JP2002083768A - Method of manufacturing single crystal film, and single crystal film substrate, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single crystal film, which is suitable for making of a device of high performance and stable properties, demarcating with respect to conventional polycrystalline film, and also whose manufacturing process is sufficient with short time, and to provide its manufacturing method. SOLUTION: A single crystal film 34 of a structure, in which the crystallization is advanced is made by making setting conditions of heat treatment, such as laser application, as those where polycrystalline grains are drawn up substantially regularly on an insulating substrate 31 when monocrystalizing a non-single crystal film, and heat-treating it, while keeping the surface condition of the polycrystalline grains being substantially aligned as it is.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin film transistor (TFT) used for a liquid crystal display, a single crystal thin film applied to a memory and other electronic devices, a single crystal thin film substrate, and a semiconductor device. In particular, the present invention relates to a method for forming a single crystal thin film on an insulating substrate such as a glass substrate, a single crystal thin film substrate having the single crystal thin film, and a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, as a semiconductor thin film such as silicon formed on an insulating substrate, SOI (Silicon On Insulato) is used.
r) A structure, an amorphous silicon thin film, a polycrystalline silicon thin film, etc. on a glass substrate practically used for a liquid crystal display and the like are known.

[0003] An SOI structure is often formed through various steps such as bonding a single crystal silicon wafer and then polishing the same. Since a single crystal silicon wafer is basically used, an almost complete single crystal silicon wafer is used. Can be used as a channel portion of an active element such as a thin film transistor (TFT). For this reason, the manufactured element can have high mobility and has good characteristics as an electronic device. However, since the manufacturing method includes a step of bonding and polishing a single crystal silicon wafer, the number of steps increases, the production time increases, and the manufacturing cost tends to increase.

On the other hand, silane gas contains hydrogen or SiF.
₄ is a method of crystallizing a thin film to be deposited by using reduced pressure CVD or plasma CVD, or a method of forming an amorphous silicon thin film on a substrate using amorphous silicon as a precursor and then crystallizing the amorphous silicon thin film Is known. In the former method of crystallizing a thin film to be deposited, crystallization is promoted simultaneously with formation of a silicon thin film.
Therefore, it is necessary to use an expensive quartz substrate or the like that can withstand high temperatures. When an inexpensive glass substrate is used, problems such as deformation and distortion occur in the substrate due to heat resistance. As the latter method of once forming an amorphous silicon thin film and crystallizing the same, a solid phase growth method in which annealing is performed for a long time (for example, 20 hours) is also known. And the problem that the manufacturing cost increases. Therefore, as a method actively researched and developed, there is known a method of irradiating an excimer laser and proceeding crystallization with the beam.

In the method of crystallization by irradiating an excimer laser, an amorphous silicon thin film or a polycrystalline silicon thin film is formed on a substrate, and the thin film is heated by excimer laser irradiation to perform crystallization. For example, Xe
In the case of Cl excimer laser, the emission wavelength is 308 nm and its absorption coefficient is about 10 ⁶ cm ^-1 , so that it is absorbed in the area of about 10 nm from the surface of the amorphous silicon thin film, and the temperature of the substrate almost rises. Instead, the vicinity of the surface of the amorphous silicon thin film is crystallized.

[0006]

However, in such a technique of recrystallizing a melted material by irradiating an excimer laser, it is possible to grow polycrystalline silicon grains of an amorphous silicon thin film or a polycrystalline silicon thin film. However, it is extremely difficult to stably control the crystal quality of the thin film formed by the number of shots of the laser beam, and the threshold voltage of the manufactured thin film transistor tends to vary.

Accordingly, the present invention provides a method for producing a single-crystal thin film which is distinct from conventional polycrystalline thin films, is suitable for producing a device having high performance and stable characteristics, and has a sufficient production process in a short time. The purpose is to provide. Another object of the present invention is to provide a semiconductor device and a single crystal thin film substrate utilizing such a single crystal thin film of high crystal quality.

