JP2003282476A - Method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device which can facilitate the manufacturing process of TFTs and decrease the number of apparatuses used to manufacture the TFTs by performing hydrization treatment in a chamber for laser crystallization as well as laser crystallization. <P>SOLUTION: A hydrogen gas is mode to flow to a discharge chamber 56, electric discharge is caused by a radical source, and a hydrogen radical is supplied into a laser irradiation chamber 50 through a radial transport pipe 55. When the hydrogen radical is supplied, a gate valve 53 is in an open state and the hydrogen radical supplied to a cleaning chamber 54 is supplied to a substrate in a laser irradiation chamber 50. While the hydrogen radical is supplied, the laser crystallization is carried out, to instantaneously subjected to hydrogen termination unpaired electron pairs in a polycrystalline silicon film formed by the laser crystallization. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device formed on an insulator and used as a display pixel of a liquid crystal display device or a constituent element of a liquid crystal drive circuit.

[0002]

2. Description of the Related Art Conventionally, polycrystalline silicon (poly-S) has been used.
i) a thin film transistor having a semiconductor film (hereinafter, T)
Polycrystalline silicon TFTs (referred to as FTs) are liquid crystal display devices (LCDs) and liquid crystal displays (LCDs) and liquid crystals (LCDs) that can be made on a transparent and insulating substrate such as a glass substrate while allowing high mobility. It is widely used as a light modulator of a projector or the like or a component of a built-in driver for driving a liquid crystal.

The performance of a TFT, which is a field-effect transistor, is naturally determined by the film quality of the gate insulating film, the film quality of the semiconductor film forming the active portion thereof, and the quality of the interface between the gate insulating film and the semiconductor film. If a high-quality semiconductor film, a gate insulating film, and a clean interface are obtained, a high-performance TFT corresponding thereto can be obtained. Conversely, if all of these requirements are not satisfied at the same time, a high-performance TFT can be obtained. Can never be realized.

There is a technique called a low temperature process for realizing a high mobility polycrystalline silicon TFT using a relatively inexpensive heat resistant glass substrate, and a polycrystalline silicon TFT manufacturing process in which the maximum process temperature is generally 600 ° C. or lower is used. It is generally called a low temperature process. In the low-temperature process, a technique of crystallizing a silicon film using a pulse laser with 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 instantly melted by irradiating it with high-power pulsed laser light, and is crystallized in the process of solidification. Recently, a technique for forming a large-area polycrystalline silicon film by scanning an amorphous silicon film on a glass substrate while repeatedly irradiating an excimer laser beam has been widely used. As the gate insulating film, a relatively high quality silicon dioxide (SiO2) film is formed by a plasma CVD method.
It became possible to form a film, and the prospect for practical application was obtained. With these technologies, polycrystalline silicon T is now formed on a large glass substrate with a side of several tens of centimeters.
FT can be created.

[0005]

However, in the prior art, a polycrystalline silicon film obtained by laser crystallization always produces an unpaired electron pair (dangling bond) that is chemically very active. When oxygen, water, carbon monoxide, carbon dioxide, dust, dust, etc. come into contact with the semiconductor film,
Since these substances are taken into the semiconductor film as impurities, a hydrogenation process for terminating unpaired electron pairs with hydrogen is required, and a chamber for hydrogenation is required in addition to the chamber for laser crystallization. And TFT
There is a problem that the manufacturing process of is complicated and many devices used for manufacturing the TFT are required.

The present invention has been made in view of the above problems, and an object thereof is to manufacture a TFT by performing a hydrogenation process together with a laser crystallization in a chamber for laser crystallization. TF can be simplified process
Another object of the present invention is to provide a method of manufacturing a semiconductor device that can reduce the number of devices used for manufacturing T.

[0007]

The present invention has the following constitution in order to solve the above problems.

