JPH10294279A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform heat treatment for a large area with good uniformity by performing heat treatment for a semiconductor thin film after casting strong light emitted from a lamp light source provided in an upper surface side of a semiconductor film and from a lamp light source provided to a lower surface side of a semiconductor thin film on a semiconductor thin film. SOLUTION: After a foundation film 102 of a silicon oxide film is formed on a light transmitting glass substrate 101, an amorphous silicon film is deposited on the foundation film 102. A crystalline silicon film 103 is obtained by crystallizing an amorphous silicon film through heating treatment or laser beam irradiation. Ultraviolet light 107 is cast from an upper surface side of the crystalline silicon film 103. Then, infrared light 111 is cast to the crystalline silicon film 103 from a lower surface. In the process, the infrared light 111 is not absorbed by a glass substrate, and the crystalline silicon film 103 is heated to 600 to 1200 deg.C and becomes a crystalline silicon film 112 which is excellent in crystallinity. Thereafter, strain energy generated in a semiconductor film is removed or reduced by lamp anneal by carrying out furnace anneal of 500 to 700 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device for manufacturing a pixel matrix circuit, a driver circuit, a logic circuit, and the like using thin film transistors using a semiconductor thin film on the same substrate having a light transmitting property.

[0002]

2. Description of the Related Art In recent years, a semiconductor thin film (typically, a thin film containing silicon as a main component) formed on a glass substrate has been developed.
The development of the FT has made remarkable progress. The demand for electro-optical devices in which a pixel matrix circuit, a driver circuit, a logic circuit, and the like are monolithically mounted on a glass substrate is increasing.

[0003] The greatest constraint that arises when forming a TFT on a glass substrate is the process temperature. That is, the restriction that the heat treatment at a temperature higher than the heat-resistant temperature of the glass cannot be performed narrows the process margin.

Therefore, a laser annealing method is used as a means for selectively annealing a thin film. In the laser annealing method, the sample temperature is instantaneously increased by irradiating the sample with pulsed laser light, and only the thin film can be selectively heated. However, the complicated optical system for handling laser light and the difficulty in ensuring uniformity are problems in the mass production process.

Therefore, a lamp annealing method using intense light emitted from an arc lamp, a halogen lamp or the like has recently been spotlighted. This technology is based on RTA (Rapid Thermal An
nealling) or RTP (Rapid Thermal Processing)
The film to be processed is heated by irradiating the film to be processed with strong light in a wavelength region that is easily absorbed.

[0006] Usually, the lamp annealing method utilizes a visible light to infrared light region as intense light. Since light in this wavelength region is not easily absorbed by the glass substrate, heating of the glass substrate can be minimized. In addition, since the temperature rise / fall time is extremely short, high-temperature treatment at 1000 ° C. or higher can be performed in a short time of several seconds to several tens of seconds.

Further, since a complicated optical system such as that used for processing a laser beam is not required, it is suitable for processing a relatively large area with uniformity. Further, since the processing is basically performed by single-wafer processing, the yield and the throughput are high.

[0008]

SUMMARY OF THE INVENTION In the present invention, a process using an apparatus improved from the conventional lamp annealing method and a subsequent heat treatment provide high uniformity and good crystallinity. It is an object to obtain a semiconductor thin film.

Further, in the conventional lamp annealing method, since irradiation is performed only from the upper surface side of the film to be processed, a layer (for example, an electrode made of metal) that does not transmit light partially or entirely on the film to be processed, Or if there is a layer that prevents light irradiation,
The film to be processed under the layer could not be annealed. Especially,
When a conventional lamp annealing is used in the step of activating doped impurities in a semiconductor thin film, an electrode made of metal or an insulating film laminated on the semiconductor thin film prevents light irradiation, and is uniformly formed. A source / drain region having excellent properties could not be formed.

Another object of the present invention is that impurities are doped.
A semiconductor thin film having a source / drain region having excellent uniformity by activating impurities by a process using a device obtained by improving a conventional lamp annealing method on a pinged semiconductor thin film and a subsequent heat treatment. Is one of the issues.

[0011]

According to a first aspect of the invention disclosed in this specification, a step of irradiating a semiconductor thin film formed on a light-transmitting substrate with strong light and performing a heat treatment is described. A method of manufacturing a semiconductor device, comprising: at least one semiconductor device provided on an upper surface side of the semiconductor thin film with respect to the semiconductor thin film.
Irradiating the semiconductor thin film with intense light emitted from one lamp light source and at least one lamp light source provided on the lower surface side of the semiconductor thin film; and, after the process, performing a heat treatment on the semiconductor thin film. A method for manufacturing a semiconductor device.

