JP3165324B2 - Method for manufacturing semiconductor device - Google Patents

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 (thin film transistor (TFT) and its integrated circuit, etc.) having a thin-film active layer and an apparatus therefor.

[0002]

2. Description of the Related Art Thin film transistors (generally referred to as TFTs) using a thin film silicon semiconductor formed on a glass substrate as a semiconductor element are known. It is useful to use a crystalline silicon film as the thin film silicon semiconductor constituting the TFT. In addition, T having good characteristics
In order to obtain FT, it is necessary to form an insulating film (generally, a silicon oxide film) on a surface of a silicon film with a good interface characteristic. However, forming a gate insulating film having sufficient interface characteristics has been problematic in conventional techniques.

[0003] As a gate insulating film, a silicon oxide film formed by thermal oxidation has the best characteristic. However, when trying to obtain such a film by thermal oxidation,
A high temperature exceeding 900 ° C. was required. This is T
It places great restrictions on the substrates and materials that make up the FT,
This was a major obstacle to the flow of lowering the temperature of the FT process. On the other hand, a vapor growth method (that is, a CVD method or a PVD method)
The film formation by the method (1) did not require such a high temperature, but the obtained interface characteristics between the insulating film and the semiconductor were not preferable.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is basically an object of the present invention to form an insulating film having good interface characteristics without requiring a high temperature such as thermal oxidation. The main purpose is. Another object is to improve the stability of the productivity of the process of forming the insulating film.

[0005]

The main components of the present invention are a processing apparatus for irradiating a laser beam or a strong light equivalent thereto, and a vacuum film forming apparatus (for example, plasma CVD) using a vapor phase growth method.
Equipment, low pressure CVD (LPCVD) equipment, atmospheric pressure CVD
(APCVD) apparatus, a sputtering film forming apparatus (sputtering apparatus, etc.), and a semiconductor processing apparatus that irradiates a laser beam or a strong light equivalent thereto with an amorphous semiconductor formed on a substrate. A step of irradiating a non-single-crystal semiconductor film such as a film, a polycrystalline semiconductor film, and a microcrystalline semiconductor film with laser light or strong light, and exposing the laser light or a processing device that irradiates strong light equivalent thereto to outside air. Transferring the front substrate to another vacuum processing apparatus without performing a predetermined process, irradiation of the laser light or an equivalent strong light,
This is performed in an oxidizing atmosphere such as an oxygen atmosphere or a nitriding atmosphere such as an ammonia atmosphere to improve the crystallinity of the non-single-crystal semiconductor film and oxidize its surface or form an oxide film on the surface (in the oxidizing atmosphere). ), Or nitriding the surface or forming a nitride film on the surface (in the case of a nitriding atmosphere).

[0006] In the above structure, the processing apparatus for irradiating a laser beam or an equivalent strong light has a function of irradiating a laser beam or an equivalent strong light, a means for introducing a required gas, and reducing the atmosphere to a reduced pressure. It is necessary to have an exhaust means for exhausting air. Excimer laser, various YAG lasers, ruby laser, and the like can be used as the laser light. As a non-coherent light source other than a laser, a rare gas lamp such as a xenon lamp or a krypton lamp, or a halogen lamp can be used. The wavelength of the light source used can be in a wide range from infrared to ultraviolet. However, in order to prevent the temperature of the substrate from rising, the light irradiation is preferably performed in a pulse shape, and the pulse width is 1 μsec or less. Is preferred.

As a vacuum film forming apparatus, a plasma CVD apparatus, a low pressure CVD (LPCVD) apparatus, an atmospheric pressure CVD (A)
A PCVD) device, a sputtering film forming device (sputter device), or the like can be used. In addition to the above devices, a heat treatment device in various atmospheres, an ion implantation device, an etching device, and a device for carrying a substrate in and out of the outside may be connected as a vacuum processing device. It is desirable that each of these apparatuses has a gas introduction system and an exhaust system required for each of them, and has a configuration connected to a common transfer chamber for carrying out substrate transfer exclusively. The reason why the substrate is transferred without being exposed to the outside air is to prevent an object to be processed (for example, a silicon film on the substrate) from being contaminated in each processing step.

According to another structure of the present invention, a non-single-crystal semiconductor film is irradiated with a laser beam or an equivalent strong light in a nitriding or oxidizing atmosphere to nitride or oxidize the surface of the non-single-crystal semiconductor. And a step of improving the crystallinity of the non-single-crystal semiconductor film, and a step of stacking an insulating film on the oxide film.

In the above structure, as the non-single-crystal semiconductor film, an amorphous silicon film formed by a plasma CVD method or a low pressure thermal CVD method can be used. Further, a polycrystalline or microcrystalline semiconductor film crystallized by annealing such an amorphous semiconductor film at a temperature of 650 ° C. or lower can also be used. Irradiation with laser light or equivalent strong light in a nitriding or oxidizing atmosphere is performed by forming a nitride, oxide, or oxynitride film on the surface of these non-single-crystal semiconductor films, This is for improving the crystallinity of the film. The oxidizing atmosphere refers to an atmosphere containing a large amount of oxidizing gas in order to actively perform oxidation, and includes nitrous oxide (N
Atmosphere containing large amounts of ₂ O) and nitrogen dioxide (NO ₂ ),
Alternatively, it is a mixed atmosphere of these and oxygen or the like.
Therefore, it is different from an atmosphere in which these gases are simply contained in a small amount. The atmosphere contains chlorine, trichlorethylene (trichlene, TCE, CHCl = CCl ₂ ), trans-
1,2-Dichloroethylene (CHCl = CHCl) may be contained. Such a gas promotes the oxidizing action.

