JP3654464B2 - Non-single crystal thin film forming equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-single crystal thin film forming apparatus. More specifically, the present invention relates to a forming apparatus capable of producing a non-single crystal thin film having a small specific resistance.
[0002]
[Prior art]
Conventionally, in a forming apparatus for producing an amorphous silicon film which is one of non-single-crystal thin films, (Ar + H ₂ ) gas is frequently used as a carrier gas, but there is a problem that plasma damage to the thin film is large.
[0003]
In order to solve this problem, the present inventor uses Xe having a larger ionization cross section than Ar, and using a (Xe + H ₂ ) gas as a carrier gas and a sputtering apparatus having parallel plate electrodes shown in FIG. An amorphous silicon thin film was formed.
[0004]
In the conventional apparatus, hydrogen gas and xenon gas are introduced into the film forming chamber 201 from a pipe 216 for introducing hydrogen gas and a pipe 207 for introducing xenon gas. Then, by applying AC power to the electrode 210 on which the Si target 212 having a predetermined composition is disposed, the Si target 212 was sputtered to form an amorphous silicon film on the substrate 211. As a result, plasma damage to the amorphous silicon film is reduced, but hydrogen radicals are not easily generated in the plasma, so that dangling bonds are not sufficiently terminated in the amorphous silicon film.
[0005]
In order to form a high-quality amorphous silicon film with a small specific resistance, development of an apparatus for forming a non-single-crystal thin film that has little plasma damage to the thin film and has sufficient hydrogen radicals in the plasma has been desired. .
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a forming apparatus capable of producing a non-single crystal thin film having a small specific resistance.
[0007]
[Means for Solving the Problems]
In the invention according to claim 1, means for generating hydrogen radicals outside the film forming chamber;
Possess means for introducing the generated hydrogen radicals into said deposition chamber, and means for generating the xenon gas plasma by introducing at least xenon gas into the deposition chamber,
The means for introducing the generated hydrogen radicals into the film forming chamber has a differential pressure function , and plasma damage to the thin film is small and plasma containing hydrogen radicals can be generated. . As a result, a non-single crystal thin film having a small specific resistance can be formed.
[0008]
In the invention according to claim 2, thin film formation, the order of the xenon gas is performed by a sputtering method using xenon gas plasma and carrier gas, without using a special gas such as silane tricky handling of resistivity small non A single crystal thin film can be formed.
In the invention according to claim 3, thin film formation, the xenon gas to be done by the CVD method using a carrier gas and xenon gas plasma, depending on selecting the reaction gas as appropriate, it can be formed of various non-single crystal thin film It becomes.
The invention according to claim 4 is characterized in that the non-single-crystal thin film is an amorphous silicon film.
The invention according to claim 5 is characterized in that dangling bonds of the amorphous silicon film are terminated by the hydrogen radicals.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
An apparatus for forming a non-single-crystal thin film according to the present invention (FIG. 1) includes a film formation chamber 101, a plasma generation mechanism 102 that generates hydrogen plasma, and plasma that introduces the generated hydrogen plasma into the film formation chamber 101. An introduction mechanism 103 is included. Reference numeral 107 denotes an introduction pipe for xenon (Xe) gas used as a carrier gas in the film forming chamber 101. Inside the film forming chamber 101, there is a plasma generation mechanism comprising parallel plate electrodes 109 and 110. The plasma introduction mechanism 103 and the Xe gas introduction pipe 107 are provided on the side surface of the film forming chamber 101. Xe gas is directly introduced into the film forming chamber 101 and excited by a plasma generation mechanism including the parallel plate electrodes 109 and 110. As a result, Xe plasma is generated between the electrodes. On the other hand, hydrogen (H ₂ ) gas is excited by the plasma generation mechanism 102 to become hydrogen radicals (H ^* ), and enters the film formation chamber 101 via the plasma introduction mechanism 103 having a differential pressure function including an orifice valve or a stop valve. be introduced. Since this H ^* diffuses into the film forming chamber 101, a state in which a large amount of H ^* exists in the Xe plasma can be created. The plasma introduction mechanism 103 only needs to have a differential pressure function. Therefore, a device other than the orifice valve or the stop valve may be used as the plasma introduction mechanism 103.
[0010]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.
(Example 1)
In this example, the sputtering apparatus shown in FIG. 1 was used as the non-single crystal thin film forming apparatus. In the sputtering apparatus of FIG. 1, an inductive-coupled glow discharge tube (ICP) is provided as a plasma generation mechanism 102 for generating hydrogen plasma on the side surface of the film forming chamber 101 having parallel plate type electrodes. In order to make a pressure difference between the internal pressure of the film formation chamber 101 and the internal pressure of the plasma generation mechanism 102, an orifice valve was installed as the plasma introduction mechanism 103 between the film formation chamber 101 and the plasma generation mechanism 102.
[0011]
Xenon (Xe) gas was introduced from the pipe 107 through the mass flow controller 108 into the film forming chamber 101 of the sputtering apparatus and used as a carrier gas. After setting the pressure in the film forming chamber 101 to 7 mTorr, 150 W and 182.5 MHz of electric power was supplied to the electrode 110 from the high frequency power supply 113 to generate Xe plasma between the electrodes.
[0012]
Hydrogen radicals (H ^* ) generated in the ICP were introduced into the film formation chamber 101 through an orifice valve, and the total pressure in the film formation chamber 101 was adjusted to 10 mTorr.
An n-type Si (As-3 × 10 ¹⁹ doped) was used as the target 112 to be sputtered, and an amorphous silicon film having a thickness of 100 nm was formed on the SiO ₂ substrate 111 at a substrate temperature of 300 ° C.
[0013]
The sheet resistance and film thickness of the n-type amorphous silicon film produced in this example were measured, and the specific resistance of the film was obtained from these two values. As a sheet resistance measuring device, Model HA-6100 / RG-1000E manufactured by Napson was used, and as a film thickness measuring device, DEKTAK-3030 manufactured by Sloan Technology was used. As a result, the specific resistance of the n-type amorphous silicon thin film produced in this example was 0.04 Ω · cm.
[0014]
(Comparative Example 1)
In this example, an n-type amorphous silicon film was formed using the conventional sputtering apparatus shown in FIG. 2 as a non-single crystal thin film forming apparatus. A xenon (Xe) gas of 7 mTorr and a hydrogen (H ₂ ) gas of 3 mTorr were introduced into a film forming chamber 201 having parallel plate electrodes to generate plasma between the electrodes.
[0015]
The other points were the same as in Example 1.
Using the same method as in Example 1, the specific resistance of the n-type amorphous silicon film produced in this example was determined to be 0.6 Ω · cm.
[0016]
From the results described above, it can be seen that the non-single-crystal thin film forming apparatus according to the present invention can obtain an amorphous silicon film having a specific resistance smaller by one digit than the non-single-crystal thin film forming apparatus according to the comparative example. It was.
[0017]
Further, it has been found that the action confirmed by the sputtering apparatus can be similarly obtained by the CVD method using xenon gas as a carrier gas.
[0018]
【The invention's effect】
As described above, the non-single-crystal thin film forming apparatus according to the present invention can produce a non-single-crystal thin film typified by an amorphous silicon film having a small specific resistance.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a thin film manufacturing apparatus according to the present invention.
FIG. 2 is a schematic cross-sectional view of a thin film manufacturing apparatus according to a conventional example.
[Explanation of symbols]
101 201 deposition chamber,
102 plasma generation mechanism,
103 plasma introduction mechanism,
104, 113, 213 high frequency power supply,
105, 108, 208, 217 Mass flow controller,
106, 216 Pipes for introducing hydrogen gas,
107, 207 Piping for introducing xenon gas,
109, 110, 209, 210 electrodes,
111, 211 substrate,
112, 212 targets,
114, 214 exhaust device,
115, 215 Main valve.

