JP2003086505A - Method of manufacturing semiconductor device and semiconductor manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a TFT which can have high-level uniform transistor characteristics in applying to system-on-glass or the like and can be driven at a high speed with superior mobility especially in a peripheral circuit region. SOLUTION: An a-Si film 2 is patterned on a glass substrate 1 into lines (ribbon forms) (Fig. 1(a)) or into islands (Fig. 1(b)), the surface of the a-Si film 2 or the rear surface of the glass substrate 1 is irradiated and scanned in an arrowed direction with an energy beam emitted from a CW laser 3 timewise continuously to thereby crystallize the film 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, a method of manufacturing the same, and a semiconductor manufacturing device, and more particularly, to a pixel region and a pixel region each having a plurality of thin film transistors on an amorphous substrate such as alkali-free glass. A semiconductor device provided with the peripheral circuit area, so-called system-on-device
It is suitable to be applied to a panel.

[0002]

2. Description of the Related Art Thin film transistor (TFT)
Transistor) is formed on an extremely thin and fine operating semiconductor thin film, and is considered to be mounted on a large-screen liquid crystal panel in consideration of the recent demand for a large area.
In particular, it is expected to be applied to system on panel, etc.

In the system on panel, a plurality of polycrystalline semiconductors TF are formed on an amorphous substrate such as alkali-free glass.
T (especially polycrystalline silicon TFT (p-Si TFT)) is formed. In this case, by forming an amorphous silicon (a-Si) film as a semiconductor thin film and then irradiating it with an excimer laser having an ultraviolet wavelength and a short pulse, only the a-Si film is melted and crystallized without affecting the glass substrate. The mainstream method is to obtain a p-Si film that functions as an operating semiconductor thin film.

[0004]

An excimer laser which emits a linear beam having a high output corresponding to a large area of a system-on-panel has been developed, but a p-Si film obtained by laser crystallization has been developed. Is susceptible to not only the irradiation energy density but also the beam profile and the state of the film surface, and it is difficult to uniformly form a large crystal grain size over a large area. When the sample crystallized by the excimer laser is observed by AFM, as shown in FIG. 37, the crystal grains that are isotropically grown from the randomly generated nuclei each have a shape close to a regular polygon, and the crystal grains collide with each other. Protrusions are observed at the crystal grain boundaries, and the crystal grain size is less than 1 μm.

As described above, when a TFT is manufactured using the p-Si film obtained by crystallization using an excimer laser, the channel region contains many crystal grains. If the grain size is large and the number of grain boundaries existing in the channel is small, the mobility is high, and if the grain size in the part that became the channel region is small and there are many grain boundaries in the channel, the mobility decreases. In addition, there is a problem that the transistor characteristics of the TFT easily vary depending on the particle size. Also,
The crystal grain boundaries have many defects, and the existence of grain boundaries inside the channel suppresses the transistor characteristics. The mobility of the TFT obtained by this technology is 150 cm ² /
It is about Vs.

The present invention has been made in view of the above problems, and when applied to a peripheral circuit integrated type TFT-LCD, a system-on-panel, a system-on-glass, etc., the transistor characteristics of the TFT have a high level. Homogenize with
In particular, it is an object of the present invention to provide a semiconductor device including a TFT that has excellent mobility and can be driven at high speed in a peripheral circuit region, a manufacturing method thereof, and a semiconductor manufacturing device.

Further, in the present invention, when the transistor characteristics of the TFT are homogenized at a high level, a TFT having excellent mobility, especially in the peripheral circuit region and capable of high-speed driving is realized.
A semiconductor device capable of supplementing the insufficient output of an energy beam that continuously outputs energy with respect to time, improving throughput in crystallization of a semiconductor thin film, and realizing the TFT having excellent efficiency, and a manufacturing method thereof. It is an object of the present invention to provide a method and a semiconductor manufacturing device.

[0008]

In order to solve the above-mentioned problems, the present invention has the following aspects.

A first aspect of the present invention is a method of manufacturing a semiconductor device in which a pixel region having a plurality of thin film transistors and a peripheral circuit region thereof are provided on a substrate, and at least the peripheral circuit region is provided. It is characterized in that the semiconductor thin film formed in the peripheral circuit region is crystallized by an energy beam that continuously outputs energy with respect to time to form an operating semiconductor thin film of each thin film transistor.

In this case, as a specific example of the energy beam, CW laser light, and further semiconductor excited solid state laser light (DPSS laser light) is preferable.

As described above, by crystallizing the semiconductor thin film with the energy beam that continuously outputs energy with respect to time, the crystal grain size becomes large, specifically, in the scanning direction of the energy beam. As a result, the crystalline state of the semiconductor thin film is formed into a streamlined flow pattern having long crystal grains. In this case, the crystal grain size is 10 to 100 times as large as that when crystallized by currently used excimer laser light.

In the first aspect, it is preferable that each of the semiconductor thin films is patterned on the substrate in a linear or island shape.

The crystallization technique using a CW laser has been studied for a long time in the field of SOI, but it was considered that a glass substrate cannot be thermally endured. surely,
When laser irradiation is performed in the state where the a-Si film is formed on the entire surface as a semiconductor thin film, the temperature of the a-Si film rises and the temperature of the glass substrate rises, and damage such as cracks is observed. In the present invention, by patterning the semiconductor thin film in a linear or island shape in advance, the temperature of the glass substrate does not rise and cracks and diffusion of impurities into the film are prevented. As a result, TF can be attached
Also when forming the operating semiconductor thin film of T, it is possible to use an energy beam that continuously outputs energy for a time represented by a CW laser without any inconvenience.

In the first aspect, on the substrate,
It is preferable that a marker for irradiation position alignment of the energy beam corresponding to each of the patterned semiconductor thin films is formed.

With this, it is possible to suppress the deviation of the irradiation position of the energy beam, so that so-called lateral growth becomes possible by the stable supply of the continuous beam, and the operating semiconductor thin film having large crystal grains can be surely formed. It becomes possible.

In the first aspect, a plurality of slits are formed in each of the semiconductor thin films patterned on the substrate, or an insulating film on a plurality of thin lines is formed on each of the semiconductor thin films, and the slits are formed. It is preferable to irradiate the energy beam substantially along the longitudinal direction of.

In this case, at the time of crystallization by energy beam irradiation, the slits or the insulating film (hereinafter, simply referred to as a slit for convenience) block the crystal grains and grain boundaries growing from the peripheral portion toward the inside, Only crystal grains that grow parallel to the slits are formed between the slits. If the region between the slits is sufficiently narrow, a single crystal will be formed in this region. Thus, by forming the slits such that the slits are regions in which formation of large-sized crystal grains is desired, for example, the regions between the slits are the channel regions of the thin film transistors, the channel regions are selectively in a single crystal state. Can be

In the first aspect, the pixel region and the peripheral circuit region may have different irradiation conditions of the energy beam for continuously outputting energy with respect to time, or may be formed in the pixel region. The semiconductor thin film is crystallized by an energy beam that outputs energy in a pulsed manner, and the semiconductor thin film formed in the peripheral circuit region is crystallized by an energy beam that continuously outputs energy with respect to time (more specifically, , After crystallizing the semiconductor thin film formed in the pixel region, crystallizing the semiconductor thin film formed in the peripheral circuit region),
A semiconductor thin film formed in the peripheral circuit region is crystallized by an energy beam that continuously outputs energy with respect to time to form an operating semiconductor thin film, and the semiconductor thin film formed in the pixel region is directly used as an operating semiconductor thin film. Etc. are preferred.

The thin film transistor provided in the peripheral circuit region has a higher required accuracy than that in the pixel region, and it requires optimization during manufacture. Therefore, it is possible to surely form an operating semiconductor thin film having large-sized crystal grains, and apply an energy beam that continuously outputs energy that can homogenize the operating characteristics of each thin film transistor at a high level, especially in the peripheral circuit region. However, in the pixel region in which the required accuracy is relaxed, the irradiation time of the energy beam is shortened, a pulsed energy beam is applied, or the like, and a process difference is provided between the peripheral circuit region and the pixel region. As a result, it becomes possible to extremely efficiently realize a desired system-on-panel that meets the accuracy requirement of each place.

A second aspect of the present invention is a semiconductor device in which a pixel region having a plurality of thin film transistors and a peripheral circuit region thereof are provided on a substrate, and at least the peripheral circuit region is formed. The operating semiconductor thin film of each thin film transistor is formed in a crystalline state having a streamlined flow pattern with large crystal grains.

In this case, the operating semiconductor thin film can have a large crystal grain state along the streamline shape of the flow pattern, preferably a single crystal state. Therefore, for example, the channel region of the thin film transistor can be in the single crystal state. This makes it possible to realize a high-speed driving thin film transistor having extremely high transistor characteristics.

On the substrate, Si and N, or
The semiconductor thin film is formed through a buffer layer having a thin film containing Si, O and N, and the hydrogen concentration of the semiconductor thin film is 1 × 10 ²⁰ pieces / cm ³ or less, and more preferably the hydrogen concentration of the thin film is 1 ×. 10 ²² pieces / cm ³ or less.

This makes it possible to homogenize the transistor characteristics of the thin film transistor at a high level by utilizing crystallization by an energy beam which outputs energy continuously with respect to time, and to prevent the thin film transistor from pinholes or peeling. It is possible to stably form a thin film transistor having extremely high reliability.

A third aspect of the present invention is a semiconductor manufacturing apparatus for emitting an energy beam for crystallizing a semiconductor thin film formed on a substrate, wherein the energy beam is continuously output with respect to time. And has a function of scanning the irradiation object with the energy beam, and the output instability of the energy beam is smaller than ± 1% / h.

In this case, the output instability of the energy beam is smaller than ± 1% / h, more preferably the noise (optical noise) indicating the instability of the energy beam is 0.1.
By setting the rms% or less, a stable continuous beam can be supplied, and by operating the continuous beam, the operating semiconductor thin films of a large number of thin film transistors can be uniformly formed in a large grain size crystalline state (flow pattern). Is possible.

A fourth aspect of the present invention is, similarly to the third aspect, a semiconductor manufacturing apparatus, in which a substrate having a semiconductor thin film formed on the surface thereof is installed, and the substrate is arranged in the in-plane direction of the semiconductor thin film. Installation means that can be freely moved, laser oscillation means having a function of continuously outputting an energy beam with respect to time, and the energy beam emitted from the laser oscillation means is optically divided into a plurality of sub-beams. Beam splitting means for splitting, and each sub-beam is scanned relative to each predetermined portion of the semiconductor thin film to crystallize each predetermined portion.

In this case, each of the divided sub-beams causes
Since a plurality of predetermined portions of the semiconductor thin film corresponding to each sub-beam are crystallized at the same time, the operating semiconductor thin films of a large number of thin film transistors can be uniformly formed in a crystal state (flow pattern) having a large grain size. In addition, even a laser oscillator having a function of continuously outputting an energy beam such as a CW laser having a lower output than an excimer laser can achieve an extremely high throughput comparable to that of an excimer laser and efficiently. It is possible to achieve crystallization of the thin film transistor.

In the fourth aspect, each sub-beam irradiates only the formation portion of each thin film transistor with an energy intensity optimum for crystallization, and passes through the non-formation portion of each thin film transistor at high speed. It is preferable to control. As a result, even better throughput is obtained, and extremely efficient crystallization of the transistor is realized.

