JP2001110861A - Check method and device of semiconductor film, and manufacturing method of thin film transistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycrystalline semiconductor film check method and a device capable of forwarding only a substrate where a polycrystalline semiconductor film of normal quality is formed to an after process in a TFT manufacturing process and a device of manufacturing TFTs, by a method wherein the surface conditions of the semiconductor film are checked through a non- destructive manner. SOLUTION: If the surface of a polycrystalline semiconductor film 12 formed through laser annealing by a line beam is very rough, light is scattered by the surface of the semiconductor film 12 and detected when light impinges on the surface of the semiconductor film 12 at an angle of 45 deg.. Therefore, when the output of scattered light is kept at a high level, it is judged that the surface of a semiconductor film 12 formed on a substrate 10 is high in roughness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a polycrystalline semiconductor film used for producing a thin film transistor (hereinafter referred to as TFT), a method for producing a TFT using a semiconductor film which has been inspected by this inspection method, And an inspection apparatus for a crystalline semiconductor film.

[0002]

2. Description of the Related Art In manufacturing a TFT used as an active element of a liquid crystal display, a low-temperature process is being adopted so that an inexpensive glass substrate can be used instead of a quartz substrate. In general, a low temperature process has a maximum process temperature (maximum temperature at which the entire substrate simultaneously rises) of less than about 600 ° C., whereas a high temperature process has a maximum process temperature (maximum temperature at which the entire substrate simultaneously rises). The temperature is about 800 ° C. or more, and a high-temperature process of 700 ° C. to 1200 ° C. such as thermal oxidation of silicon is performed.

As an example of a method of manufacturing a TFT using this low-temperature process, as shown in FIG. 1A, after preparing a substrate 10 made of glass or the like cleaned by ultrasonic cleaning or the like, the substrate temperature is reduced. Under a temperature condition of about 150 ° C. to about 450 ° C., as shown in FIG. 1B, an underlayer protective film 1 made of a silicon oxide film having a thickness of about 200 nm is formed on the entire surface of the substrate 10.
1 is formed by a plasma CVD method. Next, a semiconductor film 12 made of an amorphous silicon film having a thickness of 60 nm is formed on the entire surface of the substrate 10 by a plasma CVD method at a substrate temperature of about 150 ° C. to about 450 ° C. Next, as shown in FIG. 1C, laser annealing is performed by irradiating the semiconductor film 12 with laser light.

In this laser annealing step, for example,
As shown in FIG. 2, the semiconductor film 12 applies a line beam L0 (for example, a line beam having a laser pulse repetition frequency of 200 Hz) whose laser light irradiation region L is long in the X direction.
And the irradiation area is shifted in the Y direction. As a result, the amorphous semiconductor film 12 is once melted and crystallized through a cooling and solidification process. In this case, the irradiation time of the laser beam to each region is very short, and the irradiation region is local to the entire substrate, so that the entire substrate is not heated to a high temperature at the same time. Therefore, even if the glass substrate used as the substrate 10 is inferior in heat resistance as compared with the quartz substrate, deformation or cracking due to heat does not occur.

However, the amorphous semiconductor film 1
If the laser energy density at the time of annealing is excessively increased when performing laser annealing on the substrate 2, the surface of the semiconductor film 12 becomes rough and the gate withstand voltage of the TFT decreases.
There is a problem that it cannot be used for manufacturing FT. On the other hand, if the energy density at the time of laser annealing is weakened, crystallization does not proceed, and it cannot be used for the manufacture of TFTs. In addition, when the cleaning state of the substrate 10 and the semiconductor film 12 is poor, the surface of the semiconductor film 12 may be roughened. Therefore, if the film quality of the annealed semiconductor film 12 can be inspected during the TFT manufacturing process, only those determined to be normal in the inspection result can be sent to the subsequent process, so that the TFT manufacturing cost can be reduced. However, in order to perform such an in-line inspection, it must be a method that can be performed nondestructively within a short time. For this reason, Raman spectroscopy inspection methods, ellipsometer inspection methods, and atomic force microscopes and transmission electron microscope inspection methods conventionally used to evaluate film quality in laboratories have been used in the manufacturing process. Cannot be incorporated.

An object of the present invention is to inspect the surface state of a semiconductor film in a non-destructive manner in a short time during the manufacturing process of a TFT or the like, so that a polycrystalline film having a normal film quality can be obtained in the manufacturing process of a TFT or the like. Method for inspecting a polycrystalline semiconductor film in which only a substrate on which a conductive semiconductor film is formed can be sent to a subsequent process, a method for manufacturing a TFT for selecting a substrate using this method, and a polycrystalline used for carrying out these methods An object of the present invention is to provide an inspection device for a conductive semiconductor film.

[0007]

According to experiments repeatedly performed by the present inventor, damage caused when crystallization treatment such as laser annealing is performed on an amorphous semiconductor film is shown in FIG. As shown in the above, a new finding has been obtained that the determination can be made based on whether or not large irregularities exist on the surface of the semiconductor film. Further, as shown in FIG. 2, a laser beam irradiation region L has a line beam L0 that is long in the X direction (for example,
In the method of shifting a laser beam having a repetition frequency of 200 Hz (a line beam having a repetition frequency of 200 Hz) in the Y direction, the surface roughness is almost constant in the X direction as shown in FIG.
As shown in FIG. 3C, since the surface roughness periodically changes in the Y direction, it is necessary to eliminate the anisotropy of the surface roughness in order to uniformly form a highly reliable TFT. I also learned that it was necessary. Based on such new knowledge, the present invention evaluates the film quality of a semiconductor film in a short time in a non-destructive manner during a manufacturing process of a TFT or the like by performing the following film quality evaluation. It is proposed that only a substrate on which a normal crystalline polycrystalline semiconductor film is formed be transferred to a subsequent process in the manufacturing process of (1).

In the invention according to the present invention, the surface of a semiconductor film formed on a substrate is irradiated with directional light, the intensity of scattered light from the surface of the semiconductor film is measured, and the intensity of the scattered light is measured based on the intensity of the scattered light. In this case, the unevenness of the surface of the semiconductor film is determined.

In such an inspection method, the film quality of the semiconductor film can be evaluated in a short time without destruction. Therefore, the film quality is evaluated in-line in the TFT manufacturing process, and the normal polycrystalline semiconductor film is formed. Only the substrate on which is formed can be sent to a post-process. Therefore, the yield and reliability of an active matrix substrate of a liquid crystal panel using a TFT as a switching element are improved. The directional light is a laser light. Further, the semiconductor film is characterized in that the semiconductor film is a polycrystallized film obtained by irradiating a laser beam to an amorphous semiconductor film formed over a substrate.

The irradiation area of the laser beam for polycrystallizing the semiconductor film is a rectangle long in one direction and smaller than the substrate area, and the laser beam is scanned at a constant feed width in the laser beam scanning direction. The film is characterized in that the film is polycrystallized by irradiating while being polycrystallized.

