon thin film 4. The thin film portion 6 is formed, and the amount of movement of each pulsed energy beam or pulsed laser beam for each irradiation of the laser beam is such that the amorphous silicon thin film 4 grows laterally by one irradiation. Irradiate repeatedly by setting it to be shorter than that. Under the same laser light irradiation conditions, a good molten state can be obtained for patterns of various shapes and sizes, and a high-quality crystalline thin film can be formed. Further, the amorphous silicon thin film 4 is patterned into a shape having the fine line portion 5 and repeatedly irradiated with a pulsed energy beam or a pulsed laser beam while moving substantially parallel to the longitudinal direction of the fine line portion 5. A high-quality crystalline thin film having no crystal grain boundary in the portion 5 can be formed. By forming a pn junction, a pin junction of a diode, or a channel region of a transistor in the crystalline thin film 9 of the thin line portion 5, the characteristics are close to those obtained when a single crystal is used. A uniform high-performance crystalline thin film semiconductor device can be manufactured.

  In the first to fifth embodiments, the thin line portion 5 is formed by a photolithography process and an etching process. However, an amorphous thin film is formed so as to have the thin line portion 5 at the time of film formation as in a photo-CVD method using a laser beam. A film may be formed.

  In the first to sixth embodiments, a glass substrate is used as the substrate, but a quartz substrate, a silicon substrate, a ceramic substrate, or the like may be used as long as it is a material that can transmit an energy beam. In addition, another film that can transmit an energy beam may be formed on these substrates. However, in the sixth embodiment, at least one of the substrates needs to be made of a material that transmits visible light.

  Further, if the absorption coefficient of the energy beam by the thin film (the amorphous silicon film in the first to sixth embodiments) is larger than the absorption coefficient by the substrate, the energy beam is absorbed by the thin film and is not so much absorbed by the substrate. The temperature is unlikely to rise, and a material having a low strain temperature such as glass or a material having a low melting point can be used as the substrate. Accordingly, the absorption coefficient of the energy beam by the thin film is preferably larger than the absorption coefficient of the substrate.

  Further, in the fifth embodiment, impurities such as B (boron) and P (phosphorus) are not implanted into the channel region, but B and P ions are implanted in an amount necessary for controlling the threshold voltage of the transistor. You may go.

  In the fifth embodiment, B and P ions are simply implanted using the gate electrode 17 as a mask. However, the LDD (Lightly Doped Drain) structure, the GOLD (Gate Overlapped Lightly Doped Drain) structure, or the like may be used. Good.

  Further, in the first to fifth embodiments, the amorphous silicon film 4 is exposed when the excimer pulse laser beam is irradiated. However, the laser beam is capped with a silicon dioxide film or the like as necessary. Irradiation may be performed.

  Furthermore, if the amount of movement for each irradiation of the pulsed energy beam or pulsed laser beam becomes longer than the length of the crystal growing in the lateral direction by the irradiation of the pulsed energy beam or pulsed laser beam once, Since crystal growth does not proceed using a crystal formed by irradiation with a pulsed energy beam or pulsed laser beam as a seed, there are crystal grain boundaries and amorphous regions at each irradiation boundary of the pulsed energy beam or pulsed laser beam. Only crystals can be obtained. Therefore, the amount of movement for each irradiation of the pulsed energy beam or pulsed laser beam is shorter than the length of crystal growth of the amorphous thin film in the lateral direction by one irradiation of the pulsed energy beam or pulsed laser beam. It is preferable to set so that

  Furthermore, in Embodiment 1 described above, the width of the thin line portion 5 is set to 500 nm. However, if the width is made thinner than 10 nm, the lateral crystal growth does not proceed smoothly in the thin line portion 5 even if the pulse laser beam is repeatedly irradiated while moving. Further, if the width of the thin line portion 5 is larger than 2 μm, a crystal grain boundary is generated in the thin line portion 5. Therefore, the width of the thin wire portion 5 or the plurality of thin wire portions 5 is preferably set within a range of 10 nm or more and 2 μm or less.

  Further, in the first to fifth embodiments, the distance between the thin wire portion 5 and the thin film portion formed in a state separated from the thin wire portion 5 around the thin wire portion 5 is set to 2 μm, but when this interval is smaller than 100 nm, When melted by irradiating with pulsed laser light, the thin wire portion 5 and the thin film portion formed around the thin wire portion 5 are connected. Further, if this interval is larger than 10 μm, the pulse laser beam is not absorbed in the portion where the island-like thin film portion is not provided. The temperature difference from the non-region (wide region) becomes too large, and it becomes difficult to melt both regions (the thin line portion 5 and the wide regions on both sides thereof) under the same pulse laser light irradiation conditions. That is, under the irradiation conditions that melt the fine wire portion 5 well, the temperature of the wide region (wide portion) rises too much and the thin film scatters. Under the condition that the wide region melts well, the thin wire portion 5 does not melt sufficiently. . Therefore, the distance between the thin wire portion 5 and the surrounding thin film portion is preferably in the range of 100 nm to 10 μm.

