JPS59219461A - Amorphous silicon film forming device - Google Patents

Abstract

PURPOSE:To provide a titled film forming device which supplies stably an electromagnetic wave of specified electric power during film formation by providing a magnet for electronic cyclotron resonance which supplies an external magnetic field and a magnet for sweeping magnetic field which controls the intensity of the electromagnetic wave in an electric discharge chamber. CONSTITUTION:An electromagnet 8 for electronic cyclotron resonance and an electromagnet 9 for sweeping magnetic field are disposed in an electric discharge chamber 6. Gas for excitation is introduced into the chamber 6 and is excited by the microwave passing through a waveguide 4 then plasma is generated by electronic cyclotron resonance. The magnet 8 supplies the external magnetic field by which a resonance condition is satisfied. The plasma decomposes and excites the gaseous raw material introduced into a reaction chamber 10, and the generated radical sticks on a base body 13. The magnetic field is swept by the magnet 9 during the film formation and the absorbing intensity of the electromagnetic wave is detected. The microwave is adjusted by a control device to control the intensity of the electromagnetic wave. The amorphous silicon having a good film characteristic is formed by such device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an amorphous silicon film forming apparatus for manufacturing a photoreceptor photoelectric conversion member used, for example, in electrophotography.

[Technical background of the invention and ranking points]

Conventionally, as a method for forming an amorphous silicon film, a radio frequency (RF) glow discharge decomposition method, a snobbing method, a tsuttering method, and the like have been mainly used.

For example, in the glow discharge decomposition method, a silicon-containing gas such as silane (5iH4) is introduced into a vacuum chamber, and a high frequency (13
, 56MHz) 'e is applied to generate plasma,
Among the ions, radicals, etc. of electrolytic decomposition products present in the plasma, the radicals are mainly attached to the conductive substrate placed in the chamber to form a film. This high-frequency glow discharge decomposition method has better film properties than the Nuno and Tsuttering methods, but because the conductive substrate is exposed in the plasma generated during film formation, the surface of the grown amorphous silicon film is There is a problem in that electrons, ions of decomposition products, etc. collide with each other, and these adversely affect membrane properties. In addition, in order to obtain amorphous silicon with uniform and good film formation characteristics, it is essential that when plasma is generated by high frequency, the applied power is efficiently absorbed by the plasma and a good matching state is achieved. It is necessary that the nokwa matching f' is stable in the film.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to prevent electrons, ions, etc. from colliding with the amorphous silicon surface during film formation as much as possible, and to maintain stability during forming 5. An object of the present invention is to provide an amorphous silicon film forming apparatus that can supply electromagnetic waves of constant power and thereby form a film of Amonotofanu silicon having uniform and good film characteristics.

[Summary of the invention]

In an amorphous silicon film deposition system that uses electromagnetic waves to decompose silicon-containing raw materials and deposit amorphous silicon on a conductive substrate, the second article states that the magnetic waves interact with the magnetic field. tj for supplying an external magnetic field to generate electron cyclotron resonance, a magnet for child cyclotron resonance, and the absorption intensity of the electromagnetic wave due to electron cyclotron resonance, and control the intensity of the electromagnetic wave based on the result. The present invention is characterized in that it is equipped with a magnetic field sweeping magnet provided for the purpose.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to all the drawings. In FIGS. 1 and 2, reference numeral 1 is a microwave oscillator, and the microwaves generated by this are split by the magic 2 and then proceed to a tuner 3 and a waveguide 4.

The tip of the waveguide 4 faces the discharge chamber 6 through the alumina window 5. An excitation gas introduction pipe 7 is connected to the discharge chamber 6, and an electromagnet 8 for electron cyclotron resonance and an electromagnet 9 for sweeping the magnetic field are installed. Also,
A reaction chamber 10 is provided below the discharge chamber 6, and these chambers communicate through an opening 1. A grounded support 12 is provided in the reaction chamber 10, and a conductive substrate 13 is placed on the support 12.

Further, a raw material gas introduction pipe 14 and an exhaust pipe 15 are connected to the reaction chamber 10, and a pulp 16 is disposed in the exhaust pipe 15.

On the other hand, the output of the magic 2 is supplied to a recorder 19 via a crystal detector 17 and an amplifier 18 sequentially, and this recorder 19 is also supplied with a sweeping magnetic field signal from the magnetic field sweeping magnet 9. It has become. The signal 1d from the recorder 19 is supplied to the drive circuit 21VC via the pressure comparator 2o, and this drive circuit 2 is matched by a stepping motor. This drives the Nurine tab tuner inside the Tsukunu 22.

Note that 23 is a power meter.

Therefore, the excitation gas introduction pipe 7 contains, for example, H2rN
2 t 02 r An excitation gas such as rare gas is introduced into the discharge chamber 6, and is excited through the entire alumina window 5 from the micro pump that has passed through the waveguide 4 gold, causing Ri-electrotron resonance. Plasma is generated by -1'-. At this time,
The electron cyclotron resonance magnet 8 supplies an external magnetic field that satisfies the electron cyclotron resonance condition of equation (1), which will be described later.