[0008]

Means for Solving the Problems In order to solve the above-mentioned technical problems, the present inventors have intensively studied and as a result, one of the reasons why the crystal grain size of the polycrystalline thin film is not sufficiently large is as follows. The present inventors have found a point in the method of laser irradiation itself, and have created an epoch-making semiconductor thin film that is distinct from the conventional polycrystalline thin film and a manufacturing method thereof. That is, the present inventors, when crystallizing a non-single-crystal thin film by laser irradiation, irradiate the laser irradiation conditions so that substantially regular polycrystalline grains are aligned and formed on the thin film surface. The present inventors have devised that a semiconductor crystallized thin film having a structure with advanced crystallization can be formed by performing a heat treatment in a surface state having a portion.

That is, in the method for producing a single-crystal thin film of the present invention, a step of forming a non-single-crystal thin film on an insulating substrate and a step of subjecting the non-single-crystal thin film to a first heat treatment so that polycrystalline grains are substantially regularly formed. A step of forming an aligned polycrystalline thin film; and a step of performing a second heat treatment on the polycrystalline thin film to form a single crystal thin film in which the polycrystalline grains are combined.

[0010] In order to grow a single crystal region in which polycrystal grains are bonded together, it is preferable that adjacent polycrystal grains are easily bonded to each other. By forming such a state, a common crystal orientation of polycrystalline grains during recrystallization after heat treatment, for example, a common interface of an orientation plane such as a (100) plane can be obtained. Smooth bonding between polycrystalline grains occurs. Therefore, at the time of heat treatment, bonding between polycrystalline grains is easily promoted, and single crystallization is promoted.

Another method for producing a single-crystal thin film according to the present invention comprises the steps of: forming a non-single-crystal thin film on an insulating substrate; And converting to a thin film. By irradiating the non-single-crystal thin film with laser light, the non-single-crystal thin film grows into a polycrystalline semiconductor film or a single-crystal semiconductor film, and the non-single-crystal thin film can be converted into a single-crystal thin film. .

Still another method of manufacturing a single-crystal thin film according to the present invention comprises the steps of forming a non-single-crystal thin film on an insulating substrate and performing a first heat treatment on the non-single-crystal thin film to introduce a common boundary condition. While forming a polycrystalline thin film, and performing a second heat treatment on the polycrystalline thin film to form a single crystal thin film in which the polycrystalline grains are crystallized.

By performing the first heat treatment to introduce a common boundary condition to the polycrystal grains, the crystal orientation of the polycrystal grains common during recrystallization after the heat treatment, such as the (100) plane, is obtained. A common interface such as an orientation plane is obtained, and smooth bonding between polycrystalline grains occurs while utilizing the order. Therefore, at the time of heat treatment, bonding between polycrystalline grains is easily promoted, and single crystallization is promoted.

The single-crystal thin-film substrate of the present invention is characterized in that the insulating substrate has a single-crystal thin film that is single-crystallized by laser irradiation. According to an example of the single-crystal thin-film substrate of the present invention, the crystallization of the single-crystal thin film is performed by subjecting the polycrystalline thin film to substantially regular arrangement of the polycrystalline grains in the thin film, and then performing a heat treatment.

The present invention also includes a semiconductor device formed using the single crystal thin film substrate.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a single crystal thin film of the present invention, a single crystal thin film substrate and a semiconductor device using the substrate as a part of the structure will be described with reference to the drawings.

First, a step of forming a non-single-crystal thin film on an insulating substrate, a step of performing a first heat treatment on the non-single-crystal thin film to form a polycrystalline thin film in which polycrystalline grains are arranged in a substantially regular manner, Subjecting the polycrystalline thin film to a second heat treatment to form a single crystal thin film in which the polycrystalline grains are combined.

Next, a method for manufacturing a single crystal thin film of the present invention will be described with reference to FIGS.

