JPS6042766A - Formation of deposited film - Google Patents

Abstract

PURPOSE:To maintain a good film characteristic without using plasma reaction and to increase the rate of deposition by introduction separately an active seed obtd. from a specific silicon halide and a mixture of active seed botd. from a silane compd. and hydrogen into a deposition space and forming deposited films on a substrate. CONSTITUTION:An active seed (a) obtd. by decomposing the silicon halide expressed by Six2n+2(n=1, 2-) and a mixture composed of an active seed (b) obtd. from a silane compd. having a cyclic structure of silicon and an active seed of hydrogen are respectively separately introduced into a deposition space 1 and deposited films are formed on a substrate 101. The active seeds (a), (b) and H active seed are formed by introducing gaseous raw materials of the kinds, amt., etc. meeting the characteristics required for the deposited films, for example, an itermediate layer 102, a photoconductive layer 103, a surface layer, etc. into decomposition spaces 2, 3 and exciting the same by excitation energy such as heat, light or the like. Such seeds are introduced into the space 1 and are used for formation of the deposited films. The active seeds (a), (b) are formed in the spaces 2, 3 separate from the space 1 in the abovementioned way and since no plasma is used, the equipment is simplified and the rate of deposition is increased, by which mass production is made easy and the good film characteristic is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a functional film, particularly a deposited film useful for applications such as semiconductor devices or photosensitive devices for electrophotography.

Examples: Formation of Evaporative Amorphous Silicon Film Kid, vacuum evaporation method, plasma CVD method, C'VD method, reactive sputtering method, ion blasting method, photo-CVD method, etc. have been tried, and generally the plasma CVD method is used. is widely used and commercialized.

In both years, deposited films composed of amorphous silicon have excellent electrical and optical properties, fatigue properties during repeated use, use environment properties, and productivity, including uniformity and reproducibility.
In terms of mass production, there is room to further improve the overall characteristics.

The reaction process in forming an amorphous silicon deposited film by the conventionally popular plasma CVD method is considerably more complicated than that of the conventional CVD method, and there are many aspects of the reaction mechanism that are unclear. In addition, there are many formation parameters for the deposited film (e.g., substrate temperature, flow rate and ratio of introduced gas, pressure during formation, high frequency power, electrode structure 1 reaction vessel structure, pumping speed, plasma generation method, etc.). Due to the combination of many parameters, the plasma sometimes becomes unstable, which often has a significant adverse effect on the deposited film formed. Furthermore, the actual situation is that parameters unique to each device must be selected for each device, making it difficult to generalize manufacturing conditions.

On the other hand, it is electrically active as an amorphous silicon film.

In order to develop optical properties that can satisfy each application by +1 minute, it is currently considered best to form by plasma CVD.

Depending on the application of the deposited film, it is necessary to fully satisfy the requirements of large area, uniform film thickness, and uniform film quality, and to achieve mass production with reproducibility. In the formation of deposited films, a large amount of equipment investment is required for mass production equipment, and the management items for mass production are also complicated. This has been pointed out as an issue that should be improved in the future.

On the other hand, the conventional technique using the normal CVD method requires high humidity and has not been able to provide a deposited film with practically usable characteristics.

As mentioned above, in forming an amorphous silicon film, there is a strong desire to develop a method of forming an amorphous silicon film that can be mass-produced using low-cost equipment while maintaining its practically usable characteristics and uniformity.

The same can be said of other functional films, such as silicon nitride films, silicon carbide films, and silicon oxide films.

The present invention eliminates the drawbacks of the plasma CVD method described above, and at the same time provides a new method for forming a deposited film that does not rely on conventional forming methods.

The purpose of the present invention is to maintain the characteristics of a film formed without using a plasma reaction in a deposition space (A) in which a deposited film is formed, to improve the deposition rate, and to simplify the management of film forming conditions. The objective is to easily achieve mass production of membranes.

In the present invention, 5inX, H+2 (n=1.2.--) is placed in a deposition space for forming a desired deposited film on a desired substrate.
Introducing separately an active species (a) obtained by decomposing a silicon halide represented by , an active species (b) obtained from a silane compound having a silicon cyclic structure, and a mixture of hydrogen active species. The method is characterized in that a deposited film is formed by doing so.