A fifth aspect of the present invention is, like the third aspect, a semiconductor manufacturing apparatus, in which a substrate having a semiconductor thin film formed on the surface thereof is installed, and the substrate is arranged in the in-plane direction of the semiconductor thin film. An installation means that can be freely moved, a laser oscillation means having a function of continuously outputting an energy beam with respect to time, a passage area and a cutoff area of the energy beam, and the energy beam is intermittently provided. An intermittent emitting means for passing the substrate, while relatively scanning the substrate with respect to the energy beam, intermittently irradiate the semiconductor thin film with the energy beam, selectively forming only the formation site of each thin film transistor. It is characterized by being crystallized.

In this case, the desired portion of the semiconductor thin film can be selectively crystallized by controlling the transmission of the energy beam mainly by the intermittent emitting means. That is, since a desired portion of a so-called solid semiconductor thin film can be crystallized intermittently, it is not necessary to previously provide a beam irradiation portion, that is, a thin film transistor formation portion (ribbon-shaped or island-shaped formation portion). The number of steps can be reduced and the throughput can be improved.

In the fifth aspect, a portion of the semiconductor thin film different from a portion where the thin film transistor is formed is intermittently irradiated with the energy beam to form an alignment marker for the thin film transistor which is crystallized into a predetermined shape. Is preferred. As described above, by forming the alignment marker along with the crystallization of the formation portion of the thin film transistor, the number of manufacturing steps can be reduced, and the thin film transistor can be formed efficiently and accurately.

The semiconductor device corresponding to the fifth and fourth aspects and the method for manufacturing the semiconductor device are also included in the present invention.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings.

(First Embodiment) -Crystallization by Energy Beam Continuously Output with Time-First, the main configuration of the present embodiment, that is, energy beam continuously outputting energy with respect to time Here, crystallization of a semiconductor thin film using a semiconductor-pumped (LD-pumped) solid-state laser (DPSS laser) is disclosed.

An energy beam continuous with respect to time is applied to a semiconductor thin film such as an amorphous silicon film (a-Si).
By irradiating and scanning a film, it is possible to form a polysilicon crystal having a large grain size. The crystal grain size at this time is about several μm, and a very large crystal can be formed. This crystal grain size is 10 to 100 times as large as the currently used excimer laser. Therefore, it is very advantageous for the TFT in the peripheral circuit portion that requires high-speed operation.

As shown in FIGS. 1 and 2, the buffer S
The a-Si film 2 is patterned into a linear shape (ribbon shape) (FIG. 1A) or an island shape (island shape) (FIG. 1B) on the glass substrate 1 on which iO ₂ is formed. The front surface of the Si film 2 or the back surface of the glass substrate 1 is irradiated and scanned with an energy beam continuously output from the CW laser 3 in the direction of the arrow. Thereafter, as shown in FIG. 3, the ribbon-shaped semiconductor thin film 2 (FIG. 3A) or the island-shaped semiconductor thin film 2 (FIG. 3B) is patterned and etched so that each semiconductor thin film 2 Then, an island region 6 of the TFT having a region serving as a source / drain 5 sandwiching the channel region 4 is formed.

Microcrystals are formed in the periphery of the island region 6 due to the rapid cooling rate due to thermal diffusion to the surroundings. Inside, however, the irradiation conditions (energy and scanning speed) of the CW laser 3 are appropriately selected. As a result, the cooling rate can be made sufficiently slow, and crystal grains having a width of several μm and a length of several tens of μm are formed. Thereby, the crystal grain size of the channel portion can be increased.

The crystallization technique using an energy beam continuous with respect to time is based on SOI (Silicon On Insulat)
Although research has been conducted for a long time in the field of (or), it was thought that glass substrates could not withstand heat. Certainly, when laser irradiation is performed in a state where the a-Si film is formed on the entire surface, the temperature of the glass substrate rises as the temperature of the a-Si film rises, and damage such as cracks is observed.
By processing the a-Si film into a ribbon shape or an island shape in advance, the temperature of the glass substrate does not rise and cracks and diffusion of impurities into the film do not occur.

In order to form a large number of TFTs over a large area, the stability of the energy beam is important.
A solid-state laser excited by a semiconductor LD has a noise (optical noise) indicating instability of its energy beam of 10 Hz to 2 Hz.
The energy beam output instability is <± 1% / h in the MHz region of 0.1 rms% or less, which is far superior to other energy beams.

A specific example of crystallization using a semiconductor-excited (LD-excited) solid-state laser (DPSS laser) will be described below. The wavelength of the solid-state laser is 532 nm (Nd: YVO
₄ second harmonic, Nd: YAG second harmonic, etc.). The noise (optical noise) indicating the instability of this energy beam is <0.1 rm in the range of 10 Hz to 2 MHz.
s%, time instability of energy beam output is <± 1
% / H. The wavelength is not limited to this value, and a wavelength that can crystallize the semiconductor thin film may be used. The output is 10 W, and the substrate is NA35 glass which is an amorphous substrate. The material of the amorphous substrate is not limited to this, and other non-alkali glass, quartz glass, silicon single crystal, ceramics, plastic, etc. may be used.

SiO is formed between the glass substrate and the semiconductor thin film.
_{2 The} buffer layer is formed to a film thickness of about 400 nm. The buffer layer is not limited to this, but Si
A laminated structure of an O ₂ film and a SiN film may be used. The semiconductor thin film is a silicon thin film formed by plasma CVD. Before the energy irradiation, heat treatment for hydrogen removal is performed by heat treatment at 450 ° C. for 2 hours. Here, the dehydrogenation is not limited to the heat treatment, and may be performed by irradiating the energy beam many times while gradually increasing the energy beam from the low energy side. In this example, the glass is transmitted and the irradiation is performed from the back surface, but the invention is not limited to this and irradiation may be performed from the semiconductor thin film side.

The energy beam has a size of 400 μm ×
It is molded into a long linear beam (or elliptical beam) of 40 μm. Here, the size and shape of the energy beam are not limited to this, and may be adjusted to the optimum size required for crystallization. For example, as the beam shape, a rectangular beam (or elliptical beam), a linear beam (or elliptical beam), or the like is suitable. Note that the long linear beam (or elliptical beam), rectangular beam (or elliptical beam), or linear beam (or elliptical beam) preferably has uniform energy intensity in the beam, but it is not always required to be uniform. Instead, the energy profile may have the highest intensity at the center position of the beam.

In this example, the silicon region where the TFT is formed has the ribbon-shaped a-Si film 2 patterned as shown in FIG. 2, and the adjacent ribbon-shaped a-Si films 2 are separated by a predetermined distance. Therefore, there is a region where the a-Si film 2 does not exist. By configuring the arrangement of the a-Si film 2 as described above, it is possible to significantly reduce the heat damage to the NA35 glass substrate 1. The a-Si film is not limited to the ribbon shape, but may be an island shape.

The scanning speed of the energy beam is 20 cm /
The result of crystallization of the a-Si film as s is shown in FIG. It can be seen that crystals having a crystal grain size of 5 μm or more are formed. This crystal grain size corresponds to 10 to 100 times the grain size of crystallization by excimer laser. Although crystal grains that flow in the scanning direction are observed, such a crystal pattern is defined as a "flow pattern" in this example. This name is not limited to this, but is given for convenience in this example. The crystal grain size of a type different from that of the flow pattern may form a pattern similar to the excimer laser crystallization pattern of FIG. 37 as shown in FIG. In this example, this crystal grain pattern is defined as an “excimer pattern”. This excimer pattern is formed due to improper energy density or scanning speed (or both).

Here, the results of observation of how a large amount of impurities existing in the glass affect the crystallized film will be described. In this example, NA35
Between the glass substrate 1 and the a-Si film 2 which is a semiconductor thin film, a SiO film having a thickness of about 400 nm formed by PECVD.
_Two membranes are present as buffer layers. The buffer layer is not limited to this, and may be 200 nm or more for SiO ₂ alone, or may have a laminated structure of a SiO ₂ film and a SiN film.

The results of SIMS analysis are shown in FIG. It is confirmed that impurities (aluminum, boron, sodium, barium) in the glass do not exist in the crystallized semiconductor thin film. Note that although aluminum is observed in the data, this is a ghost, and aluminum does not actually exist in the film.

FIG. 7 shows the result of examining the thermal damage to the NA35 glass (the result of observing the cross-section TEM). In this way, the boundary between the glass and the buffer layer is clear, and it can be confirmed that there is no damage to the glass.

In this example, the output is 10 W and the wavelength is 532 n.
It was crystallized using one DPSS laser of m.
When the arrangement of the semiconductor thin film pattern is already known as described above, a plurality of beams may be formed and each energy beam may be aligned with the semiconductor thin film region and simultaneously irradiated. At this time, a plurality of energy beam generators may be used, or one energy beam may be separated into a plurality of energy beams.

-Fabrication of TFT- An example of fabrication of an n-channel thin film transistor using an energy beam continuously output for the above time will be described below. Figure 8 ~
FIG. 11 is a schematic cross-sectional view showing the method of manufacturing the thin film transistor in the order of steps.

As the substrate, the glass substrate 21 of NA35 which is an amorphous substrate is used as described above. First, as shown in FIG. 8A, a film thickness of 400 is formed on the glass substrate 21.
A SiO ₂ buffer layer 22 having a thickness of about nm and a patterned Si thin film formed with an amorphous silicon thin film (a-Si film) are formed, and heat treatment is performed at 450 ° C. for 2 hours to remove hydrogen. Note that the hydrogen discharge is not limited to the heat treatment and may be performed by irradiating the energy beam many times while gradually increasing the energy beam from the low energy side.

Then, the a-Si film 2 is crystallized by using the energy beam continuously output for the above-mentioned time, and the operating semiconductor thin film 11 is formed. Specifically, for example, as shown in FIG. 2A, a semiconductor thin film, here, an a-Si film 2 is formed in a ribbon shape, a wavelength of 532 nm, and energy beam instability <0.1 rm using a DPSS laser.
With s% noise and output instability <± 1% / h, the a-Si film 2 is irradiated and scanned with a linear beam having an energy beam size of 400 μm × 40 μm at a scanning speed of 20 cm / s for crystallization.

Subsequently, as shown in FIG. 3, for example, the TFT island region 6 is formed in the crystallized ribbon-shaped semiconductor thin film. At this time, processing is performed so that the channel region 4 of the TFT is located on the central axis of the ribbon-shaped semiconductor thin film. That is, the current flowing through the completed TFT matches the scanning direction of the laser light. In this case, as shown in the lower part of FIG. 2A, a plurality (three in the illustrated example) of T
FT may be formed.

Subsequently, as shown in FIG. 8B, a silicon oxide film 23 to be a gate oxide film is formed on the operating semiconductor thin film 11 to a film thickness of about 200 nm by PECVD. At this time, another method such as an LPCVD method or a sputtering method may be used.

Then, as shown in FIG.
An aluminum film (or aluminum alloy film) 24 is formed by a sputtering method so as to have a thickness of about 00 nm.

Subsequently, as shown in FIG. 9A, the aluminum film 24 is patterned into an electrode shape by photolithography and subsequent dry etching to form a gate electrode 24.

