JP2001223208A - Semiconductor element manufacturing device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor element manufacturing device and a method by which a MOS interface of high quality can be formed at a low processing temperature. SOLUTION: A MOS interface of low interface state density is formed through an oxygen radical treatment, and an insulating film is consecutively formed through the deposition of SiO in an oxygen radical atmosphere, causing less damage in a series of processes, and the above processes are applied to a substrate of large area by the use of a substrate scanning-type device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field effect transistor formed on a single crystal semiconductor substrate, a thin film transistor formed on an insulator, and a logic circuit, a memory circuit, a display pixel or a liquid crystal of a liquid crystal display formed by the same. The present invention relates to an apparatus and a method for manufacturing a semiconductor element such as a thin film transistor used as a component of a drive circuit.

[0002]

2. Description of the Related Art Semiconductor films such as polycrystalline silicon are widely used in thin film transistors (hereinafter referred to as TFTs) and solar cells. In particular, polycrystalline silicon (poly-Si) TFTs can be formed on a transparent and insulating substrate such as a glass substrate while being able to have a high mobility, and are used for a liquid crystal display (LCD).
It is widely used as a light modulation element for LCDs and liquid crystal projectors, or as a component of a built-in driver for driving liquid crystals, and has successfully created a new market.

As a method of forming a high-performance TFT on a glass substrate, a manufacturing method called a high-temperature process has already been put to practical use. As a method of manufacturing a TFT, a process using a high temperature of about 1000 ° C. is generally called a high-temperature process. The features of the high-temperature process are that relatively high-quality poly-Si can be formed by solid-phase growth of silicon, and that a high-quality gate insulating film (generally silicon dioxide) and a clean poly-
That is, an interface between Si and the gate insulating film can be formed. Due to these characteristics in a high-temperature process, a high-performance TFT with high mobility and high reliability can be stably manufactured. However, in order to use a high-temperature process, a substrate on which a TFT is formed must be able to withstand a high-temperature heat process of 1000 ° C. or higher. Currently, the only transparent substrate that meets this condition is quartz glass. For this reason, the recent poly-S
All iTFTs are formed on a small and expensive quartz glass substrate, and are not suitable for a large size due to cost issues. In addition, the solid phase growth method requires a heat treatment for a long time of about ten hours, and there is a problem that productivity is extremely low. In addition, in this method, since the entire substrate is heated for a long time, thermal deformation of the substrate becomes a big problem, and there is a problem that it is not possible to use a substantially inexpensive large glass substrate. Also hinder cost reduction.

On the other hand, a technique called a low-temperature process is intended to solve the above-mentioned disadvantages of the high-temperature process and to realize a poly-Si TFT with high mobility. In order to use a relatively inexpensive heat-resistant glass substrate, poly-Si with a process maximum temperature of approximately 600 ° C or less
The TFT manufacturing process is generally called a low temperature process. In a low-temperature process, a laser crystallization technique for crystallizing a silicon film using a pulse laser having an extremely short oscillation time is widely used. Laser crystallization is a technique that utilizes the property that an amorphous silicon film on a glass substrate is instantaneously melted by irradiating it with a high-power pulsed laser beam and then crystallized in the process of solidification. Recently, a technique of forming a large-area poly-Si film by scanning while repeatedly irradiating an amorphous silicon film on a glass substrate with an excimer laser beam has been widely used. Further, as a gate insulating film, a silicon dioxide (SiO 2) film of relatively high quality can be formed by a film forming method using plasma CVD, and the prospect of practical use can be obtained. With these techniques, a poly-Si TFT can now be formed on a large-sized glass substrate having a side of about several tens of centimeters.

However, the problem with this low-temperature process is that the laser-crystallized poly-Si film has a high defect density, which greatly affects the mobility and threshold voltage of the TFT. . After a detailed investigation,
10 ¹⁸ to 10 ¹⁹ is contained in the laser-crystallized poly-Si film.
It was found that defects were present at a high density of (cm ⁻³ ). This is a 50nm poly-S which is currently used
Assuming an i film, the surface density is 5 × 10 ^{11 to} 5 × 1
It will be a value of 0 ¹² (cm ^-2 ). As a more serious task, T
The FT MOS interface also has a high-density interface order. Its value is about 10 ¹² (cm ⁻² ). As can be seen, defects exist at the same high density both in the MOS interface and in the poly-Si film. In the case of a field effect transistor, when a voltage is applied to the gate electrode, M
Carriers determined by the OS capacitor capacitance are induced on the semiconductor side. However, the semiconductor side, that is, poly-S
If there are defects at the i film and the MOS interface, the induced carriers are trapped by these defects and cannot contribute to conduction. As a result, a drain current cannot be obtained unless a higher gate voltage is applied to induce more carriers than defects. This is the reason why the threshold voltage of the TFT is increased. At present, there is no effective means for actively controlling the above defects, which results in a high threshold voltage of the TFT or a large variation between lots, which is the biggest problem in the current manufacturing process. I have.
At present, the threshold voltage of a TFT manufactured using a laser-crystallized poly-Si film is about 3 to 4 V. If the threshold voltage can be reduced to, for example, about 1 V, the driving voltage of a circuit made of a TFT can be reduced to one third or less of the current level. The power consumption of the circuit is 2 of the drive voltage.
Since it is proportional to the power, if the driving voltage can be reduced to one third or less, the power consumption can be drastically reduced to about one tenth. By doing so, for example, an ultra-low power consumption liquid crystal display suitable for a display for a portable information device can be realized.
In order to achieve such an object, it is required to reduce both the defect surface densities at the poly-Si and MOS interfaces to about 10 ¹⁰ (cm ⁻² ).

As a prior art for solving the above-mentioned problem, there is Japanese Patent Application Laid-Open No. 61-260625, for example. This discloses a technique for modifying a silicon-insulating film interface by irradiating a laser to a laminated structure of a silicon film and an insulating film. The silicon film is heated by a laser to modify the interface. In such a method, local heating is performed in a state where the silicon-insulating film structure is already formed. However, there is a drawback that it is difficult to reconstruct the bond of the compound and the interface order density cannot be sufficiently reduced.

[0007]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention has been made in consideration of the above-mentioned problems, and it has been found that a laser crystallization poly by a low temperature process.
It is intended to provide a semiconductor device manufacturing apparatus and a semiconductor device manufacturing method capable of reducing both the defects in the film of Si and the defects at the MOS interface, and making it possible to apply the characteristics of poly-Si TFTs and circuits to large-area substrates. .

[0008]

According to a first aspect of the present invention, there is provided an apparatus for manufacturing a semiconductor device, comprising: a substrate stage capable of two-dimensionally scanning a substrate in a vacuum; and a SiO vacuum deposition cell. Features. Here, "in vacuum" means that the pressure is at least lower than atmospheric pressure.
Here, "scanning two-dimensionally" means that the substrate can be moved in the first direction and, at the same time, the substrate can be moved in the second direction orthogonal to the first direction. Here, the SiO vacuum deposition cell means an apparatus having a function of forming a film on a substrate by diffusing an SiO molecular beam having a vapor pressure higher than the atmospheric pressure in a vacuum toward the substrate.