In the method of the present invention, a deposition space (
7V) and does not use plasma, the formation parameters of the deposited film are the amount of active species introduced, the temperature in the substrate and the deposition space, and the internal pressure in the deposition space, and therefore the deposited film formation can be easily controlled. A deposited film can be formed with reproducibility and mass production.

In the present invention, the decomposition space CB introduced into the deposition space (A)
), those having a lifetime of 150 seconds or more are selected and used as desired, and the constituent elements of this active species constitute the main components constituting the deposited film formed in the deposition space (A). Become something. Furthermore, the active species introduced from the decomposition space (C) have a short lifespan. When this active species forms a deposited film in the deposition space (A), it is simultaneously introduced into the deposition space (A) from the decomposition space (B), and active species containing constituent elements that will be the main components of the deposited film to be formed are introduced into the deposition space (A) from the decomposition space (B). chemically interacts with As a result, a desired deposited film can be easily formed on a desired substrate.

According to the method of the present invention, plasma is not generated in the deposition space (A), and thus the deposited film that is formed is substantially not affected by etching effects or other adverse effects such as abnormal discharge effects.

Further, according to the present invention, a more stable CVD method can be achieved by arbitrarily controlling the atmospheric temperature of the deposition space (A) and the substrate temperature as desired.

One of the differences between the method of the present invention and the conventional CVD method is that active species activated in advance in a space different from the deposition space (A) are used.

As a result, the deposition rate can be dramatically increased compared to the conventional CVD method, and in addition, the substrate temperature during deposition film formation can be further lowered, resulting in a deposited film with stable film quality. can be provided industrially in large quantities and at low cost.

In the method of the present invention, by using a silane compound having a cyclic structure as the raw material gas introduced into the decomposition space (C), the decomposition rate when decomposing into active species can be greatly improved, and the decomposition can be reduced. It can be done with energy.

Furthermore, compared to the conventional method, the deposition rate when forming a deposited film can be dramatically improved. Therefore, the deposited film can be formed stably and mass-produced easily.

In the present invention, the raw material introduced into the decomposition space (B) has the general formula 5inX2n+2 (n: □, 2.1.-
, ), for example, SiF, , Si,
F6.5i3F, .

Examples include S'2cls*S'tClsFs.

Active species are generated by adding decomposition energy such as heat, light, and discharge to the above-described material in the decomposition space (B).

In this case, it is necessary that the active species have a lifetime of 150 seconds or more to promote the increase in deposition efficiency and deposition rate.
To increase the efficiency of the activation reaction with the active species introduced from the decomposition space (C), if necessary, heat, light, etc. may be applied in the deposition space or on the substrate without using discharge energy such as plasma. Formation of the desired deposited film is achieved by applying energy of .

In the present invention, the raw material introduced into the decomposition space (C) to generate active species is a silane compound having a silicon cyclic structure, such as (SiHt)s-(SiH, ),
(SiH,), (SiH,), 54H-8LH8
Alternatively, a combination of hydrogen and a higher-order chain silane compound, or SiH4 may be used.

In the present invention, the ratio of the amount of active species introduced from the decomposition space (B) to the amount of active species introduced from the decomposition space (C) in the deposition space (A) depends on the deposition conditions.

It is determined by the type of active species, etc., but it is 10:1 to 1:10.
(Introduction and exclusion ratio) is appropriate, and preferably 8:2 to 4:6.

In the present invention, as a method for generating active species in the decomposition space (B) and the decomposition space (C), excitation energy such as discharge energy, thermal energy, light energy, etc. is used in consideration of Fi, each condition, and equipment. be done.

Next, the present invention will be explained with reference to a typical example of an electrophotographic image forming member formed by the deposited film manufacturing method of the present invention.

FIG. 1 is a schematic diagram for explaining an example of the structure of a typical photoconductive member obtained by the present invention.

A photoconductive member 100 shown in FIG. 1 can be applied as an electrophotographic image forming member, and includes an intermediate layer 102 and a surface layer provided on a support 101 for use as a photoconductive member, if necessary. It has a layered structure composed of a layer 104 and a photoconductive layer 103.