Subsequently, as shown in FIG. 9B, the silicon oxide film 23 is patterned using the patterned gate electrode 24 as a mask to form the gate oxide film 23 following the shape of the gate electrode.

Then, as shown in FIG. 9C, ion implantation is performed on both sides of the gate electrode 24 of the operating semiconductor thin film 11 using the gate electrode 24 as a mask. Specifically, n
Type impurities, here phosphorus (P), acceleration energy 20k
Ion doping is performed under the conditions of eV and a dose amount of 4 × 10 ¹⁵ / cm ² to form source / drain regions.

Subsequently, as shown in FIG. 10A, excimer laser irradiation is performed to activate phosphorus in the source / drain regions, and then the entire surface is covered as shown in FIG. 10B. Then, SiN is deposited to a film thickness of about 300 nm to form an interlayer insulating film 25.

Subsequently, as shown in FIG. 11A, contact holes 26 for exposing the gate electrode 24 and the source / drain regions of the operating semiconductor thin film 11 are formed in the interlayer insulating film 25.

Subsequently, as shown in FIG. 11B, after forming a metal film 27 of aluminum or the like so as to fill each contact hole 26, as shown in FIG. 11C.
The metal film 27 is patterned to form wirings 27 which are electrically connected to the gate electrode 24 and the source / drain regions of the operating semiconductor thin film 11 through the contact holes 26, respectively.
Then, after a protective film covering the entire surface is formed, n-type TF
Complete T.

The relationship between the TFT characteristics and the crystal quality was examined by using the n-channel TFT manufactured through the above steps. The experimental results are shown in FIG. It can be seen that the mobility when the crystal pattern of the channel region is the flow pattern is higher than that of the excimer laser pattern. The maximum mobility reaches 470 cm ² / Vs. Further, the mobility has a strong correlation with the flow pattern shape, and as shown in FIG. 13, it was confirmed that the strongly flowing flow pattern shape has a higher mobility than the weak flow pattern shape.

As described above, according to this embodiment, the transistor characteristics of the TFT are homogenized at a high level,
In particular, a TFT having excellent mobility and capable of high speed driving can be realized in the peripheral circuit region. As a result, it is possible to realize a high-performance peripheral circuit integrated TFT-LCD, a system-on-panel, a system-on-glass, etc., which is provided with a large number of the TFTs.

-Modification- Hereinafter, various modifications of the first embodiment will be described.

(Modification 1) FIG. 14 is a schematic plan view showing a state on a glass substrate in Modification 1. Here, a ribbon-shaped a- as a semiconductor thin film is formed on the glass substrate 1.
The Si film 2 is formed, and the position marker 31 is provided at the end of the glass substrate 1 corresponding to each a-Si film 2. Although a ribbon-shaped a-Si film is shown in the illustrated example, an island-shaped a-Si film may be used.

During the irradiation scanning of the energy beam by the CW laser 3 on the a-Si film 2, the irradiation position can be automatically searched by using the position marker 31 as a guide. After determining the position, crystallization is performed by scanning the energy beam.

According to the present example, it is possible to suppress the irradiation position deviation of the energy beam, and by the stable supply of the continuous beam, so-called lateral growth becomes possible, and an operating semiconductor thin film having large-sized crystal grains can be surely obtained. It is possible to form

(Modification 2) FIG. 15 is a schematic plan view for explaining this embodiment. First, as shown in FIG. 15A, the a-Si film is formed with an island region 6 having two slits 32 substantially parallel to each other.

From the surface of the a-Si film, a CW laser, for example, an Nd: YVO ₄ laser (2ω, wavelength 532 nm) (or similar laser) was used with an energy of 6 W and a beam diameter of 400.
Slit 32 at μm × 40 μm and scanning speed of 20 cm / s
The irradiation scanning is performed in the direction of (indicated by an arrow). Of course, irradiation from the front surface can also crystallize without problems, but irradiation from the back surface also heats the sample holder together, so that a heat retaining effect on the film surface side is obtained, and better crystals are easily obtained. Although the a-Si film is melted and crystallized, microcrystals are formed in the peripheral portion of the island region 6 due to thermal diffusion to the surroundings, so that fine crystals are formed, but inside the CW laser irradiation conditions (energy and scanning). By appropriately selecting the (speed), the cooling rate can be made sufficiently slow, and crystal grains having a width of several μm and a length of several tens μm are formed.

At this time, as shown in FIG. 15B, the crystal grains and grain boundaries that grow inward from the peripheral portion and try to cross the channel region are blocked by the slits 32, and the gaps between the slits 32 are concerned. Only crystal grains that grow parallel to the slit 32 are formed. If the gap between the slits 32 is sufficiently small, this region becomes a single crystal. The slits 32 have a function of blocking grain boundaries, and the slits 3 prevent the regions between the slits 32 from being crystallized.
It is preferable to form each slit width of 2 as thin as possible. In addition, the gap between the slits 32 may be set to an extent that a margin is added to match the channel width of the device.

Then, as shown in FIG. 15C, the TF is patterned by dry etching so that the single crystallized portion between the slits 32 becomes the channel region 4.
Complete T.

Thereafter, as shown in FIG. 15D, a gate insulating film and a gate electrode are formed by a known method,
After introducing and activating the impurities, the source / drain may be formed into a TFT.

If crystallization is performed by such a method, the TFT
It is possible to selectively obtain a single crystal in a portion required for the channel region of. Therefore, since the TFT formed by using the thus-formed operating semiconductor thin film has only one crystal grain in the channel deposit area, its characteristics are improved and the variation due to the crystallinity or the crystal grain boundary is improved. Significantly reduced. Further, various processes on the glass substrate are possible, and it is possible to provide a high-performance and high-value-added display while maintaining low cost.

(Modification 3) FIG. 16 is a schematic plan view for explaining the present example and a schematic cross-sectional view taken along the line AA '. First, a base SiO ₂ film and an a-Si film 2 are continuously formed on the glass substrate 1, and then, as shown in FIG.
The Si film 2 is patterned into an island shape.

Then, as shown in FIG. 16B, a-
The SiO ₂ film is formed to a thickness of about 50nm by CVD or the like on the Si film 2, to process the SiO ₂ film in parallel fine line pattern 33 of the two.

Then, as shown in FIG. 16C, a-
The surface of the Si film 2 is irradiated and scanned with a CW laser. The irradiation conditions may be the same as in the case of the first embodiment. At this time,
Although the a-Si film 2 is melted and recrystallized by laser heating, the melted Si is easily gathered due to the surface tension because the thin wire pattern 33 exists on the upper portion, and thus the thin wire pattern 33 is formed.
A thin wire 33a of Si independent of the surroundings is formed in the lower part of the. Therefore, the Si thin wires block the crystal grains and the crystal grain boundaries that try to cross the channel. as a result,
Between the two fine line patterns 33, only crystal grains that grow parallel to the fine lines are formed.

After that, the SiO ₂ film of the fine line pattern 33 is removed by an HF aqueous solution or the like, and as shown in FIG. 16D, the single crystallized portion between the fine line patterns 33 is dried so as to become the channel region 4. Process by etching. After that, the gate insulating film and the gate electrode are formed, and the TFT may be manufactured by a known method.

If crystallization is performed by such a method, the TFT
It is possible to selectively obtain a single crystal in a portion required for the channel region of. Therefore, since the TFT formed by using the thus-formed operating semiconductor thin film has only one crystal grain in the channel deposit area, its characteristics are improved and the variation due to the crystallinity or the crystal grain boundary is improved. Significantly reduced. Further, various processes on the glass substrate are possible, and it is possible to provide a high-performance and high-value-added display while maintaining low cost.

(Modification 4) This embodiment is almost the same as the modification 2 except that the manufacturing process is the same, but the shape of the slit is different. Figure 1 shows the slit shape of this example.
7 shows. What is different from FIG. 15 is that the two slits 32 are not perfectly parallel but have a little spread in the laser scanning direction. With this shape, it is possible to more efficiently block the crystal grain boundaries that obliquely go inward from the peripheral portion, and it is easier to select the crystal grains that extend from the lower side in the figure due to the effect of necking. The subsequent process is
This is the same as the second modification.

(Fifth Modification) FIGS. 18A and 18B are schematic views for explaining the present embodiment. The upper part of FIG. 18A is a plan view of a patterning portion, and the lower part is a sectional view taken along line AA ′. ,
(B), (c) shows the manufacturing process following (a).

In the a-Si film 2, the thin film region 34 is surrounded by the thick film region 35, and the scanning irradiation of the CW laser is performed along the longitudinal direction of the thin film region 34 (FIG. 18).
(See (a)). At this time, the thick film region 35 has a large heat capacity due to its thickness, and the cooling rate becomes slow after melting. Therefore, the thick film region 35 acts as a heat bath on the thin film region 34. As a result, the crystal grain boundaries in the thin film region 34 expand toward the thick film region 35 in the periphery (see FIG. 18B). This means that the defect (crystal grain boundary) density is reduced in the thin film region 34. That is, it is possible to improve the quality of the crystal.

By using the thin film region 34 as the channel region of the TFT, a high performance TFT can be realized (see FIG. 18C).

(Second Embodiment) Next, a second embodiment of the present invention will be described. Here, the configuration of the DPSS laser device used in the first embodiment will be described.
FIG. 19 is a schematic view showing the overall configuration of the DPSS laser device of the second embodiment.

This DPSS laser device includes a solid-state semiconductor-excited DPSS laser 41 and an optical system 42 for irradiating a predetermined position with laser light emitted from the DPSS laser 41.
And a glass substrate to be irradiated is fixed, and an XY stage 43 that can be driven in horizontal and vertical directions is provided.

In this example, the material of the glass substrate is NA35 glass (alkali-free glass), and the laser wavelength is 53.
2 nm is selected. The noise (optical noise) indicating the instability of the energy beam is 0.1 rms% or less in the region of 10 Hz to 2 MHz, and the output instability is <± 1%.
/ H, and the energy beam output is 10 W.
Note that the wavelength is not limited to this value, and a wavelength that can crystallize the silicon film may be used. The beam output is not limited to this value, and a device having an appropriate output may be used. .

The energy beam has a size of 400 μm.
It is shaped into a linear beam (rectangular beam) of m × 40 μm. The size and shape of the energy beam are not limited to this, and may be adjusted to the optimum size necessary for crystallization. The energy variation in the longitudinal direction is within 40% with the maximum strength at the center.

The glass substrate is placed on the XY stage 43 perpendicularly to the optical axis. In this example, the semiconductor thin film (a-Si film) on which the TFT is formed is the same as in the first embodiment.
As shown in Fig. 1, it is ribbon-shaped or island-shaped,
Adjacent a-Si films are separated from each other, and there is a region without the a-Si film. This is to reduce thermal damage to the glass substrate used in this example.

The scanning speed of the energy beam is 20c / sec.
m. In this example, a motor-driven XY stage 43 is used. The drive mechanism of the XY stage 43 is not limited to this, and another stage can be used as long as it can be driven at 15 cm / sec or more. The scanning of the energy beam is performed by
It suffices that the Y stage 43 is relatively scanned, and the energy beam itself may be scanned or the stage may be scanned.

In the case where polycrystalline silicon is formed on a glass substrate, the substrate size is currently 400 mm × 5.
Since the length is 00 mm or more, position control during scanning is important. In the XY stage 43 of this example, the position variation per 1 m movement is within 10 μm.

