JPS63234516A - Formation of thin film multilayer structure - Google Patents

Abstract

PURPOSE:To obtain the multilayer structure having excellent interfacial characteristics by a method wherein a layer of semiconductor thin film, which is activated and subjected to forbidden band width control by bringing a specific precursor and a compound respectively into contact with a heating element having a catalytic effect for activation, is formed, and other one layer is formed by introducing a precursor and an activating species separately into deposition space. CONSTITUTION:The raw material substance to be used for formation of a deposition film containing, in a molecule, a kind of elements of halogene and hydrogen is introduced into film-forming space and/or the precursor grown from the raw material substance to be used for formation of a deposition film, is introduced into the activation space provided separately from the above-mentioned film-forming space. Said substance or the precursor is activated by the catalytic effect of the heating element consisting of a single substance or alloy of transition metal provided in the film-forming space, the precursor and/or the activating species to be used for formation of the deposition film is grown and the forbiden band width-controlled thin film is formed. Then other one layer is formed on a substrate as a deposition film by introducing a precursor and the activating species which performs interaction with the precursor separately. As a result, the interfacial characteristics of the thin film multilayer structure can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a thin film multilayer structure, such as a photovoltaic device, a thin film semiconductor device, a photosensitive device for electrophotography, etc.

(Prior Art) Conventionally, functional films, particularly amorphous or polycrystalline semiconductor films, have been formed using film formation methods that are individually suited from the viewpoint of desired physical properties and applications.

For example, if necessary, amorphous or polycrystalline non-single crystal silicon (rNON-5i (H, X
) J, especially when it represents amorphous silicon, it is abbreviated as r8-5i (H, Vacuum evaporation, plasma CV
D method, thermal CVD method, reactive sputtering method, ion blating method, optical CVD method, etc. have been tried, and in general, plasma CVD method is widely used and commercialized.

However, plasma CV, which has been popular for a long time,
The reaction process in forming a silicon-based deposited film using the D method is considerably more complicated than that of the conventional CVD method.
The reaction mechanism also has many unknown points. In addition, there are many formation parameters for the deposited film (for example, substrate temperature, flow rate and ratio of introduced gas, pressure during formation, high frequency power, electrode structure,
(reaction vessel structure, pumping speed, plasma generation method, etc.)
Due to the combination of these many parameters, the plasma sometimes becomes unstable, which often has a significant adverse effect on the deposited film formed. Moreover, it is necessary to select device-specific parameters for each device, making it difficult to generalize manufacturing conditions.

On the other hand, in order to develop a silicon-based deposited film that satisfies the electrical and optical characteristics for each application, it is currently considered best to form it by plasma CVD.

However, depending on the application of the silicon-based deposited film, it is necessary to achieve mass production with reproducibility by satisfying the requirements of large area, uniform film thickness, and uniform film quality. When forming a film, a large amount of capital investment is required for mass production equipment, and the control items for mass production are also complex, and the tolerance for control is narrow.
Since the adjustment of the device is also delicate, these have been pointed out as problems that should be improved in the future.

In addition, in the case of plasma CVD method, since plasma is directly generated by high frequency waves or microwaves in the deposition space where the substrate to be deposited is placed, the generated electrons and many ion species are This damages the film during the process, causing a decline in film quality and non-uniform film quality.

In particular, in the case of a semiconductor device having a multilayer structure, it is known that the state of the interface between each layer greatly influences the characteristics of the device.

For example, in photovoltaic devices, amorphous silicon is
In the case of a layer, two layers and an n layer are formed with the layer in between, and the formation conditions for each layer are different, such as raw material gas type, flow rate, plasma discharge intensity, pressure, etc., so when forming each deposited layer, In addition, the discharge may be stopped to perform complete gas exchange, the gas type, flow rate, and plasma discharge intensity may be gradually changed to provide variable layers, or each deposited layer may be formed in a separate deposition chamber. In this way, the interface conditions between the deposited layers are improved to improve device characteristics.

However, with any of these methods, if the surface of the already deposited film is again exposed to plasma discharge for forming the next deposited film in the process of stacking the second and subsequent deposited films, it will be damaged by the plasma. In order to receive
It cannot be said that the interface conditions between the deposited films have been improved satisfactorily, and no significant change or improvement in device characteristics was observed. In addition, various studies have been conducted on the optimal method for forming deposited films in order to improve the film characteristics of each deposited layer. However, when forming a thin film multilayer structure, each deposited layer is It is necessary to consider combinations of deposited film formation methods that take advantage of the characteristics of

[Problem that the invention seeks to solve]

The present invention has been made to solve the above-mentioned problems, and it is possible to improve the interface state of thin film multilayer structures such as photovoltaic elements, thin film transistors, and electrophotographic photoreceptors, while maintaining the characteristics of the elements. The object of the present invention is to provide a method for forming a thin film multilayer structure that can be mass-produced using inexpensive equipment and energy saving.

[Means for solving problems]

That is, the present invention provides a method for forming a thin film multilayer structure having a semiconductor thin film with a controlled bandgap, in which a halogen is added to a heating element made of a simple substance or an alloy of a transition metal element having a catalytic effect and provided in a film forming space. and/or a precursor produced from the deposited film forming raw material in an activation space provided separately from the film forming space. The forbidden band width is adjusted by contacting the compound containing the element that serves as the forbidden band width adjusting agent and activating it through a thermal dissociation reaction to generate precursors and/or active species that serve as raw materials for forming the deposited film. In order to form at least one layer of a controlled semiconductor thin film and at least one layer of another thin film, a precursor that is a raw material for forming a deposited film and an active species that interact with the precursor are separately introduced into a deposition space. It is characterized by being formed by

According to the above-described thin film multilayer structure and method for forming the same according to the present invention, a multilayer structure with good interfacial properties can be obtained, and the formation of each deposited layer improves the usage efficiency of raw material gas, and improves film thickness uniformity and film quality. By fully satisfying the uniformity of the data, management can be simplified and mass production can be achieved, and there is no need for large capital investments in mass production equipment.In addition, the management items for mass production have become clear, the management tolerance range has been widened, and the equipment has been improved. It is also easy to adjust.

