JPS63177416A - Film forming apparatus - Google Patents

Abstract

PURPOSE:To form a plurality of films having different materials or characteristics to have desired characteristics without influence of a material used in a previous step by providing conveying means for moving a plurality of reaction chambers without exposing a substrate to be treated to the atmosphere therebetween. CONSTITUTION:A plurality of reaction chambers 45, conveying means for moving a substrate 31 to be treated at the chambers 45 without exposing it with the atmosphere, means 40-42 for introducing reaction gas into the chambers 45, means 36 for exhausting the gases of the chambers 45, means 35 for heating the substrate 31 of the chamber 45, and means 33 for supplying induction energy for decomposing and activating the reaction gas to the gas at a position separate from the substrate 31 of the chamber 45 are provided. Thus, since a plurality of films of different materials are manufactured in a reaction furnace, the influence of the material used in a previous step is not affected to the manufacture of a film in a next step. Further, a film in which no specific material is irregularly disposed or so-called lumped cluster is not presented in the film to be formed can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a semiconductor or conductor film on a substrate by a vapor phase method.

In the present invention, after producing a film containing a semiconductor, especially silicon, as a main component, hydrogen in an active state is filled into the film together with helium or neon, so that induction energy (high frequency or microwave energy) is used to chemically transform the film into an active state. The present invention relates to a method of immersing a substrate on which a semiconductor film is formed in a hydrogen or helium atmosphere.

Conventionally, when attempting to produce a film containing silicon as a main component, particularly a silicon film, a vapor phase method, particularly a reduced pressure vapor phase method, has been known. This reduced pressure gas phase method was invented by the present inventor and is fully described in Japanese Patent Publication No. 1389/1989. However, this reduced pressure vapor phase method is intended to produce a film with a uniform thickness over a large area on a large number of substrates, and silicide gas, especially silane, is thermally decomposed at a reduced pressure of 0.1 to 10 T orr. The film was intended to be formed on a substrate, and the temperature required to form the film was a high temperature of 600 to 800°C. However, this high-temperature treatment is permissible if the substrate is made of semiconductor silicon or a heat-resistant ceramic material such as silicon compound such as silicon oxide or silicon nitride, but if the substrate is made of an organic material such as epoxy or glass or has a certain degree of thermal expansion coefficient, This has become a very serious drawback when using large, fragile substrates (eg glass) or substrates coated with conductive films.

On the other hand, the film is formed at a low temperature ranging from room temperature to 300°C, but the glow discharge method is known as a method in which the film formed on only one substrate has a very non-uniform film thickness. .

This means that a ~2cm square or ~3cm diameter substrate can be
The substrate is immersed in an atmosphere with a reduced pressure of ~1 O Torr, particularly 0.1 to 1 Torr, and a silicide gas, particularly silane, is introduced into this reactor, and at this time, the vicinity of the substrate is caused to glow discharge by an induction furnace, thereby activating the silicide gas. It forms a film on top.

However, in this case, it is necessary to mix hydrogen into the coating many times, so the carrier gas is 100% hydrogen, and the silane is also 100% or a method using a cylinder diluted with hydrogen, nitrogen, or argon gas is known. It is being

However, the present invention allows for multi-meter production, and the number of substrates is 10 to 10.
The film is uniformly formed on a large area of 20 cm square, and the substrate temperature required to create this film is room temperature to 400°C.
A major feature is that it is possible with

For this purpose, the present invention performs the chemical activation or reaction of the reactive gas at a location away from the substrate, and the activated state σ
It has been experimentally discovered that the duration of the reactive gas is maintained by surrounding it with helium or neon, and that the helium or neon forms a homogeneous film on the surface on which the reactive gas is formed.

Examples will be described below with reference to the drawings.

Example 1 The substrate can be a conductive substrate (stainless steel, titanium, titanium nitride, or other metal), a semiconductor (silicon, silicon carbide, germanium), an insulator (organic material such as alumina, glass, epoxy, polyimide resin, etc.), or a composite substrate (insulating A transparent S-electrode film such as tin oxide or ITO is formed on a substrate, a conductor electrode is selectively formed on an insulating substrate, and a P or N type semiconductor is formed in a single layer or in multiple layers on a substrate. (formed) was used. These are collectively referred to as a substrate not only in this embodiment but also in all of the present invention. Of course, this substrate may be flexible or may be a rigid plate.