The gist of the invention according to claim 1 is to crystallize a semiconductor film formed on a substrate carried into a laser irradiation chamber or a semiconductor substrate by irradiating laser light through a laser light introducing window. A method of manufacturing a semiconductor device for performing a crystallization process or an annealing process, comprising supplying a hydrogen radical to the laser irradiation chamber for performing the crystallization process, and performing the crystallization process in an atmosphere of the hydrogen radical to form the crystal. The hydrogenation treatment for terminating the unpaired electron pair generated by crystallization with hydrogen is performed at the same time as the hydrogenation treatment.

A second aspect of the present invention is the method for manufacturing a semiconductor device according to the first aspect, wherein a transfer pipe for supplying an etching gas for cleaning the laser beam introduction window is used, It is characterized in that hydrogen radicals are supplied into the laser irradiation chamber.

A third aspect of the present invention is the method for manufacturing a semiconductor device according to the first or second aspect, in which a cleaning processing chamber provided in the laser irradiation chamber near the laser beam introducing window is provided. The etching gas may be supplied to the cleaning processing chamber in a state of being isolated from other regions in the laser irradiation chamber.

A fourth aspect of the present invention is the method for manufacturing a semiconductor device according to any one of the first to third aspects, wherein the cleaning processing chamber is isolated from other regions in the laser irradiation chamber. In this state, the substrate is unloaded from the laser irradiation chamber and the substrate is loaded into the laser irradiation chamber.

A fifth aspect of the present invention is the method for manufacturing a semiconductor device according to any one of the first to fourth aspects, wherein the cleaning processing chamber is not isolated from other regions in the laser irradiation chamber. In this state, the hydrogen radicals are supplied to the cleaning processing chamber.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the structure of a thin film transistor manufacturing apparatus in which the embodiment of the method for manufacturing a semiconductor device according to the present invention is used, and FIG. 2 shows the structure of the laser irradiation chamber shown in FIG. It is a block diagram.

Referring to FIG. 1, a schematic structure of a TFT manufacturing apparatus in which the present embodiment is used includes a transfer chamber 10 in which a transfer robot 11 for transferring a substrate is arranged, and a transfer chamber 10 is provided around the transfer chamber 10. Load lock room 20 for loading and unloading
A preheating chamber 30 for heating the substrate, a CVD method or PV
A semiconductor film forming chamber 40 for forming a semiconductor film by the D method;
Laser irradiation chamber 5 for crystallization by laser annealing
0 and an oxide film forming chamber 60 for forming a silicon oxide film (first gate insulating film). The transfer chamber 10 and the load lock chamber 20 are connected via a shutter S2, the transfer chamber 10 and the semiconductor film forming chamber 40 are connected via a shutter S3, and the transfer chamber 10 and the laser irradiation chamber 50 are shuttered. The transfer chamber 10 and the oxide film forming chamber 60 are connected via a shutter S5. The load lock chamber 20 has a substrate loading / unloading port that is opened and closed by the shutter S1.

The transfer chamber 10, the preheating chamber 30, the semiconductor film forming chamber 40, the laser irradiation chamber 50, and the oxide film forming chamber 60.
Are shielded from the outside air, and the substrate carried into the load lock chamber 20 is carried into each processing chamber by the transfer robot 11 and is shielded from the outside air in the state where the substrate protective film and the semiconductor film forming process are performed. A crystallization process and a first gate insulating film forming process are performed.

Referring to FIG. 2, the laser irradiation chamber 50 has a laser light introduction window 51 disposed in the upper part of a housing, and a high energy laser light from a laser (not shown) is placed on a holder 52 through the laser light introduction window 51. The substrate is irradiated. A heater is provided in the holder 52 to heat the substrate from about 25 ° C to 400 ° C.
It can be heated to a certain degree, and the holder 52 can move back and forth and right and left, and the movement of the holder 52 irradiates the entire surface of the substrate on the holder 52 with laser light.