FIG. 1 shows an example of an excimer laser irradiation apparatus used in the method of manufacturing a semiconductor thin film according to the present invention. First, the excimer laser irradiation device will be described. The excimer laser irradiation device is a device for irradiating a semiconductor thin film 22 formed on a low heat-resistant insulating substrate 21 such as a glass substrate with an excimer laser.
The low heat-resistant insulating substrate 21 on which the substrate 2 is formed is placed. The excimer laser irradiation apparatus has a laser oscillator 23, an attenuator (attenuator) 24, and an optical system 25 including a homogenizer outside the chamber 20. A stage 27 movable in the XY direction is provided in the chamber 20, and the insulating substrate 21 on which the semiconductor thin film 22 is formed is mounted on the stage 27. Laser oscillator 23
Includes an excimer laser light source, for example, a pulse width of 60
The laser light 26 of nanoseconds or more is emitted intermittently. For example, the optical system 25 including the homogenizer is a laser oscillator 2
The laser light emitted from 3 is received via the attenuator 24, and is shaped so that each side has a rectangular cross section of 10 mm or more, and is irradiated on the semiconductor thin film 22. Attenuator 2
4 adjusts the energy of the laser light emitted from the laser oscillator 23. The optical system 25 shapes the laser light into a rectangular cross section and adjusts the energy so that the energy is uniformly distributed in the rectangular cross section. The inside of the chamber 20 is maintained in an inert atmosphere such as nitrogen gas. At the time of irradiation with the laser light 26, the stage 27 moves so that the ends of the beam overlap each other, and irradiates the surface of the semiconductor thin film 22 intermittently. The semiconductor thin film 22 formed on the main surface of the insulating substrate 21 placed in the chamber 20 of the excimer laser irradiation device is an amorphous silicon film formed by a plasma CVD device.

As the excimer laser used for the laser oscillator 23, various light sources can be used as long as they can form a semiconductor thin film having a surface state with minute projections. XeCl, XeF, Ar
One or more excimer lasers selected from F can be used.

Excimer lasers can be broadly classified into excimer lasers that emit linear laser light and excimer lasers that emit planar laser light.
Excimer lasers that irradiate linear laser light have a linear pattern of laser light to irradiate, and when irradiating an area with a predetermined spread, the substrate side or light source side can be moved in a certain direction. Done. That is, linear laser light irradiation is performed by overlapping irradiation in a scanning direction perpendicular to the longitudinal direction of light irradiation. An excimer laser that irradiates a planar laser beam has a planar pattern of the laser beam to be radiated, and is moved on the substrate side or the light source side while overlapping the irradiation surface at an end. An excimer laser that emits a linear laser beam typically has an energy density of 350 mJ / cm ² and a pulse width of 20 mJ / cm ^2.
For example, an excimer laser manufactured by Lambda, which is relatively short, such as about nanoseconds, can be used. An excimer laser that emits a planar laser beam typically has an energy density of 480 mJ / cm ² and a pulse width of 1.
For example, an excimer laser manufactured by Sopra, which is relatively long, for example, about 50 to 200 nanoseconds can be used.

Next, referring to FIGS. 2 to 6,
An example of the method for manufacturing a semiconductor thin film according to the present invention will be described. First, as shown in FIG. 2, an insulating substrate 31 such as glass, quartz, ceramic, or sapphire is prepared, and an amorphous semiconductor thin film 32 is formed on a main surface thereof by, for example, a plasma enhanced CVD method. Since the excimer laser is used as the light source, so-called white glass having low heat resistance (low melting point) may be used as the insulating substrate 31. As an example of the amorphous semiconductor thin film 32, an amorphous silicon film is formed by using a plasma enhanced CVD method or the like. The thickness of the amorphous semiconductor thin film 32 is, for example, 50 nm.
To a lesser extent, the preferred film thickness can be adjusted according to the characteristics of the device to be manufactured. An example of the thickness of the amorphous semiconductor thin film 32 is about 500 nm or less, and usually about 10 nm.
It is 0 nm or less, preferably 80 nm or less, and more preferably 60 nm or less.

After the formation of the amorphous semiconductor thin film 32, the insulating substrate 31 on which the amorphous semiconductor thin film 32 is formed is mounted on an excimer laser irradiation apparatus as shown in FIG. 1, and the excimer laser irradiation is performed as a first heat treatment. Do. The laser irradiation conditions at this time were as follows: an X-ray having a wavelength of 308 nm as an excimer laser.
eCl excimer laser is used and energy intensity 3
At 40 mJ / cm ² , the overlap ratio in the scanning direction is 95
%. By this excimer laser irradiation, the amorphous semiconductor thin film 32 is melted and recrystallized, and a polycrystalline semiconductor thin film 33 composed of substantially aligned polycrystalline grains is formed. The shape of each polycrystalline particle of the polycrystalline semiconductor thin film 33 is substantially rectangular, and its size is 0.2 μm to 0.6 μm in diagonal length.
It is about μm. A crystal grain boundary is also formed by excimer laser irradiation, and a microprojection 35 exists at a position where at least three or more polycrystalline grains form a boundary at the grain boundary portion due to a bump caused by crystal collision. When the height of the minute projection 35 is large, it has a size of about 50 nm, and the height is generally about 25 nm or more.

