JP2002118061A - Formation method of crystalline semiconductor film, semiconductor device, and display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form large crystal grain using a single-crystal grain as a seed, or a crystalline semiconductor film having large area, while keeping temperature in substrate at a flexibility point or lower. SOLUTION: One portion of the semiconductor film 3 formed on the substrate 1 is removed for forming a constriction section 4 and island-like regions 31A and 31B of the semiconductor film that are wider than the constriction section 4, a line-like energy beam 5 is applied intermittently, while performing scanning from the island-like region 31A at one side at the construction section 4 to the island-like region 31B at the opposite side, and the island-like region 31B is subjected to crystal growth by using the crystal grain passing through the constriction section 4 of the crystal grain growing from a crystal nucleus generated in the island-like region 31A as the seed. A shape where at least two island-like regions are connected at a connection section is formed, the line-like energy beam is applied intermittently, while performing scanning from the island like region at one side at the connection section to the island- like region at the opposite side, and the island-like region at the opposite side is subjected to crystal growth, by using the crystal grain passing through the connection section of the crystal grain growing from a crystal nucleus generated in the island-like region 31A at one side as the seed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a crystalline semiconductor film, a semiconductor device using the same, and a display device provided with the semiconductor device, and more particularly to a non-single-crystal insulating film or a non-single-crystal insulating substrate. A crystal capable of obtaining large crystal grains or a large-area crystalline semiconductor film using a single crystal nucleus as a seed by applying energy to an amorphous or polycrystalline non-single-crystal semiconductor film formed thereon. The present invention relates to a method for forming a conductive semiconductor film, a semiconductor device such as a liquid crystal driver, a semiconductor memory, a semiconductor logic circuit, or the like, which can exhibit excellent performance using the semiconductor film, and a display device using the semiconductor device.

[0002]

2. Description of the Related Art Conventionally, an amorphous or polycrystalline semiconductor film is formed on a non-single-crystal insulating film or a non-single-crystal insulating substrate formed on a substrate, and energy is applied to the semiconductor film to form a semiconductor film. A method for crystallizing is known. In this method, in order to obtain large crystal grains having a uniform crystal orientation or a large-area crystalline semiconductor film having a uniform crystal orientation, irregular nucleation is suppressed and a controlled crystal nucleus is used as a seed crystal. It is important to grow the crystal as.

[0003] For example, Appl. Phys. Lett.
Vol. 69 No. 19 pp. 2864-2866
As shown in FIG. 14, the excimer laser light source 2
After shaping the laser beam emitted from 6 by a mask 27, the sample 29 held on the stage 28 is irradiated in pulses while moving the irradiation position in sub-micron steps, and the Si film is laterally (parallel to the substrate). (Conventional direction 1). FIG.
In the figure, 30 is a dimmer, 31 is a mirror, and 32 is a lens.

Further, US Pat. No. 4,576,676 discloses that FIG.
As shown in FIG. 1, a method is disclosed in which a constricted portion 36 is formed in a polycrystalline Si film 34 on a substrate 33, and only a crystal grain having one crystal orientation is selected by the constricted portion 36. 2). In FIG. 15, 35
Indicates a crystal orientation filter part.

Further, Appl. Phys. Lett. V
ol. 41 No. 8 p. 747-p. At 749,
As shown in FIG. 16, a part of the polycrystalline Si film 37 is removed by etching to form a thin portion 39 like an hourglass, and the melted portion of the polycrystalline Si film 37 passes through the thin portion 39. The crystal orientation is selected (conventional example 3). In FIG. 16, reference numeral 38 denotes a polycrystalline Si film 37.
Indicates a crystal growth direction.

Further, in Japanese Patent Application Laid-Open No. 6-244103, an amorphous Si film 43 is formed on a substrate 41 via an SiO ₂ film 42 as shown in FIGS. And a crystallization-promoting element, F,
e, Co, Ni, and Pt are entirely covered with a catalyst material film 44 containing at least one of them (in the case of FIG. 17A).
A method is disclosed in which an amorphous Si film 43 is crystallized to form a crystalline Si film by annealing after forming the film or partially (in the case of FIG. 17B) (FIG. 17B) (conventional example). 4).

[0007]

However, in the above-mentioned prior art example 1, since crystal growth proceeds using a large number of crystal nuclei generated by the first laser irradiation as seeds, crystal grains elongated in the direction of laser movement can be obtained. However, crystal grains do not expand.

In the above-described methods of Conventional Examples 2 and 3, polycrystalline Si is melted by a zone melting method, and the melted portion passes through a thin portion formed by etching. It is not possible to use an inexpensive substrate that rises and has a low softening point temperature such as glass.

In the method of forming the catalyst material film 44 over the entire surface of the prior art 4 shown in FIG. 17A, crystal growth nuclei are generated irregularly over the entire surface of the amorphous Si film 43. It is only possible to obtain crystal grains on the order of μm, and it is difficult to obtain large crystal grains or single crystal regions with uniform crystal orientation.

On the other hand, in the method of partially forming the catalyst material film 44 shown in FIG. 17B of the conventional example 4, the crystal grows from the region where the catalyst material film 44 is formed to the region where the catalyst material film 44 is not formed. However, nucleation occurs irregularly in the region where the catalyst material film 44 is formed. Therefore, FIG.
Although a longer crystal grain or single crystal region can be obtained as compared with the method shown in (1), the width of the crystal grain can only be obtained on the order of μm, and it is difficult to obtain a larger crystal grain or single crystal region. .

When a semiconductor device such as a liquid crystal driver, a semiconductor memory, or a semiconductor logic circuit is manufactured using a semiconductor film having a non-uniform crystal orientation or a semiconductor film having a crystal defect, the carrier mobility of the transistor is reduced. There is a problem that the threshold voltage decreases and the variation increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. A large crystal grain or a large-area crystalline semiconductor film using a single crystal grain as a seed is formed by using a glass or the like. It is an object of the present invention to provide a method for forming a crystalline semiconductor film which can be formed on a substrate softening at a temperature lower than the melting temperature of Si, and a high-performance semiconductor device and a display device using the same.

[0013]

According to the method of forming a crystalline semiconductor film of the present invention, a semiconductor film is formed on a non-single-crystal insulating film formed on a substrate or on a non-single-crystal insulating substrate, and In a method of crystallizing by applying energy, a part of the semiconductor film is removed to remove one or more constrictions, and a semiconductor connected to both sides of the constriction and having a width wider than the constriction. Forming a film island region; and forming a linear energy from the semiconductor film island region on one side of the constricted portion to the semiconductor film island region on the opposite side of the constricted portion. By repeatedly intermittently irradiating and melting the semiconductor film while scanning the beam, crystal grains grown from crystal nuclei generated in the island region of the semiconductor film on one side with respect to the constricted portion. home,
Using the crystal grains that have passed through the constricted portion as seeds to crystal-grow an island-shaped region of the semiconductor film opposite to the constricted portion, thereby achieving the object described above.

According to the method of forming a crystalline semiconductor film of the present invention, a semiconductor film is formed on a non-single-crystal insulating film or a non-single-crystal insulating substrate formed on a substrate, and the crystal is formed by applying energy to the semiconductor film. Forming the semiconductor film into a shape in which two or more island-shaped regions are connected by a bonding portion; and forming the bonding portion from the island-shaped region of the semiconductor film on one side with respect to the bonding portion. By repeatedly intermittently irradiating the semiconductor film while scanning with a linear energy beam to the island region of the semiconductor film on the opposite side to the semiconductor film, one side with respect to the bonding portion Of the crystal grains grown from the crystal nuclei generated in the island regions of the semiconductor film, the crystal grains that have passed through the joint are used as seeds to grow the island regions of the semiconductor film opposite to the joint. Including the step of causing The above-mentioned object can be achieved by the.

A substance that facilitates crystallization may be introduced into the entire surface of the semiconductor film.

In the semiconductor film, a substance for facilitating crystallization may be introduced into the island region on the side where crystal nuclei are to be generated.

The substance that facilitates crystallization may be introduced into the semiconductor film at a position away from a constricted portion or a bonded portion.

According to the method for forming a crystalline semiconductor film of the present invention, a semiconductor film is formed on a non-single-crystal insulating film formed on a substrate or a non-single-crystal insulating substrate, and the crystal is formed by applying energy to the semiconductor film. In the method of forming a semiconductor film, a part of the semiconductor film is removed, and one or more constricted portions are connected to both sides of the constricted portion, and an island-shaped region of the semiconductor film wider than the constricted portion. Forming, and in the island-shaped region of the semiconductor film on which a crystal nucleus is to be generated,
A step of introducing a substance that facilitates crystallization at a position away from the constriction, and scanning a linear energy beam from the region where the substance that facilitates crystallization is introduced toward the constriction. Intermittently irradiating while repeating the step of melting and solidifying the semiconductor film until the lateral crystal growth passes through the constricted portion, and heating the whole to form crystal grains that have passed the constricted portion. A step of laterally solid-phase growing an island-shaped region of the semiconductor film on the side where the substance that facilitates crystallization is not introduced, thereby achieving the above object.