The present invention will be explained in more detail below.

In the film forming space for forming a thin film with controlled bandgap according to the present invention, instead of generating plasma,
A raw material for forming a deposited film containing in its molecule at least one element selected from halogen and hydrogen in the film forming space and/or a material for forming the deposited film in an activation space provided separately from the film forming space. A precursor produced from a raw material is introduced, and the material or precursor is activated by the catalytic action of a heating element made of a single transition metal or an alloy provided in a film forming space to produce a raw material for forming a deposited film. A precursor and/or an active species is generated. Since a deposited film is thereby formed, the deposited film thus formed is not adversely affected by etching action or other adverse effects such as abnormal discharge action during film formation.

The precursors and/or active species that serve as the raw materials for forming the deposited film are generated by a thermal dissociation reaction catalyzed by a simple substance or an alloy of transition metals.
,: SiF2. : A radical such as 5iHF can be assumed as a starting material, and the reaction mechanism becomes extremely simple.

In addition, since plasma is not used in the film forming space, the parameters for forming the deposited film are the amount of introduced material for forming the deposited film, the temperature of the heating element and the base, the distance and position of the heating element from the base, and the pressure. Therefore, the conditions for forming a deposited film can be easily controlled, and a deposited film with reproducibility and mass production can be formed.

Note that the "precursor" in the present invention refers to something that can serve as a raw material for a deposited film to be formed. "Active species" means chemical interaction with the precursor, for example, giving energy to the precursor, or chemically reacting with the precursor to form a deposited film more efficiently. It refers to something that is responsible for making things possible. Therefore, the active species may contain constituent elements constituting the deposited film to be formed, or may not contain such constituent elements.

Furthermore, since precursors and/or active species containing at least one element among halogen and hydrogen can be generated near the substrate by the catalytic action of a single transition metal or an alloy,
The efficiency of raw material gas usage can be significantly improved.

In addition, since the means for activating the raw material gas is a heating element made of a single transition metal or an alloy, the shape of this heating element can be arbitrarily adjusted according to the size of the film formation surface of the substrate. A uniform deposited film can be formed over a large area even on a substrate with a complex shape.

Further, since the heating element made of a single transition metal or an alloy is located near the base, there is no particular restriction on the lifespan of the precursor and/or active species generated from the raw material gas.

It is desirable to select transition metals or alloys that are difficult to mix into the deposited film due to sublimation, scattering, etc. as the transition metals or alloys that serve as the heating element used in the present invention. It is necessary to choose activation conditions that are unlikely to cause contamination. Such materials include those found in the fourth part of the periodic table.
Mention may be made of metals and alloys of the elements of the period or the fifth and sixth periods, among which are IV and V.

Transition metals belonging to groups (1), (2), and (2) can be suitably used.

Specifically, for example, Tj, Nb, V, Cr,
Mo, W.

Fe, Zr, IH, Ta, Ni, Go, Rh
, Pt, Pd, Au, Mn.

Ag, Zn, Cd, Pd-8g, Ni
-Cr, W-Th, W-Re, W-Mo and the like.

In the invention, the distance from the substrate of the heating element made of a single transition metal or an alloy provided in the film forming space is determined in order to prevent damage to the substrate due to heat or to efficiently transfer the precursor to the substrate. Therefore, it is preferably 1 to 200 mm, more preferably 2 to 50 mm, and optimally 5 to 20 mm.

Further, in the present invention, the heating temperature of the heating element made of a single transition metal or an alloy provided in the film forming space is preferably 100°C to 3000°C, more preferably 200°C to 200°C.
The temperature is desirably 500°C, most preferably 500°C to 2000°C.

By selecting the shape of the heating element, such as linear, filament, mesh, flat plate, or honeycomb, the cross-sectional area of the precursor and/or active species can be changed. By controlling the reaction with active species, it is possible to produce a uniform deposited film that matches the shape of the substrate.

In the invention, the raw material gas for forming a deposited film containing in its molecules at least one element of halogen and hydrogen used for forming a thin film with a controlled bandgap has a main skeleton of silicon. Compounds, compounds with carbon as the main skeleton,
Examples include compounds having germanium as a main skeleton, hydrogen, hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, and the like.

These compounds are mixed and used as appropriate.

As the compound having silicon as the main skeleton, for example, a chain or cyclic silane compound and a compound in which some or all of the hydrogen atoms of the chain or cyclic silane compound are substituted with halogen atoms are used, and specifically, for example, As a linear silane compound] nH7n+z (n = 1.'2.3.
4.5.6.7.8), as a branched chain silane compound, 5iH3SfH(SjH:lI) SiH2Si
H3, Si, 821 (n
= 3.4.5.6), and a chain halogen represented by 5iuY2u+2 (u is an integer of 1 or more, Y is F, (at least one element selected from J, Br, and I) silicon oxide, 5ivY2v (v is an integer of 3 or more,
Y has the meaning given above. ), 5iJXY, linear or cyclic silicon compounds represented by (u and Y have the above-mentioned meanings, x+y=2u or 2u+2), and the like.

Specifically, for example, SiF4, (SiF2)5,
(SiF2)6.

(SiF2)4, 5i7F6, 5i3FB, 5
jHF3, SiH2F2゜5iCA4, (S
iCl2)5, 5iBr,1, (SjBT2)5
．． 5i2CI6Sf2ET6.5iHG13.5iH2
G12, 5iHBr3.5iHI3.

5i2C13F3.5i2H3F3, 5i2H7F4
, 5i7H3CI3°5i282C14, etc., or those that can be easily gasified.

These silicon compounds may be used alone or in combination of two or more.

Examples of the compound containing the forbidden band widening element used in the wood invention include carbon-containing compounds, oxygen-containing compounds, nitrogen-containing compounds, and the like.