[0010] By irradiating the silicon film having crystallinity with the laser light or the strong light equivalent thereto, a thin silicon oxide film can be formed on the surface of the silicon film.
In particular, when ultraviolet rays are irradiated, a chemical reaction is accelerated, and a high-quality silicon oxide film can be obtained. After irradiation with laser light or intense light, an insulating film, for example, silicon oxide is formed by a film forming method such as a plasma CVD method, so that good interface characteristics formed on the semiconductor surface during irradiation with laser light or the like can be obtained. An insulating film can be formed to a required thickness over the oxide film or the nitride film.

[0011]

By irradiating a semiconductor, especially a silicon semiconductor, with a laser beam or a strong light equivalent thereto in a nitriding or oxidizing atmosphere, an oxide film having good interface characteristics can be formed on the semiconductor surface. . In particular, by using silicon as a semiconductor and irradiating a non-single-crystal silicon film with a laser beam or equivalent strong light in a nitriding or oxidizing atmosphere, the non-single-crystal semiconductor surface has good interface characteristics. In addition to forming the silicon nitride film, the silicon oxide film, or the silicon oxynitride film, the crystallinity of the non-single-crystal semiconductor film can be improved. In particular, in the case of a silicon oxide film manufactured in this manner, the fixed charge is small and the interface state density is low enough to be comparable to a silicon oxide film obtained by thermal oxidation at a temperature of 1000 to 1200 ° C. in ordinary dry oxygen. (Q _ss ) is also low. Therefore, T
It is excellent as a gate insulating film of an insulating gate type device such as FT.

By forming an insulating film such as a silicon oxide film on the above-mentioned oxide film, a gate insulating film having a sufficient thickness for use as a gate insulating film of a TFT and having excellent interface characteristics is formed on the semiconductor film. Can be formed. That is, in the present invention, the gate insulating film is composed of at least two layers, and the thin oxide film in contact with the semiconductor is formed by oxidizing the semiconductor by irradiation with a laser or the like, and has excellent interface characteristics. However, this alone is insufficient in terms of withstand voltage and the like for use as a gate insulating film. Therefore, by forming an insulating film having a required thickness and a withstand voltage by a vapor deposition method on top of it, a film preferable as a gate insulating film can be obtained for the first time.

It is desirable that all such film forming processes be performed in an environment substantially isolated from the atmosphere. If the semiconductor surface is exposed to the air once after the laser irradiation step, the surface will be contaminated, and the good quality oxide film etc. obtained by the laser irradiation will be ruined. . Therefore, a step of exposing the semiconductor surface to the air must not be performed between the irradiation of the laser or the like and the formation of the insulating film by the vapor deposition method. Therefore, the present invention requires special means for transferring substrates between these devices. Examples are shown below,
A number of examples of the invention will now be described.

[0014]

【Example】

[Embodiment 1] FIG. 1 shows an example of an apparatus for carrying out the present invention. In this example, a plasma CVD film forming apparatus and a laser processing apparatus (for example, a laser annealing apparatus) are combined, and one preliminary chamber is provided between the two apparatuses. In the figure, reference numeral 1 denotes a chamber of a plasma CVD apparatus, and 2 denotes a chamber of a laser annealing apparatus. These chambers are provided with gas introduction valves 7 and 18 and exhaust valves 8 and 19 so that necessary gases can be introduced and exhausted, and the internal pressure can be maintained at an appropriate value.

The chamber 1 is further provided with electrodes 4 and 5, and a substrate (sample) 6 to be processed is provided on the electrode 5.
, And the electrode 4 has an RF power source (for example, a frequency of 13.5).
6 MHz) 3 is connected. Then, an appropriate gas (for example, monosilane or disilane and oxygen,
Nitrous oxide) to cause a discharge between the electrodes,
A coating is formed on the substrate 6. The substrate may be heated if necessary.

A window 14 is provided in the chamber 2, and a laser beam from a laser device 11 through a mirror 12 and a lens 13 is applied to a substrate 17 on a sample holder 15 through the window. The substrate is heated 200 by the heater 16.
To 500 ° C, preferably 300 to 400 ° C. This heating is indispensable when performing crystallization with good reproducibility. In the chamber 2, the characteristics are improved by improving the crystallinity by laser annealing. At this time, by setting the inside of the chamber of the laser annealing apparatus to an oxygen atmosphere, the improvement of the crystallinity of the non-single-crystal silicon film such as the amorphous silicon film and the formation of the oxide film on the surface thereof are simultaneously performed. Similarly, when laser annealing is performed in a nitriding atmosphere such as an ammonia atmosphere, a nitride film is formed. Nitrous oxide atmosphere,
Alternatively, in a mixed atmosphere of oxygen and ammonia, an oxynitride film is formed.