According to the method of forming a crystalline semiconductor film of the present invention, a semiconductor film is formed on a non-single-crystal insulating film formed on a substrate or on a non-single-crystal insulating substrate, and the crystal is formed by applying energy to the semiconductor film. A step of patterning the semiconductor film into a shape in which two or more island-shaped regions are connected by a bonding portion; and, in the island-shaped region of the semiconductor film on which a crystal nucleus is to be generated, A step of introducing a substance that facilitates crystallization at a position away from the joint, and scanning a linear energy beam from the region where the substance that facilitates crystallization is introduced toward the joint. While intermittently irradiating, repeating the step of melting and solidifying the semiconductor film until the lateral crystal growth passes through the bonding portion, and heating the whole to remove the crystal grains passing through the bonding portion. As a seed , And a step of solid phase growth of the island region on the side of the semiconductor film that does not introduce a material that facilitates the laterally crystallized, the objects can be achieved.

The method of forming a crystalline semiconductor film according to the present invention comprises forming a semiconductor film on a non-single-crystal insulating film formed on a substrate or on a non-single-crystal insulating substrate and applying energy to the semiconductor film to form a crystalline semiconductor film. In the method of forming a semiconductor film, a part of the semiconductor film is removed, and one or more constricted portions are connected to both sides of the constricted portion, and an island-shaped region of the semiconductor film wider than the constricted portion. Forming, and in the island-shaped region of the semiconductor film on which a crystal nucleus is to be generated,
A step of introducing a substance that facilitates crystallization at a position distant from the constriction, and heating the entirety, so that a solid phase growth in a lateral direction from the region where the substance that facilitates crystallization is introduced is constricted. A step of solid-phase growing the semiconductor film until passing through the portion, and intermittently scanning a linear energy beam from the region where the lateral solid-phase growth has been completed in a direction away from the constricted portion. By irradiating and solidifying the semiconductor film, the crystal grains that have passed through the constriction are used as seeds to laterally move the island regions of the semiconductor film on the side where the substance that facilitates crystallization is not introduced. And a step of growing a crystal, whereby the above object is achieved.

According to the method of forming a crystalline semiconductor film of the present invention, a semiconductor film is formed on a non-single-crystal insulating film or a non-single-crystal insulating substrate formed on a substrate, and the crystal is formed by applying energy to the semiconductor film. A step of patterning the semiconductor film into a shape in which two or more island-shaped regions are connected by a bonding portion; and, in the island-shaped region of the semiconductor film on which a crystal nucleus is to be generated, A step of introducing a substance that facilitates crystallization at a position distant from the bonding part, and heating the whole, so that a solid phase growth in a lateral direction from a region where the substance that facilitates crystallization is introduced is performed at the bonding part. Solid-phase growth of the semiconductor film until passing through, and intermittently irradiating while scanning a linear energy beam from the region where the lateral solid-phase growth has been completed in a direction away from the coupling portion. Then Melting and solidifying the conductor film to crystal-grow the island-like regions of the semiconductor film on the side where the substance facilitating the crystallization is not introduced, using the crystal grains that have passed through the bonding portion as seeds. And thereby the above object is achieved.

In the island-shaped region of the semiconductor film opposite to the region where the crystal nucleus is to be generated with respect to the constricted portion, two sides extending from the constricted portion are perpendicular to the moving direction of the linear energy beam. It may be inclined from the direction.

In the island region of the semiconductor film opposite to the region where a crystal nucleus is to be generated with respect to the coupling portion, the two sides extending from the coupling portion are substantially parallel to the moving direction of the linear energy beam. The non-existing side may be inclined from a direction perpendicular to the moving direction of the linear energy beam.

The semiconductor film may be formed using a silicon material.

It is preferable to introduce at least one of Fe, Co, Ni, Cu, Ge, Pd, Au and a compound containing these metals as a substance for facilitating the crystallization.

It is preferable that the distance between the region into which the substance for facilitating crystallization is introduced into the semiconductor film and the constricted portion is 5 μm or more.

The width of the constricted portion is 0.1 μm or more and 10 μm or more.
m or less.

The length of the constriction is 0.5 μm or more and 10 μm or more.
It is preferable that the thickness be 0 μm or less.

[0029] It is preferable that the distance between the region where the substance for facilitating crystallization is introduced into the semiconductor film and the bonding portion is 10 μm or more.

Preferably, the width of the connecting portion is formed to be 20 μm or less.

It is preferable that the step of intermittently irradiating the linear energy beam be in a range of 0.1 μm or more and 10 μm or less.

The semiconductor device of the present invention uses the semiconductor film obtained by the method of forming a crystalline semiconductor film of the present invention, thereby achieving the above object.

A display device according to the present invention includes the semiconductor device according to the present invention, thereby achieving the above object.

In the present invention, the width of the constricted portion indicates the dimension of W shown in FIG. 13 (a), and the length of the constricted portion indicates the dimension of L shown in FIG. 13 (a). The distance between the region and the constricted portion indicates the dimension H shown in FIG. FIG. 13B shows the width of the joint.
, And the distance between the catalytic substance introduction region and the bonding portion indicates the dimension K shown in FIG. 13B.

The operation of the present invention will be described below.

In the present invention, a part of the semiconductor film is removed to form a constricted portion and an island-shaped region of the semiconductor film wider than the constricted portion connected to both sides thereof. From the island-shaped region of the semiconductor film on one side to the island-shaped region of the semiconductor film on the opposite side, the line-shaped energy beam is intermittently radiated while scanning to melt and solidify the semiconductor film. On the other hand, of the crystals grown from the crystal nuclei generated in the island regions of the semiconductor film on one side, the crystal grains that have passed through the constriction are used as seeds to grow the island regions of the semiconductor film on the opposite side. The crystal nucleus generated by the first irradiation of the linear energy beam grows laterally by the second irradiation of the linear energy beam at a position slightly shifted from the first irradiation position. By repeating this, the crystal growth in the lateral direction proceeds, and crystal grains in a substantially parallel and elongated shape grow. When this lateral crystal growth reaches the constriction, one of the crystal grains is selected in the constriction, and the crystal grain grows through the constriction, and the entire island region on the opposite side to the constriction is formed. Crystal growth is performed using the crystal grains as seeds. Since the irradiation of the linear energy beam is performed intermittently, the substrate temperature does not rise to the softening point temperature of the substrate. This makes it possible to obtain a large crystal grain or a large-area crystalline semiconductor film using a single crystal grain as a seed while maintaining the substrate temperature at or below the softening point temperature of the substrate.

Alternatively, the semiconductor film is patterned in a shape in which two or more island-shaped regions are connected by a joint, and the island-shaped region of the semiconductor film on the opposite side from the island-shaped region of the semiconductor film on one side with respect to the joint. By repeatedly irradiating the semiconductor film by intermittently irradiating it while scanning the line-shaped energy beam to the region, the semiconductor film grows from the crystal nuclei generated in the island region of the semiconductor film on one side with respect to the joint. Using the crystal grains that have passed through the joint portion as seeds, the island-like region of the semiconductor film on the opposite side is grown. Similarly to the above, of the substantially parallel crystal grains elongated in the lateral direction, the endmost crystal grain is selected at the joint of the two island-like regions, and the island-like region on the opposite side to the joint is formed. The whole crystal grows using these crystal grains as seeds. Since the irradiation of the linear energy beam is performed intermittently, the substrate temperature does not rise to the softening point temperature of the substrate. This makes it possible to obtain a large crystal grain or a large-area crystalline semiconductor film using a single crystal grain as a seed while maintaining the substrate temperature at or below the softening point temperature of the substrate.

By introducing a substance that facilitates crystallization into the entire surface of the semiconductor film, crystal nuclei are easily generated, and as a result, crystal growth proceeds more easily.

By introducing a substance that facilitates crystallization into the island-like region of the semiconductor film on the side where crystal nuclei are to be generated, crystal nuclei are easily generated, and as a result, crystal growth is more easily performed. I will go forward. The crystallization-facilitating substance introduced into the island region on the side where the crystal nuclei are to be generated diffuses through the constricted portion or the joint portion to the opposite island region with the scanning of the linear energy beam. Thus, a large crystal grain or a large-area crystalline semiconductor film using a single crystal grain as a seed can be obtained while the substrate temperature is kept low.

By introducing a substance that facilitates crystallization to a position away from the constriction or bonding part of the semiconductor film, crystal nuclei are easily generated, and as a result, crystal growth proceeds more easily. At the same time, crystal grains grow from the portion where the crystal nucleus is generated to the constricted portion or the bonded portion, so that only a single crystal grain can more reliably pass through the constricted portion or the bonded portion.

The linear energy beam is intermittently radiated while scanning the constricted portion or the joint to cause crystal growth in the lateral direction. After passing through the constricted portion or the joint, the whole is heated and solidified in the lateral direction. By performing the phase growth, it is possible to improve the throughput as compared with the method of scanning the linear energy beam until after passing through the constricted portion or the coupling portion.

By heating the entire portion up to the constricted portion or the joint portion and performing solid phase growth in the lateral direction, crystal grains grow larger than in the case where a linear energy beam is irradiated to be melted and solidified. Is more reliably obtained. In addition, after passing through the constriction or joint, the crystallinity is compared with solid phase growth by intermittently irradiating while scanning with a linear energy beam and repeating melting and solidification to grow crystals in the lateral direction. It is possible to improve.

