JPH0324269A - Deposited film forming device - Google Patents

Abstract

PURPOSE:To simplify the device and to form a deposited film which has good quality and is uniform by incorporating an active species forming part of a coaxial antenna having a flat shape at the time of introducing the precursor for the deposited film and an active species into a vacuum vessel, thereby forming the deposited film. CONSTITUTION:The inside of a vacuum vessel 101 is evacuated to a prescribed vacuum degree and a glass substrate 111 on a heating holder 110 is heated to a prescribed temp. Gaseous raw materials for active species are then introduced from an introducing port 106 into a coaxial pipe 102 and plasma is excited by adjusting an actuator 105 at the terminal of a waveguide and a tuner 115 at the terminal of the coaxial central body to form the active species, which are introduced into the vacuum vessel 101. On the other hand, the gaseous raw materials for the precursor are introduced from an introducing port 115 into the vacuum vessel 101 and current is passed to a magnetic field generating coil of an electromagnet 108, by which the film is formed on the substrate 111. The active species forming part of the coaxial pipe 102 for forming and introducing the active species is constituted of the coaxial antenna having a flat shape. The deposited film having various desired characteristics is obtd. uniformly with the large reproducibility in this way without increasing the size, complexity and diversification of the device.

Description

Detailed Description of the Invention [Technical Field to which the Invention Pertains] The present invention relates to a film deposited on a substrate, particularly a functional film, particularly a semiconductor device, a photovoltaic element, a thin film semiconductor element, a photoreceptor device for electrophotography, and an image forming apparatus. This article relates to a deposited film forming apparatus suitable for forming functional deposited films such as amorphous or polycrystalline for use in input line sensors, imaging devices, etc. [Description of Prior Art] As a deposited film deposition method that does not require a high-temperature process like the thermal CVD method and does not damage the deposited MI film by being exposed to plasma like the plasma CVD method, A deposited film type method such as that disclosed in 179869/1982 and Japanese Patent Application Laid-Open No. 184817/1984, that is, a precursor serving as a raw material for forming a deposited 4N film is placed in the tS space for forming a deposited film on a substrate. A method of forming a deposited film is known in which a deposited film is formed on the substrate by introducing an active species that interacts with the precursor. In these deposited film formation methods, the raw material gas for active species containing hydrogen is generally activated to preserve the active species, but since the lifespan of active species containing hydrogen is short, they are generated near the film formation space. There is a need to.

Therefore, when attempting to deposit a uniform film over a large ifl area, the conventional approach was to increase the size or increase the number of activation devices for generating active species depending on the size of the film space. However, as the equipment becomes larger and more complex, a large amount of capital investment is required for the production equipment, and the management items for its operation also become more complex. On the other hand, an ECR plasma device is known as a device used in a deposited film forming method using microwave plasma, but this also uses a large-diameter plasma when trying to obtain a uniform film over a large area. The drawback was that a resonator was required to generate the electricity, and the electromagnet was correspondingly large. [Object of the Invention] An object of the present invention is to provide a deposited film forming apparatus that further improves the conventional deposited film forming apparatus described above. That is, the object of the present invention is to provide elements used in semiconductor devices, photovoltaic elements, thin film semiconductor elements, photoreceptor devices for electrophotography, line sensors for image input, imaging devices, and various other electronic elements, optical elements, etc. A deposited film forming device that can uniformly obtain a deposited film having various desired characteristics over a large area with good reproducibility without increasing the size, complexity, or number of devices when forming a functional deposited film as a component. The goal is to provide the following. [Structure and Effects of the Invention] The present invention has been made to solve the aforementioned problems in the conventional deposited film forming apparatus for forming functional deposited films such as amorphous or polycrystalline, and to achieve the objects of the present invention. Through repeated research, we have found that in a deposited Mi film forming device that forms a deposited film on a substrate by interacting precursors and active species, the active species generation section can be made into a coaxial antenna with a flat shape to increase the surface area. We obtained the knowledge that it is possible to form a deposited film uniformly.