According to a second aspect of the present invention, there is provided a semiconductor device manufacturing apparatus according to the first aspect, wherein the SiO vacuum deposition cell is formed by projecting a shape of the SiO vacuum deposition cell onto a substrate surface. The stage is arranged at a position where the center axis is parallel to one of the scanning directions of the stage. Here, the central axis is defined as a straight line drawn in the direction in which the molecular beam is emitted from the SiO vacuum deposition cell.

According to another aspect of the present invention, there is provided an apparatus for manufacturing a semiconductor device, comprising: a substrate stage capable of two-dimensionally scanning a substrate in a vacuum; an SiO vacuum deposition cell; and a radical generation source. I do. Here, the radical means an electrically neutral atom or molecule in an active state having higher energy than the ground state.

According to a fourth aspect of the present invention, there is provided a semiconductor device manufacturing apparatus according to the third aspect, wherein the radical generating source generates radicals by any of an inductively coupled plasma discharge and an ECR plasma discharge. It is characterized by performing. Here, ECR plasma means plasma generated by the electron cyclotron resonance method.

According to a fifth aspect of the present invention, there is provided a semiconductor device manufacturing apparatus in which a substrate stage capable of two-dimensionally scanning a substrate in a vacuum, a SiO vacuum deposition cell, a radical generation source, and a sample are irradiated with light. It is characterized by having a window.

According to another aspect of the present invention, there is provided a semiconductor device manufacturing apparatus comprising: a stage capable of two-dimensionally scanning a substrate in a vacuum; a SiO vacuum deposition cell; and a window for irradiating light to a radical generation source and a sample. And a capacitively coupled plasma discharge electrode.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of:
The method is characterized in that an insulating film is formed on a substrate by scanning the substrate while irradiating an O molecular beam.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: performing radical processing on a surface of a semiconductor film on a substrate by scanning the substrate while generating radicals by a radical generating source. Features.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a semiconductor device according to the eighth aspect, wherein the radical is an oxygen radical.

According to a tenth aspect of the present invention, there is provided a method of manufacturing a semiconductor device, wherein a radical processing is performed on a surface of a semiconductor film on a substrate by scanning the substrate while generating oxygen radicals by a radical generating source. Thereafter, irradiation of SiO molecular beam is started by a SiO vacuum deposition cell while the supply of oxygen radicals is maintained, and an insulating film is formed on the semiconductor film by scanning the substrate in this state.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below.

The semiconductor device manufacturing apparatus of the present invention has a vacuum vessel equipped with a vacuum exhaust device for executing a manufacturing process under reduced pressure. The device material is stainless steel or aluminum, and the exhaust device is composed of a turbo molecular pump, an oil diffusion pump, a cryopump and a rotary pump, a dry pump, and the like. From the viewpoint of the influence of impurities on the semiconductor and the vacuum pumping speed, it is desirable to perform vacuum pumping using a combination of a turbo molecular pump and a dry pump. The vacuum vessel is provided with an XY stage, on which a substrate to be processed is held.
It is desirable that the holder holding the substrate also has a heating mechanism, and a mechanism capable of heating the substrate up to about 400 ° C. is required. The XY stage is configured to move the substrate in the X direction and the Y direction orthogonal thereto at least a distance of about two to three times the diameter of the substrate. Specifically, there are ball screws at the bottom of the holder that holds the substrate,
Driving in the Y direction is performed. The substrate moving speed in the X and Y directions can be controlled at an arbitrary speed, and it is necessary that the substrate can be moved at a maximum speed of about 10 cm per second.

Next, the SiO vacuum deposition cell will be described. In principle, it refers to a vapor deposition apparatus having a function of generating a molecular beam by heating SiO and irradiating it with a substrate to form an SiO film. The SiO vacuum deposition cell mainly comprises a crucible holding powdered SiO and a filament for heating the crucible by resistance. A crucible made of ceramic or PBN can be used. For the filament formed so as to surround the crucible in a ring shape, a high melting point metal such as tungsten or tantalum is suitable, and the resistance value of the filament is 0.1 to 0.5 (Ω).
The degree is suitable for efficient heating. 1000 ° C. to 1 so that the vapor pressure of SiO becomes 10 ⁻⁴ to 10 ⁻² (torr)
It needs to be heated to 200 ° C. Since the vapor pressure curve with respect to the temperature of SiO has a steep slope, stable S
Temperature control is important for obtaining the iO molecular beam flux. Usually, a platinum thermometer is placed behind the crucible, and while monitoring the temperature of the crucible, the power supplied to the filament is fed back to stabilize the flux. A shutter is provided on the front surface of the SiO vacuum deposition cell, and a rotary type is often used. It is necessary to start heating of SiO and gradually increase the temperature while performing preheating until a stable molecular beam flux is obtained. When unnecessary, the shutter is closed so that the molecular beam flux is not irradiated on the substrate, and when the flux is stabilized, the shutter is opened to form a film.

Conventionally, there is almost no example in which SiO deposition is applied to a TFT manufacturing process. This is because the area in which the film can be formed is limited, and it is difficult to ensure the uniformity of the film. However, the semiconductor device manufacturing apparatus disclosed in the present invention employs an X-Y
It has a SiO vacuum deposition cell with the function of scanning.
With reference to FIG. 5, a description will be given, with reference to FIG. 5, of the fact that this structure enables uniform formation of a SiO film over a large area. For example, while moving the substrate (501) in the Y direction (503) parallel to the direction (center axis) (511) of the SiO flux,
When O vacuum deposition is performed, a three-dimensional film thickness profile (500) as schematically shown in the figure is obtained. The SiO vacuum deposition cell (510) is often used in an oblique direction as shown in the figure, but when its shape is projected on the substrate surface, the center axis is parallel to one of the scanning directions of the stage. By arranging them at such positions and making the relative positional relationship with the XY stage as shown in the figure, uniformization in the Y direction becomes possible. Next, the substrate is shifted in the X direction (502) by an appropriate amount, and SiO evaporation is performed while moving the substrate in the Y direction (503) again. Here, as shown in the lower part of FIG. 5, the appropriate amount is a distance corresponding to just the half width from the SiO film thickness distribution in the X direction. By repeating the film formation in the order of 505 → 506 → 507... While shifting in an appropriate amount in the X direction, the film thickness distribution in the X direction is finally made uniform (508), and a uniform film is formed on the entire surface of the substrate. This makes it possible to form a thick SiO film.