The sample holder is movable, and can be gradually moved to the right side in the figure while the substrate is placed on the sample holder. As a result, laser processing can be performed on the entire surface of the substrate. For example, if the substrate has a size of 300 mm × 400 mm, the entire surface of the substrate can be laser-treated by forming the laser beam into a 2 × 350 mm linear shape.
If the moving speed of the holder at this time is 20 mm / sec, the processing time for one substrate is 400/20 = 20 seconds.

The substrate on which the island-shaped amorphous silicon film or the polycrystalline silicon film is formed is processed in the following order. First, the preliminary chamber is evacuated to 10 ^{-5 to 1} torr. On the other hand, the chamber 2 of the laser processing apparatus is also evacuated to the same extent. Then, the gate between the preliminary chamber and the laser processing apparatus is opened, and the substrate is transferred from the preliminary chamber to the laser processing apparatus. After the transfer, the gate is closed, and gas at an appropriate pressure is introduced into the chamber 2. Further, the sample holder 15 is heated to an appropriate temperature by the heater 16. When the temperature is stabilized and the precise alignment of the substrate set in the laser processing device is completed, laser processing is performed. The laser irradiation improves the crystallinity of the silicon film. At this time, the atmosphere is
At a pressure of 1 to 1000 torr, oxygen or nitric oxide (for example, nitrous oxide (N ₂ O), nitrogen dioxide (N
The partial pressure of O ₂ ) should be 10% or more. As a result, a thin silicon oxide film is formed on the silicon film surface simultaneously with the laser irradiation.

Thereafter, the chamber 2 is evacuated to 10 ^-5
The pressure is reduced to about 1 torr, the substrate is returned to the preliminary chamber 9 again, and the plasma C exhausted to the same degree as the preliminary chamber
It is transferred to the VD film forming chamber 1. Then, an insulating film of silicon oxide, silicon nitride, or the like is formed according to a film forming procedure. During this film forming step, another substrate may be processed in the chamber 1. After the film formation, the inside of the film forming apparatus 1 is evacuated to a pressure of 10 ^{-5 to 1} torr, the gate between the film forming apparatus 1 and the preliminary chamber is opened, and the substrate is also evacuated to the same extent. The substrate is transferred to the chamber, the preparatory chamber is set to the same pressure as the atmospheric pressure, and the substrate is taken out to the atmosphere.

In the above steps, for example, the substrate 1 including the steps from setting the substrate to positioning and taking out the substrate 1
If the processing time of the wafer with the laser apparatus is almost equal to the film forming time of the plasma CVD apparatus including the setting of the substrate and the exhaust, the plasma processing is performed by the laser processing apparatus.
Processing can be performed without waiting time up to the VD device. If substrate 1
If the processing time of one laser is half of the film forming time by plasma CVD, the film forming by plasma CVD is performed at a time.
You only need to do this. In this case, first 2
One substrate is stocked in the spare room, and one of them is sent to the laser processing apparatus for processing, and the other one is stored in the spare room. Then, after the first one is processed, the one stored in the spare room is processed. After both are processed, they are sent to a plasma CVD apparatus, and two films are simultaneously formed.

An outline of a process for manufacturing a TFT using the present apparatus will be described. The process diagram is shown in FIG. First, a silicon oxide base film 102 is formed on a glass substrate 101 such as Corning 7059. The thickness of the silicon oxide film 102 is
10 so that ions from the glass substrate 101 are not mixed.
00 to 5000 ° is preferred. Here, it was set to 2000 mm. Thereafter, an amorphous silicon film was deposited. The thickness is preferably 300 to 1000 °. Here, 5
00 °. And 400-500 degreeC, for example, 4
Hydrogen is removed from the film by annealing at 50 ° C. for an appropriate time. Then, the amorphous silicon film was processed into an island shape to form an island region 103. The substrate subjected to such a treatment was irradiated with laser by the laser processing apparatus 2 of the apparatus in FIG. 1 to change the amorphous island-like silicon film 103 into a crystalline silicon film.

As a laser, a KrF excimer laser was used. Laser irradiation conditions were as follows: energy density was 350 to 450 mJ / cm ² , the number of shots was one, 2 to 20 shots, and the substrate temperature was 200 to 400 ° C. The laser irradiation was performed in an oxygen / argon atmosphere of 1 atm. The partial pressure of oxygen was 20%. As a result of this laser irradiation, a thin silicon oxide film 104 having a thickness of several tens of degrees was formed on the surface of the island region 103. (Figure 2
(A)) Thereafter, the substrate was transferred to the plasma CVD apparatus 1 of the apparatus in FIG. 1, where a silicon oxide film was formed. Until the substrate was carried into the plasma CVD film forming apparatus from the laser processing apparatus, the substrate did not come into contact with atmospheric components such as moisture.