Specifically, as the carbon-containing compound, for example, a chain or cyclic hydrocarbon compound and a compound in which some or all of the hydrogen atoms of the chain or cyclic hydrocarbon compound are replaced with halogen atoms are used, and specifically, , for example, CTIH
Saturated and unsaturated hydrocarbons represented by 2n+2 (n is an integer of 1 or more), ++Ln+1 (n is an integer of 1 or more), cn)l, n (n is an integer of 1 or more), or CtaY
2u+2 (u is an integer greater than or equal to 1, Y is F, CI, Br
and at least one element selected from I. )
Chain halogenated carbon represented by CvY2V (V is an integer of 3 or more, Y has the above-mentioned meaning), cyclic silicon halide, c, nXy, (u and Y have the above-mentioned meaning). x+y=2u or 2u+2), etc.).

Specifically, for example, CF4. (CF2) Ri, (GFz
)6°(OF2)4. [l:2F6. C3F8.
CHF3. CH2F2. cc, 4゜ccc+2)
, , CBr4. (CBr2),, ,
c, ct6. C2Br6.

C8013, OH, +GI2, CHI3, C
H+T2, 13F3 on C2.

Examples include those that are in a gaseous state or can be easily gasified, such as C2H3Fa and C2H2F4.

These carbon compounds may be used alone or in combination of two or more.

As the oxygen-containing compound, 02. CO2, NO.

NO7, N, 0.03. Go, H20, GH30H
, (:H3CH2).

Examples of nitrogen-containing compounds include H7, Nl+3. N2H5
N3°N2 H4, NHJ 3, etc. can be mentioned.

Effective examples of the compound containing forbidden band convergence/eleven elements used in the present invention include germanium compounds and tin compounds.

Specifically, as a compound having germanium as a main skeleton, for example, a chain or cyclic germanium hydride compound and/or
A compound in which part or all of the hydrogen atoms of an In-like or cyclic germanium compound is replaced with a halogen atom is used,
Specifically, for example, a chain germanium halide represented by GeuY2u+ (u is an integer of 1 or more, Y is at least one element selected from F, CI, Br, and I), GevY2v ( v is an integer of 3 or more, Y
has the meaning given above. ), a linear or cyclic compound represented by GeuHxY y (u and Y have the above-mentioned meanings; X+V==2u or 2u+2), and the like.

Specifically, for example, GeH4, Ge2H6, GeF4.

(GeF2)5 , (GeF2)r, , (GeF
2) 4, Ge2F6.

Ge3FB, Ge liver 3, GeH2F2. Ge
CI4, (GeCI2)51GeBr4, (
Ge2Er6)5. Gc2CI6. Ge2Er6.
GeHGI3゜GeH2CI2, Ge1
(8-3. GeHT3, Ge2CI
3F3゜Ge7H3F3, Ge7H3CI3. G
Examples include those that are in a gaseous state or can be easily gasified, such as e2H+F4 and Ge+H2CI4.

Furthermore, examples of the tin compound include tin hydride such as SnH4.

Although the method of forming a deposited film with a controlled forbidden band width and the method of forming a deposited film with an uncontrolled forbidden band width are different, both methods of forming a deposited film can be performed using the same deposited film forming apparatus. It may be placed inside.

However, when using one of the forming means, it is necessary to stop the other forming means.

It is also possible to connect both of the above deposited film forming means via a gate valve or the like to form both deposited films continuously.

In addition, as a valence electron control agent for forming a deposited film with controlled valence electrons, in the case of silicon-based semiconductor films and germanium-based semiconductor films, a p-type valence electron control agent, so-called P
Elements from group A of the periodic table that act as type impurities, such as B
, AI, Ga, Tn, TI, etc., and n-type valence electron control agents, elements of group Ⅰ A of the periodic table that act as so-called n-type impurities, such as N, P, 8S,
Compounds containing Sb, Bi, etc. can be mentioned.

Specifically, NH3, HN3. N2H5N3. N2H
,,N)14N3゜PH3,P2H418sH3,Sb
H3, BiH3, B2H6, B4H16°B, H9・
”,>HII・H61”+16・86HI2・A
I (CH3)3.

8] (C2Hs)3. Ga(CH3)3. In(C
H3) 3 etc. can be cited as effective examples.

In addition, these valence electron control agents can also be used as a bandgap adjusting agent by adding a large amount.

The method for forming at least one deposited film other than the bandgap-controlled semiconductor thin film in the thin film multilayer structure of the present invention will be described with reference to FIGS. 1 and 2. In the deposition space (8), a precursor that is a raw material for forming a deposited film produced in the decomposition space (B) and an active species that is produced in the decomposition space (C) and interacts with the precursor are mixed. The method is characterized in that a deposited film is formed on the substrate by introducing each separately.

In this way, since plasma is not used in the deposition space (8), the formation parameters of the deposited film are the amount of introduced precursors and active species, the temperature in the substrate and the deposition space, and the internal pressure in the deposition space. Control of film formation becomes easier, and deposited films can be formed with reproducibility and mass production.

In the present invention, the decomposition space (B) introduced into the deposition space (A>
) is selected and used as desired, having a lifetime of preferably 0.01 seconds or more, more preferably 0.1 seconds or more, optimally 1 second or more, and the composition of this precursor The elements constitute the main components constituting the deposited film used in the deposition space (A). Also, the decomposition space (
The active species introduced from C) preferably has a lifetime of 10
It is less than 1 second, more preferably less than 8 seconds, optimally less than 5 seconds. When forming a deposited film in the deposition space (A), these active species are simultaneously introduced into the deposition space (8) from the decomposition space (B), and are introduced into the precursor containing the constituent elements that will become the main constituents of the deposited film to be formed. Interacts chemically with the body. As a result, a desired deposited film can be easily formed on a desired substrate.

According to this method, the deposited film formed without generating plasma in the deposition space (8) is substantially not adversely affected by etching action or other effects such as abnormal discharge action.

Furthermore, by arbitrarily controlling the atmospheric temperature of the deposition space (A) and the substrate temperature as desired, more stable CVD can be achieved.
One of the differences between this method 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 present invention, the active species generated in the decomposition space (C) are not only excited by energy such as electric discharge, light, and heat, or by a combination thereof, but also by contact with or addition of a catalyst, etc. good.