Next, the radical generating source will be described. La
Zical is used for plasma discharge, hot filament, light excitation, etc.
But can be generated relatively easily
Because plasma can be supplied, plasma can be used as a radical source.
Often used. Plasma is simplified by RF discharge
Plasma generation that can only be generated, but is applicable to the present invention
Raw methods include inductively coupled plasma and ECR plasma.
There is a ma. The reason is that a plasma discharge of 10^-3(Tor
r) It can be sustained even in the low pressure range below
You. The semiconductor device manufacturing apparatus according to the present invention employs the above-described SiO vacuum evaporation.
Equip the same vacuum chamber with the deposition device and the radical generation source
Therefore, these two devices operate efficiently under the same pressure.
Need to be As mentioned earlier, the saturated vapor pressure of SiO is
10^-Four-10 ^-2(Torr)
The source can efficiently generate radicals in the same pressure range.
Ability is required. Parallel often used in film forming equipment
Since the flat plate type RF discharge is a capacitively coupled discharge, the operating pressure
Range is 10^-2~ 1 (torr), and in the low pressure region
Since it is difficult to maintain discharge, it is suitable as a radical source in the present invention.
Not. Also, the electron density of the plasma is 10^Ten(Cm^-3)When
In general, a low level is disadvantageous for efficient radical generation.
You. On the other hand, inductively coupled plasma and ECR plasma
Ramo 10^-Four-10^-2Discharge at low pressure (torr)
And 10¹²(Cm^-3Plasma with electron density of
Can be generated, so that radical generation can be performed with high efficiency. this
For these reasons, the radical source of the present invention is an inductively coupled radical source.
Plasma and ECR plasma are the most suitable.

Generally, a radical source obtains neutral particles in an excited state by plasma discharge, but the discharge region and the processing region are usually separated by a mesh or the like. This is because the plasma is confined in the discharge region, neutral radicals reach the substrate by diffusion, and cause a reaction without (or very little) charged particles. High-energy ions are present in the plasma, and generally contain a considerable amount of energy higher than the bonding energy between atoms. Although there is a process for positively utilizing these ion energies, it is important to reduce ion damage as much as possible in forming a MOS interface to which the present invention is applied. For this reason, it is desirable that the inductively coupled plasma and ECR plasma be confined only in the discharge region and separated from the process region by a mesh. Furthermore, if this mesh is connected to a ground potential via a capacitor to form a high-pass filter, the potential of the mesh can be stabilized without swinging to a high-frequency fluctuation potential.

Since the radical source needs to generate radicals with high efficiency, the discharge source generally has a diameter of about 10 cm or less. Therefore, in order to apply this to a large-area substrate, the semiconductor device manufacturing apparatus of the present invention can perform radical processing on a large-area substrate by using a small radical source by scanning the substrate. In particular, by using it in combination with an SiO vacuum deposition cell, it is possible to apply vacuum deposition, which was previously unsuitable for large-area deposition, to large-area processing, and at the same time, to use a low-damage SiO vacuum deposition method and a low-damage reaction energy. Due to the synergistic effect of the radical treatment that plays a role of supply, the formation of a high-quality MOS interface and an insulating film can be realized even in a low-temperature process.

Next, a method of manufacturing a semiconductor device according to the present invention will be described with reference to FIG.

(1. Formation of Semiconductor Thin Film) In order to carry out the present invention, a base protective film (1) is usually formed on a substrate (101).
02) and a semiconductor thin film (103) are formed thereon. A series of forming methods will be described.

The substrate (101) to which the present invention can be applied is a conductive substance such as a metal, silicon carbide (Si).
C), alumina (Al ₂ O ₃ ), aluminum nitride (Al
Ceramic materials such as N), transparent or non-transparent insulating materials such as fused quartz and glass, semiconductor materials such as silicon wafers, and LSI substrates processed therefrom are possible. The semiconductor film is deposited directly on the substrate or via a lower protective film, a lower electrode, and the like.

As the underlying protective film (102), a silicon oxide film (SiO _x : 0 <x ≦ 2) or a silicon nitride film (Si ₃ N _x : 0)
<X ≦ 4). When it is important to control impurities in a semiconductor film, such as when a thin-film semiconductor device such as a TFT is formed on a normal glass substrate, mobile ions such as sodium (Na) contained in the glass substrate are removed from the semiconductor film. It is preferable to deposit a semiconductor film after forming a base protective film so as not to mix in the semiconductor film. The same situation applies when various ceramic materials are used as the substrate. The underlayer protective film prevents impurities such as a sintering aid material added to the ceramic from diffusing and mixing into the semiconductor portion. When a conductive material such as a metal material is used as a substrate and the semiconductor film must be electrically insulated from the metal substrate, a base protective film is indispensable to ensure insulation. In addition, semiconductor substrates and LSI
When a semiconductor film is formed on an element, an interlayer insulating film between transistors and between wirings is also a base protective film.

The undercoat protective film is first washed with an organic solvent such as pure water or alcohol, and then is deposited on the substrate by atmospheric pressure chemical vapor deposition (APCVD) or low pressure chemical vapor deposition (LPCV).
D method), a CVD method such as a plasma enhanced chemical vapor deposition method (PECVD method), or a sputtering method. When a silicon oxide film is used as the base protective film, the atmospheric pressure chemical vapor deposition method can deposit the substrate using monosilane (SiH ₄ ) or oxygen as a raw material at a substrate temperature of about 250 ° C. to about 450 ° C. In the plasma chemical vapor deposition method and the sputtering method, the substrate temperature is from room temperature to about 400 ° C. The thickness of the base protective film must be sufficient to prevent diffusion and mixing of the impurity element from the substrate, and the value is at least about 100 nm or more. Considering the variation between lots and substrates, the thickness is preferably about 200 nm or more, and if it is about 300 nm, it can sufficiently function as a protective film. When the underlayer protective film also serves as an interlayer insulating film between IC elements or wiring connecting these, usually 4
The thickness is about 00 to 600 nm. If the insulating film is too thick, cracks occur due to stress in the insulating film. Therefore, the maximum thickness is preferably about 2 μm. When it is strongly necessary to consider productivity, the upper limit of the insulating film thickness is about 1 μm.