Further, according to the present invention, the intensity of the scattered light is measured for each predetermined wavelength region of the scattered light, and the semiconductor film is measured based on a comparison between the intensity of the scattered light in the short wavelength region and the intensity of the scattered light in the long wavelength region. Is determined. Specifically, when the intensity of the scattered light in the long wavelength region is lower than the intensity of the scattered light in the short wavelength region, it is determined that the unevenness of the surface of the semiconductor film is large. That is, the larger the irregularities on the surface of the semiconductor film,
Since the intensity of the dispersed light in the long wavelength region is relatively increased, the film quality can be more reliably evaluated by taking into account the intensity ratio of the dispersed light in each wavelength region. As means for measuring the intensity of the dispersed light for each wavelength region, the wavelength of the incident light may be switched, or the incident light may include a plurality of wavelength regions, and the scattered light may be spectrally separated and measured.

Further, according to the present invention, a laser beam is made incident in the in-plane direction of the substrate in the laser beam scanning direction and in a direction orthogonal thereto, and the intensity of scattered light from the semiconductor film surface is separately measured. The unevenness state of the surface of the semiconductor film is determined based on a difference in intensity of scattered light in incident light in two directions. Specifically, it is characterized in that the smaller the difference in the intensity of the scattered light in the incident light in the two directions, the more isotropic the unevenness of the surface of the semiconductor film is determined. In the method of annealing the entire surface of the semiconductor film while shifting the irradiation area of the line beam, the longitudinal direction of the line beam (X direction in FIG. 2 or FIG. 3; hereinafter, referred to as a main scanning direction) and the line beam are moved. The direction (the Y direction in FIG. 2 or FIG. 3 and the specific direction according to claim 2; hereinafter, referred to as a sub-scanning direction) is different in the unevenness of the polycrystalline surface. That is, in the sub-scanning direction in which the line beam is moved, there is a temperature gradient as compared with the main scanning direction, so that the crystal is likely to grow in this direction. For this reason,
The shape of the concavities and convexities is accordingly different between the sub-scanning direction and the main scanning direction. Therefore, it can be determined that the smaller the intensity difference in the two orthogonal incident light directions, the more anisotropic the surface unevenness of the polycrystalline semiconductor film is.

Further, the present invention measures the in-plane distribution of the intensity of the scattered light from the semiconductor film surface on the substrate, and determines the unevenness state of the surface of the semiconductor film based on the intensity difference in the in-plane distribution. It is characterized by doing. Specifically, it is characterized in that the smaller the difference in intensity in the in-plane distribution, the more uniform the in-plane unevenness of the surface of the semiconductor film is determined.

Further, based on the measurement result of the scattered light, two directions of a scanning direction of the laser and a direction orthogonal thereto are provided.
It is characterized in that a change in the amount of scattered light in at least one of the directions is quantified. In the method of performing annealing on the entire surface of the semiconductor film while shifting the irradiation area of the line beam, the unevenness distribution is anisotropic, and stripes are formed in an overlapping portion of the line beam in the sub-scanning direction as compared with the main scanning direction. The uneven distribution of the shape tends to occur. For this reason, it is possible to accurately measure the fluctuation of the annealing condition by determining whether the distribution of the surface roughness in the main scanning direction and the sub-scanning direction is within a predetermined range, or by relatively comparing the distributions. .

Further, according to the present invention, a Fourier transform of the intensity change of the scattered light in at least one of two directions is used as the quantifying means, and a sum of absolute values of complex Fourier components in a predetermined period range is used. The unevenness state of the surface of the semiconductor film is determined based on Specifically, it is characterized that it is determined that the greater the sum of the absolute values of the complex Fourier components in the predetermined frequency range, the greater the unevenness of the surface. In the sub-scanning direction, the irregularities have a relatively short periodicity in correlation with the feed pitch of the line beam, so that the absolute value of the Fourier component having a relatively short period tends to increase. On the other hand, since it has only a relatively long periodicity in the main scanning direction, it is possible to quantify the different directionality of the irregularities by comparing the Fourier component corresponding to an appropriate predetermined period band in the main scanning direction and the sub-scanning direction become. Of course, these quantifications are more effective if performed for each wavelength range of the scattered light. That is, by comparing the Fourier component in the predetermined period range in the low wavelength region with the Fourier component in the high wavelength region, it is possible to more accurately determine the size of the irregularities that appear periodically.

Further, the predetermined cycle range includes either the laser irradiation feed width cycle or a cycle obtained by dividing the laser irradiation feed width by an integer. Since the period of the concavo-convex in the sub-scanning direction basically matches the feed pitch of the laser beam, the anisotropy can be determined with higher accuracy by setting the predetermined wavelength region in this manner.

Further, the present invention provides a method of forming a thin film transistor by using a polycrystalline semiconductor film whose surface unevenness is determined to be within a predetermined level range by an inspection method of the polycrystalline semiconductor film as an active layer. Features. This makes it possible to stably produce a thin film transistor substrate having excellent uniformity and reliability.

A polycrystalline semiconductor film inspection apparatus for performing a semiconductor film inspection method, comprising: a film quality evaluation light source for irradiating a laser light or a parallel light onto a polycrystalline semiconductor film surface on a substrate; A light detector that detects the intensity of scattered light at a position deviating from the direction of reflection of the light emitted from the film quality evaluation light source on the surface of the polycrystalline semiconductor film, and the intensity of the scattered light, the in-plane distribution, When one of the sub-scanning direction and the main scanning direction is out of a predetermined range, there is provided film quality determining means for determining that the irregularities on the surface of the polycrystalline semiconductor film are abnormal.

Further, the light source for film quality evaluation is a light source for outputting light including at least two kinds of wavelength bands of a predetermined wavelength or more and a predetermined wavelength or less, and the photodetector disperses the wavelength of the scattered light. And has a function of measuring the intensity for each wavelength region. Thus, the magnitude of the unevenness of the semiconductor film can be determined by comparing the scattering intensity of the light in the long wavelength range and the scattering intensity of the light in the short wavelength range.

The light source for evaluating film quality is a light source that outputs light including at least two wavelength ranges of a predetermined wavelength or more and a predetermined wavelength or less, and the photodetector detects the intensity of the scattered light for each specific wavelength region. It is characterized by comprising a means for measuring. By comparing the scattered light intensity at the time of selecting the long wavelength and the scattered light intensity at the time of selecting the short wavelength, the scattering intensity of light in the long wavelength region and the short wavelength region is compared to determine the size of the unevenness of the semiconductor film. it can.

The predetermined wavelength is from 400 nm to 500
It is characterized in that a wavelength of nm is used. According to the experiments of the present inventor, there is no significant difference in the scattered light intensity in the wavelength region of 400 to 500 nm or less in the substrate having large irregularities due to the substrate annealed under appropriate conditions and the laser irradiation energy being too high, There is a relatively larger difference in the longer wavelength range. Therefore, the state of the unevenness of the semiconductor film can be accurately determined.