In the present invention, the raw material introduced into the decomposition space (B) is one in which an atom or atomic group having high electron-withdrawing properties, or a polar group is bonded to a silicon atom. As such, for example, 5iJ21+2 (n
=I, 2.3-, X=F, CI, Br.

1), (SiX2)n (n≧3.X=F, CI
, Br, I).

5inH2n++ (n = 1, 2.3 =, X
=: F, CI, Br, I).

5ilH2X71 (n = 1. 2. 3 = -,
Examples include X=F, C1, Br, and I).

Specifically, for example, 5jF4, (SiF2)5,
(SiF+)6.

(SiF,)4. Si2F6. SiHF3. Si
H2F2゜5iCI4 (SiC12)rSiBr4
, (SiBr4)s, etc.) or those that can be easily gasified.

Also, SiH2(C6H5)2, SiH2(ON)
, etc. may also be used depending on the intended use of the deposited film to be formed.

A precursor is generated by adding decomposition energy such as heat, light, or discharge to the above-described material in the decomposition space (B). This precursor is introduced into the deposition space (8). On this occasion,
It is necessary that the lifetime of the precursor is preferably 0.01 seconds or more, which promotes the increase in deposition efficiency and deposition rate, and increases the activity in the deposition space (A) with the active species introduced from the decomposition space (C). In order to increase the efficiency of the chemical reaction, if necessary, the desired deposited film can be formed by applying energy such as heat or light to the deposition space (A) or onto the substrate without using discharge energy such as plasma. Formation is achieved.

In the present invention, the raw materials introduced into the decomposition space (C) to generate active species include H2 and SiH4.

SiH3F, 5it (301,5iH3Br, 5i
In addition to H31, rare gases such as He and 8R can be used.

In the present invention, the decomposition space (B) in the deposition space (A)
The ratio of the amount of precursor introduced from the decomposition space (C) to the amount of active species introduced from the decomposition space (C) is determined as desired depending on the deposition conditions, the type of active species, etc., but is preferably 10:1.
~1:10 (introduction flow rate ratio) is appropriate, more preferably 8:2 ~ 4:6.

Further, in order to dope a valence electron control agent for controlling valence electrons, a raw material for introducing impurities may be introduced in a gaseous state into the decomposition space (B) or (C) during layer formation.

In the case of silicon-based semiconductor films and germanium-based semiconductor films, the valence electron control agent used in the present invention is a p-type valence electron control agent, an element of group Ⅰ A of the periodic table that acts as a so-called p-type impurity. , for example B, AI, Ga,
Compounds containing In, TI, etc., and n-type valence electron control agents, V1b of the periodic table that act as so-called n-type impurities,
A elements such as N, P, As.

Compounds containing Sb, Bj, etc. can be mentioned.

Specifically, NH3, HN3. N, H, N3. N2
H4゜N)14N3, PH3, P2H4, AsH3
,SbH3,8iH3,821-16゜B4H,◇・
P5H9・BSHII・n6H16・B6H12
・Al(CH3)3. Al(C2H5)3. Ga(
CH3)3. In(CH3)3 and the like can be cited as effective examples.

The substrate used in the present invention may be electrically conductive or electrically insulating, as long as it is appropriately selected depending on the intended use of the deposited film to be formed. Examples of the conductive substrate include NiCr, stainless steel,
Or, Mo, Au, Ir, Nb.

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

As the electrically insulating substrate, 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 substrates is subjected to a conductive treatment, and another layer is preferably provided on the conductive treated surface side.

For example, if it is glass, its surface is NiCr, [8].

Cr, Mo, 8u, Ir, Nb,
Ta, V, Ti, Pt, Pd.

In2O3, 5n02. ITO (In203 +5n
Conductive treatment is performed by providing a thin film such as 02),
Or, in the case of a synthetic resin film such as a polyester film, NiCr, Ag, Pb, Zn, Au, Cr, Mo.

The surface is treated with a metal such as Ir, Nb, Ta, V, Tj, or Pt by vacuum evaporation, electron beam evaporation, sputtering, or the like, 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 according to desire.

The substrate is preferably selected from the above in consideration of the adhesion and reactivity between the substrate and the membrane. Furthermore, if the difference in thermal expansion between the two is large, a large amount of distortion will occur in the film, and a good quality film may not be obtained. Therefore, select and use a substrate with a close difference in thermal expansion between the two. is preferable.

In addition, the surface condition of the substrate is directly related to the structure (orientation) of the film and the generation of chain structures, so it is important to treat the surface of the substrate so that it has a film structure and structure that provides the desired properties. is desirable.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

First, FIG. 1 is a schematic diagram of a deposited film forming apparatus for carrying out the method for forming a thin film multilayer structure according to the present invention.

This device is equipped with a heating element made of a single transition metal or an alloy and two activation chambers (^) and (B) as means for generating precursors and/or active species for forming a deposited film. ing.

101 is a vacuum chamber, in which a heating element 105 made of a single transition metal or an alloy is placed facing a base 117. The heating element is connected to a power supply device (not shown) by a conductive wire 106, and is supplied with electric power and generates heat.

Reference numeral 102 denotes a raw material introduction pipe for forming a deposited film, into which raw material is introduced from a cylinder (not shown) through a valve 104 and a gas supply pipe 103.

Reference numeral 120 denotes a heater for heating the substrate 117 for heating the substrate 117 to an appropriate temperature during film formation, preheating the substrate 117 before film formation, and further heating for annealing the film after film formation. It is.

[Substrate heating heater] 20 is supplied with electric power by a temperature controller 122 via a conductive wire 127.

121 is a thermocouple for measuring and controlling the temperature of the substrate (Ts), and is connected to the temperature controller 122 by a conductive wire 108.

Further, the substrate holder 118 on which the substrate 117 is installed is connected to the heating element 105 using a fixing jig 119. I'i
I+ can be changed as appropriate.

The vacuum chamber 101 also includes an activation chamber (A) 11.
2 and (B) 107, an infrared heating furnace 114 is connected to the activation chamber (A), and a microwave generator 109 is connected to the activation chamber (B).