Next, the semiconductor thin film (103) will be described. As a semiconductor film to which the present invention is applied, silicon (S
i) or a semiconductor film of a simple substance of Group 4 such as germanium (Ge), as well as silicon germanium (Si _x Ge ₁ -x: 0 <
x <1) or silicon carbide (Si _x C _1-x : 0 <
x <1) or germanium carbide (Ge _X C _1-X :
Semiconductor film of a group 4 element complex such as 0 <x <1), gallium arsenide (GaAs), indium antimony (InS
b) or a composite compound semiconductor film of a Group III element and a Group V element, or a composite compound semiconductor film of a Group II element and a Group 6 element such as cadmium selenium (CdSe). Alternatively, silicon, germanium, gallium, arsenic (Si _X G
_{e Y Ga Z As Z: x} + y + z = 1) and the further complex compound semiconductor film say and phosphorus in these semiconductor films (P), arsenic (As), N-type semiconductor obtained by adding a donor element such as antimony (Sb) The present invention is applicable to a film or a P-type semiconductor film to which an acceptor element such as boron (B), aluminum (Al), gallium (Ga), or indium (In) is added. These semiconductor films are formed by a CVD method such as an APCVD method, an LPCVD method, or a PECVD method, or a PVD method such as a sputtering method or an evaporation method. When a silicon film is used as a semiconductor film, disilane (Si ₂ H ₆ ) or the like can be deposited at a substrate temperature of about 400 ° C. to about 700 ° C. by LPCVD. PECVD
In this method, deposition can be performed at a substrate temperature of about 100 ° C. to about 500 ° C. using monosilane (SiH ₄ ) as a raw material.
When using the sputter method, the substrate temperature is set to 400 from room temperature.
It is about ° C. The initial state (as-deposited state) of the semiconductor film thus deposited is amorphous, mixed crystal,
There are various states such as microcrystalline or polycrystalline, but in the present invention, the initial state may be any state. Incidentally, in the present specification, not only amorphous crystallization,
The term “crystallization” includes recrystallization of polycrystalline and microcrystalline materials. The thickness of the semiconductor film is 2 when it is used for a TFT.
About 0 nm to about 100 nm is suitable.

(2. Laser Crystallization of Semiconductor Thin Film) After forming a base insulating film and a semiconductor film on a substrate, the semiconductor film is crystallized by laser irradiation. Usually, LPCV
The surface of a silicon film deposited by a CVD method such as the D method or the PECVD method is often covered with a natural oxide film. Therefore, it is necessary to remove the natural oxide film before irradiating the laser beam. For this purpose, there are a method of immersing in a hydrofluoric acid solution for wet etching, a method of dry etching in plasma containing fluorine gas, and the like.

Next, the substrate provided with the semiconductor film is set in a vacuum vessel. The vacuum vessel is partially made of a quartz window for laser irradiation, and irradiates a laser beam from the quartz window after evacuation.

Here, the laser beam will be described. It is desired that the laser light is strongly absorbed on the surface of the semiconductor thin film (103) and hardly absorbed by the insulating film (102) and the substrate (101) directly below. Therefore, as the laser light, an excimer laser, an argon ion laser, a YAG laser harmonic, or the like having a wavelength in or near the ultraviolet region is preferable. Further, in order to heat the semiconductor thin film to a high temperature and to prevent damage to the substrate at the same time, it is necessary to have a large output and an extremely short pulse oscillation. Accordingly, among the above laser beams, an excimer laser such as a xenon chloride (XeCl) laser (wavelength 308 nm) or a krypton fluoride (KrF) laser (wavelength 248 nm) is most suitable. Next, a method for irradiating these laser beams will be described with reference to FIG. Laser pulse intensity half width is about 10ns to 500n
This is a very short time of about s. Laser irradiation is performed on the substrate (20
0) between room temperature (about 25 ° C.) and about 400 ° C.
The process is performed in a vacuum having a background vacuum degree of about 10 ⁻⁴ Torr to about 10 ⁻⁹ Torr. One irradiation area of the laser irradiation has a square or rectangular shape with a diagonal of about 5 mm to about 60 mm. A case will be described in which a beam that can crystallize a square area of, for example, 8 mm by one irradiation of laser is used. After one laser irradiation (201) is performed in one place, the position of the laser is slightly shifted relative to the substrate in the horizontal direction (203). Thereafter, one laser irradiation (202) is performed again. By continuously repeating the shot and scan, it is possible to cope with a substrate having a large area. More specifically, the irradiation area is shifted from about 1% to about 99% for each irradiation (for example, 50%).
%: 4 mm in the above example). After scanning first in the horizontal direction (X direction), then in the vertical direction (Y direction), an appropriate amount (20
4) The laser beam is shifted and scanned again by a predetermined amount (203) in the horizontal direction. Thereafter, this scanning is repeated to perform the first laser irradiation on the entire surface of the substrate. The first laser irradiation energy density is from about 50 mJ / cm ² to 600
It is preferably between about mJ / cm ² . After the first laser irradiation is completed, a second laser irradiation is performed on the entire surface as necessary. When performing the second laser irradiation,
The energy density is preferably higher than the first time.
From mJ / cm ² about it may be between about 1000 mJ / cm ^2. The scanning method is the same as that of the first laser irradiation, and scans the square irradiation area by shifting it by an appropriate amount in the Y direction and the X direction. Further, if necessary, the third or fourth laser irradiation with a higher energy density can be performed. When such a multi-step laser irradiation method is used, it is possible to completely eliminate the variation caused by the end portion of the laser irradiation area. The laser irradiation is performed not only at each irradiation of the multi-stage laser irradiation but also at an ordinary one-step irradiation at an energy density that does not damage the semiconductor film.
In addition, as shown in FIG.
Line-shaped (3 μm or more and several tens cm or more in length)
01), and the crystallization may be advanced by scanning this linear laser beam. In this case, the overlap in the width direction of the beam for each irradiation is about 5% to about 95% of the beam width. If the beam width is 100 μm and the amount of overlap of each beam is 90%, the beam advances 10 μm for each irradiation, so that the same point receives 10 laser irradiations. Normally, at least about five times of laser irradiation is desired to uniformly crystallize the semiconductor film over the entire substrate, so that the beam overlap amount for each irradiation needs to be about 80% or more. In order to reliably obtain a polycrystalline film having high crystallinity, it is preferable to adjust the overlap amount from about 90% to about 97% so that the same point is irradiated about 10 to 30 times.

(3. Plasma Treatment of Semiconductor Thin Film) The poly-Si film immediately after laser crystallization contains 10 ¹⁸ (c)
Defects are present at a density as high as m ⁻³ ). This is because laser crystallization is an extremely high-speed crystal growth, and particularly, many defects are localized at crystal grain boundaries. The nature of these defects is dangling bonds of silicon, which are usually neutral but have the property of capturing carriers and being charged. If these defects are present in the poly-Si film at a high density, all the carriers induced by the field effect are trapped by the defects when trying to operate the TFT, so that no current flows between the source and drain electrodes. It will be. As a result, it becomes necessary to apply a higher gate voltage, which causes an increase in the threshold voltage. In order to prevent this, after the entire crystallization is completed by the above-mentioned laser crystallization step, hydrogen, oxygen, and nitrogen gas are introduced into the laser crystallization chamber, which was in a vacuum atmosphere, through a mass flow controller, and the entire sample is scattered by a parallel plate RF electrode. To perform plasma discharge. Here, the gas is, for example, 1
The flow rate is adjusted so that the pressure becomes about Torr. Plasma can also be generated by inductively coupled RF discharge, DC discharge, or ionization using thermoelectrons by a hot filament. Po immediately after laser crystallization
By subjecting the ly-Si film to hydrogen plasma treatment for 5 seconds to 300 seconds, the defects in the film are dramatically reduced to a density of about 10 ¹⁶ (cm ⁻³ ), and an electrically excellent poly-Si film is obtained. I can do it.