FIG. 5 is a scanning electron micrograph at the time when the thin film becomes a polycrystalline semiconductor thin film by laser irradiation. In the figure, the polycrystalline grains (polysilicon grains) developed in a crocodile pattern are arranged substantially regularly in the vertical and horizontal directions.
A plurality of minute protrusions are formed at positions where at least one polycrystalline grain forms a boundary. Such approximately regular alignment of polycrystalline grains can be caused by diffraction at the edge of an opening or the like when irradiating a linear laser or interference or diffraction phenomena such as an intensity modulation mask such as a phase shift mask when irradiating a planar laser. It can be understood as a phenomenon that appears by giving a periodic pattern to the light intensity, and more comprehensively it can be understood that a common boundary condition is introduced to polycrystal grains by laser irradiation. it can. In order to grow a single crystal region in which the polycrystal grains are bonded to each other, it is preferable that adjacent polycrystal grains are easily bonded to each other. By forming them, a common crystal orientation of polycrystalline grains during recrystallization after heat treatment, for example, a common interface of oriented planes such as (100) plane can be obtained, and smooth polycrystalline grains can be obtained by utilizing the order. Bonding of crystal grains occurs. Therefore, in the next second heat treatment, the bonding between the polycrystalline grains is easily promoted, and the single crystallization is promoted.

Subsequent to the first heat treatment by laser irradiation, a second heat treatment is also performed by excimer laser irradiation. The irradiation conditions of this excimer laser irradiation are as follows:
eCl excimer laser is used and energy intensity 3
00mJ / cm ² with 95% overlap in scanning direction
%. The energy of the excimer laser irradiation as the second heat treatment is lower than that of the excimer laser irradiation of the first heat treatment, and the heat treatment temperature of the polycrystalline semiconductor thin film 33 is lower than that of the excimer laser irradiation of the first heat treatment. Further, the heat treatment temperature may be set to be lower than the melting point of polycrystalline silicon.

By the excimer laser irradiation as the second heat treatment, the polycrystalline semiconductor thin film 33 is converted into a single crystal thin film 34 as shown in FIG. That is, by excimer laser irradiation, adjacent polycrystalline grains of the polycrystalline semiconductor thin film 33 formed by the first heat treatment are bonded to each other, and include at least a large single crystal region of 1 × 10 ⁻⁹ cm ² or more, preferably 1 × 10 ⁻⁹ cm ² or more. ⁻⁸ cm ² or more, more preferably a single crystal thin film 3 that is entirely a single crystal
4 are formed. The single-crystal thin film 34 may include a mixture of polycrystalline and amorphous semiconductor regions. After the excimer laser irradiation as the second heat treatment, the minute protrusions 36 are formed to be lower in height than the minute protrusions 35 on the surface of the polycrystalline semiconductor thin film 33. The range is extremely low from 20 nm to 5 nm or less. Further, the diameter of the minute projection 36 is also 0.1 μm or less. The minute protrusions 36 on the surface of the single crystal thin film 34 are formed at positions corresponding to positions where at least three or more interfaces of the polycrystalline grains obtained by the first heat treatment collide and protrude. Therefore, the minute protrusions 35 on the surface of the polycrystalline semiconductor thin film 33 are flattened, and the portions that remain as protrusions are minute protrusions 36 on the surface of the single crystal thin film 34.

The small protrusions 36 on the surface of the single crystal thin film 34 are also assumed to have a reduced density, for example, 1 × 10 ⁹ / c.
m ² or less. In the microprojection 36, the radius of curvature of the microprojection 35 on the surface of the polycrystalline semiconductor thin film 33 is also large, and the radius of curvature of the microprojection 36 is 60 nm or more, preferably 180 nm or more, It is more preferably at least 250 nm.