As the light source for film quality evaluation, a laser light source capable of performing laser annealing on an amorphous semiconductor film formed on the substrate is used, and the laser light source is used for inspecting the polycrystalline semiconductor film. And shared for laser annealing of the amorphous semiconductor film. Thereby, the polycrystalline laser annealing apparatus and the polycrystalline semiconductor film inspection apparatus can be integrated compactly and inexpensively.

A laser light source capable of performing laser annealing on an amorphous semiconductor film formed on the substrate is provided together with the light source for film quality evaluation.

As a stage on which the substrate is mounted, there is a shared stage which is used both when using at the time of laser annealing and when inspecting the surface roughness of the polycrystalline semiconductor film by the intensity of scattered light. It is characterized by doing. Thereby, the polycrystalline laser annealing apparatus and the polycrystalline semiconductor film inspection apparatus can be made more compact and inexpensive.

As a stage for mounting the substrate, a first stage is used when laser annealing is performed, and a second stage is used when inspecting the surface roughness of the polycrystalline semiconductor film by laser light intensity after laser annealing. And a cooling stage for cooling the substrate after the laser annealing.

When the film quality judging means judges that the surface of the polycrystalline semiconductor film is rough, it issues a command signal for discharging the substrate or an alarm indicating that the substrate is defective. It is characterized by comprising. As a result, a substrate determined to be abnormal in the polycrystalline semiconductor inspection is quickly discharged, and only the substrate determined to be normal is advanced to the subsequent steps, whereby a TFT substrate excellent in reliability and uniformity can be obtained at low cost. . Further, when it is determined that there is an abnormality, the result can be immediately notified to the manufacturing apparatus / operator to feed back to the subsequent manufacturing conditions or to urge the maintenance of the apparatus.

A sample having predetermined irregularities for calibrating the light source and the photodetector is arranged on a stage.

[0028]

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

[Manufacturing Method of Polycrystalline Semiconductor Film] To manufacture a TFT on a glass substrate, first, it is necessary to form a polycrystalline semiconductor film on the glass substrate without deforming the glass substrate. . In order to form a polycrystalline semiconductor film under such restrictions, as shown in FIG. 1A, a substrate 1 made of alkali-free glass or the like cleaned by ultrasonic cleaning or the like is used.
0, the substrate temperature is about 150 ° C to about 450 ° C
As shown in FIG. 1B, under the above temperature condition, a base protective film 11 made of a silicon oxide film having a thickness of about 200 nm is formed on the entire surface of the substrate 10 by a plasma CVD method. As the raw material gas at this time, for example, a mixed gas of monosilane and laughing gas, TEOS and oxygen, or disilane and ammonia can be used. In addition, as the base protective film 12, an insulating film such as a silicon nitride film or a multilayer film thereof can be used. Next, when the substrate temperature is about 150
A semiconductor film 12 made of an amorphous silicon film having a thickness of 60 nm is formed on the entire surface of the substrate 10 by a plasma CVD method under a temperature condition of about 450 ° C. to about 450 ° C. As the source gas at this time, for example, disilane or monosilane can be used. In addition, a low pressure CVD or a normal pressure CVD using disilane or the like may be used. Next, as shown in FIG. 1C, laser annealing is performed by irradiating the semiconductor film 12 with laser light.

In this laser annealing step, for example,
As shown in FIG. 2, a line beam L0 whose laser light irradiation region L is long in the X direction (main scanning direction) (for example, the laser pulse repetition frequency is 200 Hz, the beam length is 20
The semiconductor film 12 is irradiated with a line beam (0 mm, width 0.5 mm). As a result, the amorphous semiconductor film 12 is once melted and crystallized through a cooling and solidification process. In this case, the irradiation time of the laser beam to each region is very short, and the irradiation region is local to the entire substrate, so that the entire substrate is not heated to a high temperature at the same time. Therefore,
The glass substrate used as the substrate 10 is inferior in heat resistance as compared with the quartz substrate, but does not deform or crack due to heat.

With respect to the semiconductor film 12 thus formed, as described above with reference to FIG.
By evaluating the surface condition of No. 2, it can be inspected whether the semiconductor film 12 is properly polycrystallized or whether damage such as surface roughening has occurred. An inspection method for that will be described below for each embodiment.

[First Embodiment] FIG. 4 is a perspective view schematically showing a main part of an annealing apparatus used in a laser annealing step performed before a method of inspecting a polycrystalline semiconductor film according to the present embodiment. is there. FIG. 5 is a perspective view schematically showing a main part of a polycrystalline semiconductor film inspection apparatus according to the present embodiment. FIG.
7 and FIG. 7 are a side view of a main part of the inspection apparatus of the present embodiment viewed from the Y-axis direction and a side view of the inspection apparatus viewed from the X direction.

The inspection apparatus 100 of this embodiment is a dedicated inspection apparatus for performing inspection in a step different from the laser annealing step. Therefore, the laser annealing step is performed by the annealing apparatus 300 shown in FIG.

In the annealing apparatus 300 shown in FIG.
An XY stage 31 on which a glass substrate 12 on which a semiconductor film 12 made of an amorphous silicon film is formed is mounted.
0, a laser light source 320, and an optical system 325 that emits and condenses the laser light emitted from the laser light source 320 as a line beam L0 toward the substrate 12 mounted on the stage 310. . In the example shown here, since the irradiation area L of the line beam L0 extends in the X direction,
To perform laser annealing on the entire surface of the substrate 12, the XY stage 310 moves in the Y direction.

After performing laser annealing using such an annealing apparatus 300, the inspection of the semiconductor film 12 is performed by the inspection apparatus 100 shown in FIG. 5, FIG. 6, and FIG.

An inspection apparatus 100 includes an XY stage 110 on which a glass substrate 12 on which a polycrystalline semiconductor film 12 having undergone an annealing process is mounted, and an objective lens 1.
26 are arranged. In addition, the autofocus is performed by moving the objective lens 126 or the XY stage 110 up and down along the apparatus optical axis ML.

Further, the inspection apparatus 100 of this embodiment has a Z
Approximately 45 ° approximately 45 ° with respect to the substrate 10 on the X plane
A first offset illumination light source 122 (light source for evaluating film quality) that emits white light from a direction forming an angle of
And approximately 45 ° with respect to the substrate 10 on the YZ plane
A second method of emitting white light from a direction forming an angle of approximately 45 °
The light source 123 for offset illumination (light source for film quality evaluation) is disposed. In addition, on the apparatus optical axis ML, a color CCD (Coup) arranged in a direction perpendicular to the substrate 10 is provided.
led-Charge Device) camera 160
(Light receiver), and the detection result of the CCD camera 160 is output to the personal computer 150. This personal computer 150
Based on the detection result of the CCD camera 160, whether the semiconductor film 12 formed on the substrate 10 is normal (polycrystallized),
Alternatively, it functions as a film quality judging means for judging whether it is abnormal (whether it is not polycrystallized or its surface is abnormally rough). Here, the film quality determination means is realized by an operation performed according to an operation program stored in the personal computer 150 in advance. The personal computer 150 also controls the drive control of the XY stage 110 and the like. Further, the personal computer 150 also performs automatic replacement of the objective lens 126, on / off of the light source, and adjustment of the gain of the CCD camera 160. Further, the personal computer 150 outputs an inspection result, which will be described later, to a host computer for process management or the like via a communication interface, and enables feedback to an annealing apparatus.