The support 101 may be electrically conductive or electrically insulating. Examples of the conductive support include NiCr, STYS, Kl, Cr, Mo,
Au.

Examples include metals such as Ir, Nb, Ta, V, Ti, Pt, and Pd, and alloys thereof.

Polyester is used as an electrically insulating support.

polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride.

Films or sheets of synthetic resins such as vinylidene chloride, polystyrene, polyamide, and glass.

It is preferable that at least one surface of an electrically insulating support such as ceramic, paper, etc., which is usually used is electrically conductive treated, and that another layer is provided on the electrically conductive treated surface side. .

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

Ae, Cr, Mo, Au, Ir, Nb, Ta
, V, Ti, Pt, Pd.

In2O,, 8nOt, ITO(In2O, + Sn
Providing a thin film such as O, ) 1. If it is conductive treated or a synthetic resin film such as polyester film, NiCr, Al2, Ag, Pb
, Zn, Ni, Au, Or, Mo
, Ir.

The surface is treated with a metal such as Nb, Ta, V, 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. For example, the photoconductive member lOO shown in FIG. If it is to be used as a member for continuous high-speed copying, it is desirable to have an endless belt shape or a cylindrical shape.

The intermediate layer 102 is made of a non-photoconductive amorphous material containing, for example, silicon atoms and carbon atoms, nitrogen atoms, oxygen atoms, or halogen atoms (X), and is
This effectively prevents carriers from flowing into the photoconductive layer 103 from the side of the photoconductive layer 103 and prevents photocarriers generated in the photoconductive layer 103 and moving toward the side of the support 101 by electromagnetic wave irradiation. It has a function of easily allowing passage from the side to the side of the support body 101.

When forming the intermediate layer 102, it can be performed continuously up to the formation of the photoconductive layer 103.

In that case, the raw material gas for forming the intermediate layer is mixed with a diluting gas such as He or Ar at a predetermined mixing ratio as needed, and each is mixed in a predetermined decomposition space (B) and decomposition space (C). ) and apply desired excitation energy to each space to generate each active species, and introduce them into the deposition space (A) for vacuum deposition where the support 101 is installed. Intermediate Fi is formed on the support 101 by the action of each activated species.
z 102 may be formed.

An effective starting material for generating active species is introduced into the decomposition space (C) which can be effectively used as a raw material gas for forming the intermediate layer 102.

H,, a silane compound having a silicon cyclic structure containing Si and H as constituent atoms, for example, (St)(,).

(SiH2) or them and hydrogen and 5i2H,
.

those used in combination with higher-order chain silanes such as st, H, or 8iH, those containing N as a constituent atom, or those containing N and H as constituent atoms, such as nitrogen (Nx), ammonia (N) I
), hydrazine (H2NNH2), hydrogen azide (H
N, ), gaseous or gasifiable nitrogen such as ammonium azide (NH4N3), nitrogen compounds such as nitrides and azides, saturated hydrocarbons containing C and H as constituent atoms, e.g. having 1 to 5 carbon atoms, Ethylene hydrocarbons having 2 to 5 carbon atoms, acetylenic hydrocarbons having 2 to 4 carbon atoms, etc. Specifically, saturated hydrocarbons include meta y (C) t, ), engineering p
y (C, H6), 7”.

Bread (C, H,), n-buta 7 (n C+H+o
)e Pentane (C3H,t), ethylene hydrocarbons include ethylene (CtL)-propylene (C-He)-
Butene-1(C4H3)-Butene-2(C4HII)
-isobutylene (C4H3)-pentene (C,H,.)
, acetylene hydrocarbons include acetylene (C, H
Methylacetylene (C-H4)-butyne (C4H6)
) etc. In addition to these, for example, oxygen (02), ozone (0,), -carbon oxide (CO)S carbon dioxide (COJ
- Nitric oxide (NO).

Nitrogen dioxide (NO2), dinitrogen oxide (N, O), etc. can be mentioned.

These starting materials for forming the intermediate layer 102 are appropriately selected and used during layer formation so that predetermined atoms are included in the formed intermediate layer 102 as constituent atoms.