Since hydrogen has a very high diffusion rate in a silicon film, for example, poly-S having a thickness of about 50 nm is used.
For i, a processing time of about 160 seconds is sufficient. Hydrogen has a small atomic radius and can efficiently passivate defects to a deep position of the poly-Si film, that is, an interface with the underlayer. The hydrogen plasma has the effect of the silicon etching mode depending on the substrate temperature. In order to avoid this, it is necessary to keep the substrate temperature at approximately 100 ° C. to 400 ° C. In order to shorten the tact time of the process, it is effective to move the substrate to another vacuum chamber by a vacuum robot arm after performing the laser crystallization and perform the hydrogen, oxygen and nitrogen plasma treatment.

As a process for reducing defects, hydrogen plasma is suitable for the above-described reason, but it is also possible to reduce defects by plasma treatment such as oxygen plasma, nitrogen plasma, or fluorine plasma.

(4. Formation of MOS interface)
Although it is possible to achieve high quality of the y-Si film,
A more important process is a step of forming a high-quality poly-Si film-gate insulating film interface. It is necessary to reduce the interface order density by successfully bonding oxygen atoms to silicon atoms existing on the poly-Si surface. There are approximately 10 ¹⁵ (cm ⁻² ) bonds on the surface of the silicon film. T
In order to improve the transistor characteristics of the FT, it is necessary to suppress the interface order density to about 10 ¹⁰ (cm ⁻² ).
That is, only about one defect is allowed for 100,000 silicon bonds, and the other bonds must be bonded to oxygen atoms in an orderly manner, which is very severe. In the conventional process, the poly-Si surface is exposed to a photoresist or a chemical solution and is not actively controlled, so that the interface order density is at most 10 ¹² (c).
m ⁻² ). However, in the oxygen radical atmosphere disclosed in the present invention, S
An extremely good interface is formed even in a low-temperature process of 400 ° C. or less by the technique of performing iO vapor deposition. p
A considerable amount of carbon atoms are present on the surface of the poly-Si film, which hinders formation of a clean MOS interface. The oxygen radical treatment is extremely effective in removing the carbon atoms from the surface and forming a good silicon-oxygen bond with the silicon atoms. This is because oxygen radicals play a role both in reacting with and separating carbon on the surface, and in forming a bond by bonding with a silicon atom that subsequently appears on the surface. Oxygen radicals are formed even by simple oxygen plasma treatment, but high-energy ions present in the plasma can easily break good bonds between silicon and oxygen atoms, resulting in lower interface order density. You can't. After a high-quality MOS interface is formed by oxygen radicals, the SiO molecular beam coming to the surface reacts with the oxygen radicals, so that a good insulating film with low damage can be continuously formed. Since the MOS interface formed by oxygen radicals is limited to the very surface, the first-layer gate insulating film (10
5) When the formation is performed by a method such as plasma CVD, a favorable MOS interface is disturbed. Therefore, MO deposition with low interface order density can be performed by depositing SiO in an oxygen radical atmosphere.
The S interface is maintained. Thus, the presence of oxygen radicals is essential in forming a good silicon-oxygen bond. Although the MOS interface can be formed by simply depositing SiO in an oxygen atmosphere, the interface order density is inferior to that formed in an oxygen radical atmosphere. FIG. 6 shows a MOS capacitor (600) manufactured by the MOS interface forming method of the present invention and a MOS capacitor (60) manufactured by vacuum-depositing SiO without using oxygen radicals and oxidizing an insulating film by oxygen plasma.
It shows the difference in the high frequency CV characteristic (1 MHz) of 1). The insulating film thickness is 50 to 60 nm in both cases, but the MOS capacitor formed by vapor deposition of SiO in oxygen radicals has a small interface order and shows a very steep rising curve (600). As can be seen, the interface treatment with oxygen radicals is extremely important for reducing the interface order density.

As a specific process, the poly-Si film formed by laser crystallization is subjected to a hydrogen plasma treatment continuously in a vacuum, and then the MO
Proceed to the S interface formation process. In order to reduce the tact time of the process, it is desirable that the substrate be processed while constantly maintaining a constant temperature during the processes of laser crystallization, plasma processing, and MOS interface formation process. An appropriate substrate temperature at this time is approximately 100 ° C. to 350 ° C. Holding the substrate at 100 ° C. to 350 ° C. in a vacuum chamber,
Vacuum evacuation is performed until the background vacuum degree reaches the order of 10 ⁻⁷ (torr). For the deposition of SiO, there is a method of using a K cell having a mechanism in which a powder is put in a crucible and the periphery thereof is heated to a temperature of 1000 to 1200 ° C. by a heater, or a method of electron beam deposition. The saturated vapor pressure of SiO is 1 at the above heating temperature.
Since the shutter reaches 0 ^-4 to 10 ^-3 (torr), a molecular beam of SiO is irradiated toward the substrate when the shutter is opened. Here, silicon may be used in addition to SiO as the evaporation source, but in this case, a sufficient vapor pressure cannot be obtained unless heating is performed at a higher temperature. In this state, an oxygen gas, a nitrogen gas, or a mixed gas of an inert gas, an oxygen gas, and a nitrogen gas is introduced into the processing chamber, and the pressure is set to 10 ⁻⁵ to 10 ⁻² (to
rr). When evaporating SiO and supplying oxygen radicals by inductively coupled plasma discharge, an oxygen gas pressure of 1 × 10 ⁻⁴ to 1 × 10 ⁻³ (torr) is appropriate. Under this pressure, oxygen radicals and nitrogen radicals are generated. To increase the radical generation efficiency,
It is also effective to discharge using a mixed gas of an inert gas such as helium or krypton, oxygen gas, and nitrogen gas. As described above, since the most important first layer at the MOS interface is formed by the effect of oxygen radicals, first, the surface treatment of the poly-Si film with oxygen radicals is performed while the shutter of the SiO vapor deposition source is closed. The substrate is scanned on the XY stage while supplying radicals from the radical source. The entire surface is processed at an appropriate substrate moving speed so that the entire surface of the substrate is subjected to radical processing. After a good interface is formed in this way, the shutter of the K cell is opened and SiO is continuously supplied to the substrate surface in an oxygen radical atmosphere. In this way, a good quality insulating film is deposited successively on the well-formed MOS interface, so that an extremely excellent MOS structure can be formed by the above method. When the shutter of the K cell is opened, the substrate is scanned again using the XY stage, and S
An iO ₂ film is formed. The scanning of the substrate is determined from the film thickness profile of the SiO vapor deposition cell as described above. The thickness of the insulating film (105) formed at this time needs to be such that the high quality MOS interface is not affected by the subsequent process. Therefore, at least 10n
An insulating film having a thickness of about m is formed. As described above, the MOS interface forming process according to the present invention provides a very high quality MOS interface while being a low temperature process of 400 ° C. or less.

