JPS62229826A - Deposit film forming method - Google Patents

Abstract

PURPOSE:To form the deposit films with high quality securing the evenness of electrical and optical properties and the stability of quality even in case of forming thick and hardly peeling off deposit films over broad space by a method wherein the stay time and atmospheric temperature of a gaseous material and a valued electron control agent in a deposit chamber are specified. CONSTITUTION:The stay time r of a gaseous material AaHbXc (A: element selected from Si and Ge, X; halogen atoms, a.b,c: positive integers a>=2, cnot equal to O) and a valued electron control agent in a deposit chamber is specified to be 0.l sec <=r<=50 sec, likewise the atmospheric temperature T in deposit chamber to be 200 deg.C<=T<=1000 deg.C while the product of stay time r and atmospheric temperature T to be 100 deg.C sec<=rT<=3000 deg.C sec. Through these procedures, the deposit films subject to even physical properties and easy film quality control can be formed over broad space.

Description

[Detailed description of the invention] [Description of the field to which the invention pertains] The present invention is directed to forming a photoconductive film, a semiconductor film, or an insulating film on a predetermined support using excitation energy such as thermal energy. The present invention relates to a deposited film forming method.

(Description of prior art) Amorphous silicon lt?GrA-5i (H,X) containing hydrogen atoms and/or halogen atoms as required at present
The film (denoted as J) has been put into practical use or is being put into practical use in solar cells and electrophotographic photoreceptors. In these technical fields, LtA-5i (H,X) films are produced by glow discharge decomposition of SiF4°S i H4 gas or Si2H6 gas.

A-St(H) prepared by glow discharge decomposition method.

X) The film is formed by active species such as ions present during glow discharge being accelerated by the electric field and colliding with the A-Si(H,X) film during deposition. Defects inside are increasing.

Currently, in order to improve the characteristics of each of the above applications, A-5i (H,
) It is desired to improve the electrical properties of the film.

As a deposited film formation method without ion collision as described in Section 11n, the raw material gas is decomposed by thermal energy to form A-3i (H,
) Methods for depositing films are attracting attention.

Conventionally, SiH has been used as a raw material gas in such a method.
4, Si2H6 and other silane gases were used as in the glow discharge decomposition method.

However, with silane gases such as SiH4 and Si2H6, when the deposition rate is increased, the deposited film tends to grow abnormally, making it difficult to deposit an A-Si(H) film with good electrical and photoconductive properties.

Furthermore, films deposited by thermal decomposition such as S i H4 and S i 2 H6 have a problem in that they have a large internal stress and are easily peeled off.

Furthermore, when a valence electron control agent is mixed with a deposited film forming substance such as SiH4,5i2Hs to form a deposited film with valence electrons controlled by thermal decomposition, the decomposition of the monovalent electron control agent is insufficient and the efficiency is low. There was a problem that good valence electron control was not performed.

[Purpose of the invention]

The present invention aims to solve the above problems.

Another object of the present invention is to produce a high-quality deposited VK film that ensures uniformity of electrical and optical properties and stability of quality even when forming a large-area, thick deposited film. The goal is to provide a method that can be used.

[Means to solve the problem]

The deposited film forming method of the present invention that achieves the above object provides thermal energy to a gaseous source material (shown in equation (1)) and a valence electron control agent introduced into a deposition chamber, and then placed in the deposition chamber. In the deposited film forming method of forming a deposited film on a support, the residence time (τ) of the gaseous source material and the valence electron control agent in the deposition chamber is 0.1 seconds≦τ≦50 seconds, and The atmospheric temperature (T) in the deposition chamber is 200°C≦T≦1000
℃, and further characterized in that the product of residence time (τ) and ambient temperature (T) satisfies 100 ['C seconds]≦τT≦30000 [°C seconds].

A aHbXc --- Formula (1) (where, A is an element selected from Si and Ge, X is a halogen atom, a, b, and c are positive integers, a≧2, and C#O.) The present invention is based on the investigation of the conventional deposition mechanism of SiH4 and Si2H6 by thermal decomposition.

As a result, they found that in the case of the deposited film formation method by thermal decomposition of the gaseous raw material, the residence time of the gaseous raw material in the deposition chamber is important in controlling the active species generated by the thermal decomposition. Ta. Residence time is closely related to atmospheric temperature within the deposition chamber. When the ambient temperature is high, it is desirable that the residence time be short.

However, even if the active species generated by thermal decomposition within the deposition chamber are controlled by the residence time and atmospheric temperature within the deposition chamber, it is insufficient to obtain a deposited film of good quality.