On the other hand, the starting material that can be introduced into the decomposition space (B) and generate active species when forming the intermediate layer 102 is Si.
F4.84. Effective examples include F', etc., which easily generate active species such as Sir at high temperatures.

The thickness of the intermediate layer 102 is preferably 3O-10
It is desirable that it be 0OA, more preferably 50 to 6oooλ.

The photoconductive layer 103 is made of silicon atoms, contains halogen (X), and optionally contains a halogen (X) so as to have photoconductive properties that can fully exhibit its function as a photoconductive member for electrophotography. It is composed of amorphous silicon a-8iX (H) containing hydrogen (H). Similarly to the intermediate layer 102, the photoconductive layer 103 is formed in the decomposition space (B) K S
iF, Si, F, fz and cr) raw material gases are introduced and activated species are produced by decomposing them at high temperatures. This active species is introduced into the deposition space (A). On the other hand, in the decomposition space (C), (SiHt)a, (S'H2)
A raw material gas such as 41 (S'H2)a is introduced, and active species are generated by a predetermined excitation energy. This active species is introduced into the deposition space (A) and chemically interacts with the active species from the decomposition space (B) to form the desired photoconductive layer 10.
3 is deposited.

The thickness of the photoconductive layer 103 is appropriately determined according to the purpose of the application.

The layer thickness of the photoconductive layer 103 shown in FIG. It can be determined as appropriate and desired, and in normal cases, it is preferably several hundred to several thousand times or more thicker than the thickness of the intermediate layer 1020.

A specific value is preferably in the range of 1 to 100μ, more preferably in the range of 2 to 50μ.

l contained in the photoconductive layer of the photoconductive member shown in FIG. 1]
Or M of X (halogen atom such as X=F) is preferably 1 to 40 atomic 9i; more preferably 5 to
It is preferable to set it to 30 atomlc%.

The surface layer 104 of the photoconductive member shown in FIG. and is formed in the same manner as the photoconductive layer 103. If there is a silicon carbide membrane, for example, the decomposition space (B)
5iF4 into one decomposition space (C) (SiH2), and C and H2 or (Sil(,), and 5iH2(CH,)
The surface layer 1 is formed by introducing raw material gases such as 2 and 2, excitation with decomposition energy to generate respective active species in the respective spaces, and introducing them separately into the deposition space (A).
Further, as the surface layer 104, a deposited film with a wide band gap such as silicon nitride or silicon oxide film is preferable, and the film composition may be changed continuously from the photoconductive layer 103 to the surface layer 104. It is possible. surface layer 1
The layer thickness of 04 is preferably in the range of 0.01μ to 5μ, more preferably in the range of 0.05μ to 1μ.b To make the photoconductive layer 103 n-type or p-type as necessary, during layer formation. This is accomplished by doping an n-type impurity, or both impurities, into the layer to be formed while controlling the amount thereof.

The impurities doped into the photoconductive layer include elements of group A of the periodic table, such as B, as n-type impurities,
, kl, Ga, In, 'r/, etc. are preferred, and as the n-type impurity, elements of Group V A of the periodic table, such as N, P, As, Sb, Bi, etc. are preferred. However, especially B.

Ga, P, Sb, etc. are optimal.

In the present invention, the photoconductive layer 10 has a desired conductivity type.
The amount of impurities to be doped into 3 is appropriately determined depending on the desired electrical and optical properties, but in the case of impurities in group Ⅰ A of the periodic table, the amount range is 3 x 10 atomic% or less. All you have to do is dope, and the periodic table ■
In the case of group A impurities, 5 X 10, atomi
Doping may be carried out in an amount of c% or less.

To dope impurities into the photoconductive layer 103, j-
At the time of formation, a raw material for introducing impurities may be introduced in a gaseous state into the decomposition space (B) or (C). In that case, instead of the decomposition space (B), the decomposition space (C)
It is preferable to introduce the active species into the deposition space (A) from there. As the raw material for introducing such impurities, those that are in a gaseous state at room temperature and normal pressure, or that can be easily gasified at least under layer-forming conditions, are employed.