A second structure is a method for manufacturing a semiconductor device, comprising a step of irradiating strong light to a semiconductor thin film on which impurities are doped and activating the impurities by heat treatment. Irradiating the semiconductor thin film with intense light emitted from at least one lamp light source provided on the upper surface side of the semiconductor thin film and at least one lamp light source provided on the lower surface side of the semiconductor thin film;
Performing a heat treatment on the semiconductor thin film after the step.

In the first or second configuration, the heat treatment is performed by furnace annealing at 500 to 700.degree. Here, the furnace annealing is a heat treatment for several hours performed in a heating furnace such as an electric heating furnace.

When lamp annealing is performed by strong light from a lamp light source as in the present invention, strain energy is generated in the semiconductor film. That is, it is very effective to remove or reduce strain energy by furnace annealing.

Further, since the conventional lamp annealing method is a batch processing of the entire surface, if the processing time is long, heat propagates from the film to be processed to the insulating substrate, generating distortion energy, and the substrate warps or shrinks. The problem was that the deformation occurred. In addition, in the case of lamp annealing in a batch processing of the entire surface, subtle unevenness occurs in the irradiation of light to the film to be processed, and a thin film having characteristics of high quality and excellent uniformity required can be obtained. could not. Therefore, in the first or second configuration, the problem can be solved by scanning the strong light from one end to the other end of the substrate in a state of being processed into a linear shape.

Further, in the first or second configuration, there is provided a method of manufacturing a semiconductor device, wherein the intense light is scanned while irradiating the same portion of the thin film.

In the first or second configuration, the intense light in a wavelength region capable of electronically exciting a bond of an atom of the thin film is ultraviolet light, and a wavelength region in which a bond of an atom of the thin film can be excited by vibration. The strong light is infrared light, which is a method for manufacturing a semiconductor device.

The first or second configuration is characterized in that the intense light is scanned from one end to the other end of the substrate in a state of being processed into a linear shape.

Further, in the first or second configuration, the intense light is scanned in a state where all of the intense light irradiates the same portion of the thin film.

In the first or second configuration, the strong light from the upper surface side is a light having a wavelength region (typically, 10 to 600 nm) capable of electronically exciting a bond of an atom of the thin film as a main component. Intense light from the lower surface side emits light in a wavelength region (typically 500 nm to 20 μm) in which vibrational bonds of atoms of the thin film can be excited.
m) is a light whose main component is light.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The feature of the present invention is that a film to be processed is irradiated with light from both sides, in particular, a combination of ultraviolet light (UV light) and infrared light (IR light) from the top and bottom sides. A semiconductor device using a semiconductor thin film obtained by an apparatus for irradiating a semiconductor device, and a manufacturing method thereof.

In the present invention, ultraviolet light is described as a typical light that gives photon energy, but visible light is also included as long as it is light in a wavelength range that can electronically excite the film to be processed. Typically, light in a wavelength range of 10 to 600 nm can be used.

Similarly, infrared light is described as a typical light for providing vibration energy (also referred to as heat energy). However, visible light can be used as long as the light has a wavelength range that can excite the film to be processed. May also be included. Typically 500 nm to 20μ
Light in the wavelength region of m can be used.

The above-mentioned wavelength region overlaps with the visible light region of 500 to 600 nm, because the wavelength region that can be electronically excited or vibrationally excited differs depending on the film to be processed. That is, this does not mean that the electronic excitation and the vibration excitation can be simultaneously generated by the light in the same wavelength region.

The ultraviolet light is a low-pressure metal vapor lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a halogen arc lamp, a hydrogen arc lamp, a metal halide lamp, a deuterium lamp, a rare gas resonance line lamp, a rare gas molecule. A lamp that emits ultraviolet light such as a light-emitting lamp can be obtained as a light source.

The infrared light can be obtained by using a lamp emitting infrared light such as a halogen lamp, a halogen arc lamp, a metal halide lamp or the like as a light source.

In the light irradiation treatment using ultraviolet light, the energy of photons is given to the film to be processed in the form of light absorption, and the bonds of molecules constituting the film to be processed are directly excited.
Such an excitation phenomenon is called electronic excitation. Since ultraviolet light is easily absorbed by the glass substrate, it is desirable to irradiate the semiconductor thin film containing silicon as a main component from the upper surface side.

The infrared light can be obtained from a lamp that emits infrared light such as a halogen lamp, a halogen arc lamp, and a metal halide lamp as a light source.