  In the first to sixth embodiments, a silicon material is used as the amorphous thin film. However, a material such as SiGe, GaAs, GaAlAs, InP, or a mixed crystal thereof may be used.

  Furthermore, although the pn junction is formed in the fourth embodiment, a p-i-n junction may be formed.

  In Embodiments 4 and 5, a crystalline thin film diode or a crystalline thin film transistor is manufactured as the crystalline thin film semiconductor device. However, other crystalline thin film semiconductor devices may be used, or a combination thereof. It may be produced.

  In the first to sixth embodiments, excimer pulse laser light is used as the energy beam. However, other laser light or pulsed energy beam may be used.

  Furthermore, although the liquid crystal display apparatus was mentioned as the example in the said Embodiment 6, the liquid crystal display apparatus was mentioned as the example, This invention is applicable also to other display apparatuses, such as an organic thin film EL display.

  As mentioned above, although this invention has been illustrated using preferable Embodiment 1-6 of this invention, this invention should not be limited and limited to this Embodiment 1-6. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments 1 to 6 of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  The present invention relates to a crystalline thin film forming method for crystallizing an amorphous thin film patterned on a substrate by applying energy, a crystalline thin film produced by using this crystalline thin film forming method, and the crystallinity thereof. Various shapes are used in the field of crystalline thin film semiconductor devices such as crystalline thin film diodes and crystalline thin film transistors capable of exhibiting excellent performance using thin films, and display devices including these crystalline thin film semiconductor devices. A large output energy beam can be repeatedly stepped in only one direction and repeatedly irradiated to an amorphous thin film with a large or small pattern without the need for highly accurate alignment on the substrate. Thus, it is possible to form a high-quality crystalline thin film having no crystal grain boundaries in a desired region by making all the amorphous thin films into a good molten state. By using such a high-quality crystalline thin film, it is possible to arbitrarily select a high-quality crystalline thin-film semiconductor device such as a crystalline thin-film diode or a crystalline thin-film transistor that has characteristics similar to those obtained when a single crystal is used. It becomes possible to produce in this area. For this reason, a liquid crystal display device having a high aperture ratio, a display device incorporating a high-performance peripheral circuit, an OA device such as a personal computer using such a display device as a display unit, and an AV device such as a television device. It can be widely used, and it is possible to improve productivity and reduce manufacturing costs.

(A) And (b) is principal part sectional drawing for demonstrating the crystalline thin film formation method of Embodiment 1 of this invention, and its top view. (A) And (b) is a top view for demonstrating the two examples in Embodiment 2 of the crystalline thin film formation method of this invention. (A)-(c) is a top view for demonstrating the three examples in Embodiment 3 of the crystalline thin film formation method of this invention. (A)-(c) is a top view of each process (the 1) for demonstrating the method to produce a crystalline thin film diode as a crystalline thin film semiconductor device of Embodiment 4 of this invention. (D) And (e) is a top view of each process (the 2) for demonstrating the method to produce a crystalline thin film diode as a crystalline thin film semiconductor device of Embodiment 4 of this invention. (A)-(d) is a top view of each process for demonstrating the method to produce a crystalline thin-film transistor as a crystalline thin film semiconductor device of Embodiment 5 of this invention. It is a figure for demonstrating the method to produce a liquid crystal display device as a display apparatus of Embodiment 6 of this invention, Comprising: (a) And (b) shows a pair of board | substrate part arrange | positioned across the liquid crystal layer. It is a principal part sectional view shown. (A) And (b) is a top view for demonstrating the longitudinal direction and width | variety of the thin wire | line part of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Silicon nitride film 3 Silicon dioxide film 4 Amorphous silicon film 5 Thin wire | line part 6, 6A-6E Amorphous silicon film part around an amorphous silicon film 7 Line excimer pulse laser beam 8 Line excimer Pulsed laser beam scanning direction 9 Crystalline silicon film 10 Silicon dioxide film 11 Resist 12 Resist 13 Opening 14 Contact hole 15 Electrode 16 Gate insulating film 17 Gate electrode 18 Silicon dioxide film 19 Silicon nitride film 20 Contact hole 21 Source electrode 22 Drain Electrode 23 Resin film 24 ITO film 25 Polyimide film 26 Glass substrate 27 Color filter 28 ITO film 29 Polyimide film 30 Longitudinal direction of fine wire portion W Fine wire portion width

Claims (27)