In the island region of the semiconductor film opposite to the region where the crystal nucleus is to be generated with respect to the constriction, two sides extending from the constriction are inclined from a direction perpendicular to the moving direction of the linear energy beam. By doing so, it is possible to prevent random nucleation from occurring at the corners of the island-like region, and it is possible to more reliably promote crystal growth using only crystal grains that have passed through the constricted portion as seeds.

In the island region of the semiconductor film opposite to the region where the crystal nucleus is to be generated with respect to the coupling portion, of the two sides extending from the coupling portion, the side not substantially parallel to the moving direction of the linear energy beam. Is tilted from a direction perpendicular to the direction of movement of the linear energy beam,
Preventing random nucleation at the corners of the islands,
Crystal growth can be made to proceed more reliably using only the crystal grains that have passed through the bonding portion as seeds.

When a silicon material is used as the semiconductor film, since it is a semiconductor film made of a single element, stable crystallization is possible without causing a composition shift unlike a compound semiconductor. Silicon is a material widely used for ordinary LSIs, and a semiconductor film formed by using the present invention can be widely used for these.

Materials (catalytic materials) for facilitating crystallization include Fe, Co, Ni, Cu, Ge, Pd,
At least one of Au and a compound containing these metals can be used.

The distance between the catalytic substance introduction region and the constricted portion is 5
μm or more, and the width of the constricted part is 0.1 μm or more
μm or less, and the length of the constricted part is 0.5 μm or more and 1
By setting the thickness to be equal to or less than 00 μm, the effect of selecting crystal grains can be further ensured. If the width of the constricted portion is made smaller than 0.1 μm or the length of the constricted portion is made longer than 100 μm, crystal nuclei generated on the catalyst material introduction side of the constricted portion pass through the constricted portion and take over the crystal orientation to the opposite side. Stops growing. If the width of the constricted portion is made wider than 10 μm, the length of the constricted portion is made shorter than 0.5 μm, or the distance between the catalyst substance introduction region and the constricted portion is made smaller than 5 μm, the crystal orientation in the constricted portion is selected. The effect is reduced, and the crystal grains having multiple crystal orientations generated on the catalyst material introduction side of the constriction part grow through the constriction part to the opposite side, and a large crystal seeded from a single crystal grain A crystalline semiconductor film having a grain or a large area cannot be formed.

The distance between the catalytic substance introduction region and the joint is 10
When the width is set to be equal to or more than μm or the width of the bonding portion is set to be equal to or less than 20 μm, the effect of selecting the crystal grains becomes more reliable. When the distance between the catalytic material introduction region and the bonding part is shorter than 10 μm or the width of the bonding part is wider than 20 μm, the effect of selecting the crystal orientation at the bonding part is reduced, and this occurs on the catalyst material introduction side of the bonding part. Crystal grains having a plurality of crystal orientations pass through the bonding portion and grow to the opposite side, making it impossible to form a large crystal grain or a large-area crystalline semiconductor film using a single crystal grain as a seed. .

By setting the step of irradiating the line-shaped energy beam intermittently (interval between irradiation center positions) in the range of 0.1 μm or more and 10 μm, it becomes possible to surely carry out lateral crystal growth.

When a large crystal grain or a large-area crystalline semiconductor film having a single crystal grain as a seed obtained in this manner is used, the carrier mobility of the transistor can be increased and the threshold voltage can be reduced. In addition, since these variations can be reduced, the characteristics can be improved.

Further, by providing the semiconductor device having the improved characteristics as described above, it is possible to realize a display device with high definition and high aperture ratio.

[0052]

Embodiments of the present invention will be specifically described below with reference to the drawings.

(Embodiment 1) In Embodiment 1, an amorphous or polycrystalline semiconductor film formed on a non-single-crystal insulating film or a non-single-crystal insulating substrate is partially removed to form a constricted portion. ,
Forming an island-shaped region of the semiconductor film wider on both sides of the constricted portion than the constricted portion, from the island-shaped region on one side of the constricted portion to the island-shaped region on the opposite side through the constricted portion One of the many crystal grains grown from the crystal nuclei generated in the island-like region on one side of the constriction by repeating the intermittent irradiation and melting and solidification while scanning with a linear laser beam Is selected at the constricted portion, and the crystal grains that have passed through the constricted portion are used as seeds to grow the island region of the wide semiconductor film on the opposite side. An object is to obtain a crystalline semiconductor film having an area while maintaining the substrate temperature at or below the softening point temperature of the substrate.

FIG. 1 is a perspective view for explaining a method for forming a crystalline semiconductor film according to the first embodiment.

[0055] First, as shown in FIG. 1 (a), SiO ₂
On a glass substrate 1 on which a film 2 is formed to a thickness of 200 nm,
An amorphous Si film 3 is formed to a thickness of 100 nm by using a Si ₂ H ₆ gas by a low pressure CVD (chemical vapor deposition) method, and a part thereof is formed by a RIE (reactive ion etching) method.
Etching is performed using ₄ gas and O ₂ gas to form a constricted portion 4 having a width of 1 μm and a length of 5 μm.

Next, in the direction indicated by the arrow V in FIG.
0.5 μm while moving the linear laser beam 5
Irradiation is performed intermittently in steps to heat the amorphous Si film 3 so that the amorphous Si film 3 is locally melted, and the heated portion is moved from the island-like region 31A on one side of the constricted portion 4 through the constricted portion 4 to the opposite side. The crystal is moved to the island region 31B to continue the lateral crystal growth. The moving speed of the laser beam at this time depends on the pulse interval of the laser. For example, when using a laser oscillating at 300 Hz, 0.5 μm × 300
= 150 μm, that is, a moving speed of 9 mm / min. Thereby, the temperature of the amorphous Si film 3 becomes
The temperature locally rises to 1414 ° C., which is the melting temperature of Si. In this case, the entire glass substrate 1 was heated at 400 ° C.
And heat it. Here, the whole glass substrate 1 is heated because if the temperature difference between the local heating portion and the surrounding substrate is too large during heating, the substrate will be stretched due to thermal distortion, and the entire substrate will be heated. This prevents the substrate from warping. However, if the heating temperature of the entire substrate is excessively increased, irregular nuclei are generated even in portions other than the local heating portion, and large crystal grains or a large-area crystalline semiconductor film cannot be obtained. To heat the entire substrate.

As described above, the width of the amorphous Si film 3 is 1 μm.
m, a constricted portion 4 having a length of 5 μm is formed, and the constricted portion 4 is irradiated with a linear laser beam on one of the island regions 31A to locally melt and solidify the amorphous Si film 3, After forming a large number of fine crystal grains, the fine crystal grains are laterally grown by moving the laser beam while intermittently applying a linear laser beam. By selecting one of them at the constricted portion 4 and further growing the crystal to the island region 31B on the opposite side to the constricted portion 4, a large crystal seeded by a single crystal grain, which is the object of the present invention, is obtained. A crystalline semiconductor film having a grain or a large area can be obtained while maintaining the substrate temperature at or below the softening point temperature of the substrate.

FIG. 2 is a diagram schematically showing a state of crystal grain growth in the present embodiment. A crystal nucleus generated by the first irradiation of the linear laser beam grows laterally by the second irradiation of the linear laser beam at a position shifted from the first irradiation position by 0.5 μm. By repeating this, the crystal growth progresses in the lateral direction, and the crystal grains 6 having a substantially parallel and elongated shape grow. When the lateral crystal growth reaches the constricted portion 4, one of the crystal grains 6 is selected in the constricted portion 4, the crystal grain grows through the constricted portion 4, and the entire island region 31B on the opposite side is grown. The crystal grows using the crystal grains as seeds.

Embodiment 2 In Embodiment 2, an amorphous or polycrystalline semiconductor film formed on a non-single-crystal insulating film or a non-single-crystal insulating substrate is partially formed by two island regions. The pattern is formed into a shape connected by the joints that are in contact with each other, and from the island area on one side to the island area on the other side of the joint, it is intermittently irradiated while scanning with a linear laser beam and melted and solidified. By repeating this, the endmost crystal grain of the many crystal grains grown from the crystal nuclei generated in the island region on one side of the bonding portion passes through the bonding portion, and this crystal grain is As a seed, by growing a crystal in an island region of the semiconductor film on the opposite side, a large crystal grain using a single crystal grain as a seed or a large-area crystalline semiconductor film is kept at a substrate temperature equal to or lower than the softening point temperature of the substrate. It is intended to be obtained as it is.

FIG. 3 is a perspective view for explaining a method for forming a crystalline semiconductor film according to the second embodiment.

[0061] First, as shown in FIG. 3 (a), SiO ₂
On a glass substrate 1 on which a film 2 is formed to a thickness of 200 nm,
An amorphous Si film 3 is formed to a thickness of 100 nm by using a Si ₂ H ₆ gas by a low pressure CVD method, and a part thereof is etched by a RIE method using a CF ₄ gas and an O ₂ gas to form two islands. The pattern is formed so that the shape-like regions 32A and 32B have a shape connected by the joint 7 having a width of 10 μm.