Here, electron cyclotron resonance (gcm) is caused by the interaction of the electrical component of an electromagnetic field, mainly a microwave magnetic field, with an external magnetic field parallel to it; in this case,
The angular velocity ω of the moving electron is proportional to the strength H of the external magnetic field, and is inversely proportional to the mass m of the heel electron. Therefore, the relationship between the electron cyclotron resonance frequency ω and the external magnetic field Ho is +e+ω−H6・four-phase (1 ). Note that e is the electric charge and C is the speed of light. As a result, when an orbiting electron is supplied with radiation at a frequency suitable for resonance, the electron absorbs the photon energy and at the same time expands its cyclotron orbit.

The plasma generated in this way is transferred to the raw material gas introduction pipe 1
4. Reaction chamber. A raw material gas containing silicon, such as SiH4, introduced into the chamber is decomposed and excited through the opening.

The radicals thus generated adhere to the conductive substrate 13 to form a film. Therefore, it is possible to prevent electrons and ions in the plasma from directly colliding with the surface of the amorphous silicon on which the film has been formed, so that it is possible to form an amorphous silicon film with uniform and good film properties. .

During film formation performed in this manner, the tuner 3 adjusts and reflects the microwaves reflected from the waveguide 4 side so as to cancel them.

Therefore, if no electron cyclotron resonance occurs in the discharge chamber 6 and no microwave power is supplied to the discharge chamber 6, all the microwaves will be reflected back through the waveguide 4 and reflected by the tuner 3. This cancels out the microwave, and as a result, the input to the crystal detector 17 becomes zero.

On the other hand, if absorption of microwaves occurs in the discharge chamber 6 due to electron cyclotron resonance, the microwaves will be generated depending on the intensity difference between the microwaves reflected through the waveguide 4 and the microwaves reflected from the tuner 3. The output, that is, the absorption signal due to electron cyclotron resonance, is supplied from the magic 2 to the crystal detector 17. At this time, a magnetic field sweeping electromagnet 9 placed inside the electron cyclotron resonance electromagnet 8
which satisfies the conditions for electron cyclotron resonance by
The magnetic field is swept in a narrow range compared to the strength of the external magnetic field from the electron cyclotron resonance electromagnet 8. This results in
If electron cyclotron resonance occurs, crystal detector 1
A current flows through the amplifier 18 and the recorder 19 obtains an absorption spectrum 24 of electron cyclotron resonance. However, microwave amplification requires magnetic field modulation. As described above, the state of electron cyclotron resonance within the discharge chamber 6 can be monitored, and the power of the microwave can be observed.

Next, the half width of the resonance line of the electron cyclotron resonance obtained as described above or the intensity of the resonance line in an arbitrary magnetic field is read by the voltage comparator 20. Therefore, if the microwave loss becomes large and the absorption of electron cyclotron resonance becomes weak, the voltage comparator 20
The control signal gold drive circuit 21 increases the absorption intensity by
send to Then, this driving circuit 21 drives the two-lead stab tuner in the matching gear 22 by the stepping motor, and the microwave is reflected at the 'fCETA' node. Therefore, the plasma state can be maintained constant by the microwave power supplied into the discharge chamber 6, so that an amorphous silicon film having more uniform and better film characteristics can be formed.

In addition, as the excitation gas, H2* N2 + 02+
Gases such as O3 and rare gas (mainly 'Te r Ne +Δr) are used. Monkey, raw materials include St but 7 fr, for example 5IH4* J2H6+ 515
Silicon hydride such as HB tSl 4H+ o, SiF4
+ Si2F6*5xct4. Silicon halides such as SiBr4, alkyl silicides such as 51(CH3)4, halogen-converted alkyl silicides such as 5Ice(CH5), halogen-converted silicones such as 5IHF2゜5IH2C42, or the above-mentioned Sl. A mixed gas of a gas containing an element 1 of group 111A of the periodic table or an element of group VA of the periodic table is used depending on the purpose.

Next, an experimental example will be explained. First, the discharge chamber 6 and the reaction chamber 1
0 is evacuated to about 10-6 Torr using a rotary pump and a diffusion pump at the bottom of the exhaust pulp 16. Next, the electromagnet 8 for applying an external magnetic field is
00 Gaussian magnet s is applied, while o-1oo is applied to electromagnet 9 for foundation sweep.

A magnetic field of the Gaussian level is applied.

In this state, hydrogen is introduced from excitation gas introduction g7,
After that, microwave oscillator 1! Generate and release 78 GHz microwave '1loOW power! The microwave is introduced into the chamber 6 and adjusted so that the reflection of the microwave from the waveguide 4 is minimized. Once the matching is achieved, apply the electromagnet 9 to ±100 Gauss.
A magnetic field sweep of s was carried out, and an absorption waveform of electron cyclotron resonance was obtained using the recorder 19 as shown in FIG. FIG. 4 shows the electron cyclotron resonance absorption waveform under the above conditions and the change in half-width of the absorption waveform when the hydrogen gas pressure is changed.