The light irradiation process using infrared light gives vibration energy in the form of lattice vibration, and indirectly excites bonds of molecules constituting the film to be processed using the vibration energy as excitation energy. Such an excitation phenomenon is called vibration excitation. Since infrared light is not easily absorbed by the glass substrate, it can be irradiated from the lower surface side of the semiconductor thin film containing silicon as a main component.

The process of the present invention can provide the following effects.

First, in addition to the conventional vibrational excitation by infrared light irradiation (excitation by thermal energy), the excitation efficiency of the crystalline silicon film 103 is drastically increased due to the synergistic effect of electron excitation by ultraviolet light irradiation. To improve.

That is, the bonding hands of the molecules constituting the crystalline silicon film 103 are loosened as a whole by the lattice vibration caused by the irradiation of the infrared light, and become extremely active electronically by the irradiation of the ultraviolet light to be connected. . Therefore, the crystalline silicon film 112 subjected to the heat treatment of the present invention is formed from a very active state (a state with a high degree of freedom of bonding).

Therefore, the crystalline silicon film 112 obtained by applying the present invention has very few crystal defects such as dangling bonds. In addition, since the crystal grain boundaries are also formed by bonding with good consistency, most of them are formed by inert grain boundaries such as tilt grain boundaries.

Since the basic absorption edge of silicon (silicon) is approximately 1 eV, it is considered that ultraviolet light is absorbed only on the surface having a thickness of about 10 nm to 1 μm. However, in the case of this embodiment, the thickness of the crystalline silicon film is 10 to 75 nm (typically, 15 to 75 nm).
(45 nm), which is extremely thin, so a sufficient excitation effect can be expected.

Further, since the conventional lamp annealing is a batch processing of the entire surface, if the processing time is long, there is a concern that heat is transmitted from the film to be processed to the glass substrate and the glass substrate warps or shrinks. I was

However, in the present invention, since the linear infrared lamp 108 is used as the light source of the infrared light 111, the propagation heat transmitted from the crystalline silicon film 103 to the substrate 101 is only local. . Therefore, it is possible to prevent the substrate 101 from warping or shrinking due to heat.

In this embodiment, the heat treatment method of the present invention is applied in the step of improving the crystallinity of the crystalline silicon film. However, the present invention can be applied to the crystallization step of the amorphous silicon film. Needless to say.

As described above, according to the present invention, in the heat treatment using the lamp annealing method, by irradiating the ultraviolet light simultaneously with the irradiation of the infrared light, the excitation effect of the semiconductor thin film containing silicon as a main component can be further enhanced. it can. That is, the effect of greatly improving the efficiency of the heat treatment can be obtained.

FIG. 4 is a conceptual diagram showing the difference between heat energy and light energy. The horizontal axis represents energy, and the vertical axis represents energy density. As shown in FIG. 4, the thermal energy has an average energy of kT, but has a wide energy distribution. on the other hand,
The light energy is a certain value depending on the wavelength, that is, hν
It has only its own energy.

Therefore, for example, when crystal growth is performed on a silicon film, the thermal energy includes not only the energy required for the growth but also the energy for breaking the crystal and the like, but the light energy efficiently uses only the energy required for the growth. Irradiation is possible.

As described above, by appropriately selecting the wavelength of the ultraviolet light, it is possible to intensively excite only a specific thin film. Excitation processing becomes possible. This is also one of the effects of the present invention in which ultraviolet light irradiation is combined with lamp annealing using infrared light.

The present invention is not limited to the combination of lamp annealing with infrared light and irradiation of ultraviolet light. For example, lamp annealing with infrared light from the upper surface side and infrared light from the lower surface side are combined. Lamp annealing by light may be combined.

When the lamp annealing method of the present invention is used in the step of crystal growing a film containing silicon as a main component, a high-quality semiconductor thin film having excellent uniformity can be obtained. Further, in the step of activating a film containing silicon as a main component doped with an impurity, by using the lamp annealing method of the present invention, a source region and a drain region having excellent characteristics can be obtained.

When furnace annealing is performed after the step using the lamp annealing method of the present invention, the strain energy generated by the step using the lamp annealing method of the present invention can be reduced or eliminated. Can be. for that reason,
When the lamp annealing method of the present invention is used, it is desirable to perform thermal annealing later.

[0045]

【Example】

Embodiment 1 In this embodiment, a process for improving the crystallinity of a crystalline film containing silicon as a main component in a method for manufacturing a semiconductor device will be described with reference to FIGS. The numerical values, materials, and the like are not limited to the present embodiment.