In order to obtain a high-quality deposited film, it is not enough for the active species generated by thermal decomposition in the deposition chamber to simply deposit on the support; it is also necessary to rearrange the active species on the support and prevent abnormal growth. prevention,
I discovered that a mechanism was necessary.

As a result of intensive studies as a gaseous raw material for generating active species having a mechanism for preventing active species rearrangement and abnormal growth as described above, it has been found that compounds containing halogen atoms are effective.

However, halogen-containing monosilanes and monogermanes cannot be used because of their high decomposition temperatures; halogenated silicon compounds containing two or more Si atoms and halogenated germanium compounds containing two or more Ge atoms are suitable.

The halogen-containing gaseous raw material generates halogen-containing active species through thermal decomposition, and the active species promotes the re-heading of the active species for forming a deposited film on the surface of the support, thereby preventing abnormal growth. It is considered that a good deposited film can be obtained.

Further, when a valence electron control agent is added to the deposited film forming substance to form a deposited film, it is necessary to sufficiently decompose the valence electron control agent before adding it to the deposited film. For this reason, it is necessary to make the residence time longer than when no valence electron control agent is added. The halogen atom-containing gaseous raw material is A
aHbXc (A: Si, Ge, X: halogen atom, a, b, c: positive integer a≧2°c#0) is effective.

Specifically, gaseous raw materials containing halogen atoms and silicon atoms include S i 2H2O, 5i2H5F, 5i2H4C
, S i 2 H4F 2 , S i H2C sentence F.

S i 2 H30 sentence 3.5i2H3F3.5i2H2
C sentence 4.5i2H2F4, 5i3H7CfL.

5i3) (7F, 5i3H6C cross 21Si3H6F2
, S i 3H5C, chain compounds such as 3,5i3H5F3, S i 4H7C, S i 4 H7F.

5i4H6Cu2, 5i4H6F2, 5i4H5C sentence 3
．． 5i4H5F3, 5i4H4F+.

5i4C sentence 4, S i 5H9O sentence, S i 5H
9F.

S i 5 HB C standing 2,5i5HaF2,5f5H
7Cu3.5i5H7F3,5i5H6F4゜S i
5 H60 sentence 4, S i 6) (10c standing 2 *
S l 6HLOF2 , S i 6HBCA4 , S
Cyclic compounds such as 18H8F4 are effective.

Further, as a gaseous raw material containing a halogen atom and a germanium atom, G e 2 CfLs is used.

Ge2F6, Ge2H5Cl,
G e 2 H5F.

Ge2H4Cu2, Ge2H4F2, Ge2H3C
Chain compounds such as L 3 , G e 2 H3F 3 are effective.

As the valence electron control agent, it is desirable to employ a compound containing an element of group IIIb of the periodic table or a compound containing an element of group Vb of the periodic table.

Specifically, as a valence electron control agent for introducing a group IIIb atom, B2H6 is used for introducing a boron atom.

B4H10, B5H9, B5H11, B6H10゜Bs
Boron hydride such as H12, BsHL4, BF3.

BCJL3. Examples include boron halides such as BBr3. In addition, AlCl3 and GaCl3.

Ga (CH3)3, I ncfL3, TC13, etc. can also be mentioned.

In the present invention, effective valence electron control agents for introducing Group Vb atoms include P for introducing phosphorus atoms.
Hydrogenated phosphorus such as H3, P2H4, PI-14I, PF3
, PF5, PC5L3.

PCl5. PBr3, PBr3. Examples include halogenated phosphorus such as PI3. In addition, AsH3.

A SF 3 , A S Cl 3 , A S
B r 3 , A S F 5 .

SbH3, SbF3. SbF5. Sb0 sentence 3゜sbc sentence 5. SiH3, 5iC13, B1Br3, etc. can also be mentioned as effective valence electron control agents for introducing Group Vb atoms.

In order to obtain a high-quality deposited film in which valence electrons are controlled by thermal decomposition by mixing the halogen atom-containing gaseous raw material and the valence electron controlling agent, it is necessary to adjust the residence time (τ) and the deposition chamber size. The ambient temperature (T) is preferably 0.1 seconds≦τ≦50 seconds, 200°C≦T≦tooo°C, too [”c seconds]≦
Tτ≦30000 ['C seconds], more preferably,
0.15 seconds≦τ≦30 seconds, 300℃≦T≦950℃, 2
It is desirable that 00 [seconds C]≦Tτ≦35000 [seconds'C].