In the plasma CVD apparatus 1, silane and nitrous oxide are used as raw materials,
For example, a silicon oxide film 105 of 1200 ° was formed. It is convenient to mix a small amount of trifluoroethylene or hydrogen chloride in the source gas because mobile ions in the silicon film can be removed. . This silicon oxide film 105 is a TFT
Also functions as a gate insulating film. (FIG. 2B) Then, aluminum, tantalum, chromium, tungsten,
The gate electrodes 106 and 108 are formed of a material such as molybdenum, silicon, an alloy thereof, or a multilayer wiring.
Further, by supplying a current to the gate electrode in an electrolytic solution, the anodic oxide film 107 is formed on the upper and side surfaces of the gate electrode.
109 is formed. The thickness of the anodic oxide film is 1000 to 25
00 °. The anodic oxide film has a function of reducing damage to the gate electrode which is caused in a subsequent ion doping, laser annealing, and interlayer insulating film forming process.

Thereafter, the P-type regions 110, 110 are formed by a known ion doping method and complementary MOS (CMOS) technology.
112, N-type regions 113 and 115 are formed. As a result, the channel region 1 of the P-channel TFT (PTFT)
11. A channel region 114 of an N-channel TFT (NTFT) is formed. This was irradiated with a laser beam to improve the crystallinity of the region damaged by ion doping. This laser irradiation may be performed by the laser processing apparatus of the apparatus shown in FIG. In this case, the laser energy does not need to be as strong as that in the process of FIG. Laser irradiation conditions are: substrate temperature is room temperature, laser energy density is 2
50 to 350 mJ / cm ² . Other conditions are shown in FIG.
It was the same as the step (A). (Fig. 2 (C))

Thereafter, the substrate was transferred to the plasma CVD apparatus shown in FIG. 1, and a silicon oxide film 116 was formed as an interlayer insulator. The thickness of the silicon oxide film was 3000 to 8000 °, for example, 5000 °. Thereafter, a contact hole is formed in the island-like region, and an aluminum film is formed at 3000 to 800
0 °, for example, 5000 ° was deposited and then etched to form wires / electrodes 117, 118, 119. When a titanium nitride film having a thickness of 500 to 1500, for example, 1000 ° was sandwiched between the aluminum and the island region, good contact characteristics were obtained. (FIG. 2 (D)) The TFT manufactured according to this example has excellent characteristics.
For example, the field effect mobility is 200 to
300cm ² / Vs, 100~250cm ² in PTFT
/ Vs was obtained stably.

Embodiment 2 FIG. 3 shows an embodiment of the present invention.
In this example, a plasma doping apparatus (also referred to as an ion doping apparatus), a plasma CVD (also dry etching) apparatus, and a laser processing apparatus (for example, a laser annealing apparatus) are combined. Is provided. In FIG.
Reference numeral 21 denotes a chamber of the plasma doping apparatus;
Reference numeral 2 denotes a chamber of an etching apparatus, and 23 denotes a chamber of a laser annealing apparatus. Necessary gas can be introduced and exhausted into these chambers, and the internal pressure can be maintained at an appropriate value.

The chamber 21 is further provided with an anode electrode 25 and a grid electrode 26, and a high voltage of up to 100 kV is applied to the anode by a high voltage power supply 24. Positive ions 27 in the plasma generated by RF discharge or the like near the grid electrode are accelerated in the direction of the sample holder 29 by the high voltage described above. As a result, the substrate (sample) 28 on the sample holder 29
Accelerated cations (boron ions, phosphorus ions, hydrogen ions, etc.) are injected.

For example, on the substrate 28, crystalline silicon and a silicon oxide layer thereon are formed on an insulating substrate.
It is assumed that the gate electrode of the thin film transistor is formed. By such doping, necessary impurities are implanted into the silicon oxide layer and the silicon layer. in this way,
Doping through a material such as silicon oxide is referred to as through doping, and is a method suitable for forming a semiconductor element with high yield. The plasma CVD apparatus / etching apparatus 22 is provided with electrodes 33 and 34,
An F power supply 32 is connected, and a substrate 35
Is placed. For example, when a discharge is generated between electrodes by power from an RF power supply in a carbon tetrafluoride atmosphere, a silicon oxide film on a substrate and a silicon oxide film deposited on an inner wall of a chamber can be etched. When RF discharge is performed in an oxygen atmosphere, organic substances such as a photoresist are oxidized and removed, and so-called ashing is performed. When an RF discharge is performed using monosilane and oxygen as an atmosphere, a silicon oxide film can be formed.

The laser processing apparatus 23 is substantially the same as that shown in the first embodiment.
The laser light is irradiated from a laser device 38 through a mirror 39 and a lens 40 to a substrate 42 on a movable sample holder 44 through a window. The substrate may be heated by the heater 43. Ultraviolet excimer laser with excellent mass productivity,
For example, KrF laser (wavelength 248 nm), XeCl
Laser (308nm) and XeF laser (350n
m) is preferred. Preparatory chambers 30, 36 are provided between the plasma doping apparatus 21, the plasma CVD apparatus 22, and the laser processing apparatus 23, respectively.