-) The amorphous silicon film was formed under the same conditions as above, including the microwave frequency, power, and strong external magnetic field. That is, the temperature of the conductive substrate No. 3 in the reaction VLO was set to 250° C., and hydrogen gas was introduced into the discharge chamber 6 from the small excitation gas introduction tube 7 at a gas pressure of I Torr to generate plasma. . At this time, the detection system and control system are operated so that matching is performed, and during film formation, the magnetic field is fully swept to about the half width of the absorption line at 1 minute intervals, and the absorption waveform is monitored and controlled. Make it.

Next, the raw material is supplied with SiH4 from the inlet pipe 14 at a flow rate of 50.
SCCM, pressure 0. It was introduced into the reaction chamber 10 with the I Torr K adjusted and reacted with the plasma, thereby depositing amorphous silicon on the conductive substrate 13-1. When we investigated the properties of the amorphous silicon that was created as described above, we found that the film formation rate was 2.0 μm/1 (r
1 optical band gap 1, 71 eV, dark resistance ρ, =
2xlOΩ”ffi, wavelength 650, number of incident photons 5
A bright resistance ρ −6×10 Ω·m was obtained when a light source sound of 1014 an″ was used. On the other hand, the characteristics of amorphous silicon obtained by the usual glow discharge decomposition method are as follows: under the same film forming conditions as above, the film forming rate is 1.6 μm/Hr, the optical resistance is 1.72 eV, the dark resistance is p,
-8X 1.0 Ω' (771% bright resistance ρ = 4X1
It was 0Ω·m.

As described above, since we are equipped with a film forming means that utilizes electron cyclotron resonance and a control means that aims to keep the matching of microwave power constant during gold film forming, the conductive substrate is exposed to plasma in the reaction chamber. We were able to produce amorphous silicon that has better optical and electrical properties than the conventional claw discharge decomposition method in which it is exposed to water.

〔Effect of the invention〕

As explained above, according to the present invention, in an amorphous silicon film forming apparatus that forms an amorphous silicon film on a conductive substrate by decomposing a silicon-containing raw material gas using electromagnetic waves, the electromagnetic waves interact with the magnetic field of the electromagnetic waves. an electron cyclotron resonance magnet for supplying an external magnetic field to generate electron cyclotron resonance; Since it is equipped with a magnetic field sweeping magnet, it is possible to avoid collisions of electrons, ions, etc. with the amorphous silicon surface during film formation as much as possible, and also to be able to stably supply electromagnetic waves with constant power during film formation. This provides excellent effects such as the ability to form an amorphous silicon film having uniform and good film properties.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 shows discharge,
Figure 2 is a configuration diagram showing the detection system and control 1 system part, Figure 3 is a diagram showing the relationship between microwave absorption strength and magnetic field strength, Figure 4 is a diagram showing the relationship between the microwave absorption strength and the magnetic field strength. FIG. 3 is a diagram showing the jyl relationship between the half width and the H2 pressure.ノ...Microwave oscillator, 2...Magic, 3...
・Chunner, 4... Waveguide, 6... Discharge chamber, 8.
... Magnet for electron cyclotron resonance, 9... Electromagnet for magnetic field sweeping, 13... Conductive substrate, 17... Crystal detector, 18... Amplifier, 19... Recorder, 20
...Voltage comparator, 2..Drive circuit, 22..Matching box. Applicant's agent Patent attorney Takehiko Suzue "-N @ KanV
! Be 0 Ken also Gomezaze Go 5 v Ta ε Ushi, 1 Kyo Kōkan Wakasugi Kazuo Tono 1. Indication of the incident Japanese Patent Application No. 58-91023-) Name of the invention Amorphous silicon film forming apparatus 3.1 Incident of fixing the irises. Related *'i license applicant 307) Tokyo Shibaura + gki Co., Ltd. 11th generation 1
411 people (i, Supplement [1- Target specification] ・1 7. Contents of amendment (1) Specification, "Magic 2" on page 4, line 9 is corrected to "Magic T2J." (2) Specification (3) "Magic 2" in page 7, line 20 of the specification is corrected as "for excitation" in line 12 of page 4.
Corrected to Magic T2J. (4) "Ma-nock" on page 13, line 18 of the specification is corrected to "ma-sic T."

Claims (1)

[Claims] In a method for forming an amorphous silicon film on a conductive substrate by decomposing a raw material gas containing silicon using electromagnetic waves, 'fJ5. A magnet for electron cyclotron resonance that supplies an external magnetic field that generates child cyclotron resonance, and absorption of the electromagnetic waves by child cyclotron resonance 115? An amorphous silicon forming apparatus each comprising a lifting and sweeping stone provided to eject a bullet and control the intensity of the electromagnetic waves based on the result π.