According to the DPSS laser device of this embodiment, the output instability of the energy beam is smaller than ± 1% / h, and more preferably the noise (optical noise) indicating the instability of the energy beam is 10 Hz to 2 MHz. By setting the area to 0.1 rms% or less, a stable continuous beam can be supplied, and by scanning the continuous beam, the operating semiconductor thin films of a large number of TFTs are homogeneous in a crystal state (flow pattern) of large grain size. It is possible to form

-Modification- Hereinafter, various modifications of the second embodiment will be described.

(Modification 1) FIG. 20 shows the entire structure of the DPSS laser device of this example. Here, the energy beam instability is noise of 0.1 rms% or less, the output instability is <± 1% / h, and the output of the DPSS laser 41 is 10 W.
I'm using two. The laser beams emitted from the two DPSS lasers 41 are integrated into one beam on the way, thereby improving the output.

The beam size is shaped to 800 μm × 40 μm so that a larger area can be irradiated than in the case of the second embodiment. Further, the function of reading and irradiating the position marker is common to the case of the first embodiment.

The XY stage 43 is placed horizontally, and the glass substrate is placed horizontally. The irradiation scanning direction has a magnetic levitation type moving mechanism, and the X-axis direction is a normal motor drive system. The energy beam is emitted vertically.

According to the DPSS laser device of this example, the second
In addition to the various effects of the embodiment of
By providing the DPSS laser 41 for each stage, a more stable continuous beam can be supplied, and by scanning the continuous beam, the operating semiconductor thin films of a large number of TFTs are each homogeneous in a crystal state (flow pattern) with a large grain size. It is possible to form

(Modification 2) FIG. 21 shows the entire structure of the DPSS laser device of this example. Here, two DPSS lasers 4 having the same output stability, output, and the like as those of the modified example 1 are used.
3 is provided to irradiate different places as different energy beams, and each energy beam has a function of reading the irradiation position with a position marker.

According to the DPSS laser device of this example, the second
In addition to the various effects of the embodiment of
By providing the DPSS laser 41 for each stage, it becomes possible to rapidly supply a more stable continuous beam,
By scanning with the continuous beam, it becomes possible to uniformly form a large number of TFT operating semiconductor thin films in a crystal state (flow pattern) of large grain size.

(Third Embodiment) Next, a third embodiment of the present invention will be described. Here, the configuration of the DPSS laser device will be described as in the second embodiment.
Further, a method of crystallizing a semiconductor thin film using this will be described. The DPSS laser device of this embodiment is different from that of the second embodiment in that the energy beam is divided and used as described below.

This example shows an example of crystallization of a pixel portion using a semiconductor-excited (LD-excited) solid-state laser (DPSS laser) Nd: YVO ₄ . Note that although the crystallization technique of the pixel portion is referred to in this example, the present invention is not limited to the crystallization technique of the pixel portion and can be used as a crystallization technique of a peripheral circuit. The laser is Nd: YVO.
_{The number} is not limited to _4, and any similar DPSS laser light (for example, Nd: YAG) may be used. Wavelength is 5
32 nm. Furthermore, the wavelength is not limited to this, and may be any wavelength at which silicon melts. The instability of this energy beam is noise of <0.1 rms%, the time instability of the output is <± 1% / h, and the output is 10 W.

A glass substrate of NA35 which is an amorphous substrate is used as the substrate. The amorphous substrate is not limited to this, and other non-alkali glass, quartz glass,
A single crystal substrate, ceramics, plastic, etc. may be used.

SiO ₂ is formed between the glass substrate and the semiconductor thin film.
Is formed to a film thickness of about 400 nm. The buffer layer is not limited to this, and may have a laminated structure of a SiO ₂ film and a SiN film.
The semiconductor thin film is a silicon thin film having a thickness of about 150 nm formed by the plasma CVD method. 5 before energy irradiation
The heat treatment for discharging hydrogen is performed by heat treatment at 00 ° C. for 2 hours. Note that the hydrogen discharge is not limited to the heat treatment and may be performed by irradiating the energy beam many times while gradually increasing the energy beam from the low energy side. In this example,
Although irradiation is performed from the semiconductor thin film side, irradiation may be performed from the back surface after passing through the glass.

-Structure of DPSS Laser Device- FIG. 22 is a schematic view showing a part of the structure of the DPSS laser device according to the third embodiment. This DPSS laser device is a solid-state semiconductor pumped DPS similar to that of the second embodiment.
An S laser 41 (not shown), a diffraction grating 51 which is a beam splitting means for optically splitting the energy beam emitted from the DPSS laser 41 into a plurality of, in this case, seven sub-beams, and a collimator lens 52, are split. And a XY stage 43 (not shown) similar to that of the second embodiment in which the glass substrate to be irradiated is fixed and can be driven in the horizontal and vertical directions. Is configured.

In this example, the diffraction grating 51 is provided as the beam splitting means, but the present invention is not limited to this. For example, a polygon mirror, a movable mirror, an AO element (Acoust-Optic Device) using the acousto-optic effect, or the like. An EO element (Electro-Optic Device) using the electro-optical effect may be used.

Each sub-beam has a size of 80 μm × 2 which is large enough to form a thin film transistor in the pixel area.
It has a size of 0 μm and has an elliptical beam shape with maximum intensity at the center of gravity. The beam shape is not limited to the elliptical beam, and may be a long linear beam (or rectangular beam). Note that the size of the energy beam is not limited to the size in this example, and may be any size as long as a pixel TFT is formed.

In this example, the silicon region where the pixel TFT is formed is formed into a ribbon shape as shown in FIG. 23, and the semiconductor thin film ribbon 54 and the adjacent semiconductor thin film ribbon 54 are separated from each other. There is a region that does not exist. This is to reduce heat damage to the NA35 glass substrate used in this example.

The semiconductor thin film is not limited to the ribbon shape but may be an island shape. Further, since the pixel TFT does not require a high-performance TFT, it is possible to reduce the beam energy density during crystallization as compared with the peripheral circuit. Therefore, even if amorphous silicon is formed on the entire surface, it is possible to crystallize without damaging the glass.

FIG. 23 is a schematic view showing how a total of 28 sub-beams are generated by using four DPSS lasers 41. In the crystallization technology of the pixel-compatible TFT in this example, the scanning speed of the energy beam is 100c.
m / s. Note that the scan speed is not limited to this value, and may be any condition as long as the performance as a pixel TFT is obtained.

In order to irradiate the entire surface of the pixel area, 28 beams are set as a set and are translated to crystallize the next 28 lines. In this way, the entire surface of the pixel is crystallized by improving the throughput. In this example,
The entire surface irradiation is performed by moving the XY stage 43 at a high speed. However, the number is not limited to this, and the stage is fixed to 28 (the number is 28 in the present invention, but the number is limited to this). It is obvious that the laser beam does not exist).

The beam irradiation method is not limited to the method shown in FIG. 23, and the irradiation method shown in FIG. 24 (a) is also suitable. In this case, a plurality of lasers (two in the illustrated example) are divided into a plurality of beams (three in the illustrated example). Each sub-beam is scanned without overlapping. In this case, less horizontal movement is required for each scan.

Further, the irradiation method as shown in FIG. 24 (b) is also suitable. In this case, one DPSS laser 41 forms one energy beam. The energy beams emitted from the DPSS lasers 41 are scanned without overlapping. Such an irradiation method is advantageous as a crystallization technique for peripheral circuits that require high energy crystallization.
Needless to say, this technique can be used as a crystallization technique for the pixel portion.

As a result of observing the crystal grains in each beam line formed by the method of FIG.
It was confirmed that m polysilicon was formed.

-Fabrication of TFT-A TFT was fabricated by using a semiconductor thin film crystallized by the DPSS laser device of this embodiment as an operating semiconductor film. The manufacturing method of the TFT is the same as that of FIGS. 8 to 11 described in the first embodiment. In this example, when the semiconductor thin film is crystallized, the semiconductor thin film is formed in a ribbon shape having a width of 50 μm such that the intervals between the ribbons match the layout of the pixels, the wavelength is 532 nm, the output is 10 W, and <
Energy beam instability with 0.1 rms% noise,
Crystallization was performed at a scanning speed of 100 cm / s with an energy beam shaped into an elliptical beam with a size of 80 μm × 20 μm and an output instability of <± 1% / h.

The mobility of the TFT manufactured through the steps similar to those of FIGS. 8 to 11 of the first embodiment was measured. The mobility was about 20 cm ² / Vs. This value is sufficiently high for practical use as a pixel transistor.

-Modifications- Modifications of the third embodiment will be described below. Here, as shown in FIG. 25, a method of efficiently crystallizing by selectively crystallizing only a region of a semiconductor thin film in which a TFT is formed is disclosed. FIG. 26 shows D used in this example.
It is a general-view figure which shows the illumination system of a PSS laser apparatus.

In FIG. 26A, a fixed mirror 61 for reflecting the sub beam in a predetermined direction, and a movable working mirror 62 for further reflecting the reflected light from the fixed mirror 61 in a predetermined direction to irradiate the irradiation area. The illumination system A is configured by including, and each illumination system A is provided for each divided sub beam.

In FIG. 26B, a rotatable fixed mirror 63 for reflecting the sub-beam in a desired direction, a collimator lens 64, and reflected light from the fixed mirror 63 is condensed through the collimator lens 64. An illumination system B is configured by including a condenser lens 65 that illuminates an irradiation area, and each illumination system B is provided for each divided sub beam.

In this case, the XY stage 43 is moved, and at the same time, the optical system shown in FIGS. 26A and 26B is mounted on each divided sub-beam. These optical systems are designed to scan only the area where each TFT is formed. That is, the moving distance of the sub-beam is less than 100 μm at most.

As the XY stage 43 moves at high speed, these mirror optical systems are repeatedly turned on at each pixel position to crystallize the pixel portion. This improves the throughput.

In this example, in the case where amorphous silicon is formed on the entire surface, or in the ribbon shape or the island shape, it is necessary that the laser irradiation portion be kept consistent with the layout of the pixel portion. Needless to say.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. Here, the configuration of the DPSS laser device will be described as in the second embodiment.
Further, a method of crystallizing a semiconductor thin film using this will be described. The DPSS laser device of this embodiment is different from that of the second embodiment in that laser irradiation can be selectively performed on an arbitrary portion as described below.

In the present embodiment, the a-Si film is not preliminarily processed into an island shape, but the beam diameter is narrowed to the width of the island (up to 100 μm or less) while the a-Si film is in a solid state, and the XY stage is used. The irradiation of the energy beam is performed intermittently while moving the. As a result, the crystallization region (melting region) becomes the same part as the island in the first embodiment. Therefore, it is possible to avoid problems such as damage to the glass substrate and film peeling.

When used for an LCD, the peripheral circuit region is required to have a high degree of integration and to have a TFT with high crystallinity and a high mobility, while in the pixel region, regions necessary for the TFT are scattered. , Mobility is not required so much. Since the occupied area is much larger in the pixel area than in the peripheral circuit area, the XY stage is operated at high speed (up to several m / s) in the pixel area.
It is possible to greatly improve the throughput by scanning with and crystallizing only the necessary parts in a stepwise manner.