FIG. 1 is a schematic diagram of a deposited film forming apparatus used in the deposited film forming method of the present invention.

The raw material for forming the deposited film and the valence electron control agent are in gas cylinder 1.
8, 19, 20.21 are filled. pressure gauge 2
2-1.22-2.22-3.22-4. Mass flow controller 24-1.24-2.24-3.24-4
The primary pressure of is monitored. Valve 23-1.23-2
゜23-3.23-4.25-1.25-2゜25-3
．． In step 25-4, a raw material for forming a deposited film is selected.

The support 11 in the deposition chamber 10 is maintained at a predetermined temperature by a heater 13 . Further, the temperature of the deposition chamber is maintained at a predetermined temperature by a heater 30 for heating the deposition chamber.

Thereafter, a raw material for forming a deposited film is introduced via the gas supply pipe 26. The internal pressure of the deposition chamber 10 is determined by the pressure gauge 3.
1 is monitored.

As described above, a deposited film is formed on the support 11 by thermal decomposition. The exhaust gas is discharged outside the system via a pipe 29 by a pump (not shown).

The support used in the present invention may be electrically conductive or electrically insulating, as long as it is selected as desired depending on the use of the deposited film to be formed. As the support, for example, NiCr, stainless steel, A
fl, Cr.

Mo, Au, Ir, Nb, Ta, V, Ti.

Examples include metals such as pt and pb, and alloys thereof.

As the electrically insulating support, films or sheets of synthetic resins such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, glass, ceramic, etc. are usually used. Preferably, at least one surface of these electrically insulating supports is subjected to conductive treatment, and another layer is preferably provided on the conductive treated surface side.

For example, if it is glass, its surface is NiCr.

AM, Cr, Mo, Au, Ir, Nb, Ta.

V, Ti, PL, Pd, In2O3,5n02゜IT
Conductive treatment is performed by providing a thin film such as O (I n 203 + S n O2), or if it is a synthetic resin film such as polyester film, NiCr, AM,
Ag, Pb, Zn, Ni.

Au, Cr, Mo, Ir, Nb, Ta, V.

The surface is treated with a metal such as Ti or Pt by vacuum evaporation, electron beam evaporation, sputtering, etc., or laminated with the metal to make the surface conductive. The shape of the support may be any shape, such as a cylinder, a belt, or a plate, and the shape is determined as desired.

It is preferable to select the support from among the above in consideration of the adhesion and reactivity between the support and the membrane.Furthermore, if the difference in thermal expansion between the two is large, a large amount of distortion will occur in the membrane, making it difficult to maintain good quality. Since a film may not be obtained in some cases, it is preferable to select and use supports whose thermal expansion differences are close to each other.

In addition, the surface condition of the support is directly related to the structure (orientation) of the membrane and the formation of cone-shaped structures, so the surface of the support must be treated to obtain the membrane structure and structure that will provide the desired properties. It is desirable to do so.

Hereinafter, the uninvention will be specifically explained according to Examples.

Example 1 Using the deposited film forming apparatus shown in FIG. 1, a deposited film was created by the deposited film forming method of the present invention under the conditions shown in Table S1 and Table 2.

As a comparative example, the results for S i 2 H6 are also shown in Table 1.

The activation energy shown in Table 1 was determined from the temperature dependence of dark conductivity.

According to the method of the present invention, the doping efficiency was improved. Example 2 Using the deposited film forming apparatus shown in FIG. 1, a solar cell having a deposited layer whose valence electrons were controlled by the deposited film forming method of the present invention did.

The structure of the solar cell is as shown in FIG. 2, on a glass support 200 coated with a transparent electrode, a P-type amorphous silicon layer (201), an i-type amorphous silicon layer (202), an
It consists of an amorphous silicon layer (203) and an Al electrode 204.

The solar cell of this example was created under the conditions shown in Table 3.

The first p-type amorphous silicon layer and the third n-type amorphous silicon layer were deposited by the deposited film forming method of the present invention.On the other hand, the second i-type amorphous silicon layer was formed using SiH4 It was formed by a deposition method that utilizes an oxidation reaction caused by F2 gas. (SiH4 and F2 were separately introduced into the composting chamber (not shown)) The solar cell formed as described above had a conversion efficiency improved by 16% compared to the conventional solar cell.

Example 3 Using the deposited film forming method shown in FIG. 1, an electrophotographic image forming member having the structure shown in FIG. 3 was produced under the conditions shown in Table 4.