First, a base film 102 made of a silicon oxide film having a thickness of 2000 ° is formed on a glass (or quartz) substrate 101 as a light-transmitting substrate. Thereafter, a thickness of 300 ° to 500 °, in this embodiment, a thickness of 500
The amorphous silicon film of Å is deposited.

Then, means for crystallizing the amorphous silicon film by heat treatment or laser beam irradiation may be used. In addition, means using a catalyst element that promotes crystallization (Japanese Patent Laid-Open No.
It is also effective to use (disclosed in JP-A-130652). Thus, the crystalline silicon film 103 is obtained. (Figure 1
(A) In this embodiment, a crystalline silicon film is taken as an example of the crystalline film 103, but a compound semiconductor containing silicon such as Si _x Ge _1-x (0 <X <1) may be used. it can.

The crystalline silicon film also includes a monocrystalline silicon film, a microcrystalline silicon film, a polycrystalline silicon film, and the like. Here, a polycrystalline silicon film (a so-called polysilicon film) will be described as an example.

Thereafter, as shown in FIG. 1B, in this embodiment, the ultraviolet light 107 is irradiated from the upper surface side of the crystalline silicon film 103.
Is irradiated. The upper surface side is a main surface side facing the ultraviolet light lamp 104 in FIG.
It points to the surface opposite to 1.

Reference numeral 104 denotes a lamp light source that emits ultraviolet light (ultraviolet light) (hereinafter, simply referred to as an ultraviolet lamp), 105 denotes a reflecting mirror, and 106 collects ultraviolet light 107 emitted from the ultraviolet lamp 104. Is a cylindrical lens. Since the ultraviolet light lamp 104, the reflecting mirror 105, and the cylindrical lens 106 are elongated in the direction perpendicular to the plane of the drawing, the crystalline silicon film 103 is irradiated linearly.

Reference numeral 108 denotes a lamp light source that emits infrared light (infrared light) (hereinafter, simply referred to as an infrared light lamp).
Reference numeral 109 denotes a reflecting mirror, and 110 denotes a cylindrical lens for collecting the infrared light 111 emitted from the infrared light lamp 107. The infrared light 111 is also configured to be linear light similarly to the ultraviolet light 107.

The infrared light is applied to the crystalline silicon film 103 from the lower surface side. Here, the lower surface refers to the back surface facing the infrared light lamp 108 in FIG. 1, that is, the surface facing the glass substrate 101 side.

At this time, the infrared light 111 is transmitted without being absorbed by the glass substrate. That is, the crystalline silicon film 103 can be efficiently heated even when irradiation is performed from the lower surface side. Therefore, the crystalline silicon film 103 is heated to 600 to 1200 ° C. (typically 700 to 850 ° C.) by the irradiation of the infrared light 111. At this time, the film surface temperature of the crystalline silicon film 103 is:
It can be measured (monitored) using a pyrometer (radiation thermometer) using a thermocouple.

The glass substrate 101 is supported by a susceptor (not shown), and linear ultraviolet light 107 is scanned in the direction of the arrow from the upper surface of the glass substrate 101, and linear infrared light 107 is scanned from the lower surface. Light 111 is scanned in the direction of the arrow. In this manner, by scanning linear light from one end of the glass substrate 101 to the other end, it is possible to irradiate the entire surface of the substrate. By performing the above treatment, a crystalline silicon film 112 having excellent crystallinity was obtained.

Next, when the above processing is completed, 500 to 7
Furnace annealing at 00 ° C. (600 ° C. in this embodiment) is performed for 2 to 8 hours (4 hours in this embodiment). By this heat treatment step, the strain energy generated in the semiconductor film by the above-described lamp annealing step is removed or reduced.

If the strain energy is left as it is, it causes film peeling (peeling) during the manufacturing process. Further, since stress and lattice distortion are generated by the strain energy, the electrical characteristics of the semiconductor device change. Therefore, the furnace annealing step as described above is a very effective step as a post-step of a heat treatment involving a rapid phase change such as lamp annealing and laser annealing.

In this embodiment, the ultraviolet light 107 and the infrared light 111 irradiate the same portion of the crystalline silicon film 103.
The same part means that the irradiation range is the same as shown in FIG. Of course, in some cases, the scanning timing can be intentionally shifted or the scanning direction can be changed.

After that, the obtained crystalline silicon film is patterned by photolithography and separated into islands, and island regions of P-channel TFTs or N regions are formed.
An island region of a channel type TFT is formed.