In a crystalline thin film forming method of forming a crystalline thin film by crystallizing an amorphous thin film on a substrate,
The amorphous thin film having a predetermined shape having a thin film portion made of the same material as the thin wire portion in a state having one or a plurality of parallel thin wire portions and being separated from the thin wire portion by a predetermined distance around the thin wire portion Patterning, and
A method of forming a crystalline thin film by applying energy to the patterned amorphous thin film to melt the amorphous thin film and then growing the crystal to form a crystalline thin film.   The crystalline thin film forming method according to claim 1, wherein the energy application is performed by irradiation with an energy beam.   The crystalline thin film forming method according to claim 2, wherein the energy beam uses a beam having an absorption coefficient by the amorphous thin film larger than an absorption coefficient by the substrate.   4. The method for forming a crystalline thin film according to claim 2, wherein the energy beam is a pulsed energy beam.   4. The crystalline thin film forming method according to claim 2, wherein the energy beam is light.   The crystalline thin film forming method according to claim 5, wherein the light is laser light.   The crystalline thin film forming method according to claim 5, wherein the light is pulsed light.   The crystalline thin film forming method according to claim 7, wherein the pulsed light is pulsed laser light.   The amount of movement for each irradiation of the energy beam is set to be shorter than the length of crystal growth of the amorphous thin film in a direction parallel to the substrate surface by the single irradiation. 6. The method for forming a crystalline thin film according to any one of 5 above.   The method for forming a crystalline thin film according to claim 2, wherein the energy beam is irradiated while being moved in a direction parallel to a longitudinal direction of the thin wire portion.   The distance between the amorphous thin film including the thin line portion and the thin film portion formed around the amorphous thin film is set in a range of 100 nm or more and 10 μm or less. The crystalline thin film formation method as described.   The method for forming a crystalline thin film according to claim 1, wherein a width of the thin line portion is set in a range of 10 nm to 2 μm.   The method for forming a crystalline thin film according to any one of claims 1 and 10 to 12, wherein a width of the thin line portion is set to a width at which a crystal grain boundary does not occur.   The crystalline thin film forming method according to claim 1, wherein the thin line portion is formed so as to connect two wide portions of the amorphous thin film with the amorphous thin film.   The thin line portion is patterned from one wide portion to the other wide portion, and the thin film portion has a width dimension between each thin line portion and a width of the wide portion at both ends from the wide portion. The method for forming a crystalline thin film according to claim 1, wherein each is patterned.   A plurality of the thin wire portions are patterned in parallel from one wide portion to the other wide portion, and the thin film portion is spaced apart from both outermost thin wire portions by a predetermined distance from the thin wire portions. The method for forming a crystalline thin film according to any one of claims 1 and 10 to 13, wherein each portion of the wide portion up to both ends in the width direction is patterned with a width dimension.   The thin line portion is patterned from one wide portion to the other wide portion, and the thin film portion is wider on one side of the outer periphery than the width of the wide portion, and on the other side of the outer periphery from the length between the two wide portions. 14. The crystallinity according to claim 1, wherein the crystallinity is patterned in a long rectangular shape in plan view, and the inner peripheral portion is patterned with a predetermined distance from the outer peripheral portions of the thin line portion and the wide width portions. Thin film forming method.   A plurality of the thin wire portions are patterned in parallel from one wide portion to the other wide portion. The patterning is performed in a rectangular shape in plan view longer than the length between the inner peripheral portions, and the inner peripheral portion is patterned with a predetermined interval from the outer peripheral portions of the outermost thin wire portions and the wide width portions. The crystalline thin film formation method in any one.   The method for forming a crystalline thin film according to claim 16 or 18, wherein the thin film portions are also patterned between the thin wire portions only when the interval between the thin wire portions exceeds 10 µm.   The method for forming a crystalline thin film according to any one of claims 1, 3, 9, 11 and 14, wherein the amorphous thin film is an amorphous semiconductor thin film.   The method for forming a crystalline thin film according to claim 20, wherein the amorphous semiconductor thin film is made of a silicon material.   A crystalline thin film produced by the crystalline thin film forming method according to claim 1.   A crystalline thin film semiconductor device using a crystalline thin film produced by the crystalline thin film forming method according to claim 20 or 21.   24. The crystalline thin film semiconductor device according to claim 23, wherein the crystalline thin film in the thin wire portion is used.   The crystalline thin film semiconductor device according to claim 24, further comprising a crystalline thin film diode having a pn junction or a pin junction in the crystalline thin film in the thin line portion.   The crystalline thin film semiconductor device according to claim 24, further comprising a crystalline thin film transistor having a channel region in the crystalline thin film in the thin line portion.   A display device provided with a crystalline thin film semiconductor device using a crystalline semiconductor thin film produced by the crystalline thin film forming method according to claim 20 or 21.

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