Since the present apparatus has a number of chambers, various processes can be performed. For example, a plasma doping apparatus 21 first implants an appropriate amount of hydrogen ions into a silicon film on a substrate on which an amorphous or polycrystalline island-like silicon film from which hydrogen has been sufficiently released is formed. Next, in the laser processing device 23, laser irradiation is performed in an oxygen or nitrous oxide atmosphere to improve the crystallinity of the island-shaped silicon region and form a thin silicon oxide film on the surface thereof. After that, the substrate is transferred to the plasma CVD apparatus 22, where an insulating film such as silicon oxide to be a gate insulating film is formed. The step of hydrogen ion implantation may not be required.

The present invention can also be used for a process including a source / drain doping step. First, a substrate coated with a photoresist and exposing only a region for forming a P-type (or N-type) TFT is doped with a P-type (or N-type) impurity by a plasma doping apparatus 21. Thereafter, the substrate is transferred to a plasma CVD device 22, where the photoresist is removed by performing RF discharge, that is, ashing, in an oxygen atmosphere. As a result, the entire surface of the substrate is exposed. And again,
Returning the substrate to the plasma doping apparatus 21, this time,
Doping with N-type (or P-type) impurities. In this doping, an N-type (or P-type) impurity is doped into a region covered with the photoresist in the previous doping step, so that the region becomes N-type (or P-type).
On the other hand, the N-type (or P-type) impurity is also doped in the region doped with the P-type impurity in the previous doping, and the dose of the first doping is set to be larger than the dose of the later doping. By reducing, P-type (or N-type) can be maintained. Thereafter, the substrate is transferred to the laser processing device 23 and, as in the case of the first embodiment,
Laser annealing is performed to activate the doped impurities.

FIG. 5 shows an example of manufacturing a thin film transistor (TFT) using such a multi-chamber system. Glass substrate (for example, Corning 7059)
An underlying silicon oxide film 2 having a thickness of 200 to 2000 .ANG.
02 is formed by a sputtering method or a plasma CVD method. Further, an amorphous silicon film is deposited at a thickness of 300 to 1000 ° by a method such as an LPCVD method, a plasma CVD method, or a sputtering method.
Crystallize by heating in nitrogen or vacuum for 4 to 48 hours. At this time, if a small amount of nickel is mixed into the film, the crystallization temperature can be lowered and the crystallization time can be shortened.

Then, the crystallized silicon film is patterned to form island regions 203. Then, FIG.
First, the substrate is set in the apparatus shown in FIG.
3 to improve the crystallinity. Unlike the case of the first embodiment, the crystallization of the island-shaped silicon region has already progressed to some extent. However, many fine amorphous components are still present in the grain boundaries. The characteristics can be dramatically improved. K as a laser
An rF excimer laser was used. Laser irradiation conditions were as follows: energy density was 350 to 450 mJ / cm ² , the number of shots was one, 2 to 20 shots, and the substrate temperature was 200 to 400 ° C. Laser irradiation atmosphere is 1
Perform in a nitrous oxide atmosphere at atmospheric pressure.

As a result of this laser irradiation, the island region 203
A thin silicon oxide film 204 having a thickness of several tens of degrees is formed on the surface of the substrate. (FIG. 5 (A)) Thereafter, the substrate is transferred to the plasma CVD apparatus 22 of the apparatus of FIG. 3, where the thickness is 1000 to 1500 °, for example,
A silicon oxide film 205 of 1200 ° is formed. (FIG. 5
(B)) Thereafter, gate electrodes 206 and 208 are formed of aluminum containing 0.1 to 0.3% by weight of scandium. Further, by supplying a current to the gate electrode in an electrolytic solution, the anodic oxide film 20 is formed on the upper and side surfaces of the gate electrode.
7, 209 are formed. The thickness of the anodic oxide film is 1000-
2500 °.

Thereafter, the right side portion of the island-shaped region 203 in FIG. 5 is masked with a photoresist and set in the apparatus of FIG.
× 10 ¹⁵ / cm ² doping. As a result, P-type regions 210 and 212 are formed on the left side of the island region 203, and a PTFT channel region 211 is also formed. Thereafter, the substrate is transferred to the plasma CVD apparatus 22, and the photoresist is ashed and removed by oxygen plasma.
Then, the substrate is transferred to the plasma doping apparatus 21 again, and doped with phosphorus. Dose amount is 0.1 ~
It is desired to set it to 2 × 10 ¹⁵ / cm ² and to make it smaller than the above-mentioned dose amount of boron. As a result, N-type regions 213 and 215 and a channel region 214 of NTFT are formed. (FIG. 5 (C))

Further, the substrate is transferred to the laser processing device 23 to activate the doped impurities. Laser irradiation conditions were a substrate temperature of room temperature and a laser energy density of 250 to 350 mJ / cm ² .
(FIG. 5D) Thereafter, the substrate is transferred to the plasma CVD apparatus 22 in FIG. 3, and a silicon oxide film 216 is formed as an interlayer insulator. The thickness of the silicon oxide film is 3000-8000Å, for example, 50
00 °. Thereafter, the substrate is taken out of the apparatus shown in FIG. 3, a contact hole is formed in the island region, and a titanium nitride film 1000
{E.g., 5000} is deposited and etched to form wiring / electrodes 217, 218, 219. Thus, a CMOS type TFT circuit is formed. (FIG. 5
(E))