FIG. 6 is a scanning electron micrograph at the time when the thin film is changed from the polycrystalline semiconductor thin film 33 to the single crystal thin film 34. It can be seen that the crocodile-like polycrystal grains seen in the photograph of FIG. 5 disappear, and the plurality of minute projections almost disappear, and a single crystal thin film 34 composed of a large single crystal region is obtained. The size of this large single crystal region is about 2 μm, which is sufficient for a channel region of a thin film transistor.

By applying the first heat treatment and the second heat treatment as described above, the single crystal thin film 34
Is formed, but the first heat treatment and the second heat treatment are not limited to irradiation with excimer laser, and irradiation with other laser light, for example, a laser such as a rare gas laser or a YAG laser,
Irradiation with other energy beams such as X-rays and electron beams that do not transmit light may be used. Also, the second
Since the heat treatment is annealing by heating, lamp annealing, furnace annealing for a relatively long time, and strip heater can be used without being limited to laser.

In the first heat treatment, unlike the annealing treatment of the second heat treatment, forming a polycrystalline thin film in which polycrystalline grains are arranged in a substantially regular manner on an insulating substrate forms minute projections. Preferred above. For this reason, in the first heat treatment, high-energy laser irradiation is performed. However, in order to obtain polycrystalline grains that are substantially regularly aligned, diffraction at the edge of an opening or the like during linear laser irradiation, When irradiating a planar laser, a periodic pattern can be given to the light intensity by an interference phenomenon or a diffraction phenomenon of a phase shift mask or the like. By giving a periodic pattern to the light intensity, the nucleus growth, which is the source of the polycrystalline grains, is also affected by the periodic pattern, and as a result, the polycrystalline grains having a substantially regular arrangement on the insulating substrate are obtained. A crystalline thin film is formed.

At least one of the first heat treatment and the second heat treatment is substantially performed in a vacuum, in an inert gas atmosphere,
Alternatively, it can be performed in a non-oxidizing gas atmosphere. In particular, after the amorphous semiconductor thin film is first formed on the insulating substrate, or between the first heat treatment and the second heat treatment, the chamber gas is kept the same or the chamber is moved without opening to the atmosphere. In this case, waste of production time due to adjustment of the atmosphere gas can be prevented.

The insulating substrate 31 may be made of a glass substrate having required rigidity and heat resistance, a so-called white glass substrate, plastic, ceramic, or other substrate material, or a quartz substrate, a silicon wafer, or another semiconductor wafer. And various substrates such as a substrate on which a nitride film is formed,
In particular, since heat treatment can be performed in a very short time, a substrate having low heat resistance (for example, 600 ° C.) can be sufficiently used. Note that various intermediate layers, reflective layers, and other functional layers can be provided on the thin film forming surface of the insulating substrate 31.

The single-crystal thin film 34 formed on the insulating substrate 31 is a single-crystal thin film crystallized from a non-single-crystal silicon film such as an amorphous silicon film or a polycrystalline silicon film. And a size of about 50 nm. The crystallized semiconductor thin film is a polycrystalline thin film before the heat treatment, and in that case, it is preferable that substantially regular polycrystalline grains are aligned. As a material other than silicon, for example, a material such as SiGe or SiC can be used.

The single-crystal thin film 34 may have a mixed state of a polycrystalline region, a single-crystal region in which polycrystalline grains are combined, an amorphous region, and the like. The size of the single crystal region in which the polycrystalline grains are combined is, for example, 1 × 10 ⁻⁹ cm ² or more, preferably 1 × 10 ⁻⁸ cm ² or more, and more preferably 16 × 10 ⁻⁸ cm ² or more.
10 ⁻⁸ cm ² or more. The larger the single crystal region in the formed single crystal thin film, the closer the crystal characteristics are to those of a perfect single crystal, and the more stable the characteristics are at the same time. The single-crystal thin film does not need to be formed on the entire surface of the insulating substrate, and may have a structure existing in a part of the polycrystalline thin film. Further, the single crystal region of the single crystal thin film preferably has one of (100), (111) and (110) orientation planes. In this embodiment, the example in which the excimer laser is scanned is described, but the scanning is not necessarily performed. Also in this case, the polycrystal grains are arranged substantially regularly. Also, an example in which the first heat treatment and the second heat treatment are performed separately has been described, but the first heat treatment for providing a common boundary condition and the second heat treatment for single crystallization are performed in substantially the same manner. Is also good.