Specifically, as a starting material for introducing impurities, P
HHt PJ (4, PF3, PF5 e PCl5
*AsH++ *AsF55AsF, , As
Cl! , , SbH,, SbF, , 13iH,,
BF, , BCl! , ,BBr,.

B2Flla, B<Hlo-BJ(o, BsHu,
Examples include BaH+o, ``aH+y, AlCl5*, etc.

Example 1 Using the apparatus shown in FIG. 2, a drum-shaped electrophotographic image forming member was produced by the following operations. In FIG. 2, l is a deposition space (A), s is a decomposition space (13), 3 is a decomposition space (C), 4 is an electric furnace, 5 is a solid Si particle, 6 is an Si-well introduction pipe, 7 is an active species introduction pipe,
8 is an electric furnace, 9 is an active species raw material introduction tube, IO is an active species introduction tube, 11 is a motor, 12 is a heating heater, 13
14 is a blowout pipe, 15 is an M cylinder, and 16q is an exhaust pulp.

An M cylinder 15 is suspended in the deposition space (A) 1 and equipped with a heating heater 12 inside, so that it can be rotated by a motor 11, and the active species from the decomposition space (B) 2 are introduced through the introduction pipe 7. , the blowout pipe 13, and the decomposition space (C
) A blowout tube 14 is provided through an introduction tube 10 for introducing active species from 3.

The decomposition space (B) 2 is filled with 81 solid particles 5, heated in an electric furnace 4, maintained at 1100°C to melt Si, and 1% Si is injected into it from a cylinder through an SiF introduction pipe 6. , SiF, are generated and introduced into the blow-off pipe 13 of the deposition space (A) 1 via the introduction pipe 7. On the other hand, (SiH2
) a was introduced, heated to 300°C in an electric furnace 8, and S
Active species such as iH, SiH, SiH, and H are generated and introduced from the inlet tube 10 to the blowout tube 14. At this time, the length of the introduction tube 10 is shortened as much as possible based on the equipment, so as not to reduce the effective efficiency of the active species. Deposition space (
The M cylinder in A) is heated and maintained at 280° C. by a heater 12 and rotated, and exhaust gas is exhausted through an exhaust pulp 16. In this way, the photoconductive layer 103 is formed, and the intermediate layer 102 and surface layer 104 are also formed in the same way.

Example 2 Using a general plasma CVD method, Sig and SiH
4 and H7 to the deposition space (A) 1 in Figure 2 to 13.
A photoconductive layer 103 was formed using a 56 MHz high frequency device.

Example 3 A deposited film is formed in the same manner as in Example 1 and '1, but the decomposition space (
C) The raw material gas introduced into 3 is 3iH4 and (SiH,).

13.56M instead of heating by electric furnace.
Generates a Hz plasma reaction and creates a plasma state,
The active species of various silanes and the active species of H were introduced into the blowing tube 14 to produce a drum-shaped electrophotographic image forming member.

Example 4 A deposited film is formed in the same manner as in Example 1, but the decomposition space (C)
The raw material gas introduced into (S 'Ht) < s (8'H
A drum-shaped electrophotographic image forming member was prepared by heating the sample to 320° C. in an electric furnace to generate various active species of silane and active species of hydrogen.

Example 5 A deposited film is formed in the same manner as in Example I, but the decomposition space (13
), and the raw material gas introduced into the decomposition space (C) is (SiH,)5, s'
rll: It was heated to 300° C. in an air furnace to generate active species of various silanes and active species of hydrogen, thereby producing a drum-shaped electrophotographic image forming member.

Example 6 A deposited film is formed in the same manner as in Example, but the decomposition space (C) is
The raw material gas to be added to Si, I circle/(Sil(,).

The mixture was heated to 310° C. in an electric furnace to generate active species of various silanes and active species of hydrogen, thereby producing a drum-shaped electrophotographic image forming member.

Table 1 shows the manufacturing conditions and performance of the drum-shaped electrophotographic image forming members of Examples 1, 2, 3, 4, 5, and 6 described above.

Examples 1, 3, 4, 5. ．． The intermediate layer 102 of 6 is SiH2 in the decomposition space (B) and (SiH2) in the decomposition space (C).
) a/H2/NO/) 132H, (No 2% in volume %)
, B, H60.2%) are respectively introduced to generate active species with each excitation energy, and introduced into the deposition space (A) to form the intermediate layer 102. The thickness of the intermediate layer 102 is 2'000.