The present invention was completed based on this knowledge, and its gist is a vacuum container, a means for holding a substrate for forming a deposited film in the vacuum container, and a method for forming a deposited film in the vacuum container. means for introducing a precursor to be used as a raw material for use, means for generating an active species that interacts with the precursor and introducing it into the vacuum container, and means for evacuating the inside of the vacuum container,
A deposited film type or apparatus for forming a deposited film on the substrate by interacting a precursor and an active species in the vacuum container,
A deposited film forming apparatus characterized in that an active species generating section of the means for generating and introducing active species is composed of a coaxial antenna having a flat shape, and the active species generated at the coaxial section is introduced into a vacuum container. be.

In the present invention, by using a coaxial antenna with a flat shape as the active species generation unit, first, a long-life and transportable inert gas plasma is formed, and the plasma is transported close to the film forming space. By activating the source gas of active species containing hydrogen atoms with plasma, active species containing hydrogen, which have a short lifetime, can be generated near the film forming space.

As a result, even when the substrate has a large area, a uniform deposited film can be obtained without increasing the size of the activation device for the raw material gas for active species. The term "precursor" used in the present invention refers to anything that can be used as a raw material for the deposited film to be formed. "Active species" are chemically interacted with the precursor, for example, giving energy to the precursor, or chemically reacting with the precursor, allowing the precursor to form a deposited film more efficiently. It refers to something that has the role of creating a state. Therefore, the active species may include constituent elements constituting the deposited film to be formed, or may not include such constituent elements. In the present invention, the produced precursor has a lifespan of 0.05% from the viewpoint of productivity and ease of handling. A time period of 1 second or more, more preferably 1 second or more, optimally 10 seconds or more is selected and used as desired.

In the deposited film forming apparatus of the present invention, the raw material gas for film formation for keeping the precursor alive includes compounds containing silicon and halogen, compounds containing carbon and halogen, compounds containing germanium and halogen, etc. ．． These compounds may be used alone or in combination of two or more as appropriate. What is an example of a compound containing silicon and halogen? A compound in which part or all of the hydrogen atoms of a chain or cyclic compound is replaced with a halogen atom is used, and specifically, for example, SluYzu+z (u is an integer of 1 or more, Y is F,
At least one element selected from CI, Br, and I. } chain silicon halide, Siv
Yzv (V is an integer of 3 or more, Y has the above-mentioned meaning.

) Cyclic silicon halide, SiuHxY, (
u and Y have the meaning of the previous series m X y = 2
u or 2u+2. ), and the like.

Specific compounds include, for example, SiFa, (SiFz
)s + (SiFz)i + (SiFz)4+Sj
zFa. Si:+Fs, Sit{Fs, SiH■
F! , SitHzF4. SizHaFj. SiCla
* (SiClx's .SiBr4, (SiBr
z) s. Sl! Cj! 6, SigBr
4. S iH C 12 3 , SiHBrz. S
iH 11, SizCj! , Fs, etc., which are in a gaseous state or can be easily gasified. These silicon compounds may be used alone or in combination of two or more.

Further, as the compound containing carbon and halogen, for example, a compound in which part or all of the hydrogen atoms of a chain or cyclic hydrocarbon compound is replaced with a halogen atom is used, and specifically, for example, CuYz@*1 ( (1 is an integer greater than or equal to 1,
Y is F, CIl, Br, and . At least one element selected from 1. ), a cyclic silicon halide represented by CvYzv (V is an integer of 3 or more, Y has the above-mentioned meaning), C.
I{. Y, (u and Y have the above meanings, x+y=
It is 2u or 2u+2. ) chain or cyclic compounds. Specific compounds include, for example, CF4. (CF), (
CFz)i. (CF2)4 ,C2Fh,C*F
a. CHFs. CHzFz , CC14 , (
cc1z)'sC Br4, (C Brx)s. Cx
C 1 b , CxBrh. CHCI,CH13
, CtC1, F3, etc., which are in a gaseous state or can be easily gasified.