Activation chamber (8) 112 is filled with 54 solid particles as required, and heated by an infrared heating furnace 114. A raw material gas for producing a precursor introduced from a cylinder (not shown) is introduced into the activation chamber (A) 112 via a valve 116 and a gas supply vibrator 115, and reacts with 54 heated solid particles to form a deposited film. A precursor for formation is generated, and the precursor is further introduced into the film forming space 125 through the introduction pipe 113.

On the other hand, in the activation chamber (11) 107, raw material gas for active species generation introduced from a cylinder (not shown) via a valve 111 and a gas supply vibrator 115 is supplied with microwave energy supplied from a microwave generator 109. Active species are generated under the action of the active species, and the active species are introduced into the film forming space 125 through the introduction pipe 127.

In the case of the present invention, the distance between the substrate 117 and the gas outlet of the inlet pipe 113, 127 is determined appropriately by considering the type of deposited film to be formed, its desired characteristics, gas flow rate, internal pressure of the vacuum chamber, etc. It is decided according to the situation.

Each gas introduction pipe, each gas supply pipeline, and the vacuum chamber 101 are evacuated by a vacuum evacuation device (not shown) via a main vacuum valve 123 and a main exhaust pipe 124, and the pressure inside the vacuum chamber 101 at that time is A total of 126 monitors are used.

FIG. 2 is a schematic diagram of a deposited film forming apparatus in which a means for forming a deposited film with a controlled forbidden band width according to the present invention and a means for forming a deposited film whose forbidden band width is not controlled are connected via a gate valve. It is a configuration diagram.

Reference numeral 201 denotes a deposition preliminary chamber, which is installed for the purpose of heating, cooling, and surface treatment of the substrate 213, and is connected to the atmosphere side and the deposition chamber 202 via gate valves 204 and 205.

Reference numeral 215 denotes a heater for heating the substrate, and power is supplied by a temperature controller 218 via a conductive wire 216.

217 is a thermocouple for measuring and controlling the temperature of the substrate holder 214, and is connected to a temperature controller 218.

Reference numeral 222 denotes a gas introduction pipe for substrate surface treatment, into which gas for substrate surface treatment is introduced from a cylinder (not shown) via a gas supply vibrator 223 and a valve 224.

Gas introduction pipe, gas supply pipeline and film deposition preliminary chamber 20
1 is evacuated by a vacuum evacuation device (not shown) via a main vacuum valve 207 and a main exhaust pipe 210, and the pressure inside the film-forming preliminary chamber 201 at this time is monitored by a pressure gauge 219.

Reference numeral 221 is a clamp for transporting the substrate, which is driven by the drive jig 220 and can transport the substrate 213 to the next room.

Reference numeral 228 denotes excitation energy generation means for substrate surface treatment, which is equipped with a high frequency generation electrode, an ultraviolet irradiation lamp, etc., and is connected to a power source 229.

202 is a film forming chamber (^) in which a heating element made of a single transition metal or an alloy is installed as a means for generating a precursor and/or an active species for forming a deposited film.

Reference numeral 230 denotes a heating element made of a single transition metal or an alloy, which is connected to a power supply device (not shown) via a conductive wire 231, and generates heat upon being supplied with electric power.

The heating element 230 is installed facing the base 213,
The distance between the heating element and the base 213 can be changed as appropriate using a fixing jig 243 provided on the base holder 214.

Reference numeral 225 denotes a raw material introduction pipe for forming a deposited film, into which the raw material is introduced from a cylinder (not shown) via a gas supply vibrator 226 and a valve 227.

Reference numeral 244 denotes an activation chamber (E) for generating a precursor for forming a deposited film, in which raw material gas for forming a deposited film is introduced from a cylinder (not shown) via a gas supply vibrator 246 and a valve 247. Accordingly, 54 solid particles are packed and heated by an infrared heating furnace 245.

The precursor generated here is introduced into the film forming chamber (A) through the introduction pipe 248.
) 202.

Gas introduction pipe, gas supply pipeline and film forming chamber (8)
202 is a main vacuum valve 208 and a main exhaust pipe 21
1, and is evacuated by a vacuum evacuation device (not shown).
The pressure inside the film forming chamber (8) at that time is monitored by a pressure gauge 219.

203 is a film forming chamber (B), an activation chamber (C), (
D) 232, 235 are provided. Activation room (C)
235 includes an infrared heating furnace 236 and an activation chamber (D).
A microwave generator 233 is connected to each of the microwave generators 232 .

Activation chamber (C:) 235 contains solid Si as needed.
The grains are packed and heated by an infrared heating furnace 236. The raw material gas for precursor generation introduced from a cylinder (not shown) is
The solids are introduced into the activation chamber (A) 235 via a valve 239 and a gas supply pipe 238 and heated.

A precursor for forming a deposited film is generated by the reaction with the Si particles, and the precursor is further introduced into the film forming space 242 through the introduction pipe 237.

On the other hand, in the activation chamber (D) 232, raw material gas for active species generation introduced from a cylinder (not shown) via a valve 241 and a gas supply pipe 240 is supplied with microwave energy supplied from a microwave generator 233. Active species are generated under the action of the active species, and the active species are introduced into the film forming space 242 through the introduction pipe 234.

In the case of the present invention, the distance between the base body 213 and the gas outlet of the inlet pipes 234 and 237 is determined appropriately by considering the type of deposited film to be formed, its desired characteristics, gas flow rate, internal pressure of the vacuum chamber, etc. It is decided according to the situation.

Each gas introduction pipe, each gas supply pipeline and film forming chamber (B
) 203 is evacuated by a vacuum evacuation device (not shown) via a main vacuum valve 209 and a main exhaust pipe 212, and the pressure inside the film forming chamber (B) 203 at this time is monitored by a pressure gauge 219.

A thin film transistor (hereinafter referred to as T
It's called PT. ), a method for manufacturing a solar cell and an electrophotographic imaging member will be specifically described.

(Example 1) FIG. 3 shows a schematic configuration diagram of a solar cell manufactured by the deposited film forming apparatus shown in FIG. 1 of the present invention.