-Structure of DPSS Laser Device- FIG. 27 is a schematic view showing the main structure of the DPSS laser device according to the fourth embodiment. This DPSS laser device is a solid-state semiconductor pumped DPSS similar to that of the second embodiment.
A laser 41, an optical system 71 having a collimator function, a light condensing function, etc., and an energy beam aS on the glass substrate.
It is provided on the optical path until it reaches the i film 70, has an energy beam passage (ON) region 72a and an energy beam cutoff (OFF) region 72b, and intermittently passes the energy beam by rotating in the direction of the arrow. A chopper 72 which is an intermittent emitting means for causing the energy beam to pass through, and a mirror 73 which reflects the energy beam passing through the ON region 72a toward the glass substrate.
And an XY stage 43 (not shown) similar to that of the second embodiment, which can be driven in the horizontal and vertical directions. Using this DPSS laser device, CW laser light, for example Nd: YAG laser light (2ω, wavelength 532 m
m) through the optical system 72, beam diameter 20 μm × 5 μm
Format to the size of.

FIG. 28 is a schematic view showing an arrangement example of TFTs in the pixel region. In this case, the pixel size is 150
μm × 50 μm, TFT area is 10 μm × 15 μm
It is enough if the size is m. SiO on glass substrate
_Two buffer layers (film thickness 200 nm) and a-Si film (film thickness 150 nm) are continuously formed, and then the chopper 72 is rotated to generate an energy beam of 7.5 μs / 1.
Irradiation is performed at a scanning speed (moving speed of the XY stage 43) of 2 m / s while turning on / off at a rate of 7.5 μs. By doing so, a necessary portion of the a-Si film (for example, FIG. 27) is formed without performing the step of forming the island of the a-Si film without causing damage to the glass substrate or film peeling.
Only the inner crystallized region 74) can be selectively crystallized.

In this case, it is effective to scan the laser beam in the direction of the arrow in FIG. 28, that is, in parallel with the short side of the rectangular pixel (the direction in which the distance between adjacent pixel TFTs is short). This is effective not only for the intermittent irradiation of the laser beam but also for the continuous irradiation as in the case of FIG. 1, for example.

The TFT alignment marker 75 formed by crystallizing the a-Si film into a predetermined shape by intermittently irradiating the area different from the TFT formation area with the energy beam.
Is preferably formed and the a-Si film is crystallized using this as an index.

If the a-Si film is crystallized by the method as described above, a crystal having a large grain size can be obtained by using a CW laser, and the number of steps and the processing time do not increase.
A TFT formed using such a crystal having a large grain size has improved characteristics and a variation due to crystal is reduced. Therefore, it is possible to provide a high-performance and high-value-added liquid crystal display device while maintaining low cost.

-Modification- Hereinafter, various modifications of the fourth embodiment will be described.

(Modification 1) In this example, a method of crystallizing the a-Si film of the TFT in the peripheral circuit region of the liquid crystal display device will be described. The peripheral circuit region has a higher degree of integration than the pixel region and a high demand for crystallinity. As the TFT formation region, for example, crystallization regions having a size of 50 μm × 200 μm are formed at intervals of 5 μm, and a circuit may be formed therein. In this case, the CW laser is shaped into a beam diameter of 50 μm × 5 μm through an optical system. SiO ₂ buffer layer (film thickness 200 nm) on the glass substrate,
After continuously forming an a-Si film (film thickness 150 nm), the chopper 72 is rotated to turn on / off the energy beam at a rate of 1 ms / 0.025 ms, while scanning speed (movement speed of the stage). 20 cm / s
Irradiate with. When the scanning speed is slowed down to about 20 cm / s, long flowing crystal grains (flow pattern) can be obtained, and a TFT having high mobility can be formed. By doing so, it is possible to form a high-quality crystal in a necessary portion without damaging the glass substrate or peeling off the film without performing the step of forming an a-Si island.

(Modification 2) In this example, this is realized by combining a small hole and a mirror as the intermittent emitting means having a mechanism for turning on / off the energy beam. FIG. 29
FIG. 8 is a schematic view showing a main configuration of a DPSS laser device according to Modification 2. This DPSS laser device is
In addition to the laser 41 and the optical system 71, in place of the chopper 72, a rotatable mirror 77 that reflects the energy beam in a desired direction, and among the energy beams reflected by the mirror 77, only those that travel in a predetermined direction are provided. A shield plate 76 having a small-diameter aperture 76a formed therethrough is provided. In this case, the energy beam is swung by rotating the mirror 77, and it is turned on only when it passes through the opening 76a. A polygon mirror may be used as the mechanism for oscillating the energy beam so as to rotate it.

(Modification 3) FIG. 30 shows D according to Modification 3.
It is a general-view figure which shows the main structures of a PSS laser apparatus. This DPSS laser device has substantially the same configuration as that of the third embodiment, but differs in that the chopper 72 is processed and a plurality of mirrors are installed accordingly.

Here, of the plurality of ON areas 72a of the chopper 72, a predetermined one is shielded by a shield plate 81 having a light reflecting function, and the energy beam reflected by the shield plate 81 is further reflected in a predetermined direction. A mirror 82 is provided. As a result, the energy beam reflected by the shielding plate 81 changes its optical path so as to irradiate the adjacent row in the a-Si film 70, and further the adjacent row.
The pixel size as shown in FIG. 28 is 50 μm × 150 μm, T
When the size of the FT region is 15 μm × 10 μm, about 2/3 of one scan is in an off state, but if two adjacent columns are irradiated during this off time, three columns can be irradiated in one scan, and the processing time is It is shortened to about 1/3.

Further, during one scan of the XY stage 43, since the non-irradiation time is several times longer than the irradiation time, the energy beams are successively moved to adjacent columns at high speed during the non-irradiation time. This makes it possible to reduce wasteful time and further improve throughput.

As described above, according to this example, the energy beam of the CW laser is focused to 100 μm or less and irradiated intermittently, so that the glass substrate is not damaged, and the film is not peeled off. Crystals of grain size can be formed. Also, by irradiating several adjacent rows by utilizing the non-irradiation time when irradiating one row, several rows can be crystallized in one scan, and the throughput is also improved. Therefore, it is possible to suppress variations in TFT characteristics depending on the crystal grain boundaries and crystal grain diameters, and it is possible to obtain good device characteristics. As a result, it is possible to provide a high quality liquid crystal display device integrated with a drive circuit.

(Modification 4) FIG. 31 shows D according to Modification 4.
It is a general-view figure which shows the main structures of a PSS laser apparatus. This DPSS laser device has substantially the same configuration as that of the modified example 3, but differs in that a polygon mirror is provided instead of the chopper 72.

In addition to the DPSS laser 41 and the optical system 71, this DPSS laser device has a polygon mirror 83 which replaces the chopper 72, and an energy beam in a predetermined direction depending on the traveling direction of the energy beam reflected by the polygon mirror 83. Multiples that pass only (here 3
And a shielding plate 84 having an opening 84a formed therein.

In this case, the polygon mirror 83 is rotated to oscillate the energy beam to irradiate three rows on the a-Si film 70 in one scan. However, since the XY stage 43 is moved by the amount of irradiation of the first row, the irradiation position of the second row (position of the opening 84a) needs to be provided at a position advanced by the movement of the XY stage 43. is there. The third row is also irradiated at the advanced position.

According to this example, as in the third modification, it is possible to form crystals with a large grain size without damaging the glass substrate, without causing film peeling, and at the time of irradiation in one row. By irradiating several adjacent columns using the irradiation time, several columns can be crystallized in one scan, and the throughput can be improved.

In the fourth embodiment and its modified examples 1 to 4, as shown in FIGS. 27 to 31, the XY stage is moved in the direction of the thick arrow while scanning.
When scanning of one row or arbitrary rows is completed, the scanning is moved in the direction of the thin arrow and the next scanning is performed.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described. In this embodiment, when the TFT is manufactured, when the a-Si film is crystallized by using the CW laser as in the first to fourth embodiments, the temperature rise of the buffer layer due to the energy beam is caused. Disclosed is a TFT provided with a suitable buffer layer, which aims at preventing film peeling of an a-Si film that occurs.

In order to prevent contamination of the glass constituting the substrate with impurities such as sodium, a glass substrate and a-
As a material for the buffer layer formed between the Si film and S
It is known that it is effective to use iN or SiON. The results of examining the hydrogen concentration distribution in the as-deposited buffer layer are shown in FIG.

An energy beam for continuously generating energy with respect to time in the a-Si film laminated with a buffer layer containing SiN or SiON, here C
When crystallized with a W laser, the buffer layer absorbs the energy beam (or heat conduction during melting of the a-Si film), and the temperature rises. When the concentration of hydrogen in the buffer layer is high, hydrogen infusion occurs and aS
A pinhole is generated in the i film and film peeling occurs. Also,
Even when the hydrogen concentration in the a-Si film is high, infusion occurs and pinholes occur. When the hydrogen concentration of both is high, the a-Si film is peeled off due to the pinhole as shown in FIG. Such a phenomenon is particularly remarkable when a continuous energy beam is used as compared with the conventional excimer laser crystallization.

Therefore, in this embodiment, as shown in FIG.
As shown in FIG.
Or a thin film 92a made of SiON and SiO₂With membrane 92b
A-Si film 9 via a buffer layer 92 formed by stacking
3 is formed, and a crystal of the a-Si film 93 is formed by using a CW laser.
When the a-Si film 93 and the thin film are hydrogenated,
Adjust the concentration respectively. Specifically, the a-Si film 93
Hydrogen concentration of 1 × 10 ²⁰Pieces / cm³Below, and thin film 92
The hydrogen concentration of a is 1 × 10^{twenty two}Pieces / cm³Below. here
And SiO₂By forming the film 92b, a-Si
It is possible to reduce the interface state between the film 93 and the buffer layer 92.
It Also, when irradiating the energy beam of the CW laser,
Direct irradiation of SiN from the front surface of the substrate rather than the back surface of the substrate
It is preferable because it is not irradiated with laser light.

[Proper Hydrogen Concentration in a-Si Film] Here,
The experimental results of investigating the proper hydrogen concentration in the a-Si film will be described. First, as shown in FIG. 34, P is formed on the glass substrate 91.
A thin film 92a made of SiN having a film thickness of 50 by the CVD method.
The SiO ₂ film 92b is sequentially formed to a thickness of about 200 nm to form the buffer layer 92, and the a-Si film 9 is formed.
3 to a film thickness of about 150 nm. The above film thicknesses are not limited to these values.

Subsequently, the a-Si film 93 is dehydrogenated by heat treatment at 500 ° C. for 2 hours in a nitrogen atmosphere, and then semiconductor excited (LD excited) solid state laser (DPSS laser) Nd: YVO ₄ Output 6.5 W, scanning speed 20 cm / s, wavelength 532 nm (second Nd: YVO ₄
Crystallization is performed under the conditions of (harmonics). This scanning is performed by moving the XY stage.

FIG. 35 shows a SIM of a glass substrate / SiN / SiO ₂ / a-Si structure after heat treatment at 500 ° C. for 2 hours.
It is a characteristic view which shows the result of S analysis. In this SIMS analysis, the a-Si film 93 is formed by heat treatment at 500 ° C. for 2 hours.
It was confirmed that the hydrogen concentration therein was 1 × 10 ²⁰ hydrogen atoms / cm ³ or less.