Next, in the direction indicated by the arrow V in FIG.
While moving the linear laser beam 5 at the same moving speed as in the first embodiment, the laser beam is intermittently irradiated in 0.5 μm steps to heat the amorphous Si film 3 so as to locally melt. Is moved from the island region 32A on one side of the joint portion 7 to the island region 32B on the opposite side through the joint portion 7 to continue the crystal growth in the lateral direction. At this time, the entire glass substrate 1 is heated to 400 ° C.

FIG. 4 is a diagram schematically showing a state of crystal grain growth in the present embodiment. A crystal nucleus generated by the first irradiation of the linear laser beam grows laterally by the second irradiation of the linear laser beam at a position shifted from the first irradiation position by 0.5 μm. By repeating this, the crystal growth progresses in the lateral direction, and the crystal grains 6 having a substantially parallel and elongated shape grow. When the lateral crystal growth reaches the joint 7, the endmost crystal grain 6 grows through the joint 7, and the entire island region 32B on the opposite side grows using the crystal grain as a seed. This makes it possible to obtain a large crystal grain or a large-area crystalline semiconductor film having a single crystal grain as a seed while maintaining the substrate temperature at or below the softening point temperature of the substrate.

(Embodiment 3) Embodiment 3 is directed to a method of forming a crystalline semiconductor film according to Embodiment 1 described above.
It introduces a catalytic substance into the semiconductor film.

First, as in the first embodiment, SiO ₂
An amorphous Si film having a constricted portion with a width of 1 μm and a length of 5 μm is formed with a thickness of 100 nm on a glass substrate having a thickness of 200 nm.

Next, after vapor-depositing Ni to a thickness of 1 nm on the entire surface, a linear laser beam is intermittently irradiated in 0.5 μm steps while moving at the same moving speed as in the first embodiment, thereby forming an amorphous layer. The Si film is heated so as to locally melt, and the heated portion is moved from the island region on one side of the constricted portion to the island region on the other side through the constricted portion to continue the crystal growth in the lateral direction. . In this case, the entire glass substrate is
Heat to 0 ° C.

As described above, by introducing the catalytic substance into the semiconductor film, crystal nuclei are easily generated, and as a result,
Crystal growth progresses more easily, and the substrate temperature is kept below the softening point of the substrate, while keeping the substrate temperature at a low temperature, making large crystal grains or large-area crystalline semiconductor films seeded by a single crystal grain. It can be obtained while keeping it.

(Embodiment 4) Embodiment 4 is directed to a method of forming a crystalline semiconductor film according to Embodiment 2 described above.
It introduces a catalytic substance into the semiconductor film.

First, in the same manner as in Embodiment 2, SiO ₂
An amorphous Si film is formed to a thickness of 100 nm on a glass substrate having a thickness of 200 nm, and a part thereof is etched to form a shape in which two island-shaped regions are connected by a joint having a width of 10 μm. Pattern.

Next, after vapor-depositing Ni to a thickness of 1 nm on the entire surface, a linear laser beam is intermittently irradiated in 0.5 μm steps while moving at the same moving speed as in the first embodiment, thereby forming an amorphous layer. Heating is performed so that the Si film is locally melted, and the heated portion is moved from the island region on one side of the bonding portion to the island region on the other side through the bonding portion to continue the crystal growth in the lateral direction. . In this case, the entire glass substrate is heated at 400 ° C.
And heat it.

As described above, by introducing the catalytic substance into the semiconductor film, crystal nuclei are easily generated as in the third embodiment. As a result, crystal growth proceeds more easily, and the substrate temperature is reduced. Further, a large crystal grain or a large-area crystalline semiconductor film using a single crystal grain as a seed can be obtained while the substrate temperature is kept at a temperature equal to or lower than the softening point temperature of the substrate.

(Embodiment 5) Embodiment 5 is directed to a method of forming a crystalline semiconductor film according to Embodiment 3 described above.
The catalyst material is introduced into a part of the island region on the side where crystal nuclei are to be generated.

FIG. 5 is a perspective view for explaining a method for forming a crystalline semiconductor film according to the fifth embodiment.

First, as shown in FIG. 5A, in the same manner as in the first embodiment, a constricted portion having a width of 1 μm and a length of 5 μm was formed on a glass substrate 1 on which an SiO ₂ film 2 was formed to a thickness of 200 nm. An amorphous Si film 3 having a thickness of 4 is formed to a thickness of 100 nm.

Next, as shown in FIG. 5 (b), the entire surface is formed by a normal pressure CVD method using a SiH ₄ gas and an O ₂ gas to form a SiO ₂ gas.
_{2 The} film 8 is formed to a thickness of 100 nm, and a part of the amorphous Si film 3 on one side is exposed to the constricted portion 4.
SiO 2 by RIE using CF ₄ gas and CHF ₃ gas
₂ Open the film 8 by etching. At this time, the amorphous S
The distance between the exposed part 9 and the constricted part 4 of the i film 3 is set to 10 μm.

Next, Ni is vapor-deposited to a thickness of 1 nm on the entire surface, and the linear laser beam 5 is moved in the direction indicated by the arrow V in FIG. Irradiation is performed intermittently in 5 μm steps to obtain amorphous S
The i-film 3 is heated so as to be locally melted, and the heating portion is moved from the island region 31A on one side of the constricted portion 4 to the island region 31B on the opposite side through the constricted portion 4 to move in the lateral direction. Continue crystal growth. In this case, the entire glass substrate 1 is
Heat to 00 ° C.

As described above, by introducing the catalytic substance into a part of the island region of the semiconductor film on which the crystal nucleus is to be generated, the crystal nucleus is easily generated, and as a result, the crystal growth can be more easily performed. To obtain large crystal grains or large-area crystalline semiconductor films using a single crystal grain as a seed while maintaining the substrate temperature at or below the softening point temperature of the substrate while keeping the substrate temperature low. Can be.

(Embodiment 6) Embodiment 6 is directed to a method of forming a crystalline semiconductor film according to Embodiment 4 described above.
The catalyst material is introduced into a part of the island region on the side where crystal nuclei are to be generated.

FIG. 6 is a perspective view for explaining a method for forming a crystalline semiconductor film according to the sixth embodiment.

First, as shown in FIG. 6A, an amorphous Si film 3 is formed to a thickness of 100 nm on a glass substrate 1 on which an SiO ₂ film 2 is formed to a thickness of 200 nm in the same manner as in the second embodiment. Then, a pattern is formed by etching a part thereof so that the two island-shaped regions 32A and 32B have a shape connected by a joint 7 having a width of 10 μm.

Next, as shown in FIG. 6 (b), the whole surface is formed by a normal pressure CVD method using a SiH ₄ gas and an O ₂ gas to form a SiO ₂ gas.
₂ is formed so as to have a thickness of 100 nm, and the R is formed so that a part of the amorphous Si film 3 on one side of the bonding portion 7 is exposed.
SiO ₂ using CF ₄ gas and CHF ₃ gas by IE method
An opening is formed by etching the film 8. At this time, the amorphous Si
The distance between the exposed part 9 of the film 3 and the coupling part 7 is set to 10 μm.

Next, Ni is vapor-deposited to a thickness of 1 nm on the entire surface, and the linear laser beam 5 is moved in the direction indicated by the arrow V in FIG. Irradiation is performed intermittently in 5 μm steps to obtain amorphous S
Heating is performed so that the i-film 3 is locally melted, and the heating unit is moved from the island-like region 32A on one side of the joint 7 to the island-like region 32B on the opposite side through the joint 7 to move in the lateral direction. Continue crystal growth. In this case, the entire glass substrate 1 is
Heat to ° C.

As described above, by introducing a catalytic substance into a part of the island region of the semiconductor film on the side where the crystal nuclei are to be generated, crystal nuclei are easily generated as in the fifth embodiment.
As a result, the crystal growth proceeds more easily, and while the substrate temperature is kept at a low temperature, a large crystal grain or a large-area crystalline semiconductor film using a single crystal grain as a seed is softened to the substrate temperature. It can be obtained while keeping the temperature below the point temperature.

(Embodiment 7) Embodiment 7 is directed to a method of forming a crystalline semiconductor film according to Embodiment 1 described above.
A plurality of constrictions are formed in the amorphous Si film.

FIG. 7 is a top view for explaining the shape of the semiconductor film in the method for forming a crystalline semiconductor film according to the seventh embodiment.

First, in the same manner as in Embodiment 1, SiO ₂
On a glass substrate 1 on which a film 2 is formed to a thickness of 200 nm,
An amorphous Si film 3 having a plurality of narrow portions 4 having a width of 1 μm and a length of 5 μm is formed to a thickness of 100 nm.

Next, a linear laser beam is intermittently irradiated in 0.5 μm steps while moving at the same moving speed as in the first embodiment, and heating is performed so that the amorphous Si film 3 is locally melted. Then, the heating portion is moved from the island region 33A on one side of the neck portion 4 through the neck portion 4 to the island region 3 on the opposite side.
Move to 3B to 33D to continue the crystal growth in the lateral direction. At this time, the entire glass substrate 1 is heated to 400 ° C.