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

In addition, compounds containing germanium and halogen include:
For example, a compound in which part or all of the hydrogen atoms of a chain or cyclic germanium hydride compound is replaced with a halogen atom is used, and specifically, for example, GeuYiu+z (
u is an integer greater than or equal to 1, Y is F, C7! , Br and [. ) chain germanium halide, GevYiv (v is an integer of 3 or more, Y has the meaning above), cyclic germanium halide, GeuH,Yy (u and Y have the meaning above, x+y=2u or 2u+2), and the like.

As a specific compound, for example, G e Fa (C+
eFz)5+ <GeFx)b, (GeFz)4. G
ezFb, GeiFa, GeHI? ,,GeHzF
Z. GetllzFaGezHsFi , GeCl
,,(GeCAz)s ,GeBr4,(Gel3rz
) s. GezCl 6 , GetBrb. G
eH C j! sGeHBrz,GeH Iz ,G
Examples include those that are in a gaseous state or can be easily gasified, such as ezCAzF*.

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

When using multiple raw material gases for film formation, they can be mixed in advance and introduced into the activation space, or these raw material gases for film formation can be supplied individually from independent sources. However, it can also be introduced into the activation space.

A gas containing hydrogen is used as the raw material gas for the active species. Examples of the gas containing hydrogen include hydrogen alone, a compound containing hydrogen and a halogen (for example, H FH C # gas, etc.), or a combination of these and an inert gas.

The inert gas refers to rare gases such as He, Ne, Ar, Kr, and Xs, and may be used alone or in combination of two or more.

The deposited film formed using the deposited film forming apparatus of the present invention is
It is possible to dope with an impurity element during or after Precept III. As the impurity element to be used, as a p-type impurity, an element of Group Ⅰ A of the periodic table, such as B, Ae
, Ga, In, Tll, etc. are mentioned as suitable ones,
Examples of n-type impurities include elements of Group V A of the periodic table, such as P. Preferred examples include As, Sb, Bi, etc., and particularly suitable are B, Ga, etc. as p-type impurities, and p, sb, etc. as n-type impurities. The amount of impurities to be doped is appropriately determined depending on desired electrical and optical properties.

The substance containing such an impurity element (substance for introducing impurities) is in a gaseous state at room temperature and normal pressure, or at least in a gaseous state under the conditions for forming a deposited film, and can be easily vaporized using an appropriate vaporization device. It is preferable to select compounds. Specific compounds include, for example, PHs, PxH
s, PFs, PFs, PCj! z , AsHi
+AsFs+AsFs. AsC1s *SbHs,
SbFs, SbHz, BF3, BCI! s,BB
rs. BzHb ,B4Hll BSH9 ,Bs
H++, B h H +. , B4Hli AICIs, etc. Compounds containing impurity elements are 1
A species may be used alone or two or more species may be used in combination.

A compound containing an impurity element as a component can be directly introduced into the film formation space in a gaseous state, or can be mixed with a hydrogen-containing gas or an inert gas and introduced into the film formation space.
Alternatively, similar to the raw material gas for film formation, it can be pre-activated and then introduced into the film formation space. In the present invention, as a method for generating active species, electric energy such as microwave discharge and high frequency discharge is used in consideration of each condition and apparatus, but if desired, in addition to the above excitation energy, heater heating, Thermal energy such as infrared heating, or activation energy such as light energy may be used to contact or add the catalyst.