Laser light introduction window 5 of laser irradiation chamber 50
A cleaning processing chamber 54, which can be isolated from the other regions of the laser irradiation chamber 50 by a gate valve 53, is provided at the lower part of 1 and is carried into the laser irradiation chamber 50 by closing the gate valve 53. It is configured such that the dirt attached to the laser beam introduction window 51 can be cleaned (etched) without affecting the substrate.

A radical transfer pipe 55 for supplying an etching gas for cleaning the laser beam introduction window 51 is attached to the cleaning processing chamber 54, and the etching gas plasma-excited in the discharge chamber 56 is radical-transferred. It is configured to be supplied to the cleaning processing chamber 54 through a pipe 55. Further, an exhaust unit (not shown) is connected to the cleaning process chamber 54, and the cleaning process chamber 54 is evacuated by the exhaust unit.
The etching gas supplied inside can be exhausted.

Hydrogen gas is also supplied to the discharge chamber 56 together with the etching gas, and hydrogen radicals plasma-excited in the discharge chamber 56 by switching to the etching gas are supplied to the cleaning processing chamber 54 through the radical transfer tube 55. Is configured to be able to.

Next, the operation of this embodiment will be described in detail with reference to FIG. FIG. 3 is a process diagram for explaining an embodiment of the method for manufacturing a semiconductor device according to the present invention.

First, a plurality of substrates are loaded in the load lock chamber 20.
Then, the transfer robot 11 loads the plurality of substrates loaded in the load lock chamber 20 into the preheating chamber 30 set to about 400 to 500 ° C. After each of the plurality of substrates is preheated in the preheating chamber 30, the transfer robot 11 carries the first substrate out of the plurality of substrates from the preheating chamber 30 into the semiconductor film forming chamber 40 (step A1).

The semiconductor film forming chamber 40 is constructed as a PECVD apparatus for forming a base protective film and a semiconductor film (amorphous silicon film or the like) on the surface of the substrate, and the susceptor temperature is set to about 400 ° C.

After forming the base protective film and the semiconductor film on the first substrate in the semiconductor film forming chamber 40 (step A2), the transfer robot 11 irradiates the first substrate with laser from the semiconductor film forming chamber 40. The second substrate is transferred from the preheating chamber 30 to the semiconductor film forming chamber 4 while being carried into the chamber 50 (step A3).
Bring it to 0.

The first substrate carried into the laser irradiation chamber 50 is heated to 200 ° C. to 400 ° C. by a heater (not shown) provided in the holder 52. It is not necessary to heat the substrate for laser crystallization, but the substrate is heated for the hydrogenation treatment.

Next, hydrogen gas is caused to flow into the discharge chamber 56 to discharge with a radical source, and hydrogen radicals are supplied into the laser irradiation chamber 50 through the radical transfer tube 55 (step A).
4). When the hydrogen radicals are supplied, the gate valve 53 is in an open state, and the hydrogen radicals supplied to the cleaning processing chamber 54 part are supplied to the substrate in the laser irradiation chamber 50.

From the viewpoint of transporting radicals over a long distance through the radical transfer pipe 55, radical discharge is performed at a low pressure (mT).
Orr) region is preferable, and high-frequency (VHF, UHF) microwave is suitable for radical discharge. Flow an appropriate amount of hydrogen gas (for example, 100 sccm), 2-3 mT
A microwave discharge of 100 W is performed in the discharge chamber under a pressure of orr to supply hydrogen radicals onto the substrate.

Simultaneously with the supply of hydrogen radicals, the irradiation of laser light is started, and the substrate is moved relative to the laser light by moving the holder 52 to perform laser crystallization of the entire substrate (step A5). By performing laser crystallization with the hydrogen radicals supplied, the unpaired electron pairs in the polycrystalline silicon film formed by laser crystallization are instantaneously hydrogen-terminated.