At this time, as in the third embodiment, Ni as a catalyst substance may be deposited on the entire surface to a thickness of 1 nm and then heated by a linear laser beam. Alternatively, similarly to the fifth embodiment, an SiO ₂ film is formed to a thickness of 100 nm so that a part of the amorphous Si film 3 is exposed, and Ni as a catalyst substance is added to the substrate.
After vapor deposition in nm, the substrate may be heated with a linear laser beam.

(Embodiment 8) Embodiment 8 is directed to a method of forming a crystalline semiconductor film according to Embodiment 2 described above.
A plurality of joints are formed on the amorphous Si film.

FIG. 8 is a top view for explaining the shape of the semiconductor film in the method for forming a crystalline semiconductor film according to the eighth embodiment.

First, in the same manner as in Embodiment 2, SiO ₂
An amorphous Si film 3 is formed with a thickness of 100 nm on a glass substrate 1 on which a film 2 is formed with a thickness of 200 nm, and a part thereof is etched to form island regions 34A and 34B and 34A and 3A.
A pattern is formed so that 4C has a shape connected by a joint 7 having a width of 10 μm.

Next, a linear laser beam is intermittently irradiated in 0.5 μm steps while moving at the same moving speed as in the first embodiment, and is heated so that the amorphous Si film 3 is locally melted. Then, the heating portion is moved from the island-like region 34A on one side of the joint portion 7 through the joint portion 7 to the island-like region 34 on the opposite side.
B, 34C to continue the crystal growth in the lateral direction. At this time, the entire glass substrate 1 is heated to 400 ° C.

At this time, similarly to the fourth embodiment, Ni as a catalyst substance may be deposited on the entire surface to a thickness of 1 nm and then heated by a linear laser beam. Alternatively, similarly to the sixth embodiment, an SiO ₂ film is formed to a thickness of 100 nm so that a part of the amorphous Si film 3 is exposed, and Ni as a catalyst substance is added to the substrate.
After vapor deposition in nm, the substrate may be heated with a linear laser beam.

(Embodiment 9) Embodiment 9 is directed to a method of forming a crystalline semiconductor film in which a catalytic substance is partially introduced according to Embodiment 5 or Embodiment 7 described above. The movement is performed up to the constricted portion, and thereafter, the crystal is grown by performing substantially uniform heating by a furnace.

First, in the same manner as in Embodiment 1, SiO ₂
A film having a width of 1 was formed on a glass substrate having a thickness of 200 nm.
An amorphous Si film having one or a plurality of constricted portions having a thickness of 5 μm and a length of 5 μm is formed to a thickness of 100 nm.

Next, as in the fifth embodiment, S
An iO ₂ film is formed to a thickness of 100 nm, and the SiO film is formed so that a part of the amorphous Si film on one side is exposed to the constricted portion.
An opening is formed by etching the O ₂ film. At this time, the amorphous S
The distance between the exposed portion and the constricted portion of the i film is 10 μm.

Next, Ni was vapor-deposited on the entire surface to a thickness of 1 nm, and a linear laser beam was intermittently irradiated in 0.5 μm steps while being moved at the same moving speed as in the first embodiment to repeatedly melt and solidify. The heating portion is moved from the island region on one side of the constricted portion to the constricted portion, and the crystal is grown in the lateral direction. At this time, the entire glass substrate is heated to 400 ° C.

Next, the whole is heated substantially uniformly to 580 ° C. in a furnace. As a result, crystal grains grown in an elongated shape by the step irradiation of the linear laser beam are used as seeds, which are selected at the constricted portion, and crystal growth in an island region on the opposite side to the constricted portion by heating in a furnace. Advances.

In the island region on the side where Ni is partially introduced, crystal grains are elongated in the lateral direction by the step irradiation of the linear laser beam, and Ni diffuses into the crystal grains selected in the constricted portion. Since it is included, random nucleation does not occur even at the time of subsequent uniform heating, and crystal growth can be advanced in the lateral direction using the crystal grains selected in the constricted portion as seeds.

When crystallizing by step-feeding a length of 10 inches with a line-shaped laser beam, considering that a step is sent at 0.5 μm using a laser oscillating at 300 Hz, it becomes 9 mm / min. It takes about 30 minutes to process one substrate. On the other hand, in the case of a heat treatment using a furnace, if a substrate having a size of about 10 inches square can process several tens of sheets at a time, the throughput is improved even if one processing takes 5 hours. can do.

(Embodiment 10) Embodiment 10 is directed to a method of forming a crystalline semiconductor film in which a catalytic substance is partially introduced according to Embodiment 6 or Embodiment 9 described above. The movement is performed up to the joint, and thereafter, the crystal is grown by performing substantially uniform heating in a furnace.

First, in the same manner as in Embodiment 2, SiO ₂
An amorphous Si film is formed to a thickness of 100 nm on a glass substrate having a thickness of 200 nm, and a part thereof is etched to form two or more island regions having one or more widths of 10 nm.
A pattern is formed so as to have a shape connected by a joint of μm.

Next, as in the sixth embodiment, S
The iO ₂ film 8 is formed to a thickness of 100 nm, and the SiO film 8 is formed so that a part of the amorphous Si film on one side of the bonding portion is exposed.
An opening is formed by etching the O ₂ film. At this time, the amorphous S
The distance between the exposed part of the i-film and the coupling part is 10 μm.

Next, Ni was vapor-deposited on the entire surface to a thickness of 1 nm, and a linear laser beam was intermittently irradiated in 0.5 μm steps while moving at the same moving speed as in the first embodiment, thereby repeating melting and solidification. The heating part is moved to the joint part to grow the crystal in the lateral direction. At this time, the entire glass substrate is heated to 400 ° C.

Next, the whole is heated substantially uniformly to 580 ° C. in a furnace. As a result, crystal grains grown in an elongated shape by the step irradiation of the line-shaped laser beam are used as seeds, and the crystal grown in the island-like region on the opposite side to the joint by heating in a furnace is used as a seed. Advances.

As in the ninth embodiment, since Ni is diffused and contained in the crystal grains selected at the bonding portion, random nucleation does not occur even in the subsequent uniform heating, and the crystal selected at the bonding portion does not occur. The crystal growth can be advanced in the lateral direction by using the grains as seeds.

When crystallizing by step-feeding a length of 10 inches with a line-shaped laser beam, considering that the laser is oscillated at 300 Hz and the step is sent at 0.5 μm, the speed becomes 9 mm / min. It takes about 30 minutes to process one substrate. On the other hand, in the case of a heat treatment using a furnace, if a substrate having a size of about 10 inches square can process several tens of sheets at a time, the throughput is improved even if one processing takes 5 hours. can do.

(Embodiment 11) Embodiment 11 is directed to a method of forming a crystalline semiconductor film in which a catalytic substance is partially introduced according to Embodiment 5 or 7 described above. After performing substantially uniform heating and solid phase growth in the lateral direction, after passing through the constricted part, it moves through the local heating part by the linear laser beam, and crystal grows using the crystal grains that passed through the constricted part as seeds. is there.

First, in the same manner as in Embodiment 1, SiO ₂
A film having a width of 1 was formed on a glass substrate having a thickness of 200 nm.
An amorphous Si film having one or a plurality of constricted portions having a thickness of 5 μm and a length of 5 μm is formed to a thickness of 100 nm.

Next, as in the fifth embodiment, S
An iO ₂ film is formed to a thickness of 100 nm, and the SiO film is formed so that a part of the amorphous Si film on one side is exposed to the constricted portion.
An opening is formed by etching the O ₂ film. At this time, the amorphous S
The distance between the exposed portion and the constricted portion of the i film is 10 μm.

Next, Ni is vapor-deposited on the entire surface to a thickness of 1 nm, and the whole is heated substantially uniformly at 580 ° C. in a furnace so that the amorphous Si film is exposed at the exposed portion of the amorphous Si film.
Solid phase growth is performed using crystal nuclei generated by the reaction between the film and Ni as seeds. When the crystal growth passes through the constriction, the heating by the furnace is stopped.

When a pulsed linear laser beam is used, one crystal grain is selected at the constricted portion, and unless a crystal is grown using the crystal grain as a seed, a crystal in which elongated crystal grains having a width of about 1 μm are arranged. Only grows in the direction of the laser beam. In contrast, when solid phase growth is performed by introducing a catalytic substance, crystal grains having crystal orientations that facilitate crystal growth are preferentially larger, and as a result, crystals composed of relatively large crystal grains are obtained. And the selection effect in the constricted part is enhanced.

Next, the linear laser beam is intermittently irradiated in 0.5 μm steps while being moved at the same moving speed as in the first embodiment to repeat melting and solidification. The crystal is moved in the opposite direction with respect to the constricted portion, and the crystal grains selected in the constricted portion are grown as seeds in the lateral direction. In this case, the entire glass substrate is
Heat to 00 ° C.

(Embodiment 12) The twelfth embodiment is directed to a method of forming a crystalline semiconductor film in which a catalytic material is partially introduced according to the sixth or eighth embodiment described above. After performing substantially uniform heating and solid phase growth in the lateral direction, after passing through the joint, the local heating part by the linear laser beam is moved, and the crystal grains that have passed through the joint are grown as seeds. is there.