FIG. 36 is a micrograph showing the semiconductor thin film after crystallization. The hydrogen concentration in the a-Si film 93 is set to 1 × 1.
It can be seen that when the number is ²⁰ or less / cm ³ , a good crystal without pinholes or peeling is obtained.

[Proper Hydrogen Concentration in SiN Thin Film] Next, the experimental results of examining the proper hydrogen concentration in the SiN thin film forming the buffer layer will be described. First, as shown in FIG. 34, a buffer layer 92 is formed by sequentially forming a thin film 92a made of SiN with a thickness of about 50 nm and a SiO ₂ film 92b with a thickness of about 200 nm on a glass substrate 91 by a P-CVD method. , A-Si film 93 is formed to a film thickness of about 150 nm. The above film thicknesses are not limited to these values.

Subsequently, the a-Si film 93 is dehydrogenated by heat treatment at 450 ° C. for 2 hours in a nitrogen atmosphere.
SIMS analysis shows that the hydrogen concentration in the SiN thin film 92a is 1 × 10 ²² pieces / cm ³ or less.
Confirmed by S analysis. Further, the hydrogen concentration in the a-Si film 93 is 1 × 10 ²⁰ pieces / cm ³ or less.

For the a-Si film 93, a semiconductor-excited (LD-excited) solid-state laser (DPSS laser) Nd:
With YVO ₄ , output 6.5W, scanning speed 20cm /
Crystallization is performed under the conditions of s, wavelength 532 nm (Nd: second harmonic of YVO ₄ ). This scanning is performed by moving the XY stage. As a result, good crystals were obtained as shown in FIG.

As described above, according to this embodiment, the transistor characteristics of the TFT are homogenized at a high level by utilizing the crystallization by the energy beam that continuously outputs the energy with respect to time, and It is possible to form a stable film without pinholes or peeling, and to realize a TFT with extremely high reliability.

In the embodiments described above, an example of the a-Si film is given as the semiconductor film, but the initial film is LPCV.
The present invention can be applied to any of a p-Si film formed by the D method, a solid-phase growth p-Si film, a metal-induced solid-phase growth p-Si film, and the like.

The various aspects of the present invention will be collectively described below as supplementary notes.

(Supplementary Note 1) A method of manufacturing a semiconductor device, comprising a pixel region having a plurality of thin film transistors and a peripheral circuit region thereof on a substrate, wherein at least the peripheral circuit region is formed in the peripheral circuit region. A method of manufacturing a semiconductor device, comprising the step of crystallizing the formed semiconductor thin film by an energy beam that continuously outputs energy with respect to time to make an operating semiconductor thin film of each thin film transistor.

(Supplementary Note 2) The method for producing a semiconductor device according to Supplementary Note 1, wherein each of the semiconductor thin films is formed on the substrate by linear or island patterning.

(Additional remark 3) The marker for irradiation position alignment of the energy beam corresponding to each of the patterned semiconductor thin films is formed on the substrate, and the semiconductor device according to the additional remark 2 is manufactured. Method.

(Supplementary Note 4) A plurality of slits are formed in each of the semiconductor thin films patterned on the substrate, and the energy beam is irradiated substantially along the longitudinal direction of the slits. A method for manufacturing a semiconductor device as described above.

(Supplementary Note 5) The method for producing a semiconductor device according to Supplementary Note 4, wherein the slits adjacent to each other in the semiconductor thin films are formed in a non-contact state in which the distance between the slits gradually changes.

(Supplementary Note 6) Two slits are formed in each semiconductor thin film, and a crystallization region between the slits formed by irradiation of an energy beam is used as a channel region of the thin film transistor. A method of manufacturing a semiconductor device according to Supplementary Note 4.

(Supplementary Note 7) A plurality of thin line-shaped insulating films are formed on each of the semiconductor thin films patterned on the substrate, and the energy beam is irradiated substantially along the longitudinal direction of the insulating films. The method of manufacturing a semiconductor device according to appendix 1, which is characterized.

(Supplementary Note 8) The manufacturing of the semiconductor device according to Supplementary Note 7, wherein the insulating films adjacent to each other on the semiconductor thin films are formed in a non-contact state in which the distance between the two is gradually changed. Method.

(Supplementary Note 9) Two insulating films are formed on each semiconductor thin film, and a crystallization region between the insulating films formed by irradiation of an energy beam is used as a channel region of the thin film transistor. A method of manufacturing a semiconductor device according to appendix 7,

(Supplementary Note 10) The method for producing a semiconductor device according to Supplementary Note 1, wherein each of the semiconductor thin films patterned on the substrate has portions having different film thicknesses.

(Supplementary Note 11) The thin film portion of each semiconductor thin film is surrounded by the thick film region, and the energy beam is scanned along the longitudinal direction of the thin film portion. The method for manufacturing a semiconductor device according to Supplementary Note 10.

(Additional remark 12) The method of manufacturing a semiconductor device according to additional remark 10, wherein the channel region is formed in conformity with the thin portion of each semiconductor thin film.

(Supplementary Note 13) The semiconductor device according to Supplementary Note 1, wherein the pixel region and the peripheral circuit region have different irradiation conditions of the energy beam for continuously outputting energy with respect to time. Production method.

(Supplementary Note 14) The semiconductor thin film formed in the pixel region is crystallized by an energy beam that outputs energy in a pulse shape, and the semiconductor thin film formed in the peripheral circuit region is continuously energized with time. 2. The method for manufacturing a semiconductor device according to appendix 1, wherein the semiconductor device is crystallized by an output energy beam.

(Additional remark 15) The semiconductor thin film formed in the peripheral circuit region is crystallized after the semiconductor thin film formed in the pixel region is crystallized.
A method of manufacturing a semiconductor device according to item 1.

(Supplementary Note 16) The semiconductor thin film formed in the peripheral circuit region is crystallized by an energy beam that continuously outputs energy with respect to time to form an operating semiconductor thin film, and the semiconductor thin film formed in the pixel region is The method of manufacturing a semiconductor device according to appendix 1, wherein the semiconductor thin film is used as it is.

(Supplementary Note 17) When the semiconductor thin film formed in the peripheral circuit region is crystallized, the semiconductor thin film is dehydrogenated by using the energy beam that continuously outputs energy with respect to time. 17. The method of manufacturing a semiconductor device according to appendix 16, characterized in that.

(Supplementary Note 18) The method of manufacturing a semiconductor device according to Supplementary Note 1, wherein the thickness of the semiconductor thin film is different between the pixel region and the peripheral circuit region.

(Additional remark 19) The method for manufacturing a semiconductor device according to additional remark 1, wherein the energy beam that continuously outputs energy with respect to time is scanned on the semiconductor thin film.

(Additional remark 20) The method for manufacturing a semiconductor device according to additional remark 19, wherein the energy beam is scanned along the short side of a rectangular pixel.

(Supplementary Note 21) The supplementary note 19 is characterized in that the scanning direction of the energy beam that continuously outputs energy with respect to time is parallel to the current direction of the portion of the semiconductor operating film which becomes the channel. Of manufacturing a semiconductor device of.

(Supplementary note 22) The semiconductor device according to supplementary note 1, wherein a plurality of the energy beams that continuously output energy with respect to time are used to simultaneously irradiate the semiconductor thin films at different positions. Manufacturing method.

(Supplementary Note 23) The scanning speed of the energy beam for continuously outputting energy with respect to time is 1
20. The method for manufacturing a semiconductor device as described in appendix 19, wherein it is 0 cm / s or more.

(Supplementary Note 24) The method for producing a semiconductor device according to Supplementary Note 1, wherein the output instability of the energy beam that continuously outputs energy with respect to time is smaller than ± 1% / h.

(Additional remark 25) The method for manufacturing a semiconductor device according to additional remark 24, wherein the noise (optical noise) indicating the instability of the energy beam is 0.1 rms% or less.

(Supplementary note 26) The method for producing a semiconductor device according to supplementary note 1, wherein the energy beam that continuously outputs energy with respect to time is CW laser light.

(Supplementary Note 27) Supplementary Note 2 characterized in that the CW laser light is a solid-state laser light excited by a semiconductor LD.
7. The method for manufacturing a semiconductor device according to 6.

(Additional remark 28) The crystalline state of the operating semiconductor thin film is formed into a streamline-shaped flow pattern with large crystal grains by the energy beam that outputs energy continuously with respect to time. A method for manufacturing a semiconductor device as described above.

(Supplementary Note 29) The method for producing a semiconductor device according to Supplementary Note 1, wherein the substrate is made of non-alkali glass or plastic, and the energy beam is irradiated from the front surface or the back surface of the substrate.

(Additional remark 30) The energy beam is optically divided into a plurality of sub-beams, and different portions of the semiconductor thin film are simultaneously irradiated with the respective sub-beams to be crystallized. Of manufacturing a semiconductor device of.

(Supplementary Note 31) The energy beam or each of the sub-beams irradiates only the formation portion of each of the thin film transistors with an energy intensity optimum for crystallization, and passes through the non-formation portion of each thin film transistor at high speed. 7. The method for manufacturing a semiconductor device according to appendix 1, further comprising:

(Additional remark 32) At least one of the beam scanning speed for crystallization, the energy intensity, and the beam shape is different in the formation site of each of the at least two types of thin film transistors described in Additional remark 1. Of manufacturing a semiconductor device of.

(Supplementary note 33) The method of manufacturing a semiconductor device according to supplementary note 1, wherein the semiconductor thin film is intermittently irradiated with the energy beam to selectively crystallize only the formation portion of each thin film transistor. .

(Supplementary Note 34) The energy beam is moved at high speed to the other formation portion during the irradiation interval period of the formation portion of the thin film transistor adjacent to the semiconductor thin film, and the other formation portion is irradiated. 34. The method for manufacturing a semiconductor device according to Supplementary Note 33.

(Supplementary Note 35) A part of the semiconductor thin film different from a part where the thin film transistor is formed is intermittently irradiated with the energy beam to form an alignment marker of the thin film transistor which is crystallized into a predetermined shape. 34. The method for manufacturing a semiconductor device according to attachment 33.

(Supplementary Note 36) The semiconductor thin film is formed on the substrate through a buffer layer having a thin film containing Si and N or Si, O and N, and the hydrogen concentration of the semiconductor thin film is set to 1 ×. 10. The method for manufacturing a semiconductor device according to appendix 1, wherein the number is 10 ²⁰ pieces / cm ³ or less.

(Supplementary Note 37) The hydrogen concentration of the thin film is set to 1 ×.
Supplementary note 36 characterized in that it is 10 ²² pieces / cm ³ or less
A method of manufacturing a semiconductor device according to item 1.

(Supplementary note 38) The semiconductor device according to supplementary note 36, characterized in that the dehydrogenation of the semiconductor thin film is performed after the semiconductor thin film is formed or after the semiconductor thin film is formed and a predetermined pattern is formed. Manufacturing method.

(Supplementary Note 39) A semiconductor device, wherein the semiconductor device includes a substrate, a pixel region provided on the substrate and having a plurality of thin film transistors, and a plurality of thin film transistors provided on the substrate. And a peripheral circuit region of the pixel region having, at least the operating semiconductor thin film of each of the thin film transistors forming the peripheral circuit region, the crystal grains are formed in a crystalline state of a streamlined flow pattern. There is.