Here, since the calibration sample 119 having predetermined irregularities is disposed on the XY stage 110, the personal computer 150 periodically or in accordance with a request from the operator performs the calibration. A first offset illumination light source 122 with respect to the
Light is emitted from the second offset illumination light source 123, and the scattered light and reflected light are received by the color CCD camera 160. Based on the result, the CCD camera 160
Calibration such as gain adjustment of Then, the personal computer 150 sends the CCD camera 16
If the light receiving result of 0 is deviated by more than a predetermined level, a warning is issued to that effect, and the first offset illumination light source 12
The second and second offset illumination light sources 123 are notified to be checked.

The thus configured polycrystalline semiconductor film 1
2, the white light emitted from the first offset illumination light source 122 as parallel light
When the semiconductor film 12 is irradiated on the semiconductor film 12 on the optical axis ML, the light is substantially 45 ° with respect to the device optical axis ML in the ZX plane.
The semiconductor film 12 on the substrate 10 is irradiated from a direction forming an angle of 5 °. Here, the ZX plane is the longitudinal direction (main scanning direction) of the line beam L0 used for the laser annealing shown in FIGS. 2 and 3.

When the semiconductor film 12 is not sufficiently polycrystallized, most of the light is reflected in a direction at an angle of approximately 45 ° to the device optical axis ML in the ZX plane. I do. Therefore, the reflected light hardly reaches the CCD camera 160 arranged on the apparatus optical axis ML.
Therefore, the microcomputer 150 determines that the output from the CCD camera 160 is at a low level, and
The semiconductor film 12 formed at 0 is not polycrystalline and is determined to be abnormal.

If the surface of the semiconductor film 12 is greatly roughened during the polycrystallization, a part of the light is almost 45 ° to the device optical axis ML in the ZX plane. However, a considerable amount of light is scattered on the surface of the semiconductor film 12, and the light scattered toward the optical axis ML of the device is color-separated by the CCD camera 160 for each of RGB and received. Therefore, the scattered light reaches the CCD camera 160 sufficiently. Therefore, the microcomputer 150 determines that the output from the CCD camera 160 is at a high level, and determines that the surface of the semiconductor film 12 formed on the substrate 10 is abnormally rough.

On the other hand, if the semiconductor film 12 is properly polycrystallized, only fine irregularities are formed on the surface thereof, and a part of the light is emitted from the device light in the ZX plane. Reflected in a direction at an angle of approximately 45 ° with respect to the axis ML,
Part of the light is scattered on the surface of the semiconductor film 12, and the light scattered toward the device optical axis ML is received by the CCD camera 160. Therefore, a predetermined amount of scattered light reaches the CCD camera 160. Therefore, the microcomputer 150 determines that the output from the CCD camera 160 is within an appropriate range, and determines that the semiconductor film 12 formed on the substrate 10 is normal.

In the inspection apparatus 100, when white light emitted from the second offset illumination light source 123 irradiates the semiconductor film 12 on the substrate 10, this light is YZ
The semiconductor film 12 on the substrate 10 is irradiated from a direction making an angle of approximately 45 ° with the device optical axis ML in the plane.
Here, the YZ plane is the width direction (the sub-scanning direction orthogonal to the longitudinal direction of the line beam 10) of the line beam 10 used for the laser annealing. When the semiconductor film 12 on the substrate 10 is irradiated with the white light emitted from the second offset illumination light source 123 as described above, the intensity of the scattered light corresponding to the state of the semiconductor film is similarly obtained. When the irregular shape on the film 12 is anisotropic, the intensity of the scattered light is different from that when the first offset illumination light source 122 is used. Therefore, when the difference in the scattered light intensity is large, the microcomputer 150 causes the semiconductor film 12 to have anisotropic roughness.
It is determined that it has occurred above.

In this embodiment, the CCD camera 16
0 detects the light amount in each wavelength region corresponding to red (R), green (G), and blue (B). Of the light in the wavelength regions corresponding to the three primary colors, if the irregularities formed on the surface of the semiconductor film 12 are fine, the scattered light contains a large amount of light in the short wavelength region (blue / B). On the other hand, if the unevenness formed on the surface of the semiconductor film 12 is large, the numerical value obtained by dividing the light amount in the long wavelength region (red / R) by the short wavelength region (blue / B) luminance in the scattered light is relative. Is larger than when the irregularities are small.
Therefore, the microcomputer 150 determines that, in the output result from the CCD camera 160, the light receiving level of the scattered light at the CCD camera 160 is within a certain range and the light receiving amount in the short wavelength region (blue / B). , Medium wavelength region (green /
G) and the light reception amount in the long wavelength region (red / R), when the light reception amount in the low wavelength region (blue / B) is larger than a certain ratio, the semiconductor formed on the substrate 10 Membrane 12
Is determined to be normal. With this configuration, the semiconductor film 12 can be evaluated in consideration of not only the amount of scattered light but also the wavelength region of light included therein, so that the quality of the semiconductor film 12 can be more accurately inspected. it can.

Further, in this embodiment, the light receiver is only the CCD camera 160, but two light sources for film quality evaluation (the first light source) for emitting white light composed of parallel light from two directions orthogonal to each other in the plane of the substrate 10. Offset illumination light source 122 and second
Offset illumination light source 123). Also,
The substrate 10 is placed on an XY stage 110,
When the Y stage 110 is moved in the X-axis direction and the Y-axis direction to move the irradiation region of the substrate 10 from the first offset illumination light source 122 and the second offset illumination light source 123, the entire surface of the substrate 10 Can be subjected to the above-described inspection. Therefore, the crystal state of the semiconductor film 12 can be grasped over the entire surface of the substrate 10.
In the microcomputer 150, if the output of each pixel from the CCD camera 160 and the coordinates are stored in the memory in association with each other, the change in the scattered light in two directions orthogonal to each other in the CCD image plane and the crystal of the semiconductor film 12 can be obtained. An in-plane distribution of states can be obtained. Here, the white light emitted from the second offset illumination light source 123 is
Irradiation on the semiconductor film 12 above the zero is in the YZ plane, and corresponds to the moving direction (sub-scanning direction) of the line beam during laser annealing. Therefore, when the irradiation region of the previous line beam and the irradiation region of the current line beam partially overlap in the annealing step, the state shown in FIG.
As shown in the figure, the film quality of the semiconductor film 12 periodically changes in the Y-axis direction. For example, if the annealing process is performed so that the line beams partially overlap in the Y direction, the portion irradiated with the line beam in the Y direction in the Y direction is annealed under severe conditions. The film quality of the semiconductor film 12 periodically changes with the feed pitch of the beam in the sub-scanning direction. That is, the CCD camera 1
The amount of received light at 60 changes periodically along the Y direction. In order to quantify the periodicity, for example, the image of the CCD camera may be Fourier-transformed in the sub-scanning direction. For example, the field of view
Assume that an image of 256 micron square is stored with a resolution of 256x256 pixels. First, an average of one line in the main scanning direction is converted into 256 number sequences (a ₀ , a ₁ , a ₂ ,..., A ₂₅₅ ) and stored as a luminance distribution number sequence in the sub-scanning direction. This is converted to a real number discrete Fourier transform, that is, a complex number sequence A _K represented by A _K = Σa _j e ^{-2πij k / N} (from j = 0 to N-1). Here simply K = 1 ~ 128
| A _K | may be added over the entire range, but it is possible to quantify with higher accuracy by focusing on the laser feed pitch in the sub-scanning direction.