First, in the same manner as in Embodiment 2, SiO ₂
An amorphous Si film is formed to a thickness of 100 nm on a glass substrate having a thickness of 200 nm, and a part thereof is etched to form two or more island regions having one or more widths of 10 nm.
A pattern is formed so as to have a shape connected by a joint of μm.

Next, as in the sixth embodiment, S
An iO ₂ film is formed to a thickness of 100 nm, and the SiO ₂ film is formed so as to expose a part of the amorphous Si film on one side with respect to the joint.
₂ Open the film by etching. At this time, the amorphous Si
The distance between the exposed portion and the constricted portion of the film is 10 μm.

Next, Ni is vapor-deposited on the entire surface to a thickness of 1 nm, and the whole is heated substantially uniformly at 580 ° C. in a furnace so that the amorphous Si film is exposed at the exposed portion of the amorphous Si film.
Solid phase growth is performed using crystal nuclei generated by the reaction between the film and Ni as seeds. When the crystal growth has passed through the joint, the heating by the furnace is stopped.

In the case where a pulsed linear laser beam is used, one crystal grain is selected at a coupling portion, and unless a crystal is grown using the crystal grain as a seed, a crystal in which elongated crystal grains having a width of about 1 μm are arranged. Only grows in the direction of the laser beam. In contrast, when solid phase growth is performed by introducing a catalytic substance, crystal grains having crystal orientations that facilitate crystal growth are preferentially larger, and as a result, crystals composed of relatively large crystal grains are obtained. Therefore, the effect of selection at the joint is enhanced.

Next, the linear laser beam is intermittently irradiated in 0.5 μm steps while being moved at the same moving speed as in the first embodiment, and is repeatedly melted and solidified. The crystal is moved in the opposite direction with respect to the joint portion, and the crystal grains selected in the narrow portion are grown as seeds in the lateral direction. In this case, the entire glass substrate is
Heat to 0 ° C.

(Thirteenth Embodiment) The thirteenth embodiment is directed to a method of forming a crystalline semiconductor film according to the first, third, fifth, seventh, ninth or eleventh embodiments described above. In the island-shaped region of the semiconductor film opposite to the side where the nucleus is to be generated, two sides extending from the constricted portion are inclined from a direction perpendicular to the moving direction of the linear energy beam.

FIG. 9A is a top view for explaining the shape of the semiconductor film in the method for forming a crystalline semiconductor film according to the thirteenth embodiment, and FIG.
FIG. 4 is a diagram schematically showing a state of crystal grain growth when crystal growth is performed in a shape different from that of FIG.

First, as shown in FIG. 9A, a constricted portion 4 having a width of 1 μm and a length of 5 μm was formed on a glass substrate having a 200 nm thick SiO ₂ film in the same manner as in the first embodiment. The amorphous Si film 3 having a thickness of 100 nm is formed. At this time, the constricted portion 4 is formed in the island-shaped region 35B of the semiconductor film opposite to the side 35A where the crystal nucleus is to be generated.
Are inclined from a direction perpendicular to the moving direction of the linear energy beam.

Next, if necessary, Ni as a catalyst substance is deposited to a thickness of 1 nm on the entire surface, or a SiO ₂ film is formed to a thickness of 100 nm so that a part of the amorphous Si film 3 is exposed. Then, Ni as a catalyst substance is deposited to a thickness of 1 nm.

As a heating method, when the catalytic substance is not introduced, or when the catalytic substance is introduced over the entire surface, the linear laser beam is intermittently irradiated in 0.5 μm steps while moving at the same moving speed as in the first embodiment. And the solidification is repeated, and the heating part is confined to the constricted part 4 on one side of the island region
The crystal is moved from 5A through the constricted portion 4 to the island region 35B on the opposite side, and the crystal grains selected in the constricted portion 4 are grown as seeds in the lateral direction. At this time, the entire glass substrate is heated to 400 ° C.

On the other hand, when the catalytic substance is introduced, all the crystal growth may be performed by heating with a linear laser beam. However, the crystal growth up to the constricted portion 4 is performed by the linear laser beam, and thereafter, the uniform growth is performed. Heating may be performed, or crystal growth up to the constricted portion 4 may be performed by uniform heating, and then heating by a linear laser beam may be performed.

FIG. 9B shows that the island-like region 36 B
In the case where two sides extending from the constricted portion 4 are perpendicular to the moving direction of the linear energy beam, the state of generation of crystal nuclei and growth of crystal grains are schematically shown. Island area 3
When the line-shaped laser beam is first irradiated on 6B, the crystal growth rate in the lateral direction is limited by using the crystal grains of the island-shaped region 36A that has grown to the constricted portion 4 as a seed.
For this reason, when the width of the island region 36B is wide, the crystal grains cannot grow as seeds, and a random crystal nucleus generation 10 occurs in a region away from the constriction 4. Then, crystal grains 11 grown using the randomly generated crystal nuclei 10 as seeds are generated, and it becomes impossible to grow the entire island-like region 36B using the crystal grains that have passed through the constricted portion 4 as seeds.

On the other hand, as shown in FIG.
In the case where the two sides extending from the constricted portion 4 are inclined from a direction perpendicular to the moving direction of the linear energy beam in the island region 35B, random nucleation is suppressed, and the entire wide island region 35B is reduced. The crystal can be grown using the crystal grains that have passed through the constricted portion 4 as seeds.

(Embodiment 14) Embodiment 14 is directed to a method of forming a crystalline semiconductor film according to Embodiment 2, Embodiment 4, Embodiment 6, Embodiment 8, Embodiment 10 or Embodiment 12 described above. In the island region of the semiconductor film opposite to the side where the nucleus is to be generated, of the two sides extending from the coupling portion, the side that is not substantially parallel to the moving direction of the linear energy beam is defined as the moving direction of the linear energy beam. Is inclined from a direction perpendicular to the direction.

FIG. 10A is a top view for explaining the shape of the semiconductor film in the method for forming a crystalline semiconductor film of Embodiment 14, and FIG. 10B is different from Embodiment 14 for comparison. It is a figure which shows typically the mode of growth of a crystal grain when crystal growth is performed in a different shape.

First, as shown in FIG. 10A, an amorphous Si film 3 having a thickness of 100 nm was formed on a glass substrate having a SiO ₂ film having a thickness of 200 nm in the same manner as in the second embodiment. Then, a part thereof is etched to form a pattern such that the two island-shaped regions are connected by a joint 7 having a width of 10 μm. At this time, in the island-like region 37B of the semiconductor film opposite to the side 37A where the crystal nucleus is to be generated, of the two sides extending from the coupling portion 7, the side that is not substantially parallel to the moving direction of the linear energy beam is It is inclined from a direction perpendicular to the moving direction of the linear energy beam.

Next, if necessary, Ni as a catalyst substance is deposited to a thickness of 1 nm on the entire surface, or a SiO ₂ film is formed to a thickness of 100 nm so that a part of the amorphous Si film 3 is exposed. Then, Ni as a catalyst substance is deposited to a thickness of 1 nm.

As a heating method, when the catalytic substance is not introduced or is introduced over the entire surface, the linear laser beam is intermittently irradiated in 0.5 μm steps while moving at the same moving speed as in the first embodiment. Then, the solidification is repeated, and the heating part is connected to the joint part 7 on one side of the island-like region 37.
A is moved from A to the island-like region 37B on the opposite side through the joint 7 and the crystal grains selected at the joint 7 are grown as seeds in the lateral direction. In this case, the entire glass substrate is
Heat to 0 ° C.

On the other hand, when a catalytic substance is introduced, all the crystal growth may be performed by heating with a linear laser beam. Heating may be performed, or crystal growth up to the bonding portion 7 may be performed by uniform heating, and then heating by a linear laser beam may be performed.

In FIG. 10B, in the island-like region 38B, of the two sides extending from the coupling portion 7, the side that is not substantially parallel to the moving direction of the linear energy beam corresponds to the moving direction of the linear energy beam. The state of generation of crystal nuclei and growth of crystal grains in the case of vertical direction is schematically shown. When the line-shaped laser beam is first irradiated on the island-shaped region 38B, the crystal growth rate in the lateral direction is limited by using the crystal grains of the island-shaped region 38A grown to the joint portion 7 as seeds. For this reason, when the width of the island region 38B is wide, the crystal grains cannot grow completely as seeds, and random crystal nucleus generation 10 occurs in a region away from the joint 7.
Then, crystal grains 11 grown by using the randomly generated crystal nuclei 10 as seeds are generated, and it becomes impossible to grow the entire island-like region 38B using the crystal grains that have passed through the coupling portion 7 as seeds.

On the other hand, as shown in FIG. 10A, in the island-like region 37B, of the two sides extending from the coupling portion 7, the side that is not substantially parallel to the moving direction of the linear energy beam is defined as a line. When tilted from the direction perpendicular to the moving direction of the energy beam, random nucleation is suppressed, and the entire wide island-like region 37B is grown using the crystal grains that have passed through the coupling portion 7 as seeds. Can be.

(Embodiment 15) In this embodiment 15,
A method for manufacturing a semiconductor device such as a liquid crystal driver including a thin film transistor, a semiconductor memory, a semiconductor logic circuit, or the like using a crystalline Si film manufactured by the method for forming a crystalline semiconductor film according to any of the above-described embodiments will be described. I do.