(Supplementary note 40) The semiconductor device according to supplementary note 39, wherein the crystal grains of the flow pattern are longer than the channel length.

(Supplementary Note 41) Each of the operating semiconductor thin films is
41. The semiconductor device according to appendix 40, wherein each semiconductor thin film patterned in a linear or island shape on the substrate is irradiated with an energy beam.

(Supplementary Note 42) Markers for aligning the irradiation position of the energy beam for crystallizing the operating semiconductor thin film are formed on the substrate, corresponding to the patterned operating semiconductor thin films. 42. The semiconductor device according to appendix 41.

(Additional Statement 43) The semiconductor device according to additional statement 39, wherein the operating semiconductor thin films have different thicknesses in the pixel area and the peripheral circuit area.

(Supplementary Note 44) The semiconductor device according to Supplementary Note 39, wherein the substrate is one selected from alkali-free glass, quartz glass, ceramics, plastic, and silicon single crystal.

(Supplementary Note 45) The semiconductor thin film is formed on the substrate via a buffer layer having a thin film containing Si and N or Si, O and N, and the hydrogen concentration of the semiconductor thin film is 1 or less. 40. The semiconductor device according to appendix 39, wherein the number is not more than 10 ²⁰ pieces / cm ³ .

(Supplementary Note 46) The hydrogen concentration of the thin film is 1 ×.
Note 45 characterized by being 10 ²² pieces / cm ³ or less
The semiconductor device according to.

(Supplementary Note 47) The buffer layer is SiO 2.
47. The semiconductor device according to appendix 45, which has a structure of ₂ / SiN or SiO ₂ / SiON.

(Supplementary Note 48) A semiconductor manufacturing apparatus for emitting an energy beam for crystallizing a semiconductor thin film formed on a substrate, wherein the semiconductor manufacturing apparatus continuously outputs the energy beam with respect to time. It has a function of relatively scanning the irradiation object with the energy beam, and the output instability of the energy beam is smaller than ± 1% / h.

(Additional remark 49) The semiconductor manufacturing apparatus according to the additional remark 48, characterized in that the energy beam is scanned along the short side of a pixel having a rectangular shape.

(Supplementary note 50) The semiconductor manufacturing apparatus according to supplementary note 48, wherein the noise (optical noise) indicating instability of the energy beam is 0.1 rms% or less.

(Additional remark 51) The semiconductor manufacturing apparatus according to additional remark 48, wherein the scanning speed of the energy beam is 10 cm / s or more.

(Supplementary Note 52) The semiconductor manufacturing apparatus according to Supplementary Note 48, which is capable of emitting an energy beam that intermittently outputs energy.

(Additional Statement 53) The semiconductor manufacturing apparatus according to additional statement 48, wherein the energy beam that continuously outputs energy with respect to time is a CW laser beam.

(Additional Statement 54) The semiconductor manufacturing apparatus according to additional statement 53, wherein the CW laser light is semiconductor-excited solid-state laser light.

(Additional remark 55) The marker for irradiating the irradiation position of the energy beam provided on the substrate is read and stored before irradiation, and the energy beam is irradiated according to the position. The semiconductor manufacturing apparatus according to.

(Supplementary Note 56) A semiconductor manufacturing apparatus,
In the semiconductor manufacturing apparatus, a substrate having a semiconductor thin film formed on the surface thereof is installed, an installation means for freely moving the substrate in an in-plane direction of the semiconductor thin film, and an energy beam continuously with respect to time. A laser oscillating means having a function of outputting and a beam splitting means for optically splitting the energy beam emitted from the laser oscillating means into a plurality of sub-beams are provided, and each of the sub-beams is provided in each of the semiconductor thin films. By scanning relative to the part, each of the predetermined parts is crystallized.

(Supplementary Note 57) The semiconductor manufacturing apparatus according to supplementary note 56, characterized in that the energy beam is scanned along the short side of a rectangular pixel.

(Supplementary Note 58) The above-mentioned sub-beams irradiate only the formation portion of each thin film transistor with an energy intensity optimum for crystallization, and pass through the non-formation portion of each thin film transistor at high speed. Appendix 5
6. The semiconductor manufacturing apparatus according to item 6.

(Supplementary Note 59) Each sub-beam is irradiated so that at least one of the beam scanning speed for crystallization, the energy intensity, and the beam shape is different at the formation site of each of the at least two types of thin film transistors. 57. The semiconductor manufacturing apparatus as described in appendix 56, wherein:

(Supplementary note 60) Supplementary note 56, wherein the sub-beams are irradiated so as not to overlap each other.
The semiconductor manufacturing apparatus according to.

(Additional Statement 61) The semiconductor manufacturing apparatus according to additional statement 56, wherein the output instability of the energy beam is a value smaller than ± 1% / h.

(Additional remark 62) The semiconductor manufacturing apparatus according to additional remark 61, wherein the noise (optical noise) indicating instability of the energy beam is 0.1 rms% or less.

(Supplementary Note 63) A semiconductor manufacturing apparatus,
In the semiconductor manufacturing apparatus, a substrate having a semiconductor thin film formed on the surface thereof is installed, an installation means for freely moving the substrate in an in-plane direction of the semiconductor thin film, and an energy beam continuously with respect to time. A laser oscillating means having a function of outputting and an intermittent emitting means having a passage region and a cutoff region of the energy beam and intermittently passing the energy beam, and the substrate relative to the energy beam. While scanning, the semiconductor thin film is intermittently irradiated with the energy beam to selectively crystallize only the formation portion of each thin film transistor.

(Supplementary note 64) The semiconductor manufacturing apparatus according to supplementary note 63, characterized in that the energy beam is scanned along the short side of a pixel having a rectangular shape.

(Supplementary Note 65) By adjusting the scanning speed of the substrate and the timing of the intermittent emission, the energy beam can be applied at high speed to the other energy beams during the irradiation interval period between the formation portions of the thin film transistors adjacent to the semiconductor thin film. 64. The semiconductor manufacturing apparatus according to appendix 63, wherein the semiconductor manufacturing apparatus is moved to a formation site and the other formation site is irradiated.

(Supplementary Note 66) Beam splitting means for optically splitting the energy beam emitted from the laser oscillation means into a plurality of sub-beams is further provided, and the substrate is scanned relative to the energy beam. While
64. The semiconductor manufacturing apparatus as set forth in appendix 63, wherein the semiconductor thin film is intermittently irradiated with each of the sub-beams to simultaneously crystallize the formation sites of the plurality of thin film transistors.

(Supplementary Note 67) A part of the semiconductor thin film different from the part where the thin film transistor is formed is intermittently irradiated with the energy beam to form an alignment marker for the thin film transistor which is crystallized into a predetermined shape. The semiconductor manufacturing apparatus according to Supplementary Note 63.

(Additional Statement 68) The semiconductor manufacturing apparatus according to additional statement 63, wherein the output instability of the energy beam is smaller than ± 1% / h.

(Supplementary note 69) The semiconductor manufacturing apparatus according to supplementary note 68, characterized in that the noise (optical noise) indicating instability of the energy beam is 0.1 rms% or less.

(Supplementary Note 70) A method of manufacturing a semiconductor device comprising a plurality of semiconductor elements provided on a substrate, wherein the semiconductor thin film of the semiconductor element is continuously energized over time. The step of crystallizing by the output energy beam is included.

(Additional Statement 71) The semiconductor device according to additional statement 70, wherein each of the semiconductor thin films is patterned on the substrate in a linear or island shape, and each of the semiconductor thin films is irradiated with the energy beam. Manufacturing method.

[0224]

According to the present invention, a peripheral circuit integrated type TFT is provided.
-LCD, system on panel, system on
When applied to glass or the like, it is possible to make the transistor characteristics of the TFT uniform at a high level, and to realize a TFT that has excellent mobility and can be driven at high speed, especially in the peripheral circuit region.

Further, according to the present invention, the transistor characteristics of the TFT are homogenized at a high level, and when realizing a TFT which is excellent in mobility, particularly in the peripheral circuit region and can be driven at high speed, energy is continuously applied to time. The above-mentioned T which is excellent in efficiency by complementing the insufficient output of the energy beam to be output and improving the throughput in crystallization of the semiconductor thin film
It becomes possible to realize FT.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing how a semiconductor thin film is crystallized in a first embodiment.

FIG. 2 is a micrograph showing a state of a semiconductor thin film patterned in a ribbon shape.

FIG. 3 is a photomicrograph showing how TFT islands are formed.

FIG. 4 is an SEM photograph showing a state of a semiconductor thin film crystallized by a CW laser.

FIG. 5 is an SEM photograph showing a state of a semiconductor thin film having an excimer pattern crystallized by a CW laser.

FIG. 6 is a characteristic diagram showing SIMS analysis in the vicinity of a semiconductor thin film.

FIG. 7 is a photograph showing a cross-sectional TEM in the vicinity of a semiconductor thin film.

FIG. 8 is a schematic cross-sectional view showing the method of manufacturing the TFT according to the first embodiment in the order of steps.

FIG. 9 is a continuation of FIG. 8 and the TFT according to the first embodiment.
FIG. 3 is a schematic cross-sectional view showing the manufacturing method of in the order of steps.

FIG. 10 is a continuation of FIG. 9 and the TF according to the first embodiment.
It is a schematic sectional drawing which shows the manufacturing method of T in process order.

11 is a diagram illustrating a T according to the first embodiment following FIG.
It is a schematic sectional drawing which shows the manufacturing method of FT in process order.

FIG. 12 is a characteristic diagram showing a relationship between a crystal pattern of a semiconductor thin film and mobility.

FIG. 13 is a micrograph showing a relationship between a flow pattern of a semiconductor thin film and mobility.

FIG. 14 is a schematic plan view showing each ribbon-shaped semiconductor thin film and a position marker in Modification 1 of the first embodiment.

FIG. 15 is a schematic plan view showing a state of a semiconductor thin film in Modification 2 of the first embodiment.

FIG. 16 is a schematic view showing a state of a semiconductor thin film in Modification 3 of the first embodiment.

FIG. 17 is a schematic plan view showing a state of a semiconductor thin film in Modification 4 of the first embodiment.

FIG. 18 is a schematic view showing a state of a semiconductor thin film in Modification 5 of the first embodiment.

FIG. 19 is a schematic view showing a DPSS laser device according to a second embodiment.

FIG. 20 is a DPSS according to Modification 1 of the second embodiment.
It is a general-view figure which shows a laser apparatus.

FIG. 21 is a DPSS according to Modification 2 of the second embodiment.
It is a general-view figure which shows a laser apparatus.

FIG. 22 is a schematic view showing a part of the configuration of the DPSS laser device according to the third embodiment.

FIG. 23 is a schematic view showing how a total of 28 sub-beams are generated by using four DPSS lasers 41.

FIG. 24 is a schematic view showing another irradiation method using the DPSS laser 41.

FIG. 25 is a schematic view showing how only a region of a semiconductor thin film where a TFT is formed is selectively crystallized.

FIG. 26 is a schematic view showing an illumination system of a DPSS laser device used in a modification of the third embodiment.

FIG. 27 is a schematic view showing a main configuration of a DPSS laser device according to a fourth embodiment.

FIG. 28 is a schematic view showing an arrangement example of TFTs in a pixel region.