In FIG. 1, a substrate 1 is placed next to a boat (eg quartz) 2. In FIG.

In this example, a 10 cm square substrate with a thickness of 200 μm was used. This substrate was sealed in a reactor 3.

This reaction vessel is 1-100MH7, for example 13.6MH7
The reactive gas and the substrate can be excited, reacted, or heated by high frequency energy from the high frequency heating furnace 4 of No. 2. Furthermore, a heater 5 using resistance heating is installed outside of the heater 5. Exhaust is performed from 6 through valve 7 and through air pump 8. The reactive gas reaches the inlet 9 and is chemically activated, decomposed or reacted at a position away from the substrate by microwave energy of high frequency induction energy 1o, here 1 to 10GH71, for example 2.46GH2. In this container 7 of 10 parts, reactive gases such as silicon compounds such as silane (S r H4>, dichlorosilane (Si 82 C12), P or N type impurities mixed in as required, and germanium or , tin, lead, or a reactive gas containing nitrogen or oxygen. In addition, in the present invention, neem or neon is mixed in an amount of 5 to 99%, particularly 40 to 90%. The energy 10 chemically activates these reactive gases, and further causes some of them to react with each other.

Reaction system 3 (including container 7) is 10-3 to 102T or
In particular, it was set to 0.01 to 5 Torr. In order to carry out chemical activation from the surface on which the formation is performed, there is a method using a catalyst proposed by the present inventor in a gas phase method.

For example, Special Publication No. 49-12033, Special Publication No. 53-145
No. 18, Special Publication No. 53-23667, Special Publication No. 51-13
Please refer to No. 89. The present invention is a catalyst vapor phase method in which the activation of the catalyst is actively utilized by high-frequency induction energy, thereby making the chemical activation or physical excitation more complete. be.

The reactive gas is silane (SiH) for the silicide gas 14.
>, dichlorosilane (S i H2Cl2), trichlorosilane (S + HCI 3), silicon tetrachloride (Sf
CI4) etc., but silane that is easy to handle was used.

Dichlorosilane is cheaper and may be used.

Boron as a P-type impurity from diborane 15 to 1011
C11-3 was added to a concentration of 10 mol%, and as an N-type impurity, phosphin (PH3) was added at 10 c
The concentration was adjusted to 20 mol %.

It may also be arsine (ASH3). carrier gas 1
2 is helium (He) or neon (Ne) during the reaction
Alternatively, these inert gases were mixed with 5 to 30% hydrogen, but low-cost nitrogen (N) was used in the form of liquid nitrogen before and after the start of the reaction.

Furthermore, additives such as tin (Sn) and germanium (G) are added.
e) For carbon (C), nitrogen (N), and lead (Pb), gases of their hydrides or chlorides were introduced from 13. When these reactants were liquid at around room temperature, the liquid was bubbled and vaporized using helium, and then introduced into the reaction system 3 using helium.

The reaction system initially contains oxygen, etc. that adhered to the inner wall of the container at a rate of 800 to 1
The boat 2 with the substrate 1 inserted therein was placed into the container 3 from the exhaust port side. After that, this container 3 was evacuated by the vacuum system 8, and 10-3T
It even went down to orr.

Furthermore, the reaction system was purged by flowing gas or neon from No. 12 for a while. In addition, high frequency energy is applied to the container 7, and reactive gases 13.14, 15.1 are
The required amount from 6 was introduced into container 7 and mixed completely. After that, I asked Reactor 3. At this time, excitation or activation may be promoted by high frequency energy 4 of 10 to 300 W.

The growth rate of the coating is shown in FIG. As is clear from the drawing, the reactive gas was applied at 10CI11~ from the 5 surfaces to be formed.
Even if the distance is 3m, for example, close to 1m, if the carrier gas is helium or neon, which accounts for 5 to 99% of the total introduced gas, for example 70%, a film will be formed as shown by curve 22, and the uniformity of this film will vary depending on the formed film. When the thickness was tested on 5000 people, it was within ±2% both between lots and within a lot.

For reference, when this carrier gas is the same amount of nitrogen, it is 2
3, and almost no film was formed. Also, when 15-30% hydrogen (H2) is added to helium,
The uniformity of the film was poor at ±3 to 4%. When microwave energy was applied at a distance from the substrate, the growth rate was 22, whereas when high-frequency energy was applied at 4, the growth rate was 21, which did not increase the growth rate much.