In the figure, a transparent electrode (not shown) and a p-type amorphous silicon carbide layer 3 are provided on a glass substrate 300.
01 (first layer, thickness 200 layers), i-type amorphous silicon layer 302 (second layer, thickness 7000 layers), n-type amorphous silicon layer 303 (third layer, thickness 300 layers), and layer electrode 3
04 are laminated.

First, the glass substrate 300 on which a transparent electrode was vapor-deposited was placed on the substrate holder 118 in the vacuum chamber 101, and the vacuum chamber 101 was evacuated from the main exhaust pipe 124 to set the pressure in the vacuum chamber 101 to about 10 Torr. The substrate heating heater 120 was heated by a temperature controller 122 to maintain the substrate temperature at 220°C.

Next, in depositing the P-type amorphous silicon carbide layer 301, H2 gas was supplied from a cylinder (not shown) at a flow rate of 5 seconds.
ccm, 5i2F 6 gas flow rate]Osccm,
BF3/H2 gas (BF3 concentration 500 ppm) is introduced into the vacuum chamber 101 at a flow rate of 3 sccm and Cl14 gas at a flow rate of 30 sccm through the gas introduction pipe 102 via the valve 104 and the gas supply pipe 103, and the internal pressure becomes OTorr for several months. While adjusting the opening degree of the main vacuum valve 123, the tungsten filament 105 was heated to about 1800° C. to form a P-type amorphous silicon carbide layer 301 whose forbidden band width was expanded with carbon. However, the distance between the filament 105 and the base 117 is 20
mm.

After forming the first layer, the heating of the filament 105 is stopped, and all gas supplies are stopped, and the vacuum chamber 10
1 was evacuated until the internal pressure became 0-6 Torr.

Next, the i-type amorphous silicon layer 302 and the n-type amorphous silicon layer 303 are deposited in a vacuum chamber 1 in which a precursor for forming a deposited film and an active species that interacts with this precursor are separately stored.
01 and was deposited by mixing and reacting.

That is, in the i-type amorphous silicon layer 302, SiF4 gas is supplied to the valve 1 from a cylinder (not shown) at a flow rate of 30 seconds.
16, activation chamber (A) 1 via gas supply pipe 115
It was introduced within the 12th. At this time, activation chamber (8) 112
The inside is filled with solid Si particles, and the infrared heating furnace 11
4 to 1150°C. Next, hydrogen gas (10% diluted with Ar) was supplied from a cylinder (not shown) at a flow rate of 200.
secm was introduced into the activation chamber (B) 107 via the valve 111 and the gas supply pipe 110. Immediately, 150 W of microwave power was supplied from the microwave generator 109 into the activation chamber (B) 107. The precursors and active species generated in the activation chambers (A) 112 and (B) 107 by these operations are introduced into the vacuum chamber 101 via the introduction pipes 113 and 127, and the internal pressure is 0.8T.
The second layer 302 of i-type amorphous silicon was formed while adjusting the opening degree of the main vacuum valve 123 so that the opening of the main vacuum valve 123 was adjusted so that the opening of the main vacuum valve 123 was adjusted.

After forming the second layer, the supply of microwave power from the microwave generator 109 is stopped, and the supply of all gases is also stopped, so that the internal pressure of the vacuum chamber 101 is reduced to IO=Tor.
It was evacuated until r.

A third layer 303 of phosphorus-doped amorphous silicon is formed by the same operating procedure as for forming the second layer 302, but using H2 gas (10% diluted with Ar) 20
secm plus PF5 gas (diluted to 000 ppm with H2) 10105e to valve 111, gas supply pipe 1
10 into the activation chamber (B) +07.

After forming the first to third layers on the substrate 300 in this way,
After cooling, the third layer 3 is removed from the vacuum chamber 101.
A layer electrode 304 was deposited on top of 03.

When the solar cell thus formed was irradiated with light (8M-1) and the energy conversion efficiency was measured, it was found to be more than 15% higher than the conventional one.

(Example 2) In Example 1, the first layer is a p-type amorphous silicon layer 30.
1 (thickness: 200 layers) and a solar cell having the same structure except that the second layer was an i-type amorphous silicon-germanium layer 302 (thickness: 6000 layers).

To deposit the first p-type amorphous silicon layer 301, H2 gas was supplied from a cylinder (not shown) at a flow rate of 5 sccm.
Si2F6 gas flow rate 12sccm, BF3/
H2 gas (BF3 concentration 500 ppm) flow rate 5 scc
m, the gas is introduced into the vacuum chamber 101 from the gas introduction pipe 102 via the valve 104 and the gas supply pipe 103,
Main vacuum valve 123 so that the internal pressure is 1.2 Torr
While adjusting the opening degree of the tungsten filament 10
5 was heated to about 1800°C.

In depositing the second i-type amorphous silicon-germanium layer 302, the BF3/H
The formation of the first layer was carried out under the same conditions as for the formation of the first layer, except that GeF4 gas (1% diluted with He) was flowed at a flow rate of 15 seconds instead of the 2 gases.

Substrate processing other than the formation of the first layer and second layer, n of the third layer
All operations such as evacuation of the vacuum chamber, attachment of electrodes, etc. performed between the formation of the mold amorphous silicon layer 304 and the formation of each deposited layer were the same as in Example 1.

When the solar cell thus formed was irradiated with light (AM-1) and the energy conversion efficiency was measured, it was found to be more than 15% higher than the conventional one.

(Example 3) FIG. 4 is a schematic diagram of a TPT manufactured by the deposited film forming apparatus shown in FIG. 1 of the present invention.

In the figure, on a glass substrate 400, an amorphous silicon layer 40] (first layer, thickness 5,000 layers) and an amorphous silicon layer 4o2 doped with phosphorus (second layer, thickness 6
50 people), insulating layer 403 (third layer, thickness 1800 people),
and A] gate electrode 4o4, source and drain electrodes 8i405.405° are formed.

The above TPT was produced using the same activation method and operation as in Example 1 under the film forming conditions shown in Table 1.

The TPT manufactured according to this example had an 0N10FF resistance ratio improved by 18% or more compared to the conventional one.