FIG. 11 is a cross-sectional view for illustrating a manufacturing process of the semiconductor device of the fifteenth embodiment.

First, on the glass substrate 1 on which the SiO ₂ film was formed to a thickness of 200 nm, the first to first embodiments were used.
The crystalline Si film 12 produced as in 5 is patterned by RIE using CF ₄ gas and O ₂ gas.
Next, in the same manner as a normal thin film transistor manufacturing process,
A gate SiO ₂ film 13 is formed by a plasma CVD method using a TEOS (tetraethoxysilane) gas and an O ₃ gas. WSi ₂ / polycrystalline Si is formed thereon by sputtering, and patterning is performed by RIE using CF ₄ gas and CHF ₃ gas to form a gate electrode 14. Subsequently, P (phosphorus) or B (boron) is implanted into the source / drain regions by an ion doping method, and S is formed by a plasma CVD method using TEOS gas and O ₃ gas.
After the iO ₂ film 15 is formed, the SiO ₂ film 15 is etched by RIE using CF ₄ gas and CHF ₃ gas to form a contact hole. An Al wiring 16 is formed thereon by sputtering, and SiN is formed by plasma CVD using SiH ₄ gas, NH ₃ gas and N ₂ gas.
A protective film 17 is formed. Then, CF _{4 was} obtained by the RIE method.
By etching a part of the SiN protective film 17 using a gas and CHF ₃ gas to open a window, a semiconductor device such as a liquid crystal driver, a semiconductor memory, a semiconductor logic circuit or the like having a semiconductor element such as a thin film transistor, a resistor, and a capacitor. Is prepared.

In the semiconductor device obtained in this manner, the carrier mobility of the transistor can be increased, the threshold voltage can be reduced, and these variations can be reduced, and the characteristics can be improved. Was.

(Embodiment 16) In this embodiment 16,
A method for manufacturing a display device including the semiconductor device of the present invention will be described.

In the sixteenth embodiment, a method of manufacturing a liquid crystal display device using a semiconductor device manufactured in the same manner as in the fifteenth embodiment will be described.

FIG. 12 is a cross-sectional view for explaining a manufacturing process of the display device of the sixteenth embodiment.

First, as shown in FIG. 12A, an SiO ₂ film 18 is formed on a semiconductor device fabricated up to the Al wiring 16 in the fifteenth embodiment by using a TEOS gas and an O ₃ gas by a plasma CVD method. RIE method
Etching is performed using F ₄ gas and CHF ₃ gas to form through holes. Next, the I
A TO film is formed, and is patterned using HCl and FeCl ₃ to form a pixel electrode 19. Then, plasma C
The SiN protective film 20 is formed by VD using SiH ₄ gas, NH ₃ gas, and N ₂ gas. A polyimide film 21 is formed thereon as an alignment film by an offset printing method, and rubbing is performed.

On the other hand, as shown in FIG. 12B, a film having a red, green, and blue photosensitive resin film is thermocompression-bonded to another glass substrate 22 and transferred and patterned by a photolithography process. . Further, a black matrix portion is similarly formed in a space between red, green, and blue, and the color filter 23 is manufactured. An ITO film 24 is formed thereon by a sputtering method, and a polyimide film 25 is formed thereon as an alignment film by an offset printing method.
A rubbing process is performed.

The glass substrate 22 on which the color filter 23 is formed and the glass substrate 1 on which a semiconductor device such as a thin film transistor is formed are bonded with a sealing resin. At this time, in order to keep the space between the two glass substrates constant, spherical silica is sprayed. Thereafter, a liquid crystal is injected between the two substrates, a polarizing plate is attached on both sides, and a driver IC and the like are mounted on the periphery to produce a liquid crystal display device.

In the display device thus obtained, the carrier mobility of the semiconductor device is high, the threshold voltage is low, and these variations are small. Therefore, the pixel transistor can be made small, and the high definition and the high aperture can be obtained. Rate.

In the above embodiment, the crystalline semiconductor film is formed on a glass substrate on which an SiO ₂ film is formed. However, a crystalline semiconductor film can be formed directly on a glass substrate, or a quartz substrate, a ceramic substrate, or a ceramic substrate. It may be formed on a substrate or the like. Alternatively, a single-layer or stacked non-single-crystal insulating film such as a SiO ₂ film, a SiN film, or a SiON film may be used over a glass substrate, a quartz substrate, a ceramic substrate, or the like.

As the semiconductor film, an Si film has been described as an example.
A semiconductor film such as a SiGe film, a GaAs film, or an InP film may be used.

In the above embodiment, a linear laser beam is used to partially apply energy. However, linearly shaped light, linearly shaped charged particles, and point light are scanned at high speed in a line. Energy obtained by scanning a point-like charged particle beam at a high speed in a line may be used. Further, in order to scan and irradiate the energy beam intermittently, the substrate on which the semiconductor film is formed may be moved and the energy beam may be intermittently irradiated.

Ni is used to facilitate crystallization of the semiconductor film.
Was deposited to a thickness of 1 nm, but 0.1 nm to 100 nm
It should just be considerable. In addition, Ni may be deposited by an evaporation method such as a sputtering method or a vacuum evaporation method, but may be introduced by applying a solution containing Ni, by ion implantation, a CVD method, or the like. As a substance that facilitates crystallization of the semiconductor film, at least one of Fe, Co, Ni, Cu, Ge, Pd, Au, and a compound containing these metals may be introduced.

Further, in the above embodiment, an amorphous Si film is used, but a crystalline semiconductor film can be formed in the same manner when a polycrystalline Si film is used.

[0152]

As described in detail above, according to the present invention,
At the time of crystal growth by applying energy to an amorphous or polycrystalline semiconductor film, it is irradiated intermittently while scanning an energy beam, and among crystal grains grown from a large number of crystal nuclei generated irregularly. By selecting one at the constricted portion or the joint portion, a large crystal grain or a large-area crystalline semiconductor film using a single crystal grain as a seed can be formed while maintaining the substrate temperature at or below the softening point. . By using a semiconductor film with improved crystallinity, the performance of a semiconductor device or a display device can be improved.

[Brief description of the drawings]

FIGS. 1A and 1B are perspective views for explaining a method for forming a semiconductor film according to a first embodiment.

FIG. 2 is a schematic view showing a state of crystal grain growth in the method of forming a semiconductor film according to the first embodiment.

FIGS. 3A and 3B are perspective views for describing a method of forming a semiconductor film according to a second embodiment.

FIG. 4 is a schematic view showing a state of crystal grain growth in a method for forming a semiconductor film according to a second embodiment.

FIGS. 5A to 5C are perspective views for describing a method for forming a semiconductor film according to a fifth embodiment.

FIGS. 6A to 6C are perspective views for describing a method for forming a semiconductor film according to a sixth embodiment.

FIG. 7 is a top view illustrating a shape of a semiconductor film in a method for forming a crystalline semiconductor film according to a seventh embodiment.

FIG. 8 is a top view illustrating a shape of a semiconductor film in a method for forming a crystalline semiconductor film according to an eighth embodiment.

9A is a top view for explaining a shape of a semiconductor film in a method for forming a crystalline semiconductor film according to Embodiment 13, and FIG. 9B is a diagram having a shape different from that of Embodiment 13 for comparison. It is a figure which shows typically the mode of growth of the crystal grain at the time of performing crystal growth.

FIG. 10A is a top view for explaining a shape of a semiconductor film in a method for forming a crystalline semiconductor film of Embodiment 14, and FIG. 10B is a diagram having a shape different from that of Embodiment 14 for comparison. It is a figure which shows typically the mode of growth of the crystal grain at the time of performing crystal growth.

FIG. 11 is a cross-sectional view for describing a manufacturing step of the semiconductor device of the fifteenth embodiment.

FIGS. 12A and 12B are cross-sectional views for explaining a manufacturing process of the display device of the sixteenth embodiment.

FIG. 13A is a diagram for explaining the definition of the width (W) and length (L) of the constricted portion and the distance (H) between the catalytic substance introduction region and the constricted portion in the present invention;
(B) is a diagram for explaining the definition of the width (D) of the joint and the distance (K) between the catalytic substance introduction region and the joint in the present invention.

FIG. 14 is an apparatus configuration diagram for describing a method of forming a semiconductor film of Conventional Example 1.

FIG. 15 is a perspective view for describing a method of forming a semiconductor film of Conventional Example 2.

FIG. 16 is a plan view for describing a method for forming a semiconductor film of Conventional Example 3.

FIGS. 17A and 17B are cross-sectional views illustrating a method for forming a semiconductor film of Conventional Example 4. FIGS.