After completion of the laser crystallization, the gate valve 5
3 is closed to isolate the cleaning processing chamber 54 from other regions in the laser irradiation chamber 50, and the laser light introduction window 51
Cleaning is started (step A6). The cleaning of the laser beam introduction window 51 is performed between the unloading of the substrate after the completion of the laser crystallization and the loading of a new substrate. Since the gate valve 53 is closed, the etching supplied to the cleaning processing chamber 54 is performed. The gas never reaches the substrate.

Dirt adhering to the laser beam introduction window 51 (S
For the cleaning of i), for example, CF4 + O2, which is an Si etching gas, is used. For example, CF4: O2 = 800.
Sccm: 300 scm is flown, 100 W of microwave discharge is performed at a pressure of 100 mTorr, and the dirt (Si) adhering to the laser beam introduction window 51 is etched.

After the cleaning (etching) is completed, the cleaning processing chamber 54 is evacuated by exhaust means (not shown), and the degree of vacuum in the cleaning processing chamber 54 becomes substantially the same as the degree of vacuum in the region of the other laser irradiation chamber 50. The gate valve 53 is opened with. When it is necessary to evacuate the cleaning processing chamber 54 in a short time, for example, a buffer chamber is provided side by side, and the cleaning processing chamber 54 and the buffer chamber are connected to each other while the buffer chamber is evacuated to a high vacuum. There is a method of exhausting in a short time. The etching rate of Si is 100 nm.
/ Min or more, the time required for one etching is about 10 s.
Considering the vacuum exhaust time of 4, the laser light introduction window 51
The dirt (Si) adhering to the substrate can be cleaned between the unloading of the substrate after the completion of laser crystallization and the loading of a new substrate.

While the semiconductor film on the first substrate is being crystallized by laser irradiation in the laser irradiation chamber 50, the second substrate transferred to the semiconductor film forming chamber 40 is provided with a base protective film and a semiconductor. A film is formed.

After the semiconductor film on the first substrate is crystallized and hydrogenated by laser irradiation, the transfer robot 11 carries the first substrate from the laser irradiation chamber 50 into the oxide film forming chamber 60. Along with (step A7), the second substrate is carried into the laser irradiation chamber 50 from the semiconductor film forming chamber 40. Further, the transfer robot 11 loads the third substrate from the preheating chamber 30 into the semiconductor film forming chamber 40.

While the first gate insulating film is being formed on the first substrate in the oxide film forming chamber 60 (step A8), the third substrate transferred to the semiconductor film forming chamber 40 is a base substrate. The protective film and the semiconductor film are formed, and the semiconductor film of the second substrate transferred to the laser irradiation chamber 50 is crystallized by the laser irradiation.

After that, this process is repeated to sequentially process the plurality of substrates, and the substrates carried into the load lock chamber 20 are sequentially carried out of the apparatus to perform the subsequent processes.

As described above, according to the present embodiment, the laser crystallization is performed while supplying the hydrogen radicals, so that the laser crystallization and the hydrogen are performed in the laser irradiation chamber (chamber) for the laser crystallization. Since a hydrogenation treatment can be performed, a device and time for performing a hydrogenation treatment are not required, and the TFT manufacturing process can be simplified.
This has the effect of reducing the number of devices used for manufacturing TFTs.

Furthermore, according to the present embodiment, laser crystallization is performed while supplying hydrogen radicals,
Since the unpaired electron pair can be instantaneously terminated with hydrogen, the electric conductivity of the semiconductor film is remarkably stabilized, and as a result, the electrical characteristics such as the on-current and off-current of the TFT are improved.

Further, according to the present embodiment, when the hydrogen radicals are supplied to the laser irradiation chamber, since the radical transfer pipe for supplying the etching gas for cleaning the laser light introducing window of the laser irradiation chamber is used, There is an effect that it is possible to reduce the number of devices used for manufacturing a TFT without requiring special equipment for supplying.