In addition, in the present invention, as a method for producing the precursor, electric energy such as microwave discharge, high frequency discharge, low frequency discharge, direct current discharge, light energy, thermal energy, etc. can be used in consideration of each condition and device. Excitation energy is used. In some cases, the raw material gas itself may be used as a precursor without applying the above energy. Hereinafter, the present invention will be explained in more detail with reference to specific embodiments, but the present invention is not limited thereto. Figure 1 shows a schematic perspective view of an example of the deposited film forming apparatus of the present invention. FIG. 2 is a schematic perspective view of an example of the active species generating section of the apparatus of the present invention shown in FIG. In Fig. 1, +01 is a vacuum container, 102 is a coaxial tube,
103 is a waveguide, 104 is a waveguide population, 105 is a tuner, 106 is a gas introduction pipe, 107 is a center conductor, 10
8 is a magnet, 109 is a waveguide end, 110 is a heating holder, 111 is a base, 112 is a valve, 113 is a pump, +
14 is a pressure gauge. In the apparatus according to the embodiment of the present invention, the coaxial tube 102 which is the activated species generating section shown in FIG.
02 is connected to a part of the vacuum vessel +01 in such a manner that the center conductor 107 is exposed, and the other end of the coaxial tube is connected to a part of the microwave waveguide 103 in such a manner that it is exposed. A tuning device 115 that introduces microwaves from the entrance 104 of the waveguide and terminates a part of the waveguide and the center conductor, and a device 105 that moves the position of the end 109 of the waveguide and performs tuning.
As a result, plasma of the gas introduced by the gas introduction pipe 106 is generated in the coaxial pipe. Inside the vacuum container 101, there is a heating holder 11 for heating the base 111.
0 and surrounding it with magnets 108, it is possible to draw out the plasma in the coaxial tube and bring it close to the substrate using a diverging magnetic field.

The active species generating portion shown in FIG. 2 in the deposited film forming apparatus of the present invention is roughly divided into two parts. One is a cylinder 201 with an insulating exterior and a linear central conductor 2 inside.
03, and the tip of this coaxial cylindrical portion is sealed to isolate it from the outside, and has a shape with an external protrusion 205 of the center conductor. The other is the connection part 210 to the coaxial cylinder part.
The central conductor 207 is connected to the linear central conductor 203 and has a plate-like shape. The coaxial cylinder part 201 is continuously connected to the flat cylinder part 204 at a joint part 210. Center conductor 203, 207 and outer coaxial tube 201, 204
There is a space between the two, and a plasma is excited in this space by raw gas for active species introduced from the gas inlet 206 and electrical energy introduced from the outside. A cylinder 201 made of an external insulator and a flat cylinder 1
The material of 04 is usually glass such as quartz, AI. 0,. S
iN. Ceramics such as BN are used. The inside and inner wall of the cylinder made of these materials may be coated with an insulating coating.

The center conductor is usually a metal that is a good conductor, such as copper, aluminum,
Brass or the like is used, but it may be plated with Ni or the like to prevent reaction with reactive gases. Regarding the shape of the part that generates active species, it is sufficient that a coaxial mode discharge is formed in the cylindrical part, and the flat part only needs to have a shape that allows this discharge to spread smoothly. Figure 3 shows an example of a coaxial antenna with a different shaped active species generating section. In the apparatus of the present invention, since the coaxial tube is flat, the plasma is formed in the form of a sheet, and it is possible to process (etch, deposit, oxidize, etc.) a long substrate with the plasma.
Also, moving these bases and controlling the magnetic field,
For example, it is possible to further increase the uniformity by increasing or decreasing the strength of the magnetic field or by using a rotating magnetic field. The strength of the magnetic field used is preferably 100-1200 Gauss, more preferably 200-1000 Gauss in the vicinity of the substrate.

Figure 4 shows an example of the large-area LFI film deposition apparatus of the present invention.
The device shown in FIG. 4 uses a roll type substrate as a base, and
This is a device that continuously deposits N-structured films. roll 481
A substrate 411 is supplied, preheated by a heating holder 470 in a vacuum container 461, and sent to the next vacuum container 401. A substrate heating holder 410 is installed in the vacuum container 401.
is installed, and has an activation section consisting of a coaxial pipe shown in Fig. 2 from the top, and J, J,
Excite a mixed gas of H2 and A with plasma to remove active species. At the same time, a raw material gas serving as a precursor is introduced from the gas inlet 416, and a film is deposited on the substrate 4[1] which extends over the holder 410.