[Explanation of symbols]

1,22 glass substrate 2,8,15,18,42 SiO ₂ film 3,43 amorphous Si film 31A, 31B, 32A, 32B, 33A, 33B, 3
3C, 33D, 34A, 34B, 34C, 35A, 35
B, 36A, 36B, 37A, 37B, 38A, 38B
Island-shaped region 4, 36 Narrow portion 5 Line-shaped laser beam 6 Crystal grain 7 Bonding portion 9 Exposed portion of amorphous Si film 10 Randomly generated crystal nucleus 11 Crystal grain grown from randomly generated crystal nucleus 12 Crystallinity Si film 13 Gate SiO ₂ film 14 Gate electrode 16 Al wiring 17, 20 SiN protective film 19 Pixel electrode 21, 25 Polyimide film 23 Color filter 24 ITO film 26 Excimer laser light source 27 Mask 28 Stage 29 Sample 30 Dimmer 31 Mirror Reference Signs List 32 Lens 33, 41 Substrate 34, 37 Polycrystalline Si film 35 Filter part of crystal orientation 38 Removal part of Polycrystalline Si film 39 Thin part 40 Crystal growth direction 44 Film of catalytic material V Moving direction of linear laser beam W Narrow part Width L Length of constricted part H Distance between catalytic substance introduction region and constricted part D Width of the joint K Distance between the catalytic substance introduction region and the joint

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H092 JA24 KA05 MA07 MA18 MA30 NA24 5F052 AA02 AA11 BA07 DA02 DB02 FA02 FA03 FA06 FA19 JA01 5F110 BB02 BB03 BB05 CC02 DD02 DD03 DD04 DD13 DD14 DD15 EE05 EE09 EE14 FF02GG04 GG02 GG04 GG02 GG04 HJ18 HL03 NN01 NN23 NN24 NN35 PP01 PP05 PP06 PP08 PP23 PP34 QQ04

Claims (21)

[Claims] 1. A method for forming a semiconductor film over a non-single-crystal insulating film or a non-single-crystal insulating substrate formed over a substrate and applying energy to the semiconductor film to crystallize the semiconductor film. Removing a portion to form one or more constricted portions and an island-shaped region of the semiconductor film connected to both sides of the constricted portion and wider than the constricted portion; On the other hand, from the island region of the semiconductor film on one side,
Up to the island region of the semiconductor film opposite to the constricted portion,
By repeating the melting and solidification of the semiconductor film by intermittently irradiating the semiconductor film while scanning with a line-shaped energy beam, the growth from the crystal nuclei generated in the island region of the semiconductor film on one side with respect to the constricted portion. Using the crystal grains that have passed through the constricted portion as seeds, crystal growing an island-shaped region of the semiconductor film opposite to the constricted portion. 2. A method for forming a semiconductor film on a non-single-crystal insulating film formed on a substrate or a non-single-crystal insulating substrate and crystallizing the semiconductor film by applying energy to the semiconductor film. Forming a pattern in a shape in which at least one island-shaped region is connected by a bonding portion; and forming an island of the semiconductor film opposite to the bonding portion from the island-shaped region of the semiconductor film on one side of the bonding portion. The semiconductor film is melted and solidified by intermittently irradiating the semiconductor film while scanning the line-shaped energy beam up to the joint region. Of crystal grown from a crystal nucleus, using as a seed a crystal grain that has passed through the bonding portion, and crystal-growing an island-shaped region of the semiconductor film on the opposite side to the bonding portion. Method. 3. The method for forming a crystalline semiconductor film according to claim 1, wherein a material that facilitates crystallization is introduced into the entire surface of the semiconductor film. 4. The method for forming a crystalline semiconductor film according to claim 1, wherein a material that facilitates crystallization is introduced into an island-shaped region of the semiconductor film on which a crystal nucleus is to be generated. . 5. The method for forming a crystalline semiconductor film according to claim 4, wherein the substance that facilitates crystallization is introduced at a position away from a constricted portion or a bonded portion of the semiconductor film. 6. A method for forming a semiconductor film on a non-single-crystal insulating film formed on a substrate or a non-single-crystal insulating substrate and crystallizing the semiconductor film by applying energy to the semiconductor film. Removing the portion to form one or more constricted portions and an island-shaped region of the semiconductor film connected to both sides of the constricted portion and wider than the constricted portion; A step of introducing a substance that facilitates crystallization at a position away from the constriction in the island-shaped region on the side where crystal nuclei are to be generated; and Repeating the step of irradiating the semiconductor film intermittently while scanning a linear energy beam in the direction of the constricted portion, and melting and solidifying the semiconductor film until lateral crystal growth passes through the constricted portion; Heat the whole And, by using the crystal grains that have passed through the constricted portion as seeds, laterally solid-phase growing the island regions of the semiconductor film on the side where the substance that facilitates the crystallization is not introduced. A method for forming a semiconductor film. 7. A method for forming a semiconductor film on a non-single-crystal insulating film formed on a substrate or a non-single-crystal insulating substrate and crystallizing the semiconductor film by applying energy to the semiconductor film. Forming a pattern in a shape in which at least one island region is connected by a bonding portion; and crystallizing the semiconductor film at a position away from the bonding portion in the island region on the side where a crystal nucleus is desired to be generated. A step of introducing a substance for facilitating the irradiation, and intermittently irradiating while scanning a linear energy beam from the region where the substance for facilitating the crystallization is introduced toward the joint, and Repeating the step of fusing and solidifying the semiconductor film until the crystal growth of the semiconductor film passes through the bonding portion; and heating the whole to facilitate the crystallization by using the crystal grains that have passed through the bonding portion as seeds. Guide the substance Method of forming a crystalline semiconductor film including an island-like region on the side of the semiconductor film that is not a step of solid-phase crystallization in the lateral direction. 8. A method for forming a 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 semiconductor film to crystallize the semiconductor film. Removing the portion to form one or more constricted portions and an island-shaped region of the semiconductor film connected to both sides of the constricted portion and wider than the constricted portion; A step of introducing a substance that facilitates crystallization at a position away from the constriction in the island region on the side where crystal nuclei are to be generated; and heating the whole to facilitate the crystallization. Solid-phase growing the semiconductor film from the region into which the substance has been introduced until the solid phase growth in the lateral direction passes through the constriction; and moving away from the constriction from the region where the solid-phase growth in the lateral direction has been completed. Towards, line-shaped energy The semiconductor film on the side where the substance that facilitates the crystallization is not introduced by using the crystal grains that have passed through the constricted portion as seeds by intermittently irradiating the semiconductor film while scanning with the energy beam to melt and solidify the semiconductor film. Forming a crystalline semiconductor film laterally in the island-shaped region. 9. A method for forming a semiconductor film on a non-single-crystal insulating film formed on a substrate or a non-single-crystal insulating substrate and crystallizing the semiconductor film by applying energy to the semiconductor film. Forming a pattern in a shape in which at least one island region is connected by a bonding portion; and crystallizing the semiconductor film at a position away from the bonding portion in the island region on the side where a crystal nucleus is desired to be generated. Heating the whole, so that the semiconductor film is solid-phased from the region where the material for facilitating crystallization is introduced until the solid-phase growth in the lateral direction passes through the bonding portion. Growing the semiconductor film by intermittently irradiating the semiconductor film while scanning a linear energy beam from the region where the lateral solid phase growth has been completed, in a direction away from the coupling portion. By Using the crystal grains that have passed through the bonding portion as seeds to laterally grow an island-shaped region of the semiconductor film on the side where the substance that facilitates crystallization is not introduced. Forming method. 10. An island region of a semiconductor film opposite to a region where a crystal nucleus is to be generated with respect to the constricted portion,
9. The crystalline semiconductor film according to claim 1, wherein two sides extending from the constricted portion are inclined from a direction perpendicular to a moving direction of the linear energy beam. Formation method. 11. An island-shaped region of the semiconductor film opposite to a region where a crystal nucleus is to be generated with respect to the coupling portion. The method for forming a crystalline semiconductor film according to any one of claims 2 to 5, wherein the non-parallel side is inclined from a direction perpendicular to a moving direction of the linear energy beam. . 12. The method for forming a crystalline semiconductor film according to claim 1, wherein the semiconductor film is formed using a silicon material. 13. A material for facilitating crystallization, wherein at least one of Fe, Co, Ni, Cu, Ge, Pd, Au and a compound containing these metals is introduced. A method for forming a crystalline semiconductor film according to claim 12. 14. The semiconductor device according to claim 5, wherein a distance between a region into which a substance for facilitating crystallization is introduced and the constricted portion is formed to be 5 μm or more.
14. The method for forming a crystalline semiconductor film according to claim 12. 15. The width of the constricted portion is 0.1 μm or more and 1
7. The semiconductor device according to claim 1, which is formed to a thickness of 0 μm or less.
15. The method for forming a crystalline semiconductor film according to any one of claims 8, 10, and 12 to 14. 16. The method according to claim 1, wherein said constricted portion is formed to have a length of 0.5 μm or more and 100 μm or less.
The method for forming a crystalline semiconductor film according to claim 2. 17. The semiconductor device according to claim 5, wherein a distance between a region into which a substance for facilitating crystallization is introduced into the semiconductor film and the coupling portion is set to 10 μm or more.
The method for forming a crystalline semiconductor film according to claim 1. 18. The connecting part according to claim 2, wherein the width of the connecting part is formed to be not more than 20 μm. Of forming a crystalline semiconductor film. 19. The method for forming a crystalline semiconductor film according to claim 1, wherein the step of intermittently irradiating the linear energy beam has a range of 0.1 μm or more and 10 μm or less. 20. A semiconductor device using a semiconductor film obtained by the method for forming a crystalline semiconductor film according to claim 1. 21. A display device comprising the semiconductor device according to claim 20.