Claims (6)

Means for generating hydrogen radicals outside the deposition chamber;
Means for introducing the generated hydrogen radicals into the film formation chamber; and means for introducing xenon gas into the film formation chamber to generate xenon gas plasma;
An apparatus for forming a non-single-crystal thin film, wherein the means for introducing the generated hydrogen radicals into the film formation chamber has a differential pressure function. 2. The non-single-crystal thin film forming apparatus according to claim 1, wherein the forming apparatus forms the thin film by sputtering using the xenon gas as a carrier gas and the xenon gas plasma. 3. 2. The non-single-crystal thin film forming apparatus according to claim 1, wherein the forming apparatus forms a thin film by performing CVD with the xenon gas plasma using the xenon gas as a carrier gas .   The apparatus for forming a non-single-crystal thin film according to claim 1, wherein the thin film is an amorphous silicon film.   4. The non-single-crystal thin film forming apparatus according to claim 3, wherein dangling bonds of the amorphous silicon film are terminated by the hydrogen radicals. Means for generating hydrogen radicals outside the deposition chamber;
Means for introducing the generated hydrogen radicals into the film formation chamber; and means for introducing xenon gas into the film formation chamber to generate xenon gas plasma;
An apparatus for forming a non-single crystal thin film for forming a film while introducing hydrogen radicals into the xenon gas plasma.

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