That is, | A _K | represents a periodic component of a 256 / k micron pitch. For example, if the feed pitch of the laser in the sub-scanning direction is 50 microns, | A _K | This value indicates the strength of the irregularity period at the feed pitch. This value increases when periodic irregularities due to the laser pitch appear strongly. In addition, | A
_The same applies to values such as _2k |, | A _3k |, ... Since | A _K | is a discrete sequence, the accuracy is still better if the | A _K | before and after K = 5, 10, 15,...

By such processing, a periodic spectrum of the surface roughness of the semiconductor film 12 can be obtained. It is determined that the smaller the periodic distribution component is, the more uniform the surface roughness of the crystalline semiconductor film 12 is. Can be. On the other hand, naturally, such a periodic component does not appear in the main scanning direction.

As described above, according to the inspection apparatus 100 of the present embodiment, it is possible to quantitatively evaluate the film quality of the semiconductor film 12 in a short time such as several seconds to several minutes during the manufacturing process of a TFT or the like. it can. Therefore, only the substrate 10 which is determined to be non-defective in such a 100% inspection is sent to a post-process,
Is manufactured, the abnormal semiconductor film 12 is subjected to TFT
Since there is no need to perform a useless process of
The manufacturing cost of the FT can be reduced. In addition, since the TFT is manufactured using only the semiconductor film 12 determined to be non-defective, a TFT having stable quality can be manufactured. Therefore, if an active matrix substrate in which such a TFT having a stable quality is formed for a pixel switching or a driving circuit is used, a liquid crystal panel using the active matrix substrate can improve display quality and reliability. Can be achieved.

[Second Embodiment] FIG. 8 is a block diagram schematically showing a main part of a laser annealing / inspection apparatus 200 for a polycrystalline semiconductor film according to the present embodiment. FIG. 9 shows a laser annealing / inspection apparatus 20 for a polycrystalline semiconductor film according to this embodiment.
FIG. 2 is a perspective view schematically showing an optical system 0 and the like. 10 and 11 are a side view of the optical system of the laser annealing / inspection apparatus 200 according to the present embodiment as viewed from the Y-axis direction and a side view as viewed from the X direction.

In FIG. 8, the laser annealing of this embodiment is performed.
The inspection apparatus 200 is configured with respect to the annealing apparatus 300 so that the laser annealing step and the inspection step can be continuously performed in the same apparatus. That is, in the laser annealing / inspection apparatus 200 according to the present embodiment, a cassette loader for loading a plurality of substrates 10 on which an amorphous semiconductor film has been formed on a cassette (not shown) with the plurality of substrates 10 mounted thereon. Unit 271, a cassette unloader unit 272 for storing the substrate 10 determined to be non-defective as a result of the inspection, and a defective substrate discharging unit 290 for discharging the substrate 10 whose semiconductor film 12 is determined to be abnormal. And an XY stage 210 to which substrates are supplied one by one from a cassette loader unit 271 by a transfer robot 280, and an optical system unit 205 for performing laser annealing and optical inspection. , The control of the stage 210, and the control of the transfer robot 280 are all performed by the microcomputer 250. It is your. Here, the optical system unit 2
05 is arranged in the vacuum chamber 209.

In this laser annealing / inspection apparatus 200, the optical system section 205 has the structure shown in FIGS.
As shown in FIG. 3, an XY stage 210 on which a glass substrate 12 on which a semiconductor film 12 is formed is mounted, a laser light source 220, and a laser beam emitted from the laser light source 220 is mounted on the stage 210. And an optical system 235 that emits and condenses a line beam toward the substrate 12 that has been irradiated. In the example shown here, since the irradiation area of the line beam extends in the X direction, to perform laser annealing on the entire surface of the substrate 12, the XY stage 210 moves in the Y direction.

The optical system unit 205 includes a first scattered light receiver 230 for receiving scattered light reflected from the substrate 10 at an angle of approximately 45 ° on the ZX plane, X
A second scattered light receiver 240 for receiving scattered light reflected from the substrate 10 at an angle of approximately 45 ° on a plane is provided. Here, the first scattered light receiver 230 and the second scattered light receiver 240 are configured to output a light reception result to the microcomputer 250. This personal computer 250
First scattered light receiver 230 and second scattered light receiver 2
Based on the detection result of 40, whether the semiconductor film 12 formed on the substrate 10 was laser-annealed normally (polycrystallized), or was not properly laser-annealed (polycrystallized, or Damaged)
Function as a film quality judging means for judging. Such a film quality determination means is realized by an operation performed according to an operation program stored in the personal computer 250 in advance. The microcomputer 2
Reference numeral 50 is set so as to issue a warning when the semiconductor film 12 is determined to be abnormal in an inspection step described later.

Here, since the calibration sample 219 having predetermined irregularities is arranged on the XY stage 210, the personal computer 250 periodically or in response to a request from the operator. The sample 219 is irradiated with laser light from the laser light source 220, and the scattered light is received by the first scattered light receiver 230 and the second scattered light receiver 240. Of the scattered light receiver 230 and the second scattered light receiver 240 are adjusted. Then, the personal computer 150 uses the first scattered light receiver 230 and the second scattered light receiver 2
If the light receiving result of 40 is deviated by more than a predetermined level, a warning to that effect is issued, and the laser light source 220 is notified to be checked.

In the laser annealing / inspection apparatus 200 configured as described above, first, one substrate 10 on which the amorphous semiconductor film 12 is formed is taken out of the cassette loader unit 271 by the transfer robot 280 and then transferred. The robot 280 rotates to place the substrate 10 on the XY stage 210 in the chamber 209. Then, after the chamber 209 is evacuated, a line beam is emitted from the laser light source 220 toward the semiconductor film 12 on the substrate 12. Here, since the irradiation region of the line beam extends in the X direction, the XY stage 210 moves in the Y direction to perform laser annealing on the entire surface of the substrate 12.