Further, a thickness of 15
In this embodiment, an insulating film is formed by depositing a silicon oxide film having a thickness of 00 to 2000, in this embodiment, a thickness of 1500.

Subsequently, a thickness of 4000 to 6000 °, in this embodiment, 5000 ° by the sputtering method.
A gate wiring pattern is formed by forming an aluminum film and etching.

Using the gate electrode 119 as a mask, the insulating film is etched to form a gate insulating film 118.

Next, the source region 115 and the drain region 117 are formed by adding impurity ions imparting one conductivity to an active layer composed of an intrinsic or substantially intrinsic crystalline silicon film. At this time, when fabricating an N-channel TFT, P (phosphorus) ions or As (arsenic)
When producing a P-channel TFT, ion
(Boron) ions may be used.

Next, a silicon oxide film is used as the interlayer insulating film 120,
Alternatively, a silicon nitride film or a stacked film thereof is formed. As the interlayer insulating film, a layer made of a resin material may be formed over a silicon oxide film or a silicon nitride film.

Then, a contact hole is formed,
A source electrode 121 and a drain electrode 122 are formed.
Thus, a thin film transistor is completed. (Figure 1
(C))

The shape of the thin film transistor of the present invention is as follows.
Although it is a planar type, it goes without saying that the present invention can be applied to an inverted stagger type.

[Embodiment 2] In this embodiment, an example in which the present invention is applied to a step of activating an impurity ion imparting N-type or P-type added to an active layer of a TFT will be described.

FIG. 2A shows the state of the glass substrate 10.
1 is in the process of manufacturing a TFT. FIG.
In (a), regions denoted by reference numerals 201 to 203 are active layers formed of island-patterned semiconductor layers,
201 is a source region, 202 is a drain region, and 203 is a channel formation region.

A gate insulating film 2 is formed on the active layer.
04 is formed. The gate insulating film 204 is processed into the same shape as the gate electrode 205 disposed thereon by using the technique described in Japanese Patent Application Laid-Open No. Hei 7-135318.

Source region 201 and drain region 20
2 is formed by adding impurity ions imparting one conductivity to an active layer composed of an intrinsic or substantially intrinsic crystalline silicon film. At this time, P (phosphorus) ions or As (arsenic) ions may be used when manufacturing an N-channel TFT, and B (boron) ions may be used when manufacturing a P-channel TFT.

Next, after the step of adding impurity ions is completed, ultraviolet light 207 is irradiated from the upper surface side of the substrate on which the thin film transistor (TFT) is formed, and infrared light 2 is irradiated from the lower surface side of the substrate.
Irradiate 11 At this time, the ultraviolet light 207 does not reach directly below the gate electrode 205, but activation is performed without any problem because the infrared light 211 is irradiated from the lower surface side. (Figure 2
(A))

The lamp annealing treatment in the present embodiment is a step of exciting and activating the added impurity ions. Therefore, by applying the present invention, the activation rate is greatly improved, so that the resistance of the source / drain regions is reduced,
Ohmic contact between the TFT and the wiring electrode can be improved.

Further, since strain energy is generated by the lamp annealing, furnace annealing at 500 to 700 ° C., in this example, 600 ° C., was performed for 4 hours to remove or reduce the strain energy. At this time, it goes without saying that the annealing temperature is appropriately adjusted within the above temperature range depending on the material of the gate electrode.

Thereafter, a thin film transistor is completed in the same manner as in the first embodiment. (FIG. 2B) Of course, if the crystalline silicon film having excellent crystallinity obtained in Example 1 is used, a thin film transistor having more excellent characteristics can be obtained.

[Embodiment 3] In this embodiment, the present invention is applied to the step of selectively forming a metal silicide on the source / drain region surface of a TFT (including the gate electrode surface if the gate electrode is silicon). An example of such a case will be described. Although FIG. 3 is used for the description, the description will be given using the above-mentioned reference numerals as necessary.

The present embodiment is characterized in that an apparatus for simultaneously irradiating infrared light and ultraviolet light from the upper surface side of the substrate is used. That is, the infrared lamp 301 and the reflecting mirror 30 are provided on the upper surface side of the substrate.
2. An optical system including a cylindrical lens 303 and an optical system including an ultraviolet lamp 304, a reflecting mirror 305, and a cylindrical lens 306 are arranged. The infrared lamp 307 emits infrared light 307, and the ultraviolet lamp 304 irradiates ultraviolet light 308.