(Example 4) FIG. 5 is a schematic diagram of an electrophotographic image forming member manufactured by the deposited film forming apparatus shown in FIG. 1 of the present invention.

In the figure, a light antireflection layer 5 is provided on an AI substrate 500.
01 (first layer, amorphous silicon germanium layer with forbidden band width controlled by Ge, thickness 0.25μII+
), charge injection prevention layer 502 (second layer, amorphous silicon layer doped with B, thickness 0.3μIn), photosensitive layer 503 (third layer, amorphous silicon layer, thickness 1
8μ=1), a surface protection layer and a light absorption increasing layer 504 (fourth layer, an amorphous silicon carbide layer whose forbidden band width is controlled by C, and a thickness of 0.5μIn) are formed in a stacked manner.

The image forming member as described above was produced using the same activation method and operation as in Example 1 under the film forming conditions shown in Table 2. However, "tungsten mesh (1800° C.)" in the deposition method in Table 2 indicates a method using a mesh-like heating element instead of the filament 105 in Example 1.

As a result, the charging characteristics were improved by 20% or more, the number of image defects was reduced by about 10%, and the sensitivity was improved by 20% or more.

(Example 5) Using the deposited film forming apparatus shown in FIG. 2, a solar cell having the layer structure shown in FIG. 3 was produced.

In FIG. 3, on a glass substrate 300 are a transparent electrode (not shown), a p-type amorphous silicon layer 301 (first layer, thickness 200 mm), an i-type amorphous silicon germanium layer 302 ( 2nd layer, 6000 layers thick), n-type amorphous silicon layer 303 (3rd layer, 300 layers thick),
Electrodes 304 are formed in layers.

First, a glass substrate 300 on which a transparent electrode has been vapor-deposited is placed on a substrate holder 214 in a pre-film-forming chamber 201 using a gate valve 204.
It is installed from the side, and is evacuated from the main exhaust pipe 210 with a pump (not shown), and the pressure inside the film-forming preliminary chamber 201 is set to 1o=Tor.
It was set to about r. The substrate heating heater 215 was heated by a temperature controller to maintain the substrate temperature at 220°C.

At this time, the film forming chamber (8) 202 and the film forming chamber (B) 2
03 is evacuated by a pump (not shown) through a main exhaust pipe 211.2]2 and maintained at a pressure of about 10 Torr, and the substrate holder 214 is also maintained at 220°C.

Next, from the gas introduction pipe 222, a gas for substrate surface treatment is supplied from a cylinder (not shown) via a gas supply vibrator 223 and a valve 224. Introduce gas at 20 sec,
Adjust the opening degree of the main vacuum valve 207 to reduce the internal pressure to 0.5
Torr, and power supply 229 to UV light irradiation lamp 228
Power was supplied to turn on the light, and the surface of the substrate 2]3 was treated for about 1 minute.

0. Stop the introduction of gas, fully open the main vacuum valve 207, exhaust the pressure inside the preliminary chamber 201 to about 10"6 TOrr, and open the gate valve 205 when the internal pressure becomes the same as that of the film forming chamber (A) 202. Clamp 2 for transporting the substrate
21. Move the base 213 to the preliminary chamber 201 using the driving jig 220.
The substrate was then transferred onto the substrate holder 214 in the film forming chamber (A). After the substrate 213 was transferred to the substrate holder 2141 in the film forming chamber (B) by the same operation, the gate valve 206 was closed.

In depositing the p-type amorphous silicon layer 301, first, the activation chamber (C) 235 is filled with solid Si grains and heated to 1150° C. by the infrared heating furnace 236, and then heated to 1150° C. (not shown). SiF4 gas from the cylinder at a flow rate of 4
5jF7 as a precursor generated here was introduced through the gas supply vibe 238 and valve 239 at 0 sec.
was introduced into the film forming space 242 from the introduction pipe 237.

At the same time, H2 gas (10% diluted with Ar) was supplied from a cylinder (not shown) at a flow rate of 300 sec to BF37 H2 scum (
BF3 concentration 500 ppm) is supplied to the activation chamber (D) via the gas supply vibrator 240 and valve 241 at a flow rate of 5 sec.
232 and immediately turn on the microwave generator 23.
3, 150 W of microwave power was supplied into the activation chamber (D). The active species generated here, such as 0, etc., are introduced into the film forming space 242 through the introduction pipe 234.

While adjusting the opening degree of the main vacuum valve 209 so that the internal pressure at this time was 0.7 Torr, a P-type amorphous silicon layer 301 was formed by interaction with the precursor and active species.

After forming the first layer, the microwave generator 233 and the infrared heating furnace 236 are stopped, all gas supplies are stopped, the main vacuum valve 209 is fully opened, and the film forming chamber (B
) 203 is evacuated until the pressure within it reaches approximately 10 Torr, and when the internal pressure becomes the same as that of the film forming chamber (A) 202, the gate valve 206 is opened, and the substrate transfer clamp 2 is opened.
21, the substrate 2]3 on which the p-type amorphous silicon layer was deposited was transported onto the substrate holder 214 in the film forming chamber (A) 202 using the driving jig 220.

The gate valve 206 was closed, and an i-type amorphous silicon germanium layer 302 and an n-type amorphous silicon layer 303 were formed in the film forming chamber (A).

In depositing the i-type amorphous silicon germanium layer 302, H2 gas is supplied from a cylinder (not shown) at a flow rate of 10105.
c, 5i7F 6 gas flow rate 25 sccm, GeF
4/He gas (GeF4 concentration 1%) at a flow rate of 8 s
ccm into the film forming chamber (A) 202 through the gas introduction pipe 225 via the valve 227 and the gas supply vibrator 226, while adjusting the opening degree of the main vacuum valve 208 so that the internal pressure becomes 1.2 Torr. , was formed by heating a tungsten filament 230 to about 1800°C.

After forming the second layer of amorphous silicon germanium layer 302, the supply of all gases and power to the tungsten filament is stopped, the main vacuum valve 208 is fully opened, and the pressure in the deposition chamber (A) is reduced to 10%. = Exhausted to about Torr.