The electrophotographic imaging member shown in FIG. a first p-type amorphous silicon layer 302 on the L support 300; Second
layer i-type amorphous silicon layer 303, third layer surface layer 30
It consists of 4.

The first p-type amorphous silicon layer is formed by the deposited film forming method of the present invention, and the second and third layers are F2 of SiH4 and CH4.
Formed by gas oxidation reaction.

When the charging ability of the electrophotographic image forming member formed as described above was measured, it was found to be improved by 20% compared to the conventional one. Furthermore, the dark decay was improved by 30%.

Example 4 Using the deposited film forming method shown in FIG. 1 and under the conditions shown in Table 5, a thin film transistor having the structure shown in FIG. 4 was fabricated.

The thin film transistor shown in FIG.
0, a first layer of amorphous silicon layer 401, a second layer of n-type amorphous 9937 layer 402, a third layer of amorphous silicon oxide layer 403, and an A-shaped electrode 405 are stacked. .

A second n-type amorphous layer 402 was deposited by the deposited film forming method of the present invention.

The first layer and the third layer were fabricated by a gas contact method using an oxidation reaction between SiH+ and F2.

The thin film transistor manufactured as described above had an SN ratio improved by 12% compared to the conventional one.

〔effect〕

From the above detailed explanation and each example, it is clear that according to the method of forming a deposited film of the present invention, 1. It is possible to achieve energy saving, easy control of film quality, and uniform physical properties over a large area.
A membrane is obtained. Furthermore, it is possible to easily obtain a film with excellent productivity and mass production, and with high quality and excellent physical properties such as electrical, optical, and semiconductor properties.

[Brief explanation of drawings]

FIG. 1 schematically shows an apparatus for producing a deposited film according to the method of the present invention. FIG. 2 is a schematic cross-sectional view of a solar cell produced by the deposited film forming method of the present invention. FIG. 3 is a schematic cross-sectional view of an electrophotographic image forming member produced by the deposited film forming method of the present invention. FIG. 4 is a schematic cross-sectional view of a thin I-transistor fabricated by the deposited film forming method of the present invention. lO: Deposition chamber 11; Support 12; Support base 13: Heater 14.31: Conductor 15-1.15-2: Gas leak 18.19.20, 21: Gas supply source 22-1.22- 2.22-3.22-4: Pressure gauge 23-1.23-2.23-3.23-4 = Valve 24-1.24-2.24-3.24-4: Flow meter 25-1 .25-2.25-3.25-4: Valve 26.26-1. 26-2.26-3.26-4 = Gas inlet pipe 27.31: Pressure meter 28; Regulator valve 29: Gas exhaust pipe 30: Deposition chamber heater 200...Glass support (with transparent electrode) 201...
・First layer (p-type amorphous silicon) 202...Second layer (
i-type amorphous silicon) 203...Third layer (n-type amorphous silicon) 300...A-pattern substrate 302...first layer (p-type amorphous silicon) 303...
・Second layer (i-type amorphous silicon) 304--Third layer (
a-5iC) 400... Glass support 401... First layer (amorphous silicon) 402... 273rd (n/amorphous silicon) 403... Third layer (insulating layer)

Claims (5)

[Claims] (1) Applying thermal energy to the gaseous source material (shown in equation (1)) introduced into the deposition chamber and the valence electron control agent to form a deposited film on the support placed in the deposition chamber; In the deposited film forming method, the residence time (τ) of the gaseous source material and the valence electron control agent in the deposition chamber is 0.1 seconds≦τ≦50 seconds, and the atmospheric temperature (T) in the deposition chamber is 200℃≦T≦1000℃
Furthermore, the product of residence time (τ) and ambient temperature (T) is 1
00 [°C seconds]≦τT≦30000 [°C seconds]. A_aH_bX_c...Formula (1) (where A is an element selected from Si, Ge, X is a halogen atom, a, b, c are positive integers (a≧2), c≠
It is 0. ) (2) The method for forming a deposited film according to claim 1, wherein at least two types of gaseous raw materials of the Si-containing gaseous raw material and the Ge-containing gaseous raw material are introduced into the deposition chamber. (3) The Si-containing gaseous raw material has a chain shape (2≦a≦6
, b+c=2a+2). The deposited film forming method according to claim 1. (4) The Si-containing gaseous raw material is cyclic (a≦6, b
+c=2a) The deposited film forming method according to claim 1. (5) The method for forming a deposited film according to claim 1, wherein the valence electron control agent is a compound containing a group IIIb element or a group Vb element of the periodic table.