In this configuration, even in a region that is shaded by the gate electrode 204, the region is heated by either the infrared light 307 from the upper surface or the infrared light 311 from the lower surface. Therefore, the silicide formation reaction can be performed uniformly over the entire substrate.

In the case of the structure as in this embodiment, it is preferable that the structure be heated first with infrared light 307 and then excited with ultraviolet light 308 immediately after. That is, it is considered that the excitation efficiency is higher if the bond is first loosened by vibration excitation by infrared light and electronic excitation by ultraviolet light is added in that state.

The silicide forming process performed with the above configuration proceeds in the following order. First, when the impurity ion activation step is completed, a metal film 309 is formed so as to cover the entire surface of the TFT in the manufacturing process. As the metal film 309, Ti (titanium), Co (cobalt), W (tungsten), Ta (tantalum), or the like is generally used.

When heat treatment is performed in this state, the source region 2
01 and the silicon component constituting the drain region 202 react with the metal film 309 to form the metal silicide 3.
10 are formed. Such a reaction proceeds at the interface between the source / drain regions 201 and 202 and the metal film 309. In this embodiment, the reaction speed is increased by the excitation effect of the irradiation of ultraviolet light, and rapid silicidation can be realized.

Further, as a feature of the lamp annealing, the constituent atoms constituting the metal film 309 are added to the channel forming region 203
Can be prevented. This effect is remarkable when infrared light is irradiated linearly as in this embodiment.

It is needless to say that the structure of irradiating infrared light and ultraviolet light simultaneously from the upper surface of the substrate as in this embodiment can be applied to the first and second embodiments. In particular, when applied to the second embodiment, it is effective because the junction between the source / drain region and the channel formation region and the region shaded by the gate electrode are completely activated. Thereafter, a thin film transistor is completed in the same manner as in the first embodiment.

[Embodiment 4] In the present embodiment, an example will be described in which the irradiation range of the ultraviolet light 107 and the irradiation range of the infrared light 111 are different from the configuration of the first embodiment. Specifically, the irradiation range of the infrared light 111 is made wider than the irradiation range of the ultraviolet light 107. This is shown in FIG.

In FIG. 5, reference numeral 501 denotes a glass substrate provided with a base film on the surface, and 502 denotes a crystalline silicon film. Substrate 5
01, an ultraviolet lamp 503, a reflecting mirror 504,
A cylindrical lens 505 is arranged, and ultraviolet light 506 is provided.
Is irradiated. On the lower surface side, an infrared lamp 507 is provided.
A reflecting mirror 508 and a cylindrical lens 509 are arranged,
An infrared light 510 is irradiated.

At this time, the irradiation range of the infrared light 510 is 511
Over an area (referred to as a first area) indicated by.
The irradiation range of the ultraviolet light 506 is a region indicated by 512 (second region).
Region).

That is, the irradiation range of the infrared light 510 is designed to be wider than the irradiation range of the ultraviolet light 506. For that purpose, the length of the linearly processed infrared light 510 in the short side direction may be longer than the length of the linearly processed ultraviolet light 506 in the short side direction. By doing so, the first region includes the second region and is wider than the second region.

Therefore, the crystalline silicon film 502 has the ultraviolet light 50
6 is heated by the infrared light 510 just before being irradiated,
Immediately after the irradiation with the ultraviolet light 506, it is heated by the infrared light 510 for a short time. That is, a weakly excited state is formed in the region 511, and a weakly excited state is maintained in the region 513 as a complete excited state in the region 512.

With the above structure, the crystalline silicon film 50
Since it is considered that the excited state of No. 2 does not change abruptly, the time required for coupling can be increased. That is, it is possible to prevent the termination of the bonding between atoms in a non-equilibrium state. Thus, a crystalline silicon film with few crystal defects can be obtained. Thereafter, a thin film transistor is completed using this crystalline silicon film in the same manner as in the first embodiment.

Embodiment 5 In this embodiment, an example in which an infrared auxiliary lamp is formed in parallel with an ultraviolet lamp in the configuration of Embodiment 1 of the present invention will be described with reference to FIG.

In FIG. 6A, 601 is a glass substrate, and 602 is an amorphous silicon film. Although an amorphous silicon film is taken as an example of a film to be processed, there is no particular limitation as long as it is a thin film on a glass substrate. Reference numeral 603 denotes an infrared lamp on the lower surface of the substrate, and 604 denotes an ultraviolet lamp on the upper surface of the substrate.