Subsequently, in depositing the third layer of n-type amorphous silicon layer 303, PF, /)I2 gas (PFS concentration 1100
The process was carried out under the same conditions as for forming the second layer, except that 0pp) was flowed at a flow rate of 10105c.

When the solar cell thus formed was irradiated with light (AM-1) and the energy conversion efficiency was measured, it was found to be more than 18% higher than the conventional one.

(Example 6) The TFT having the layer structure shown in FIG. 4, which was manufactured in Example 3, was manufactured using the deposited film forming apparatus shown in FIG. 2.

Operations such as substrate processing and substrate transport were performed in the same manner as in Example 5, and the other film forming conditions were as shown in Table 3.

The TPT manufactured according to this example had an 0N10FF resistance ratio improved by more than 20% compared to the conventional one.

S (Example 7) The electrophotographic image forming member having the layer structure shown in FIG. 5 manufactured in Example 4 was manufactured using the deposited film forming apparatus shown in FIG.

The substrate treatment was carried out by DC bombardment using a total gas of 20 seconds instead of the zero gas used in Example 5, and installing a DC discharge electrode 228 instead of the UV light irradiation lamp. Other operations such as transporting the substrate were performed in the same manner as in Example 5, and the other film forming conditions were as shown in Table 4.

When the electrophotographic properties of the electrophotographic image forming member formed as described above were measured, it was found that the charging ability was improved by 25% and the sensitivity was improved by 20% compared to the conventional electrophotographic image forming member.

(Example 8) In Example 5, the i-type amorphous silicon germanium layer 302 and the n-type amorphous silicon 2 layer 3 in the film forming chamber (A)
Instead of the 5i2F gas used in the formation of 03, solid Si particles were filled in the activation chamber (E) 244 in advance and heated to 1150°C by an infrared heating furnace 245, not shown. SiF4 gas is supplied from a cylinder at a flow rate of 35 sec to the gas supply pipe 246 and valve 24.
:S as a precursor introduced through 7 and generated here
A solar cell was fabricated using the same procedure except that iF2 was introduced into the film forming chamber (A) 202 through the introduction tube 248.

When the solar cell thus formed was irradiated with light (8M-1) and the energy conversion efficiency was measured, it was found to be more than 18% higher than the conventional one.

(Example 9) In Example 6, instead of the Si2F6 gas used when forming the insulating layer 403 in the film forming chamber (A), solid Si particles were filled in the activation chamber (E) 244 in advance. death,
SiF4 gas is supplied from a cylinder (not shown) at a flow rate of 35° C. to the area being heated to 1150° C. by the infrared heating furnace 245.
secm was introduced via the gas supply vibrator 246 and valve 247, and the same operation was performed except that SiF2 as a precursor generated here was introduced into the film forming chamber (A) 202 from the introduction pipe 248. TPT was produced.

The TPT manufactured according to this example had an 0N10FF resistance ratio improved by more than 20% compared to the conventional one.

〔Effect of the invention〕

As explained in detail above, the thin film multilayer structure obtained by the thin film forming method of the present invention has the advantage that the surface of each deposited layer is not directly exposed to plasma discharge, the interface properties are improved, and the formation of each deposited layer is Since an effective deposited film formation method is employed, a semiconductor element with excellent characteristics can be obtained as shown in each of the above embodiments.

Further, the method for forming a thin film multilayer structure according to the present invention can improve the efficiency of energy use, facilitate the control of film quality, and obtain a deposited film with uniform electrical and physical properties over a large area. In addition, it has excellent productivity and mass production, and is of high quality and electrical.
A thin film multilayer structure with excellent physical properties such as optical and semiconductor properties can be easily obtained.

[Brief explanation of drawings]

1 and 2 are schematic configuration diagrams of a deposited film forming apparatus, FIG. 3 is a schematic configuration diagram of a solar cell manufactured according to an embodiment of the present invention, and FIG. 4 is a schematic diagram of a solar cell manufactured according to an embodiment of the present invention. FIG. 5 is a schematic diagram of an electrophotographic imaging member manufactured according to an example. FIG. 5 is a schematic diagram of a TPT manufactured according to an example of the present invention. 101...Vacuum chamber 102, 222.225-...Gas introduction pipe 105, 23
0... Heating element 107... Activation chamber (B) 109, 233... Microwave generator 112...
Activation chamber (A) 113, 127.234.237.248...Introduction pipe 114, 236.245...Infrared heating furnace 117, 2
13...Base 119, 243...Fixing jig 121, 217...Thermocouple 122, 218...Temperature controller 123, 20
7.208.209... Main vacuum valve 124, 2
10.211.212--Main exhaust pipe 126, 2]
9--Pressure gauge 201--Deposition preliminary chamber 202--Deposition chamber (8) 203--Deposition chamber (B) 204, 205.206--Gate valve 220--
- Drive jig 221... Transfer clamp 232-... Activation chamber (D) 235-... Activation chamber (C) 244... Activation chamber (E) 300-... Glass substrate 303...・Third layer (n-type amorphous silicon layer) 400-
...Glass substrate 401...First layer (amorphous silicon layer) 402...
Second layer (n+ amorphous silicon layer) 403...Third layer (
Insulating layer) 404, 405...A1 electrode 500...Shoulder substrate

Claims (1)

[Claims] (1) In a method for forming a thin film multilayer structure having a semiconductor thin film with a controlled bandgap, a heating element made of a transition metal element or an alloy having a catalytic effect provided in a film formation space is heated with halogen and hydrogen. A raw material for forming a deposited film containing at least one element in its molecule and/or a precursor produced from the raw material for forming a deposited film in an activation space provided separately from the film forming space. The forbidden band width is controlled by contacting a compound containing an element serving as a band width adjusting agent and activating it by a thermal dissociation reaction to generate a precursor and/or an active species that becomes a raw material for forming a deposited film. Forming at least one layer of a semiconductor thin film and at least one layer of other thin films by separately introducing into a deposition space a precursor that is a raw material for forming a deposited film and an active species that interacts with the precursor. 1. A method for forming a thin film multilayer structure.