(5. Element Isolation Step) An extremely high-quality MOS structure was formed by a continuous process in a vacuum of laser crystallization, plasma processing, and MOS interface formation. Next, TFT
An element isolation step is performed to electrically insulate the elements. Here, as shown in FIG. 1, the insulating film and the poly-S
The i film is continuously etched. After a pattern is formed on the insulating film (105) by photolithography, SiO ₂ is etched by wet or dry etching. Subsequently, the poly-Si film is etched by dry etching. Here, SiO ₂ and poly-
Since two layers of the Si film are etched, care must be taken so that the shape of the edge after the etching does not become an eaves shape.

(6. Formation of Gate Insulating Film) After forming an island-shaped SiO ₂ or poly-Si film, a gate insulating film (106) is further formed on the entire surface of the substrate. Examples of a method for forming the gate insulating film include an ECR plasma CVD method and a parallel plate RF discharge plasma CVD method. Alternatively, the insulating film may be formed again by vapor deposition of SiO in oxygen radicals.

(7. Subsequent Steps) Subsequently, a thin film to be the gate electrode (107) is deposited by a PVD method or a CVD method. This material is desired to have a low electric resistance and to be stable to a heat process at about 350 ° C., for example, a high melting point metal such as tantalum, tungsten, and chromium is suitable. When the source and the drain are formed by ion doping, the gate electrode needs to have a thickness of about 700 nm in order to prevent channeling of hydrogen. Tantalum is the most suitable as the material which does not cause cracks due to film stress even when formed into a film having a thickness of 700 nm among the refractory metals. After depositing a thin film to be a gate electrode, patterning is performed, and then impurity ions are implanted into the semiconductor film to form source / drain regions (10
8, 109) are formed. At this time, since the gate electrode serves as a mask for ion implantation, the channel has a self-aligned structure formed only under the gate electrode. Impurity ion implantation is an ion doping method in which hydride and hydrogen of an impurity element are implanted using a mass non-separable ion implanter, and an ion implantation method in which only a desired impurity element is implanted using a mass separable ion implanter. Two types of law can be applied. As a source gas for the ion doping method, a hydride of an implanted impurity element such as phosphine (PH ₃ ) or diborane (B ₂ H ₆ ) diluted in hydrogen and having a concentration of about 0.1% to about 10% is used. In the ion implantation method, only a desired impurity element is implanted, and then hydrogen ions (protons or hydrogen molecular ions) are implanted. MO as described above
In order to keep the S interface and the gate insulating film stable, it is preferable that the substrate temperature at the time of ion implantation be 350 ° C. or lower regardless of the ion doping method or the ion implantation method. On the other hand, in order to constantly and stably activate the implanted impurities at a low temperature of 350 ° C. or less (this is referred to as low-temperature activation in this application), it is desirable that the substrate temperature at the time of ion implantation be 200 ° C. or more. In order to reliably activate low-concentration impurity ions implanted at a low temperature, such as performing channel doping to adjust the threshold voltage of a transistor or forming an LDD structure, it is necessary to perform ion doping at the time of ion implantation. Substrate temperature is 250
It is necessary that the temperature be at least ℃. When the ion implantation is performed in such a state where the substrate temperature is high, recrystallization occurs at the same time as the crystal breakage accompanying the ion implantation of the semiconductor film, and as a result, it is possible to prevent the ion implantation portion from becoming amorphous. It is. That is, the ion-implanted region remains crystalline after the implantation, and the implanted ions can be activated even if the subsequent activation temperature is as low as about 350 ° C. or less.
When fabricating a CMOS TFT, one of an NMOS and a PMOS is alternately covered with a mask using an appropriate mask material such as a polyimide resin, and the respective ions are implanted by the above-described method.

As an efficient activation method of impurities, there is laser activation by irradiating an excimer laser or the like.
This is a method in which the doped poly-Si in the source and drain portions is melted and solidified by laser irradiation through an insulating film to activate the impurities.

Next, a contact hole is formed on the source / drain, and a source / drain extraction electrode (110,
111) and wiring are formed by a PVD method, a CVD method, or the like to complete a thin film transistor.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus for manufacturing a semiconductor device according to the present invention will be described with reference to FIG. The vacuum container (400) is evacuated (418) by a turbo molecular pump and a dry pump. The substrate to be processed (401) is 300 mm × 300 mm square general-purpose non-alkali glass, is held by a substrate holder (402) with a heating mechanism, and is movable in the X-Y direction. The XY stage is driven by an external motor (403) installed on the atmosphere side via a ball screw (404) so that a sufficient torque can be obtained. A quartz laser light transmission window (409) is provided for laser crystallization of the silicon film on the substrate surface,
Excimer laser light (410) is irradiated through this window. When laser irradiation is repeated on this window, the transmittance is reduced due to the ablated silicon adhering to the inside (vacuum side). For this reason, a coil (408) is attached to the air side near this window, and when the transmittance of the window decreases, an inductively coupled plasma discharge is performed while flowing SF ₆ gas to etch the attached silicon. Since the inductively coupled discharge mechanism can naturally be used as a radical source, a movable mesh (416) that can be installed when necessary is provided on the substrate side of the discharge region. A movable electrode (4) is used to reduce defects in the laser-crystallized semiconductor film.
15). This electrode can be moved to the front position of the substrate after laser irradiation. In this state, a parallel plate type RF discharge is performed to perform a function of electrically inactivating defects in the semiconductor film. Since a window for laser transmission is provided at the front position of the substrate, the SiO vacuum deposition cell is arranged at a position where the molecular beam is irradiated from an oblique direction to the substrate. The SiO vacuum deposition cell includes a crucible (406) for holding SiO powder, a crucible temperature monitor thermocouple, a heating power supply (407), and a shutter (405). In addition, SiO
The position of the vacuum deposition cell can be moved in the front-back direction as needed. Further, if the filament is continuously used in an oxidizing atmosphere, the filament is significantly deteriorated. Therefore, a small vacuum pump for working exhaust is provided. As a result, the filament portion is kept at a high vacuum, so that deterioration can be suppressed. The radical source is a ceramic discharge chamber (42
A coil (420) is wound around 1), and RF is supplied to this to generate an inductively coupled plasma.
By this method, high-density plasma having an electron density of 1011 (cm −3) can be generated, and the plasma is confined in the discharge region by the mesh (416). Some high-energy electrons pass through the mesh and reach the reaction chamber side, but are used immediately for neutralization of neutral gas. This is a state that can be sufficiently applied to the low damage process. On the other hand, radicals, which are neutral particles, pass through the mesh and diffuse into the reaction chamber in a large amount, so that the radicals are dominant in the reaction on the substrate surface.