The feature of this embodiment is that the ultraviolet lamp 6
The first infrared light auxiliary lamp 605 and the second infrared light auxiliary lamp 606 are arranged in parallel with the auxiliary infrared light lamp 04. In the present embodiment, the infrared light auxiliary lamps 605 and 60 are provided in front of and behind the ultraviolet light lamp 604 (in the moving direction of the substrate).
6 are arranged, but it is also possible to adopt a configuration arranged only on one side.

In the above configuration, each lamp 603
Reference numerals 606 move in the direction of the arrow in the figure to scan linear light. In the configuration of the present embodiment, first, the amorphous silicon film 6 is formed.
02 is heated by being irradiated with infrared light by the first infrared light auxiliary lamp 605. This area is the preheat area 607
And moves forward with the movement of the substrate.

[0092] Behind the preheating region 607, ultraviolet light from an ultraviolet lamp 604 is irradiated from the upper surface side of the substrate.
At the same time, the main heat region 608 is formed by irradiating infrared light from the infrared light lamp 603 from the lower surface side of the substrate. In the case of this embodiment, crystallization of the amorphous silicon film 602 is performed in the main heat region 608.

[0093] Behind the main heat area 608, a post-heat area 609 heated by infrared light from the second infrared light auxiliary lamp 606 is formed. This region is a region where the crystalline silicon film obtained in the main heat region 608 is heated.

As described above, the amorphous silicon film (which becomes a crystalline silicon film in the middle) 602 has a preheat region 607, a main heat region 608, and a postheat region 609 arranged in this order. It moves forward with.

FIG. 6B shows the time (Time) and the temperature (Te) at one point of the amorphous silicon film 602.
mp.). As shown in FIG. 6B, as time passes, the preheating area firstly follows, followed by the main heating area and the post heating area.

As is clear from FIG. 6B, the temperature is raised to a certain extent in the pre-heating region 607, and plays a role of alleviating the temperature gradient with the next main heating region 608. This is a contrivance for preventing rapid heating in the main heat region 608 and accumulation of strain energy or the like in the silicon film.

Therefore, the first infrared light auxiliary lamp 605
Is desirably set smaller than the output energy of the infrared lamp 603. At this time, what kind of temperature gradient is to be adjusted may be appropriately determined by the practitioner.

Next, after passing through the preheating region 607, infrared light is irradiated from the lower surface side of the substrate, and the film surface temperature becomes 600 ° C.
The main heat region 608 rises to about 1200 ° C. In this region, the amorphous silicon film 602 is transformed into a crystalline silicon film. Note that ultraviolet light irradiated at the same time contributes to electronic excitation, so that no thermal change occurs.

The crystalline silicon film obtained in the main heat region 608 is heated by the second infrared light auxiliary lamp 606 disposed behind the ultraviolet light lamp 604. The post-heat region 609 serves to prevent crystallization from being terminated in a state where thermal equilibrium is lost due to rapid cooling of the main heat region 608. This is a contrivance for obtaining the most stable bonding state by allowing time for crystallization.

Accordingly, the output energy of the second auxiliary lamp for infrared light 606 is also set to be smaller than that of the infrared light lamp 603 disposed on the lower surface of the substrate, and is adjusted so as to form a temperature gradient such that the temperature gradually decreases. It is desirable to do.

With the above-described structure, it is possible to suppress generation of crystal defects such as stress distortion and dangling bonds which can be caused by rapid heating of the amorphous silicon film and rapid cooling of the crystalline silicon film. Thus, a crystalline silicon film having excellent characteristics can be obtained. Thereafter, a thin film transistor is completed using this crystalline silicon film in the same manner as in the first embodiment.

[0102]

As described above, in the present invention, lamp annealing can be efficiently performed by installing a lamp light source in the vertical direction of the film to be processed. In particular, by simultaneously irradiating infrared light and ultraviolet light, the excitation efficiency of the target film can be further increased, and a crystalline silicon film having excellent crystallinity can be obtained.

[0103] Furnace annealing is also one of the steps of the present invention after the lamp annealing, and a crystalline silicon film having a small strain energy can be obtained by this treatment.

By using the crystalline silicon film thus formed, a semiconductor device having excellent electric characteristics can be manufactured.

Further, when the present invention is applied when activating the source region and the drain region to which an impurity imparting N-type or P-type is added to the active layer, effective and efficient activation of the impurity is performed. be able to.

Furthermore, by performing the lamp annealing of the present invention with intense light processed linearly, it is possible to perform a heat treatment at a high temperature of 600 to 1200 ° C. without warping or shrinking the glass substrate. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a heat treatment according to the present invention.