Such a single crystal thin film formed on an insulating substrate can be used as a semiconductor substrate in the manufacture of a semiconductor device. Such a semiconductor device includes a thin film transistor and other electronic devices, and is particularly applicable to a thin film transistor of a driving circuit of a liquid crystal display as described later. The single-crystal thin film contains a single-crystal region, and when used as a device, device characteristics become stable. For example, when a thin film transistor is manufactured, variation in the threshold value is suppressed and mobility is reduced. And the device can support high-speed operation.

Next, an example of an active matrix type display device as a semiconductor device using a thin film transistor manufactured according to the present invention will be described with reference to FIG. This embodiment is an example in which a semiconductor device is configured by using a thin film having the minute projections as a channel. As shown in the drawing, the display device has a pair of insulating substrates 51 and 52.
And a panel structure including an electro-optical material 53 held therebetween. As the electro-optical material 53, for example, a liquid crystal material is used. On the lower insulating substrate 51, a pixel array section 54 and a drive circuit section are integrally formed. The drive circuit is divided into a vertical scanner 55 and a horizontal scanner 56. Further, a terminal portion 57 for external connection is formed at the upper end of the peripheral portion of the insulating substrate 51. The terminal part 57 is a wiring 58
To the vertical scanner 55 and the horizontal scanner 56. A row-shaped gate wiring 59 is provided in the pixel array section 54.
And a column-shaped signal wiring 60 are formed. A pixel electrode 61 and a thin film transistor 62 for driving the pixel electrode 61 are formed at the intersection of the two wires. The gate electrode of the thin film transistor 62 is connected to the corresponding gate line 59, the drain region is connected to the corresponding pixel electrode 61, and the source region is connected to the corresponding signal line 60. The gate wiring 59 is connected to the vertical scanner 55, while the signal wiring 60 is connected to the horizontal scanner 56. Thin film transistor 62 for switching driving pixel electrode 61 and vertical scanner 5
5 and the thin film transistor included in the horizontal scanner 56 are:
The channel portion of the thin film is formed with a crystal characteristic closer to a single crystal with a minute projection. Further, in addition to the vertical scanner and the horizontal scanner, a video driver and a timing generator can also be integrally formed in the insulating substrate 51.

[0037]

As described above, in the method for producing a single crystal thin film according to the present invention, the polycrystalline grains are substantially regularly arranged in the first heat treatment, and the crystallization is advanced in the second heat treatment. A thin film is formed. Therefore, when a semiconductor device is manufactured using the single-crystal thin film, high-speed operation with high mobility can be expected for the semiconductor device.
Variations in threshold voltage and the like can also be suppressed. Also,
In the manufacturing process, short-time processing can be performed using an excimer laser or the like, and the time required for a significant manufacturing process can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view of an excimer laser irradiation apparatus used in the method for producing a single crystal thin film of the present invention.

FIG. 2 is a process perspective sectional view showing a process of forming an amorphous semiconductor thin film in an example of the method for manufacturing a single crystal thin film of the present invention.

FIG. 3 is a perspective sectional view showing a step of forming a polycrystalline semiconductor thin film in an example of the method for producing a single crystal thin film of the present invention.

FIG. 4 is a process perspective sectional view showing a process of forming a single-crystal thin film in an example of the method for manufacturing a single-crystal thin film of the present invention.

FIG. 5 is a scanning electron micrograph showing a state when a polycrystalline semiconductor thin film is formed in an example of the method for producing a single crystal thin film of the present invention.

FIG. 6 is a scanning electron micrograph showing a state when a single crystal thin film is formed in one example of the method for producing a single crystal thin film of the present invention.