Next, an embodiment of a method for manufacturing a semiconductor device according to the present invention will be described with reference to FIGS. The substrate and the base protective film used in the present invention follow the above description, but here, as an example of the substrate, 300 mm × 300 mm
Square general-purpose non-alkali glass (101, 401) is used. First, a base protective film (102), which is an insulating material, is formed on a substrate (101). Here, the substrate temperature is set to 15
At 0 ° C., a silicon oxide film having a thickness of about 200 nm is deposited by ECR-PECVD. Next, a semiconductor film (103), such as an intrinsic silicon film, which will be an active layer of the thin film transistor later, is deposited. The thickness of the semiconductor film is about 50 nm. In this example, using a high-vacuum LPCVD apparatus, disilane (Si ₂ H ₆ ) as a source gas is flowed at 200 sccm, and an amorphous silicon film (103) is deposited at a deposition temperature of 425 ° C.
Is deposited. First, the reaction chamber of the high vacuum type LPCVD
At a temperature of 50 ° C., a plurality of sheets (for example, 17
Are placed with their front sides facing downward. After this, the operation of the turbo-molecular pump is started. After the turbo-molecular pump reaches steady rotation, the temperature in the reaction chamber is raised from 250 ° C. to a deposition temperature of 425 ° C. over about one hour.
During the first 10 minutes after the start of the temperature rise, the temperature was raised in a vacuum without introducing any gas into the reaction chamber, and then the purity was 99.99.
The nitrogen gas of 99% or more is kept flowing at 300 SCCM. The equilibrium pressure in the reaction chamber at this time is 3.0 × 10 ⁻³ T
orr. After reaching the deposition temperature, disilane (Si ₂ H ₆ ) as a source gas is flowed at 200 sccm, and helium (He) for dilution having a purity of 99.9999% or more is flowed at 1000 sccm. The pressure in the reaction chamber immediately after the start of the deposition is about 0.85 Torr. As the deposition proceeds, the pressure in the reaction chamber gradually increases, and the pressure immediately before the end of the deposition becomes approximately 1.25 Torr. The silicon film (103) thus deposited has a thickness of 286 mm except for about 7 mm at the periphery of the substrate.
In the corner region, the variation in the film thickness is within 5%.

Next, prior to the laser crystallization, the amorphous silicon film is immersed in a hydrofluoric acid solution to etch the natural oxide film on the semiconductor film (103). Generally, the surface where the silicon film is exposed is very unstable, and easily reacts with the atmospheric substance holding the silicon thin film. Therefore, it is necessary to not only remove the natural oxide film but also to stabilize the exposed surface of the silicon film in the pretreatment for performing the laser irradiation. For this purpose, treatment with a hydrofluoric acid solution is desirable. Hydrofluoric acid has a mixing ratio of 1: 3 with pure water.
Set to 0. About 20 to 30 in this hydrofluoric acid solution
Immediately after soaking for 2 seconds, pure water washing is performed for 10 to 20 minutes. Thereafter, pure water is removed with a spinner. As a result, the silicon film surface becomes a stabilized surface terminated with hydrogen atoms.

Next, laser light irradiation is performed. In the present embodiment, an excimer laser (wavelength: 308 nm) of xenon chloride (XeCl) is applied. The half width of the laser pulse intensity (half width with respect to time) is 25 ns. The substrate is placed in the vacuum container (40) of the above-described semiconductor device manufacturing apparatus.
After setting to 0), evacuation is performed. After evacuation, the substrate temperature is raised to 250 ° C. One laser irradiation area is a square shape of 10 mm square, and the energy density on the irradiation surface is 160 mJ / cm ² . Irradiation is repeated while overlapping the laser beams by 90% (that is, 1 mm each time they are irradiated) and relatively displaced (see FIG. 2). Thus, the amorphous silicon on the entire substrate having a side of 300 mm is crystallized. A second laser irradiation is performed using a similar irradiation method. The second energy density is 1
It is 80 mJ / cm ² . Repeat this for the third time, 4
While increasing the irradiation energy density by about 20 mJ / cm ² each time, the energy density finally becomes 440 mJ / cm ^2.
Irradiation of cm ² is performed and laser irradiation is completed. Here, when high energy exceeding the irradiation laser energy density of 450 mJ / cm ² was applied, p-Si grains caused microcrystallization, so that further energy irradiation was avoided.

Next, hydrogen gas is introduced into the vacuum vessel.
In this example, 99.999% hydrogen gas was introduced from a mass flow controller, and the pressure in the chamber was adjusted to 1 (torr). In this state, the parallel plate electrode (415) movable in a vacuum is moved to the front of the substrate, and discharge is performed by applying RF of 13.56 MHz to the laser. The defects in the laser-crystallized poly-Si film by hydrogen are generated. Termination was done. The substrate temperature was 250 ° C., and the input RF power was 3 W / cm ² . Hydrogen can diffuse into the film in a sufficiently short time.
-Efficiently terminate defects existing at a deep position in the Si film and at the interface with the underlying layer.

Next, a process for forming a MOS interface is performed while maintaining the vacuum. 10 ^-7 (torr) inside the chamber
Evacuate to the vacuum of the table. The SiO vacuum evaporation apparatus is 200 mesh, purity 9 with the shutter (405) closed.
Crucible containing 9.9% SiO powder (406)
Are heated from 1000 ° C. to 1200 ° C. using tantalum wire. In this state, oxygen gas is introduced into the chamber at 1 sccm while being controlled by a mass flow controller, and the pressure is maintained at 1 × 10 ⁻⁴ (torr). Oxygen gas is also supplied to the radical generation source and the ceramic discharge chamber (4
In 21), oxygen radicals were generated under the same pressure by inductively-coupled discharge (power 300 W). Although the plasma is confined in the discharge chamber (421), while generating the MOS interface of the poly-Si film by the diffused neutral oxygen radicals, while generating oxygen radicals,
The substrate was scanned by an XY stage. The substrate was moved in the X-axis direction at a speed of 1 cm / sec, moved 10 cm in the Y direction, and moved again in the X direction at a speed of 1 cm / sec. Thus, the oxygen radical treatment of the silicon film surface was performed on the entire surface of the substrate. After a while, S
Opening the shutter (405) of the iO vacuum deposition cell, irradiating the substrate with a SiO molecular beam, and the first gate insulating film (105)
Was formed to a thickness of 30 nm. The distribution of the insulating film formed by the SiO vacuum deposition cell showed a Gaussian shape with a half width of 6 cm. Accordingly, the insulating film was formed while moving the substrate in the X-axis direction at a rate of 0.2 cm / sec at the same time as starting the SiO vacuum deposition in oxygen radicals. After the operation in the X direction was completed, the substrate was moved 6 cm in the Y direction, and the insulating film was formed while being moved again in the X direction at a speed of 0.2 cm per second. By this method, an insulating film having a uniform thickness was formed on the entire surface of the substrate.