The laser light introduction window 5 of this embodiment is used.
The cleaning of the dirt (Si) adhered to No. 1 is performed for each substrate, but depending on the degree of the dirt (Si) adhered to the laser light introduction window 51, it is carried out every plural sheets (for example, 20 sheets). It may be configured like this.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it is apparent that the respective embodiments can be modified appropriately within the scope of the technical idea of the present invention. Further, the number, position, shape, etc. of the above-mentioned constituent members are not limited to those in the above-mentioned embodiment, and the number, position, shape, etc. suitable for carrying out the present invention can be adopted. In addition, in each figure, the same components are denoted by the same reference numerals.

[0041]

According to the method of manufacturing a semiconductor device of the present invention, laser crystallization is performed while supplying hydrogen radicals, so that the laser crystallization and the hydrogenation treatment are carried out in the laser irradiation chamber for laser crystallization. Therefore, there is an effect that a device and time for performing the hydrogenation treatment are not required, the manufacturing process of the TFT can be simplified, and the device used for manufacturing the TFT can be reduced.

Further, in the method for manufacturing a semiconductor device of the present invention, the laser crystallization is performed while supplying hydrogen radicals, whereby the unpaired electron pairs can be instantaneously hydrogen-terminated, so that the electric conductivity of the semiconductor film is increased. Is remarkably stable, and as a result, electrical characteristics such as on-current and off-current of the TFT are improved.

Further, in the method of manufacturing a semiconductor device of the present invention, when hydrogen radicals are supplied to the laser irradiation chamber,
Since the radical transfer pipe for supplying the etching gas for cleaning the laser light introduction window of the laser irradiation chamber is used, special equipment for supplying hydrogen radicals is not required, and it is possible to reduce the device used for manufacturing the TFT. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a thin film transistor manufacturing apparatus in which an embodiment of a method for manufacturing a semiconductor device according to the present invention is used.

FIG. 2 is a configuration diagram showing a configuration of a laser irradiation chamber shown in FIG.

FIG. 3 is a process chart for explaining an embodiment of a method for manufacturing a semiconductor device according to the present invention.

[Explanation of symbols]

10 Transport room 11 Transport robot 20 load lock room 30 Preheating chamber 40 Semiconductor film forming chamber 50 laser irradiation room 60 Oxide film deposition chamber S1-5 shutter 51 Laser light introduction window 52 holder 53 gate valve 54 Cleaning processing room 55 Radical transfer tube 56 discharge chamber

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Claims (5)

[Claims] 1. A semiconductor film or semiconductor substrate formed on a substrate carried into a laser irradiation chamber is irradiated with laser light through a laser light introduction window to perform crystallization treatment or annealing treatment. A method of manufacturing a device, wherein hydrogen radicals are supplied to the laser irradiation chamber for performing the crystallization treatment, and the crystallization treatment is performed in an atmosphere of the hydrogen radicals, whereby the crystallization treatment and the crystallization treatment occur simultaneously. A method of manufacturing a semiconductor device, which comprises performing a hydrogenation process of terminating an unpaired electron pair with hydrogen. 2. The semiconductor device according to claim 1, wherein the hydrogen radicals are supplied into the laser irradiation chamber by using a transfer pipe for supplying an etching gas for cleaning the laser light introducing window. Production method. 3. A cleaning treatment chamber provided in the vicinity of the laser beam introducing window in the laser irradiation chamber is isolated from other regions in the laser irradiation chamber,
The method for manufacturing a semiconductor device according to claim 1, wherein the etching gas is supplied to the cleaning processing chamber. 4. The unloading of the substrate from the laser irradiation chamber and the loading of the substrate into the laser irradiation chamber are performed in a state where the cleaning processing chamber is isolated from other regions in the laser irradiation chamber. The method for manufacturing a semiconductor device according to claim 1, wherein 5. The hydrogen radical is supplied to the cleaning treatment chamber in a state where the cleaning treatment chamber is not isolated from other regions in the laser irradiation chamber. Of manufacturing a semiconductor device of.