FIG. 2 is a diagram showing a configuration of a heat treatment according to the present invention.

FIG. 3 is a diagram showing a configuration of a heat treatment according to the present invention.

FIG. 4 is a diagram showing a difference between heat energy and light energy.

FIG. 5 is a diagram showing a configuration of a heat treatment according to the present invention.

FIG. 6 is a diagram showing a configuration of a heat treatment according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Glass substrate 102 Underlayer 103 Crystalline silicon film 104 Ultraviolet light lamp 105 Reflecting mirror 106 Cylindrical lens 107 Ultraviolet light 108 Infrared light lamp 109 Reflecting mirror 110 Cylindrical lens 111 Infrared light 112 Crystalline silicon film with improved crystallinity 115 source region 116 channel region 117 drain region 118 gate insulating film 119 gate electrode 120 interlayer insulating film 121 source electrode 122 drain electrode 201 source region 202 drain region 203 channel region 204 gate insulating film 205 gate electrode 207 ultraviolet light 211 infrared Light 217 Activated source region 218 Activated drain region 219 Activated channel region 220 Interlayer insulating film 221 Source electrode 222 Drain electrode 301 Infrared light lamp 02 Reflecting mirror 303 Cylindrical lens 304 Ultraviolet light lamp 305 Reflecting mirror 306 Cylindrical lens 307 Infrared light 308 Ultraviolet light 311 Infrared light 309 Metal film 310 Metal silicide 311 Ultraviolet light 501 Substrate 502 Crystalline silicon film 503 Ultraviolet light lamp 504 Reflected light 505 Cylindrical lens 506 Ultraviolet light 507 Infrared light lamp 508 Reflected light 509 Cylindrical lens 510 Infrared light 511 Region where weak excitation state is created 512 Region where complete excitation state is formed 513 Region where weak excitation state is maintained 601 Substrate 602 Non Amorphous silicon film 603 Infrared light lamp 604 Ultraviolet light lamp 605, 606 Infrared light auxiliary lamp 607 Pre-heat area 608 Main heat area 609 Post heat area

Claims (9)

[Claims] 1. A method for manufacturing a semiconductor device, comprising: irradiating a semiconductor thin film formed on a light-transmitting substrate with intense light and subjecting the semiconductor thin film to heat treatment. Irradiating the semiconductor thin film with intense light emitted from at least one lamp light source provided on the upper surface side of the semiconductor thin film and at least one lamp light source provided on the lower surface side of the semiconductor thin film; Subjecting the semiconductor device to a heat treatment. 2. A semiconductor thin film in which impurities are doped,
A method for manufacturing a semiconductor device, comprising irradiating strong light and performing heat treatment to activate the impurities, wherein at least one lamp provided on an upper surface side of the semiconductor thin film with respect to the semiconductor thin film Irradiating the semiconductor thin film with intense light emitted from a light source and at least one lamp light source provided on the lower surface side of the semiconductor thin film; and performing a heat treatment on the semiconductor thin film after the step. Of manufacturing a semiconductor device. 3. The heat treatment according to claim 1 or 2,
A method for manufacturing a semiconductor device, which is performed by furnace annealing at 500 to 700 ° C. 4. The method for manufacturing a semiconductor device according to claim 1, wherein the heat treatment reduces strain energy of the semiconductor thin film. 5. The method for manufacturing a semiconductor device according to claim 1, wherein the intense light is scanned from one end to the other end of the substrate in a state processed in a linear shape. 6. The method for manufacturing a semiconductor device according to claim 1, wherein the intense light is scanned while all of the intense light irradiates the same portion of the thin film. 7. The intense light from the lower surface side according to claim 1 or 2, wherein the intense light from the upper surface side is light having a wavelength region capable of electronically exciting a bond of an atom of the semiconductor thin film as a main component. Is light whose main component is a wavelength region that can vibrate and excite a bond of an atom of the semiconductor thin film. 8. The semiconductor device according to claim 7, wherein the intense light in a wavelength region capable of electronically exciting a bond of an atom of the semiconductor thin film is ultraviolet light, The method for manufacturing a semiconductor device, wherein the intense light is infrared light. 9. The semiconductor device according to claim 7, wherein the wavelength region in which the bonds of the atoms of the semiconductor thin film can be excited by electrons is 10 to 600 nm, and the wavelength region in which the bonds of the atoms of the thin film can be excited by vibration is: A method for manufacturing a semiconductor device, which has a thickness of 500 nm to 20 μm.