In the next vacuum container 421.44L, a different i? It is possible to deposit different types of films using raw material gases that serve as precursors.

The uniformity of the film was determined using a microwave power source of 2.45 CIIz.
The microwave energy from 9,439.459 is adjusted by each tuner 405, 415, 420,..., and the electromagnet 4 for generating a magnetic field placed in the vacuum container.
By changing the size of 08.428 and 448, it is possible to adjust the degree of plasma expansion to obtain a good result. In this case, the strength of the magnetic field is preferably 1 near the substrate.
00-1200 Gauss, more preferably 200-100
It is 0 Gauss. Specific examples of the present invention will be shown below.

Using the deposited film forming apparatus of the present invention shown in FIG. 1, which has an active species trapping section made of a coaxial tube shown in FIG. 2, an amorphous silicon thin film was deposited by the following operations did.

First, the vacuum container 101 is set to a vacuum degree of I
After the vacuum pump 113 was used to pull the glass substrate to a temperature of 50 mm x 300 mm, a glass substrate of 50 mm x 300 mm was placed as a base on the heating holder 110 and heated until the substrate temperature reached 200°C. Next, the raw starch gas inlet 106 for active species
I{. =20sec. A r =
A mixed gas of 250 scCn was introduced into a coaxial tube (cylindrical part inner diameter 30 mφ, flat part length 500 mm), and 40
Added the power of W. Next, a current was passed through the magnetic field generating coil of the electromagnet 108, and the strength of the magnetic field at a distance of 5 cm above the glass substrate was set to 300 Gauss. A three-stap tuner (not shown) is located between the power supply and the main unit for tuning.
Then, the tuner 105 at the end of the waveguide and the tuner 106 at the end of the coaxial center conductor are adjusted, and the pressure in the deposition chamber is adjusted to 0. 1
The discharge was excited after being maintained at 5 Torr. The discharge was weak inside the coaxial tube, and extended to the vicinity of the glass substrate, maintaining a stable width of 30 cm.

Next, SiF4 gas was introduced for 10 minutes at a flow rate of 30 sec from the raw material gas inlet 116 for the precursor using a gas flow controller (not shown) and a mass flow controller (not shown). -Si
(H, F) The membrane was deposited.

When the uniformity of the film obtained by the above method was measured, it was found that 3
The distribution was within ±5% within the 00 am x 50 mm glass substrate. Next, 20 m of /l gear and pull electrodes (t-pole spacing: 200 pm) for conductivity measurement were formed by vacuum clamping at 25-square intervals on the sample surface vertically and horizontally, and the dark conductivity at each part was measured. rate, photoconductivity (633 nm, 4×10”ph
otons /d ・S monochromatic light irradiation) and its variation were measured. As a result, the dark conductivity was 1.2 X I O-”S/c
m (300 k) within ±5%, photoconductivity is 2.3
The value was within ±7% of ×10-'S/cm (300k), and it was confirmed that a high-quality film was deposited almost uniformly.

Using the same deposited film forming apparatus of the present invention as used in Example 1, an amorphous silicon and genomicanium thin film was formed on a glass with a size of 50 mm x 300 am by the following operations. deposited on the substrate. Regarding the deposition procedure and various conditions during deposition, the precursor gas for the film forming raw material is S +
Fe gas 3Qsccm and GeF41. O scc
The conditions were exactly the same as in Example 1, except that the gas was added to the gas and introduced into the vacuum vessel through the gas inlet 116. 7200 a-SiG films were deposited on a glass substrate with a deposition time of IO minutes.
e (H,F) film was deposited. The uniformity of the film obtained by the above method had a distribution of ±6% within the 300 m x 5 Qm substrate.