Next, the substrate is taken out of the vacuum vessel and pol
The y-Si film and the first layer insulating film were continuously etched. Subsequently, in this example, a second layer insulating film (106) was deposited by a parallel plate type rf discharge PECVD method at a substrate temperature of 350 ° C. and a thickness of 70 nm. TEOS (Si
- employing a mixed gas _{(O-CH 2 -CH 3)} 4) and oxygen (O _2). Subsequently, a thin film serving as a gate electrode (107) is deposited by a PVD method or a CVD method. Normally, the gate electrode and the gate wiring are made of the same material in the same process. Therefore, it is desired that this material has low electric resistance and is stable to a heat process at about 350 ° C. In this example, the film thickness is 60
A tantalum thin film of 0 nm is formed by a sputtering method. The substrate temperature when forming the tantalum thin film is 180 ° C.,
An argon gas containing 6.7% of a nitrogen gas is used as a sputtering gas. The thus formed tantalum thin film has an α-structure crystal structure, and its specific resistance is approximately 40 μΩcm. After depositing a thin film to be a gate electrode, patterning is performed, and then impurity ions are implanted into the semiconductor film to form source / drain regions (108, 109) and a channel region. At this time, since the gate electrode serves as a mask for ion implantation, the channel has a self-aligned structure formed only under the gate electrode. As a source gas for the ion doping method, a hydride of an implanted impurity element such as phosphine (PH ₃ ) or diborane (B ₂ H ₆ ) diluted in hydrogen and having a concentration of about 0.1% to about 10% is used. In this example, phosphine (PH ₃ ) having a concentration of 5% diluted in hydrogen is injected at an acceleration voltage of 100 keV by using an ion doping apparatus in order to form an NMOS. PH ₃ ⁺
Total ion implantation amount including H ₂ ⁺ ions is 1 × 10 ¹⁶ c
m- ² .

Next, a contact hole is formed on the source / drain, and a source / drain extraction electrode (110,
111) and wiring are formed by a PVD method, a CVD method, or the like to complete a thin film transistor.

In the prior art, an effective process for forming a high quality MOS interface has not been clarified. However, as described above, the use of the semiconductor device manufacturing apparatus and the semiconductor device manufacturing method of the present invention makes it possible to form an extremely high-quality MOS interface. Resulting in high mobility,
It becomes possible to manufacture a field effect transistor having a low threshold voltage, and to realize an ultra-low power consumption circuit.

[Brief description of the drawings]

FIG. 1 is a process sectional view showing a method for manufacturing a field effect transistor of the present invention.

FIG. 2 shows a laser beam irradiation method during laser crystallization.

FIG. 3 shows a laser beam irradiation method during laser crystallization.

FIG. 4 is a diagram showing a semiconductor device manufacturing apparatus of the present invention.

FIG. 5 is a diagram illustrating a SiO vacuum deposition cell and a substrate moving method according to the present invention.

FIG. 6 is a diagram showing an example of M fabricated by the MOS interface forming method of the present invention.
4 illustrates an example of CV characteristics of an OS capacitor.

[Explanation of symbols]

 101. . . Substrate 102. . . Base insulating film 103. . . Semiconductor film 104. . . Laser light 105. . . First layer gate insulating film 106. . . Second layer gate insulating film 107. . . Gate electrode 108. . . Source 109. . . Drain 110. . . Source electrode 111. . . Drain electrode 201. . . Laser irradiation area 203. . . x direction movement 204. . . Movement in y direction 301. . . Line-shaped laser beam 400. . . Vacuum container 401. . . Substrate to be processed 402. . . Substrate holder 403. . . Motor 404. . . Ball screw 405. . . Shutter 406. . . Crucible 407. . . Heater power supply 408, 420. . . Coil 409. . . Laser introduction window 410. . . Excimer laser light 411. . . Matching unit 413. . . Mass flow controller 414. . . Oxygen gas 415. . . Movable electrode 416. . . mesh

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4K029 AA06 BA46 BD01 CA01 CA15 CA17 DB05 5F045 AA06 AA08 AA10 AA16 AA19 AB03 AB04 AB05 AB06 AB10 AB13 AB23 AB32 AB33 AC01 AC11 AD06 AD07 AD08 AF02 AF03 AF04 AF09 AF10 BB07 BB12 BB03 EG03 EH11 EH13 EH17 EM10 HA18 5F103 AA01 AA04 AA08 BB02 BB16 BB36 DD03 DD12 DD16 DD27 HH03 HH04 HH05 LL07 LL13 PP01 PP20 RR03 RR06 5F110 AA17 AA30 BB04 CC02 DD01 DD02 GG03 GG03 GG03 GG03 GG03 GG02 GG46 GG47 HJ04 HJ12 HJ13 HJ22 HJ23 HL24 HM15 PP03 PP04 PP06 PP31 PP38 QQ11

Claims (10)

[Claims] 1. An apparatus for manufacturing a semiconductor device, comprising: a substrate stage capable of two-dimensionally scanning a substrate in a vacuum; and an SiO vacuum deposition cell. 2. The SiO vacuum deposition cell is arranged at a position such that when the shape of the SiO vacuum deposition cell is projected onto a substrate surface, a central axis is parallel to one of the scanning directions of the stage. 2. The semiconductor device manufacturing apparatus according to claim 1, wherein: 3. A semiconductor device manufacturing apparatus comprising: a substrate stage capable of two-dimensionally scanning a substrate in a vacuum; a SiO vacuum deposition cell; and a radical generation source. 4. The apparatus according to claim 3, wherein said radical generating source generates radicals by one of an inductively coupled plasma discharge and an ECR plasma discharge. 5. A semiconductor device manufacturing apparatus comprising: a substrate stage capable of two-dimensionally scanning a substrate in a vacuum; an SiO vacuum deposition cell; and a window for irradiating a radical generation source and a sample with light. 6. A semiconductor comprising a stage capable of two-dimensionally scanning a substrate in a vacuum, a SiO vacuum deposition cell, a window for irradiating a radical generation source and a sample with light, and a capacitively coupled plasma discharge electrode. Device manufacturing equipment. 7. A method for manufacturing a semiconductor device, wherein an insulating film is formed on a substrate by scanning the substrate while irradiating an SiO molecular beam with a SiO vacuum deposition cell. 8. A method for manufacturing a semiconductor device, wherein a radical processing is performed on a surface of a semiconductor film on a substrate by scanning the substrate while generating radicals by a radical generating source. 9. The method according to claim 8, wherein said radical is an oxygen radical. 10. A substrate is scanned while generating oxygen radicals by a radical generating source to perform a radical treatment on the surface of the semiconductor film on the substrate, and then a SiO vacuum deposition cell is used while maintaining the supply of oxygen radicals.
A method for manufacturing a semiconductor device, comprising: starting molecular beam irradiation; and scanning the substrate in this state to form an insulating film on the semiconductor film.