In the case of Example 2, (S +
The intermediate layer 102 is formed by plasma CVD using gases such as H, ), /Ht /N O / B2H6, and its layer thickness is set to 2000 layers.

In the surface layer 104 of Examples 1, 3, 4, and 5.6, SiF was introduced into the decomposition space (B), and (C) was introduced into the decomposition space (C).
SiH, ) S/C1 (4/H, capacity ratio 10:100:
50, active species are generated by each excitation thermal energy, and are introduced into the deposition space (A) to form the surface layer 104, with a layer thickness of 1000 μm.

In the case of Example 2 as well, (SiH2)II /CH, /Hz with the same composition is introduced, and the surface layer 104 is formed by plasma CVD, and the layer thickness is set to lOO0.

The drum-shaped electrophotographic image forming members of Examples 1, 2, 3, 4, and 5.6 were charged, exposed, and transferred.

In the Carlson process, it is attached to a copying machine using a heat fixing method using θ toner, and A3 size copies are made of full dark areas, full bright areas, or full halftone areas.
The average number of image defects is the observation as to whether non-uniform noise occurs in the image. At that time, the uniformity of the received potential in the circumferential direction of the drum and in the generatrix direction was also measured.

These results are shown in Table 1.

Embodiment 7 In FIG. 3, J7 indicates 14 mobile units equipped with a rotation mechanism, 18 a cooling space, 19 a heating space, and 20 a deposition space.

As shown in FIG. 3, this embodiment consists of a heating chamber 19, a deposition space 20, and a cooling chamber 18. In each space, an M cylinder 15 is placed on a movable stand 17 equipped with a rotating mechanism.
This is an apparatus in which a large number of drum-shaped electrophotographic image forming members are continuously produced in one deposition space. Using this device, we attempted a production method similar to Example 1, and found that the temperature of the deposition space, the temperature of the Ae cylinder, the temperature of the deposition space, the temperature of the Ae cylinder, the temperature of the decomposition space (B) from the blowout pipe 13 via the inlet pipe 7, and the decomposition space. (C
) By controlling the flow of active species from the inlet pipe 10 and the outlet pipe 14 to e, a drum-shaped electrophotographic imaging member having a uniform and reproducible deposited film can be produced. It was confirmed that it can be mass-produced at low cost.

In the plasma CVD method, when trying to create a large number of drum-shaped electrophotographic image forming members in one deposition space, synergistic effects of complex parameters such as discharge uniformity and manufacturing conditions are required. Therefore, it has been impossible to create a drum-shaped electrophotographic image forming member having a uniform deposited film with good reproducibility.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a layered structure for explaining one embodiment of a light guide member produced using the method of the present invention. FIG. 2 is a schematic explanatory diagram showing an example of an apparatus for implementing the manufacturing method of the present invention. FIG. 3 shows a specific example of equipment showing that the manufacturing method of the present invention can be industrially produced in Europe. A −−+ month,
- 1...Deposition space (A), 2...Decomposition space (B), 3
...Decomposition space (C), 4...Electric furnace, 5...Solid S
i grain, 6... SIF''4 introduction pipe, 7... Precursor introduction pipe, 8... Electric furnace, 9... Active species raw material introduction pipe, 10... Activity, JJii Inlet pipe, 11...Motor, 12...Heating heater% 13...Blowout pipe, 14...Blowout pipe, 15...Blowout cylinder, 16...Exhaust valve, 17 River rotation mechanism ( liff
18... Cooling space, 19... Heating space, 20... Deposition space, 100... Photoconductive section, 101... Support, 102... Intermediate layer , 103・
...Photoconductive layer, 104...Surface layer.

Claims (1)

[Claims] "'nx2n+2 (n == 1.2.....
), a mixture of an active species (a) obtained by decomposing a silicon halide, an active species (b) obtained from a silane compound having a silicon cyclic structure, and an active hydrogen species, respectively. A deposited film forming method characterized by forming a deposited film by separately introducing the deposited films.