FIG. 29 is a schematic view showing a main configuration of a DPSS laser device according to Modification 2 of the fourth embodiment.

FIG. 30 is a schematic view showing a main configuration of a DPSS laser device according to Modification 3 of the fourth embodiment.

FIG. 31 is a schematic view showing a main configuration of a DPSS laser device according to Modification 4 of the fourth embodiment.

FIG. 32 is a characteristic diagram showing the results of examining the hydrogen concentration distribution in the buffer layer and Si layer when SiN or SiON is used as the material of the buffer layer.

FIG. 33 is a micrograph showing the appearance of peeling of an a-Si film.

FIG. 34 is aS through the buffer layer on the glass substrate.
It is a schematic sectional drawing which shows a mode that the i film was formed.

FIG. 35: Glass substrate / after heat treatment at 500 ° C. for 2 hours
It is a characteristic diagram showing the results of SIMS analysis of the SiN / SiO ₂ / a-Si structure.

FIG. 36 is a micrograph showing a semiconductor thin film after crystallization.

FIG. 37 is an AFM photograph showing a state in which a silicon film is crystallized using a conventional excimer laser.

[Explanation of symbols]

1, 21, 91 Glass substrate 2, 70, 93 Semiconductor thin film (a-Si film) 3 CW laser 4 Channel region 5 Source / drain 6 TFT island 11 Operating semiconductor thin film 22 SiO ₂ buffer layer 23 Gate oxide film (silicon oxide film) ) 24, 32 gate electrode (aluminum film) 25 interlayer insulating film 26 contact hole 27 wiring (metal film) 31 position marker 32 slit 33 fine line pattern 41 DPSS laser 42 optical system 43 XY stage 51 diffraction grating 52 collimator lens 53, 65 assembly Optical lens 54 Semiconductor thin film ribbon 61, 63 Fixed mirror 62 Working mirror 64 Collimator lens 71 Optical system 72 Chopper 73, 77 Mirror 74 Area 76, 81, 84 Shielding plate 83 Polygon mirror 92 Buffer layer 92a SiN or SiON thin film Film 92b SiO ₂ film

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[Procedure amendment]

[Submission date] October 17, 2001 (2001.10.
17)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title: Semiconductor device manufacturing method and semiconductor manufacturing device

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/336 H01L 29/78 627G 29/786 612B (72) Inventor Kenichi Yoshino Kamihara, Kawasaki City, Kanagawa Prefecture 4-1, 1-1 Odanaka, Fujitsu Limited (72) Inventor Nobuo Sasaki 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa F-term, Fujitsu Limited (reference) 2H092 JA24 JA46 KA05 KB25 MA05 MA07 MA27 MA30 NA21 NA24 PA01 5C094 AA13 AA21 AA25 AA43 AA48 AA53 BA03 CA19 DA09 DA13 DB01 DB04 EB02 FA01 FB12 FB14 FB15 GB10 JA01 JA20 5F052 AA02 BA01 BA04 BA07 BA11 BA13 BA14 BA18 BB02 BB04 CA04 CA09 DA02 DB03 EA07 EA12 EA15 FA02 FA07 FA22 JA01 5F110 AA01 AA16 BB02 CC02 DD01 DD02 DD03 DD05 DD13 DD14 DD15 DD17 EE03 EE38 EE44 FF02 FF28 FF30 FF32 GG02 GG13 GG16 GG24 GG45 HJ01 HJ0 4 HJ12 HJ23 HL03 NN04 NN24 NN78 PP03 PP04 PP05 PP06 PP07 PP24 PP29 PP35 QQ11 5G435 AA00 EE33 EE37 HH12 HH13 HH14 KK05

Claims (32)

[Claims] 1. A method of manufacturing a semiconductor device, comprising: a pixel region having a plurality of thin film transistors and a peripheral circuit region thereof on a substrate, wherein at least the peripheral region of the pixel region and the peripheral circuit region is provided. A method for manufacturing a semiconductor device, characterized in that a semiconductor thin film formed in a circuit region is crystallized by an energy beam that continuously outputs energy with respect to time to form an operating semiconductor thin film of each thin film transistor. 2. The manufacturing of a semiconductor device according to claim 1, wherein the pixel region and the peripheral circuit region have different irradiation conditions of the energy beam for continuously outputting energy with respect to time. Method. 3. The semiconductor thin film formed in the pixel region is crystallized by an energy beam that outputs energy in a pulsed manner, and the semiconductor thin film formed in the peripheral circuit region outputs energy continuously with respect to time. The method of manufacturing a semiconductor device according to claim 1, wherein crystallization is performed by an energy beam. 4. The semiconductor thin film formed in the peripheral circuit region is crystallized by an energy beam that continuously outputs energy with respect to time to make an operating semiconductor thin film, and the semiconductor thin film formed in the pixel region is operated as it is. The method of manufacturing a semiconductor device according to claim 1, wherein the method is a semiconductor thin film. 5. The method of manufacturing a semiconductor device according to claim 1, wherein the energy beam that continuously outputs energy with respect to time is CW laser light. 6. The method according to claim 1, wherein the energy beam is optically divided into a plurality of sub-beams, and different portions of the semiconductor thin film are simultaneously irradiated with the sub-beams to be crystallized. The method for manufacturing a semiconductor device according to claim 1. 7. The energy beam or each of the sub-beams irradiates only the formation portion of each of the thin film transistors with an energy intensity optimum for crystallization, and passes through the non-formation portion of each of the thin film transistors at high speed. The method for manufacturing a semiconductor device according to claim 1, wherein 8. The method according to claim 1, wherein at least one of the beam scanning speed for crystallization, the energy intensity, and the beam shape is different in the formation portion of at least two kinds of thin film transistors. The method for manufacturing a semiconductor device according to claim 1. 9. The semiconductor thin film is intermittently irradiated with the energy beam to selectively crystallize only a formation portion of each thin film transistor.
9. The method for manufacturing a semiconductor device according to claim 8. 10. The energy beam is moved to the other formation region at a high speed during the irradiation interval period of the formation region of the thin film transistor adjacent to the semiconductor thin film to irradiate the other formation region. The method for manufacturing a semiconductor device according to claim 9. 11. The alignment marker of the thin film transistor, which is crystallized into a predetermined shape, is formed by intermittently irradiating the portion of the semiconductor thin film different from the portion where the thin film transistor is formed with the energy beam. A method of manufacturing a semiconductor device according to claim 9. 12. Si and N or S on the substrate
The semiconductor thin film is formed via a buffer layer having a thin film containing i, O and N, and the hydrogen concentration of the semiconductor thin film is set to 1 × 10 ²⁰ / cm ³ or less. 12. The method for manufacturing a semiconductor device according to any one of 11 above. 13. The hydrogen concentration of the thin film is 1 × 10 ²² /
The method for manufacturing a semiconductor device according to claim 12, wherein the method is set to be not more than ³ cm ³ . 14. The dehydrogenation of the semiconductor thin film is performed after the semiconductor thin film is formed or after the semiconductor thin film is formed and a predetermined pattern is formed.
14. The method for manufacturing a semiconductor device according to 2 or 13. 15. A semiconductor device comprising a substrate and a pixel region each having a plurality of thin film transistors, and a peripheral circuit region thereof, wherein at least the operating semiconductor of each thin film transistor constituting the peripheral circuit region. A semiconductor device, wherein the thin film is formed in a crystalline state having a streamlined flow pattern with large crystal grains. 16. The semiconductor device according to claim 15, wherein the crystal grains of the flow pattern are longer than the channel length. 17. A marker for irradiation position alignment of an energy beam for crystallizing the operating semiconductor thin film is formed on the substrate in correspondence with each of the patterned operating semiconductor thin films. Claim 1
The semiconductor device according to 5 or 16. 18. A semiconductor manufacturing apparatus for emitting an energy beam for crystallizing a semiconductor thin film formed on a substrate, the energy beam being capable of being continuously output with respect to time, A semiconductor manufacturing apparatus having a function of scanning the energy beam relative to an object, wherein the output instability of the energy beam is a value smaller than ± 1% / h. 19. The semiconductor manufacturing apparatus according to claim 18, wherein noise (optical noise) indicating instability of the energy beam is 0.1 rms% or less. 20. The scanning speed of the energy beam is 1
20. The semiconductor manufacturing apparatus according to claim 18, which is 0 cm / s or more. 21. A substrate having a semiconductor thin film formed on its surface is installed, and an installation means for freely moving the substrate in the in-plane direction of the semiconductor thin film, and an energy beam is continuously output with respect to time. A laser oscillating means having the function of: and a beam splitting means for optically splitting the energy beam emitted from the laser oscillating means into a plurality of sub-beams. A semiconductor manufacturing apparatus characterized in that the predetermined portions are crystallized by relatively scanning with respect to each other. 22. The sub-beams irradiate only a formation portion of each thin film transistor with an energy intensity optimum for crystallization, and pass through a non-formation portion of each thin film transistor at a high speed. 21. The semiconductor manufacturing apparatus according to 21. 23. Irradiating each of the sub-beams so that at least one of a beam scanning speed for crystallization, an energy intensity, and a beam shape is different in a formation portion of each of the at least two kinds of thin film transistors. 23. The semiconductor manufacturing apparatus according to claim 21 or 22. 24. The semiconductor manufacturing apparatus according to claim 21, wherein the sub-beams are irradiated so as not to overlap each other. 25. The output instability of the energy beam is smaller than ± 1% / h.
The semiconductor manufacturing apparatus according to any one of 1 to 24. 26. The semiconductor manufacturing apparatus according to claim 25, wherein noise (optical noise) indicating instability of the energy beam is 0.1 rms% or less. 27. A substrate having a semiconductor thin film formed on the surface thereof is installed, and an installation means for freely moving the substrate in the in-plane direction of the semiconductor thin film, and an energy beam is continuously output with respect to time. A laser oscillating means having a function of, and a passage region and a cutoff region of the energy beam,
An intermittent emitting means for passing the energy beam intermittently, while relatively scanning the substrate with respect to the energy beam, intermittently irradiating the semiconductor thin film with the energy beam, A semiconductor manufacturing apparatus characterized by selectively crystallizing only a formation site. 28. By adjusting the scanning speed of the substrate and the timing of the intermittent emission, the energy beam can be rapidly moved to another formation portion during the irradiation interval between the formation portions of the thin film transistors adjacent to the semiconductor thin film. 28. The semiconductor manufacturing apparatus according to claim 27, further comprising irradiating the other formation site. 29. The apparatus further comprises beam splitting means for optically splitting the energy beam emitted from the laser oscillation means into a plurality of sub-beams, while scanning the substrate relative to the energy beam. 29. The semiconductor thin film is intermittently irradiated with each of the sub-beams to simultaneously crystallize formation sites of the plurality of thin film transistors.
The semiconductor manufacturing apparatus according to. 30. A portion of the semiconductor thin film different from a portion where the thin film transistor is formed is intermittently irradiated with the energy beam to form an alignment marker of the thin film transistor which is crystallized into a predetermined shape. The semiconductor manufacturing apparatus according to claim 27. 31. The output instability of the energy beam is smaller than ± 1% / h.
31. The semiconductor manufacturing apparatus according to any one of 7 to 30. 32. The semiconductor manufacturing apparatus according to claim 31, wherein noise (optical noise) indicating instability of the energy beam is 0.1 rms% or less.