[Embodiment 3] FIG. 4 schematically shows an apparatus of the present invention having a multi-chamber configuration. A detailed drawing of the apparatus of FIG. 4 is shown in FIG. Although the apparatus of FIG. 3 is a multi-chamber in which three apparatuses are connected in a straight line, the apparatus of this embodiment is a star-shaped multi-chamber. That is, the chamber 5 constituting the loading / unloading chamber for loading / unloading the substrate.
1. A chamber 53 constituting a heat treatment chamber for performing various heat treatments (for example, annealing in a hydrogen atmosphere) on a substrate; a chamber 55 constituting a laser treatment chamber for irradiating a laser beam; A chamber 57 forming a film formation chamber for performing film formation and a common preliminary chamber (transfer chamber) 59 are provided. The spare chamber and each chamber are connected by gates 52, 54, 56, 58. The substrate is moved by a robot hand 60 arranged in a common preliminary chamber 59 as shown in 61 to 64.
It is transferred between each chamber. When a plurality of substrates are set in a cassette state in the loading / unloading chamber, a robot automatically transfers the substrates one by one to each chamber, and the processed substrates are automatically returned to the cassette. -A cassette (C-to-C) method may be adopted.

An example of manufacturing a TFT (thin film transistor) using the apparatus shown in FIG. 4 will be described below. This embodiment will be described with reference to FIG. First, a Corning 7059 substrate is used as the glass substrate 301, and after annealing at 620 to 660 ° C for 1 to 4 hours, 0.1 to 1.0 ° C / min, preferably 0.1 to 0.3 ° C / min. Slowly cool, 450-590 ° C
It was taken out when the temperature had dropped. Then, a base film 302 was formed on the substrate, and an amorphous silicon film 303 having a thickness of 300 to 800 ° was formed by a plasma CVD method. Then, using a silicon oxide mask 304 having a thickness of 1000 °, a thickness 2
A nickel film of 0 to 50 ° was formed by a sputtering method. The nickel film need not be a continuous film. Further, instead of the sputtering method, a spin coating method may be used. At this time, the added nickel has an effect of promoting crystallization. Thereafter, heat annealing was performed at 500 to 620 ° C., for example, 550 ° C. for 8 hours in a nitrogen atmosphere to crystallize the silicon film 303. Crystallization progressed in a direction parallel to the substrate as indicated by an arrow, starting from a region 305 where the nickel and silicon films were in contact. (FIG. 6 (A))

Next, the silicon film 303 was etched to form island-shaped active layer regions 306 and 307.
At this time, nickel is present at a high concentration in the region where the nickel is directly introduced and the tip of the crystal growth, which are indicated by oblique lines in FIG. It has been found that these regions have a nickel concentration that is nearly an order of magnitude higher than the crystallized regions between them. Therefore, in this embodiment, the active layer regions 306 and 307 are formed so as to avoid these regions where the nickel concentration is high, and the regions where the nickel concentration is high are removed. Then, TF is added to a region where almost no nickel is present.
An active layer of T was formed. The nickel concentration in the active layer of this example was about 10 ¹⁷ to 10 ¹⁹ cm ⁻³ .

The substrate thus processed was loaded into the apparatus shown in FIG. 4 from a loading / unloading chamber (loader / unloader) 51. After the substrate was set in the loading / unloading chamber 51, all the chambers were in a high vacuum state. Then, the gate 52 was opened, and the substrate was transferred to a common spare chamber (transfer chamber) 59 by the robot arm 60. Next, the gate 52 was closed, the gate 54 was opened, and the substrate was transferred to the heat treatment chamber 53. Then, the atmosphere is hydrogen or nitrogen, and the substrate is 200 to
Heated to 400 ° C. Thereafter, the gate 54 and the gate 56 were opened, and the substrate was transferred to the laser processing chamber 55. Then, the gate 56 was closed, and the laser processing chamber 55 was set to an oxygen atmosphere at normal pressure. Here, an oxygen atmosphere is used, but an oxidizing atmosphere may be used. Thereafter, laser light irradiation is performed under the same conditions as in the second embodiment, and the active layers 306 and 307 are irradiated.
A silicon oxide film 308 having a thickness of 50 to 150 ° was obtained on the surface of the substrate, and the crystallinity of the silicon film in the region crystallized by the previous thermal annealing was further improved. (FIG. 6 (B)) As described above, by preheating the substrate in the heat treatment chamber before laser irradiation, the time from setting the substrate in the laser treatment chamber until the temperature of the substrate rises can be reduced. Can save.

After the end of the laser beam irradiation, the gas in the laser processing chamber 55 was evacuated to a high vacuum state. And
The gate 56 was opened, and the substrate was transferred to the common spare room 59 by the robot hand. Then, the gate 56 is closed. Next, the gate 54 was opened, and the substrate was transferred to the heat treatment chamber 53. After the transfer is completed, the gate 54 is closed and the heat treatment chamber 53 is closed.
The inside was made a normal pressure hydrogen atmosphere. Then, a hydrogen heat treatment was performed in the heat treatment chamber 53 at 350 ° C. for 30 minutes.
In this hydrogen heat treatment, the oxide film 308 and the active layer 30
The dangling bonds existing at the interface with 6, 307 and the vicinity thereof are neutralized, and the level can be lowered. And extremely good interface characteristics can be realized.