FIG. 7 is a schematic perspective view showing an active matrix display device using a semiconductor device manufactured by using the single crystal thin film of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 31 Insulating substrate 34 Single crystal thin film 35, 36 Micro protrusion 32 Amorphous semiconductor thin film 33 Polycrystalline semiconductor thin film

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Sakamoto 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Yoshifumi Mori 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F term (reference) 4G077 AA03 BA04 BE05 BE08 CA03 CA10 EA10 ED06 EJ04 HA12 JB02 JB06 5F052 AA02 AA03 AA06 AA12 AA17 AA24 BA02 BA07 BB02 BB07 CA08 DA01 DA03 DA10 DB03 FA19 JA01

Claims (52)

[Claims] A step of forming a non-single-crystal thin film on an insulating substrate; a step of performing a first heat treatment on the non-single-crystal thin film to form a polycrystalline thin film in which polycrystalline grains are arranged substantially regularly; Subjecting the polycrystalline thin film to a second heat treatment to form a single crystal thin film in which the polycrystalline grains are combined. 2. The method according to claim 1, wherein at least one of the first and second heat treatments is laser light irradiation. 3. The method according to claim 1, wherein the first and second heat treatments are performed by laser light irradiation, and the laser light intensity in the second heat treatment is lower than the laser light intensity in the first heat treatment. 2. The method for producing a single crystal thin film according to 1. 4. The method according to claim 1, wherein the second heat treatment is performed at a temperature lower than a melting point of the polycrystalline thin film. 5. The method according to claim 1, wherein at least one of the first and second heat treatments is irradiation with an excimer laser. 6. The method according to claim 1, wherein at least one of the first and second heat treatments is irradiation with a linear laser beam. 7. The method for producing a single crystal thin film according to claim 1, wherein the linear laser light irradiation is superposed and irradiated in a scanning direction perpendicular to the longitudinal direction of the light irradiation. 8. The method according to claim 1, wherein at least one of the first and second heat treatments is irradiation with a planar laser beam. 9. The method according to claim 1, wherein the irradiation of the planar laser light is performed using a mask. 10. The method according to claim 1, wherein the second heat treatment is performed by furnace annealing.
2. The method for producing a single-crystal thin film according to claim 1, wherein the method is annealing using a lamp, lamp annealing or strip heater annealing. 11. At least one of the first and second heat treatments is performed substantially in a vacuum, in an inert gas atmosphere,
2. The method according to claim 1, wherein the method is performed in a non-oxidizing gas atmosphere. 12. A method of forming a non-single-crystal thin film on an insulating substrate, and irradiating the non-single-crystal thin film with a laser beam to convert the non-single-crystal thin film into a single-crystal thin film. A method for producing a single crystal thin film. 13. The method according to claim 12, wherein the laser light is an excimer laser light. 14. The method for producing a single crystal thin film according to claim 12, wherein the irradiation of the laser beam comprises a first laser irradiation and a second laser irradiation. 15. The method of claim 12, wherein the second laser irradiation has a lower energy density than the first laser irradiation. 16. The method according to claim 12, wherein the region irradiated by the second laser irradiation is at a temperature lower than the melting point of the non-single-crystal thin film. 17. The method according to claim 12, wherein at least one of the first and second laser irradiations is linear laser light irradiation. 18. The method for producing a single crystal thin film according to claim 12, wherein the linear laser beam irradiation is superposed and irradiated in a scanning direction perpendicular to the longitudinal direction of the light irradiation. 19. The method of manufacturing a single-crystal thin film according to claim 12, wherein at least one of the first and second laser irradiations is irradiation with a planar laser beam. 20. The method for producing a single crystal thin film according to claim 12, wherein the irradiation of the planar laser light is performed using a mask. 21. The method for producing a single crystal thin film according to claim 12, wherein the laser beam irradiation is performed substantially in a vacuum, in an inert gas atmosphere, or in a non-oxidizing gas atmosphere. 22. The method according to claim 12, wherein a heat treatment is performed after the laser beam irradiation. 23. The method according to claim 22, wherein the heat treatment is furnace annealing, lamp annealing, or strip heater annealing. 24. The method according to claim 22, wherein the laser beam irradiation and the heat treatment are performed substantially in a vacuum, in an inert gas atmosphere, or in a non-oxidizing gas atmosphere.
The method for producing a single-crystal thin film according to the above. 25. A step of forming a non-single-crystal thin film on an insulating substrate; a step of performing a first heat treatment on the non-single-crystal thin film to form a polycrystalline thin film while introducing common boundary conditions;