After performing the laser annealing step in this manner, the semiconductor film 12 is inspected on the same XY stage 210. For this purpose, a laser light having a low power that does not cause recrystallization of the semiconductor film 12 is emitted from the laser light source 220 toward the substrate 12 mounted on the stage 210. As a result, when the semiconductor film 12 on the substrate 10 is not sufficiently polycrystallized, most of the light
-Reflect parallel to the device optical axis ML in the X plane. Therefore, the reflected light hardly reaches the first scattered light receiver 230 and the second scattered light receiver 240. Therefore, the microcomputer 250 includes the first scattered light receiver 230
Further, assuming that the output of the second scattered light receiver 240 is at a low level, the semiconductor film 12 formed on the substrate 10 is determined to be abnormal. Based on the determination result, the transfer robot 280 removes the substrate 12 from the defective substrate discharging unit 290.
Send to

If the semiconductor film 12 is damaged during the polycrystallization, a part of the light is reflected parallel to the optical axis ML of the device, but the scattered light is diffused by the first surface due to irregular reflection on the surface. The light reaches the light receiver 230 and the second scattered light receiver 240. Therefore, the microcomputer 250 determines that the semiconductor film 12 formed on the substrate 10 is abnormal, assuming that the outputs from the first scattered light receiver 230 and the second scattered light receiver 240 are at a high level. I do. Based on this determination result, the transfer robot 280 sends the substrate 12 to the defective substrate discharge unit 290.

On the other hand, if the semiconductor film 12 is properly polycrystallized, only fine irregularities are formed on the surface thereof, and some light is reflected parallel to the device optical axis ML. Some light is scattered on the surface of the semiconductor film 12 and
Scattered light receiver 230 and second scattered light receiver 240
Will be received. Therefore, the light is received by the first scattered light receiver 230 and the second scattered light receiver 240. Therefore, the microcomputer 250 determines that the output from the first scattered light receiver 230 and the output from the second scattered light receiver 240 are both within a certain range, and the semiconductor film 12 formed on the substrate 10 is normal. It is determined that there is. Based on this determination result, the transfer robot 280 sends the substrate 12 to the cassette unloader 272. Then, only the substrate 10 sent to the cassette unloader section is sent to a subsequent process.

If two types of wavelengths can be output from the laser light source 220, the size of the unevenness of the semiconductor film can be determined more accurately from the difference in scattered light depending on the wavelength.

Further, in this embodiment, the light source is the laser light source 2.
20, only two light receivers (first scattered light receiver 2) that receive scattered light in two directions orthogonal to each other in the plane of the substrate 10.
30 and the second scattered light receiver 240), the scattered light is received from two directions. The substrate 10
Is mounted on an XY stage 210, and the XY stage 210 is moved in the Y-axis direction to
By moving the irradiation area on the substrate 10 from above, the above inspection can be performed on the entire surface of the substrate 10. Therefore, the crystal state of the semiconductor film 12 can be grasped over the entire surface of the substrate 10. Further, in the microcomputer 250, if the movement of the XY stage 210 and the output from the first scattered light receiver 230 and the output from the second scattered light receiver 240 are stored in a memory in association with each other, the substrate 10 Change of scattered light in two directions orthogonal to each other in the plane of
In addition, the in-plane distribution of the crystalline state of the semiconductor film 12 can be obtained. Here, the second scattered light receiver 240 is
Receiving the scattered light from within the YZ plane corresponds to the moving direction (sub-scanning direction) of the line beam during laser annealing. Therefore, when the irradiation region of the previous line beam and the irradiation region of the current line beam partially overlap in the annealing step, as shown in FIG. Changes periodically. For example, if the annealing process is performed so that the line beams partially overlap in the Y direction, the portion irradiated with the line beam in the Y direction in the Y direction is annealed under severe conditions. The film quality of the semiconductor film 12 changes periodically. That is, the amount of light received by the first scattered light receiver 230 and the second scattered light receiver 240 changes periodically along the Y direction. Therefore, the in-plane distribution of the surface roughness of the semiconductor film 12 can be obtained, and it can be determined that the smaller the in-plane distribution is, the more uniform the surface roughness of the crystalline semiconductor film 12 is. In particular, substrate 1
It can be determined that the smaller the difference in the intensity of the scattered light in two directions orthogonal to each other in the plane of 0, the more uniform the surface roughness of the polycrystalline semiconductor film 12 is.

In the microcomputer 250, the movement of the XY stage 210 and the outputs from the first scattered light receiver 230 and the second scattered light receiver 240 are stored in a memory in correspondence with each other. The change in the amount of scattered light (crystal state) in the X-axis direction and the Y-axis direction of the substrate 10 can be quantified by, for example, a method of analyzing a Fourier component as described in detail in the first embodiment. . By performing such a quantitative analysis, the process state can be quantitatively fed back to the previous process, and can be used as data for investigating the cause of the occurrence of an abnormality in the semiconductor film 12.

As described above, according to the inspection apparatus 200 of the present embodiment, while the substrate 10 is mounted on the XY stage 210 on which laser annealing has been performed in the manufacturing process of a TFT or the like, a short time such as several seconds to several minutes can be obtained. The quality of the semiconductor film 12 can be evaluated nondestructively. Therefore, if only the substrate 10 determined to be non-defective in such a 100% inspection is sent to a subsequent process to manufacture a TFT, the abnormal semiconductor film 1
Since there is no need to perform a useless process of manufacturing a TFT for the TFT 2, the manufacturing cost of the TFT can be reduced. In addition, a TFT using only the semiconductor film 12 determined to be non-defective is used.
Therefore, a TFT having a stable quality can be manufactured.
Therefore, if an active matrix substrate in which such a TFT having a stable quality is formed for a pixel switching or a driving circuit is used, a liquid crystal panel using the active matrix substrate can improve display quality and reliability. Can be achieved.

Further, since the laser annealing / inspection apparatus 200 of the present embodiment has a configuration in which the inspection apparatus 200 is incorporated in the laser annealing apparatus, the laser light source 220 and the optical system are directly used for laser annealing and inspection. it can.

In the laser annealing / inspection apparatus 200 of this embodiment, the laser light source 220 is shared for laser annealing and inspection, but a dedicated laser light source may be provided for each. Further, as the light source for film quality evaluation, a light source that emits white parallel light may be used instead of the laser light source, and the amount of light received for each wavelength region may be detected using a CCD camera as a light receiver. . Furthermore, in the laser annealing / inspection apparatus 200 of the present embodiment, the XY stage 210 is also configured to be shared for laser annealing and for inspection.
A Y stage may be provided. In this case, it is necessary to arrange the XY stage (first stage) for laser annealing in a vacuum chamber. On the contrary,
The XY stage for inspection (second stage) may be arranged outside the vacuum chamber, and the XY stage for inspection (second stage) may be the substrate 10 after laser annealing. May be configured as a cooling stage (second stage) having a built-in cooling mechanism for cooling.

Further, in the laser annealing / inspection apparatus 200 of this embodiment, two light receivers including the first scattered light receiver 230 and the second scattered light receiver 240 are provided.
If the XY stage is rotated by 90 ° and inspections in two directions are performed separately, one scattered light receiver may be used.

Further, in the laser annealing / inspection apparatus 200 of the present embodiment, the scattered light during the laser annealing is monitored by the first scattered light receiver 230 and the second scattered light receiver 240 to monitor annealing conditions and the like. It may be useful for.