Next, the conductivity distribution was measured in the same manner as in Example 1. Dark conductivity is 1. l X 10”'S/cm (30
Within ±7% of 0 k), photoconductivity is 1.2 X I O
-'S/cs (300 k) within ±7.5%, and it was confirmed that a good quality film was deposited almost uniformly.

Using the deposited film forming apparatus of the present invention shown in FIG. 4, which has an active species generating section consisting of a coaxial tube shown in FIG. 41 film was formed, and this device was used to form a vacuum container 4 on the stainless steel substrate.
A pin type solar cell was fabricated by depositing an n-type layer in 01, an i-type layer in vacuum vessel 421, and a p-type layer in vacuum vessel 2i441. Among the film forming conditions, each gas inlet 406.4
+6426.436.446, /156, the flow rate of the gas species and the applied microwave power were changed as shown in Table 1, respectively. Film deposition was performed at a speed of one person/see. In the preserved film, the n- and j-type layers were amorphous and the p-type layer was microcrystalline.
A mask with a +M window was used to form a film with a thickness of 600 mm, and a comb-shaped main pole for extraction was formed using a mask to a film thickness of 2 μm. 30caX3Q. c.
Variations in the characteristics of nine pin cells (product 1-) within a m-square size were measured. 100mWecJA's AM-
1 was irradiated and the open circuit voltage and short circuit current were determined at 7Illll, the open circuit voltage was within ±2%, short circuit lightning? k was within ±6%, confirming high uniformity. [Summary of Effects of the Invention] According to the deposited film forming apparatus of the present invention, even when the substrate has a large area or is continuous in the form of a roll, the activating device can be used without increasing the size or number of activation devices. A high-quality, uniform deposited film can be formed, and the deposited film forming apparatus can be simplified.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an example of the deposited film forming apparatus of the present invention, and FIG. 2 is a schematic perspective view showing an example of the deposited film forming apparatus of the present invention. FIG. 3 is a diagram showing another example of the active species introduction part of the deposited film forming apparatus of the present invention, and FIG. The figures are a schematic diagram (A) of the deposited film forming apparatus of the present invention applied when using a roll-shaped continuous substrate and a side view (B) of the active species generation section. lot, 401.421,441...vacuum container, 10
2,202,302,402,422.442...Coaxial tube, 103,403,423,443...Waveguide, 1
04...Waveguide population, lQ5.115,405,41
5,420,425,435,440,445,455
,460...tuner, 106,116206,3
06,406,416,426.436446,456
...Gas inlet, 107, 203, 207, 208,
303,307,308.407427,447...
Center conductor, 108,408428.448... magnet,
109.209...4 wave path termination, 110,410,4
30,450...Heating holder, 111,411...
・Substrate, 1 1 2, 4 1 2.432 452・
...bulp, 1 1 3,4 1 3,4 3 3,4
53...Bomb, 114...Pressure gauge, 201,30
1 cylinder, 204.30.1... flat shape, 205,3
05...Conductor external protrusion, 210...Joint part, 41
9 439.459...Microwave power supply, 481
482...Roll, 4 8 3, 4 8 4, 4
8 5,486...Gas Gate. Figure 1

Claims (1)

[Claims] a vacuum container, a means for holding a substrate for forming a deposited film in the vacuum container, a means for introducing into the vacuum container a precursor that becomes a raw material for forming a deposited film, and an activity that interacts with the precursor. The method comprises a means for generating a species and introducing it into the vacuum container, and a means for evacuating the inside of the vacuum container, and allows the precursor and the active species to interact in the vacuum container to form a deposited film on the substrate. The deposited film forming apparatus is characterized in that an active species generating section of the means for generating and introducing active species comprises a coaxial antenna having a flat shape, and the active species generated at the coaxial section is introduced into the vacuum container. Deposited film forming equipment.