Subjecting the polycrystalline thin film to a second heat treatment to form a single crystal thin film in which the polycrystalline grains are crystallized. 26. The method according to claim 25, wherein at least one of the first and second heat treatments is laser light irradiation. 27. The method according to claim 27, wherein the first and second heat treatments are performed by laser light irradiation, and a laser light intensity in the second heat treatment is lower than a laser light intensity in the first heat treatment. 26. The method for producing a single crystal thin film according to 25. 28. The method according to claim 25, wherein the second heat treatment is performed at a temperature lower than a melting point of the polycrystalline thin film. 29. The method according to claim 25, wherein at least one of the first and second heat treatments is irradiation with laser light from an excimer laser. 30. The method according to claim 25, wherein at least one of the first and second heat treatments is irradiation with a linear laser beam. 31. The method for producing a single crystal thin film according to claim 25, wherein the linear laser light irradiation is superposed and irradiated in a scanning direction perpendicular to the longitudinal direction of the light irradiation. 32. The method according to claim 25, wherein at least one of the first and second heat treatments is irradiation with a planar laser beam. 33. The method for producing a single crystal thin film according to claim 25, wherein the irradiation of the planar laser light is performed using a mask. 34. The method according to claim 34, wherein the second heat treatment is performed by furnace annealing.
26. The method for producing a single crystal thin film according to claim 25, wherein the method is annealing by annealing, lamp annealing or strip heater annealing. 35. At least one of the first and second heat treatments is performed substantially in a vacuum, in an inert gas atmosphere,
26. The method for producing a single crystal thin film according to claim 25, wherein the method is performed in a non-oxidizing gas atmosphere. 36. A single-crystal thin-film substrate having a single-crystal thin film that is single-crystallized by laser irradiation on an insulating substrate. 37. The single crystal thin film substrate according to claim 36, wherein said single crystal thin film has a thickness of 500 nm or less. 38. The single-crystal thin-film substrate according to claim 36, wherein the insulating base is made of one of glass, quartz, and ceramic. 39. The single crystal thin film substrate according to claim 36, wherein said single crystal thin film is made of any one of Si, SiGe, and SiC. 40. The method according to claim 36, wherein the crystallization of the single crystal thin film is performed by subjecting the polycrystalline thin film to substantially regular alignment of polycrystalline grains in the thin film and then performing a heat treatment.
A single-crystal thin-film substrate according to the above. 41. A single-crystal thin-film substrate comprising a semiconductor thin film crystallized on an insulating substrate by laser irradiation so that at least a part thereof becomes a single-crystal region. 42. The single crystal thin film substrate according to claim 41, wherein said semiconductor thin film is a film in which said single crystal region, polycrystalline semiconductor region and amorphous semiconductor region are mixed. 43. The single crystal thin film substrate according to claim 41, wherein said semiconductor thin film has a thickness of 500 nm or less. 44. The single crystal thin film substrate according to claim 41, wherein said insulating base is made of one of glass, quartz, and ceramic. 45. The single crystal thin film substrate according to claim 41, wherein said semiconductor thin film is made of any one of Si, SiGe, and SiC. 46. The method according to claim 41, wherein the crystallization of the single crystal thin film is performed by subjecting the polycrystalline thin film to substantially regular alignment of polycrystalline grains in the thin film and then performing a heat treatment.
The single crystal thin film substrate according to the above. 47. A semiconductor device having a single-crystal thin film which is single-crystallized by laser irradiation on an insulating base, and an insulating film is formed on a surface of the single-crystal thin film. 48. The semiconductor device according to claim 47, wherein the semiconductor thin film is a film in which the single crystal region, the polycrystalline semiconductor region, and the amorphous semiconductor region are mixed. 49. The semiconductor device according to claim 47, wherein the semiconductor thin film has a thickness of 500 nm or less. 50. The semiconductor device according to claim 47, wherein said insulating base is made of one of glass, quartz, and ceramic. 51. The semiconductor device according to claim 47, wherein said semiconductor thin film is made of one of Si, SiGe, and SiC. 52. The method according to claim 47, wherein the crystallization of the single-crystal thin film is performed by subjecting the polycrystalline thin film to substantially regular polycrystalline grains in the thin film and then performing a heat treatment.
13. The semiconductor device according to claim 1.