[Manufacturing Method of TFT] A process of forming a TFT on a substrate 10 having a semiconductor film 12 determined to be non-defective among the semiconductor films 12 formed as shown in FIG. 1 will be briefly described. .

First, as shown in FIG. 12A, a resist mask 22 is formed on the surface of the polycrystalline semiconductor film 12 formed as shown in FIG. This semiconductor film 12 is patterned into an island-shaped semiconductor film 12 as shown in FIG.

Next, a gate insulating film 13 is formed on the entire surface of the substrate 10 at a temperature of 350 ° C. or less by a plasma CVD method. The source gas at this time is, for example, TEOS
Mixed gas of oxygen and oxygen gas can be used. .

Next, as shown in FIG.
A conductive film 21 such as a tantalum thin film is formed on the entire surface of the substrate 10 by a sputtering method or the like under a temperature condition of not more than ° C.

Next, as shown in FIG. 12D, the conductive film 21 is patterned using photolithography to form a gate electrode 15 on the surface of the gate insulating film 13.

Next, for example, phosphorus ions (impurity ions) are introduced into semiconductor film 12 using gate electrode 15 as a mask. As a result, the source / drain regions 1 are self-aligned with the gate electrode 15 in the semiconductor film 12.
6 are formed, and the portion where the impurity ions are not introduced becomes the channel region 17. For the introduction of such impurities, for example, a bucket type mass non-separation type ion implantation apparatus (ion doping apparatus) can be used. As a source gas, phosphine diluted with hydrogen gas so as to have a concentration of 5% is used. (PH ₃ ) can be used. Note that P
In the case of forming a channel type TFT, diborane (B ₂ H ₆ ) diluted with hydrogen gas to a concentration of 5% may be used as a source gas.

Next, as shown in FIG.
An interlayer insulating film 18 made of a silicon oxide film is formed by a plasma CVD method under a temperature condition of not more than ° C. As the source gas at this time, for example, a mixed gas of TEOS and oxygen gas can be used. Next, under oxygen atmosphere,
A heat treatment at 1 ° C. for one hour is performed to activate the implanted phosphorus ions and to modify the interlayer insulating film 18.

Next, a contact hole 19 is formed, and thereafter the source / drain electrode 2 conductively connected to the source / drain region 16 through the contact hole 19.
0 is formed. In this manner, the TFT on the surface of the substrate 10 is
Form 30.

When the TFT 30 is formed as a switching element in an active matrix of a liquid crystal display panel, the gate electrode 15 is formed as a part of a scanning line. In addition, one of the source / drain electrodes 20 is formed as a data line, and the other of the source / drain electrodes 20 is configured as a part of a pixel electrode or an electrode which is conductively connected to the pixel electrode. In addition, this embodiment and any of the embodiments described below are merely examples, and a low-concentration region or an offset region may be provided in a region of the source / drain region 16 facing an end of the gate electrode 15. .

In the TFT 30 configured as described above, since the polycrystalline semiconductor film 12 used as the active layer has already been subjected to the film quality inspection and determined to be non-defective, a TFT of stable quality can be manufactured. Therefore, if an active matrix substrate in which such a TFT having a stable quality is formed for a pixel switching or a driving circuit is used, the display quality and the reliability of a liquid crystal panel using the active matrix substrate are improved. Can be achieved.

[0076]

As described above, according to the present invention, the quality of a semiconductor film can be inspected in a short time without destruction.
In a TFT manufacturing process, the film quality is evaluated in-line, and only a substrate on which a normal-quality polycrystalline semiconductor film is formed can be sent to a subsequent process. Therefore, the yield and reliability of an active matrix substrate of a liquid crystal panel using a TFT as a switching element are improved.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are process cross-sectional views until a polycrystalline semiconductor film is formed over a substrate. FIGS.

FIG. 2 is an explanatory view showing a method of performing laser annealing in the step shown in FIG.

FIGS. 3A to 3C are cross-sectional views schematically showing states of a polycrystalline semiconductor film surface obtained by performing laser annealing on a amorphous semiconductor film on a substrate using a line beam; FIG. 4 is an explanatory view showing a change in roughness of the surface of a polycrystalline semiconductor film in the longitudinal direction (main scanning direction) of a line beam when laser annealing is performed; Scanning direction)
FIG. 4 is an explanatory diagram showing a change in roughness of the surface of the polycrystalline semiconductor film in FIG.

FIG. 4 is a perspective view schematically showing a main part of an annealing apparatus used in a laser annealing step performed before performing an inspection method of a polycrystalline semiconductor film according to the first embodiment of the present invention.

FIG. 5 is a perspective view schematically showing a main part of an inspection apparatus for performing the method of inspecting a polycrystalline semiconductor film according to the first embodiment of the present invention.

FIG. 6 is a side view of a main part of the inspection apparatus shown in FIG. 5, as viewed from a Y-axis direction.

FIG. 7 is a side view of a main part of the inspection apparatus shown in FIG. 5, viewed from the X-axis direction.

FIG. 8 is a block diagram schematically illustrating a main part of a laser annealing / inspection apparatus for performing an inspection method of a polycrystalline semiconductor film according to a second embodiment of the present invention;

9 is a perspective view schematically showing an optical system and the like of the laser annealing / inspection device shown in FIG.

10 is a side view of the optical system of the laser annealing / inspection apparatus shown in FIG. 9 as viewed from the Y-axis direction.

11 is a side view of the optical system of the laser annealing / inspection apparatus shown in FIG. 9 as viewed from the X-axis direction.

12A to 12E are process cross-sectional views illustrating a method of manufacturing a TFT from the polycrystalline semiconductor film formed by the method illustrated in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Substrate 11 ... Underlying protective film 12 ... Semiconductor film 13 ... Gate insulating film 15 ... Gate electrode 16 ... Source / drain region 17 ... Channel region 18 ... Interlayer Insulating film 19 Contact hole 20 Source / drain electrode 21 Conductive film 22 Resist mask 30 TFT 100 Inspection device 110, 210 XY stage 119, 219 Calibration sample 122 First offset illumination light source (light source for film quality evaluation) 123 Second light source for offset illumination (light source for film quality evaluation) 160 CCD camera (light receiver) 150, 250 Personal computer (film quality judgment means) 200 Laser annealing / inspection device 209 Vacuum chamber 230 First scattered light receiver 240 Second scattered light receiver 271 Zehnder portion 272 irradiated region L0 line beam of the cassette unloader unit 280 transfer robot 290 defective substrate discharging unit 300 annealer 310 X-Y stage 320 the laser light source L line beam