After the completion of the heat treatment step, the heat treatment chamber 53 was brought into a high vacuum state. Then, the gate 54 was opened, and the substrate was transferred to the common spare chamber 59 by the robot arm 60. After the transfer was completed, the gate 54 was closed, then the gate 58 was opened, and the substrate was transferred to the film forming chamber 57. After the transfer was completed, the gate 58 was closed, and a silicon oxide film 309 was formed in the film forming chamber 57 by a sputtering method. The sputtering target was high-purity synthetic quartz. The silicon oxide film 309 is 1
A film was formed to a thickness of 000 mm. This silicon oxide film is assimilated with the oxide film 308 thereunder, so that the film thickness can be freely controlled.
At the same time, it has the advantage of having excellent interface characteristics with the base. Thus, the silicon oxide film 309 constituting the gate insulating film of the TFT could be formed.

Since the gate insulating film formed as described above does not come into contact with the air during the film forming process,
Good interface characteristics can be obtained without contamination of the interface surface. In particular, an oxide film 308 formed by laser light irradiation in an oxygen atmosphere or an oxidizing atmosphere.
Is extremely excellent in the interface characteristics with the crystalline silicon film constituting the active layers 306 and 307, and it is possible to obtain a very preferable gate insulating film of a TFT having a low interface state density. The silicon oxide film 30 in the film forming chamber 57
After the film formation of No. 9, hydrogen heat treatment may be further performed in the heat treatment chamber 53.

After the formation of the silicon oxide film 309 in the film forming chamber 57 is completed, the film forming chamber 57 is brought into a high vacuum state. Then, the gate 58 is opened, and the substrate is transferred to the common spare chamber 59. Then, the gate 58 is closed. Next, the gate 52 is opened, and the substrate is transferred to the loading / unloading chamber 51. And close Gate 52,
The substrate is taken out of the apparatus from the loading / unloading chamber 51. Next, a film containing aluminum as a main component was formed to a thickness of 5000 ° by a sputtering method, and etching and anodic oxidation were performed in the same manner as in Example 2 to form gate electrode portions 310 and 311.

Then, phosphorus and boron were implanted in the same manner as in Examples 1 and 2, and the source / drain regions of the TFT were formed in a self-aligned manner. After the doping with phosphorus and boron, the source / drain regions were activated by irradiation with laser light or an equivalent strong light. Then, a silicon oxide film 312 is formed as an interlayer insulator by plasma CVD.
Formed to a thickness of about 5000 ° by a conventional method, and through a drilling step, to form source / drain electrodes / wirings 313, 314,
315 was formed. Further, in a hydrogen atmosphere, 35
By performing a hydrogen heat treatment at a temperature of 0 ° C., a CMOS type T
FT was completed.

[0046]

According to the present invention, a laser processing apparatus, a film forming apparatus related to the laser processing apparatus, and another vacuum apparatus are combined into a system, and mass production can be improved by efficiently using the system. . In particular, by irradiating a laser beam to an amorphous or polycrystalline silicon film in an oxygen atmosphere or an oxidizing atmosphere, it is possible to simultaneously improve the crystallinity of the film and form an oxide film on the surface thereof. Thereafter, by forming an insulating film such as silicon oxide without exposure to the outside air, a gate insulating film having excellent interface characteristics can be obtained over a crystalline silicon film.

In addition, it is possible to prevent an electrical short circuit with the island-like region at the step portion of the gate electrode. That is, as shown in FIG. 7A, in the general TFT process, when an island-shaped region was formed, holes were generated at the edge of the silicon film due to overetching. In particular, this was remarkable when the underlying silicon oxide film was soft (the etching rate was large). When a gate insulating film is formed by a conventional PVD method or CVD method, the holes cannot be filled well, and short-circuits are caused by cracks or the like, and a leak current often occurs. (FIG. 7 (B)) However, in the present invention, a dense oxide film or nitride film without a pinhole or the like having a uniform thickness around the silicon film forms a laser beam or a strong light equivalent thereto. ,
As a result, even if the above cracks occur, there is no short circuit between the gate electrode and the island region, and there is almost no problem in use. (FIG. 7C) As described above, the present invention is extremely useful for forming a gate insulating film of a TFT.

[Brief description of the drawings]

FIG. 1 shows a conceptual diagram of a multi-chamber of the present invention.
(Example 1)

FIG. 2 shows a manufacturing process of an example. (Example 1)

FIG. 3 shows a conceptual diagram of the multi-chamber of the present invention.
(Example 2)

FIG. 4 shows a conceptual diagram of the multi-chamber of the present invention.
(Example 3)

FIG. 5 shows a manufacturing process of an example. (Example 2)

FIG. 6 shows a manufacturing process of the example. (Example 3)

FIG. 7 shows a difference between a conventional gate insulating film and a gate insulating film of the present invention.