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G02F 1/1368 G09F 9/00 338 5F052 G09F 9/00 338 352 5F110 352 H01L 21/20 5G435 H01L 21/20 G02F 1 / 136 500 29/786 H01L 29/78 624 21/336 627G F-term (reference) 2F065 AA49 BB17 CC31 DD06 FF41 FF61 GG04 GG23 GG24 HH04 HH12 HH14 JJ00 JJ03 JJ05 JJ08 JJ09 MM03 NN02 NN13 PP90 AB07 AB20 BA01 BA08 BA10 BB01 BC06 CA03 CA04 CA07 CB05 DA07 DA13 EA11 EA17 EA30 EB01 2H088 EA02 FA11 FA30 HA08 HA28 MA16 2H092 JA24 JB77 KA04 KA07 MA30 MA55 NA29 NA30 4M106 AA10 AB20 BA05 CA24 DB08 DJ12 DJ12 DJ13 BB07 DA02 DB03 JA01 JA10 5F110 AA24 BB01 CC02 DD02 DD13 EE04 EE44 FF02 FF30 GG02 GG13 GG25 GG45 HJ01 HJ12 HJ23 HM14 HM15 NN02 NN23 NN35 NN40 PP03 QQ09 QQ11 5G435 AA14 KK05 KK12 KK12

Claims (25)

[Claims] 1. A semiconductor film formed on a substrate is irradiated with directional light to measure the intensity of scattered light from the surface of the semiconductor film, and the intensity of the scattered light is measured based on the intensity of the scattered light. A method for inspecting a semiconductor film, comprising determining an uneven state of a surface. 2. The method according to claim 1, wherein the directional light is a laser beam. 3. The semiconductor film according to claim 1, wherein the semiconductor film is a film obtained by irradiating a laser beam to an amorphous semiconductor film formed on the substrate and polycrystallizing the amorphous semiconductor film. Inspection method. 4. The laser light irradiation region according to claim 3, wherein an irradiation area of the laser light for polycrystallizing the semiconductor film is a rectangle that is long in one direction and smaller than a substrate area, and the laser light is fixed in a laser light scanning direction. A method for inspecting a semiconductor film, characterized in that the film is polycrystallized by irradiating while scanning at a feed width of 1. 5. The scattered light intensity according to claim 1, wherein the scattered light intensity is measured for each predetermined wavelength region of the scattered light, and the scattered light intensity in a short wavelength region and the scattered light intensity in a long wavelength region are measured. A method of inspecting a semiconductor film, wherein the state of unevenness on the surface of the semiconductor film is determined based on the comparison of the above. 6. The semiconductor device according to claim 5, wherein when the intensity of the scattered light in the long wavelength region is lower than the intensity of the scattered light in the short wavelength region, it is determined that the unevenness of the surface of the semiconductor film is large. Inspection method of a semiconductor film. 7. The laser light scanning device according to claim 2, wherein the laser light is incident on the substrate in the in-plane direction of the substrate in a direction perpendicular to the laser light scanning direction. A method for inspecting a semiconductor film, wherein the intensities are separately measured, and the unevenness state of the surface of the semiconductor film is determined based on a difference in intensity of scattered light in the incident light in the two directions. 8. The semiconductor film according to claim 7, wherein the smaller the intensity difference of the scattered light in the incident light in the two directions, the more the surface of the semiconductor film is determined to be isotropic. Inspection method. 9. The method according to claim 1, wherein an in-plane distribution of the intensity of the scattered light from the surface of the semiconductor film on the substrate is measured, and the intensity of the scattered light is measured based on an intensity difference in the in-plane distribution. A method for inspecting a semiconductor film, comprising determining an uneven state of a surface of the semiconductor film. 10. The semiconductor film inspection method according to claim 9, wherein it is determined that the smaller the intensity difference in the in-plane distribution, the more uneven the surface of the semiconductor film is in the plane. 11. The method according to claim 9, wherein
A method for inspecting a semiconductor film, comprising quantifying a change in the amount of scattered light in at least one of two directions, a scanning direction of the laser and a direction orthogonal thereto, based on the measurement result of the scattered light. 12. The absolute Fourier transform of a complex Fourier component in a predetermined period range, wherein a Fourier transform of an intensity change of the scattered light in at least one of the two directions is used as the quantifying means. A method for inspecting a semiconductor film, comprising: determining an uneven state of a surface of the semiconductor film based on a sum of values. 13. The semiconductor film inspection method according to claim 12, wherein it is determined that the larger the sum of the absolute values of the complex Fourier components in the predetermined frequency range, the larger the unevenness of the surface. 14. The inspection of a semiconductor film according to claim 12, wherein the predetermined cycle range includes either the laser irradiation feed width cycle or a cycle obtained by dividing the laser irradiation feed width by an integer. Method. 15. A thin film transistor is formed by using, as an active layer, a semiconductor film whose surface unevenness is determined to be within a predetermined level range by the semiconductor film inspection method defined in any one of claims 1 to 14. A method for manufacturing a thin film transistor. 16. A semiconductor film inspection apparatus for performing the semiconductor film inspection method according to claim 1, wherein light having directivity is applied to a surface of the semiconductor film on the substrate. A light source for evaluating film quality to be irradiated, a light detector for detecting the intensity of scattered light at a position deviating from a direction in which light emitted from the light source for evaluating film quality is specularly reflected on the surface of the semiconductor film, and an intensity of the scattered light. And a film quality judging means for judging the surface unevenness state of the semiconductor film from the above. 17. The light source for evaluating film quality according to claim 16, wherein the light source for evaluating the film quality is a light source that outputs light including at least two wavelength ranges of not less than a predetermined wavelength and not more than a predetermined wavelength. An apparatus for inspecting a semiconductor film, comprising: means for measuring an intensity for each specific wavelength region. 18. The semiconductor film inspection apparatus according to claim 16, wherein said film quality evaluation light source has a characteristic of selectively outputting light of at least two predetermined wavelength ranges. 19. The semiconductor film inspection apparatus according to claim 17, wherein the predetermined wavelength range is from 400 nm to 500 nm. 20. The laser light source according to claim 16, wherein the light source for evaluating film quality is a laser light source for performing laser annealing on an amorphous semiconductor film formed on the substrate. A semiconductor film inspection apparatus characterized by being used for film inspection. 21. A laser light source according to claim 16, further comprising a laser light source for performing laser annealing on an amorphous semiconductor film formed on said substrate, separately from said light source for evaluating film quality. An inspection apparatus for a semiconductor film. 22. The semiconductor device according to claim 20, further comprising a stage on which the substrate is mounted, wherein the stage is used at the time of laser annealing and at the time of inspection of the surface unevenness of the semiconductor film by the intensity of scattered light. An inspection device for a semiconductor film, comprising: 23. The method according to claim 22, wherein the stage on which the substrate is mounted is a first stage used at the time of laser annealing, and a second stage for inspecting the surface unevenness of the semiconductor film after the laser annealing by the intensity of scattered light. A second stage, wherein the second stage includes a cooling unit for cooling the substrate after laser annealing. 24. The semiconductor device according to claim 16, wherein the film quality determining means, when determining the unevenness of the semiconductor film, a command signal for discharging the substrate as a defective product, or the defective substrate is a defective product. A semiconductor film inspection apparatus configured to issue an alarm indicating that 25. The apparatus according to claim 16, wherein a sample having predetermined irregularities for calibrating the light source and the photodetector is arranged on a stage on which the substrate is mounted. Characteristic semiconductor film inspection equipment.