FIG. 8 shows a multi-chamber apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Film-forming chamber 2 ... Laser processing chamber 3 ... RF power supply 4, 5 ... Electrode 6 ... Substrate (during film-forming) 7 ... Vacuum valve (gas introduction side) 8 ... Vacuum valve (exhaust side) 9 ... Preparatory chamber 10 ... Substrate 11 (after laser processing) 11 ... Laser device 12 ... Mirror 13 ... Lens 14 ... Window 15 ... · Substrate holder (movable) 16 ··· Heater 17 ··· Substrate (during laser processing) 18 ··· Vacuum valve (gas introduction side) 19 ··· Vacuum valve (exhaust side)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-250178 (JP, A) JP-A-4-373178 (JP, A) JP-A-5-182923 (JP, A) JP-A-2- 239615 (JP, A) JP-A-2-81424 (JP, A) JP-A-3-293719 (JP, A) JP-A-5-251342 (JP, A) JP-A-7-99321 (JP, A) JP-A-60-66471 (JP, A) JP-A-4-152624 (JP, A) JP-A-5-243577 (JP, A) JP-A-6-84944 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/205 H01L 21/31 H01L 21/26-21/268 H01L 21/68 H01L 29/786 C23C 16/00 C30B 25/00 G02F 1/136

Claims (12)

(57) [Claims] An apparatus having a first processing chamber for irradiating a laser beam and a second processing chamber for forming a film by a vapor deposition method, wherein the first processing chamber has an oxidizing property. Irradiating the semiconductor film formed on the substrate with the laser light in an atmosphere, and moving the substrate from the first processing chamber to the second processing chamber without exposing the semiconductor film to outside air; A method for manufacturing a semiconductor device, comprising forming a film containing silicon oxide or silicon nitride over the semiconductor film. 2. An apparatus having a first processing chamber for irradiating a laser beam and a second processing chamber for forming a film by a vapor deposition method, wherein the first processing chamber has a nitriding property. Irradiating the semiconductor film formed on the substrate in an atmosphere with a laser beam, and exposing the substrate from the processing chamber to the second
A method for manufacturing a semiconductor device, comprising: transferring a film containing silicon oxide or silicon nitride to the semiconductor film in the second processing chamber. 3. The first processing chamber according to claim 1, wherein the laser light is emitted from a laser device outside the first processing chamber, and the laser light is linearly irradiated into the first processing chamber. A method for manufacturing a semiconductor device, comprising: 4. The method according to claim 1, wherein
The method for manufacturing a semiconductor device, wherein the laser light is an excimer laser, a YAG laser, or a ruby laser. 5. An apparatus having a first processing chamber for irradiating an intense light equivalent to a laser beam and a second processing chamber for forming a film by a vapor deposition method, wherein: Irradiating intense light to a semiconductor film formed on the substrate in an oxidizing atmosphere, transferring the substrate from the first processing chamber to the second processing chamber without exposing the semiconductor film to outside air, 3. The method for manufacturing a semiconductor device according to claim 1, wherein a film containing silicon oxide or silicon nitride is formed over the semiconductor film. 6. An apparatus having a first processing chamber for irradiating intense light equivalent to a laser beam and a second processing chamber for forming a film by a vapor phase growth method, wherein the processing chamber has a nitriding property. Irradiating intense light to a semiconductor film formed on the substrate in an atmosphere, transferring the substrate from the first processing chamber to the second processing chamber without exposing the semiconductor film to outside air, A method for manufacturing a semiconductor device, comprising forming a film containing silicon oxide or silicon nitride over a semiconductor film. 7. The method for manufacturing a semiconductor device according to claim 5, wherein a rare gas lamp or a halogen lamp is used as a light source of intense light equivalent to the laser light. 8. The method according to claim 1, wherein
In the second processing chamber, a plasma CVD method, a reduced pressure C
A method for manufacturing a semiconductor device, wherein a film is formed using any one of a vapor deposition method such as a VD method, an atmospheric pressure CVD method, or a sputtering film formation method. 9. The method according to claim 1, wherein
The first processing chamber and the second processing chamber are connected to a common chamber, and the substrate is moved from the first processing chamber through the common chamber to the second processing chamber. A method for manufacturing a semiconductor device. 10. A first processing chamber for irradiating a laser beam, a second processing chamber having heat treatment means, a third processing chamber for forming a silicon oxide film, A common chamber to which a processing chamber is connected, wherein in the first processing chamber, a semiconductor film on a substrate is irradiated with laser light in an oxidizing atmosphere or a nitriding atmosphere; Heat treating the semiconductor film in a hydrogen atmosphere or an atmosphere containing hydrogen in a treatment chamber, and forming a silicon oxide film over the semiconductor film in the third treatment chamber; A method for manufacturing a semiconductor device, wherein a substrate is moved to each processing chamber without being exposed to outside air through the common chamber. 11. The method for manufacturing a semiconductor device according to claim 10, wherein said laser beam is an excimer laser, a YAG laser, or a ruby laser. 12. The method for manufacturing a semiconductor device according to claim 1, wherein the semiconductor film is made of silicon.