The film formed using helium or neon as a carrier gas has a polycrystalline or amorphous non-single crystal structure because the temperature is as low as room temperature to 400°C.

It is known that this non-single crystal structure generally has a large number of dangling bonds, and for example, when nitrogen is used as the carrier gas in the apparatus of the present invention, the density of the recombination centers is 1020~
io 22cm-3, which is a lot.

However, when helium or neon is used as the carrier gas, these gases, especially helium, can move freely in the film, which has the effect of activating unpaired bonds and covalently bonding them to neutralize them. Therefore, the density is 10~
We were able to lower it to 1019cm-3.

However, in this case as well, if it is to be used as a semiconductor, it is necessary to lower this density to 1015 to 1016 cm. For this reason, a method is generally known in which a film is formed by activating hydrogen using hydrogen as a carrier gas, and neutralizing the hydrogen by bonding it to a dangling bond. However, when this hydrogen is used as a carrier gas instead of helium, the uniformity of the film becomes extremely poor, and under the same conditions as the apparatus shown in Figure 1, it is ±8%.
It has become.

Therefore, in the present invention, the carrier gas is helium or neon to form a uniform film, and after this film has been roughly formed, helium is added to hydrogen or hydrogen in the same reactor or in a different reactor. The mixed gas was chemically activated by induced energy. In the apparatus shown in FIG. 1, the high-frequency induction furnace 4 was used. At this time, it is preferable that the induced energy be directed perpendicularly to the substrate to facilitate injection and neutralization of hydrogen or helium into the substrate. This semiconductor layer is optically annealed using a laser or similar strong light energy (e.g., a xenon lamp) to convert the non-single crystal semiconductor into a single crystal, and after this single crystallization or at the same time as the subsequent annealing. Neutralization using hydrogen or helium using this induction energy is extremely effective.

In particular, the carrier mobility is 10 to 10 by laser annealing.
0 times, which is close to the ideal state of a single crystal. However, this single crystallization alone reduces the density of recrystallization centers to 10
〜1015cm−3, 10 to 1
It remained at 019 cm-3. Therefore, induced energy annealing performed after or simultaneously with laser annealing has a great effect on producing ideal single crystal semiconductors.

As a result, it is possible to make a single layer of a film as a P-type or N-type semiconductor, as well as to form a PN junction, PIN junction, PNPN junction,
N' P N... It was also possible to freely create multiple PN junctions, etc. Therefore, the coating produced by the method of the present invention can be applied to semiconductor lasers, light emitting devices, and photoelectric conversion devices such as solar cells. Of course, it can also be applied to MIS type field effect transistors, integrated circuits, etc., and has great value.

When using the microwave shown in FIG. 1, a magnetron or the like is used for the microwave energy.

However, since it is practically difficult to emit strong energy, in industrial production, activation at a position distant from the substrate may be performed using high frequency induction energy of 1 to 100 MHz.

Activation, excitation, or reaction of reactive gases by radiofrequency energy at a distance from the substrate is 0°5 to 3 m, especially 1
~Even if you are nearly 1.5m away, the system pressure is 0.01~10
At Torr, there was almost no decrease.

Example 2 Example 2 will be described with reference to FIG.

This drawing shows PN junction, PIN junction, P N P N junction, PNPN...... PN junction or Schottky junction of MIS structure, etc. on a semiconductor on a substrate of W type conductivity type or same type i9 conductivity type. This is an apparatus for automatically and continuously forming multiple semiconductor layers.

That is, in order to uniformly form a film on the objects to be formed by stacking a large number of large substrates on top of each other in pairs, the present invention reacts or activates a reactive gas at a position away from the substrates. , and the reaction product or reactive gas in the active state can be conveyed to the surface to be formed using a carrier gas with a high ionization voltage (24.19 eV 121.59 eV) such as helium or neon while maintaining the reaction state. extremely important.

This device is installed on the substrate 31, 31' from the inlet side of the substrate 30.
is inserted into the container 45 and moved to the container 45 by opening and closing the chamber 44. In the embodiment of the present invention, the back surfaces of two substrates are overlapped to double the effective formation surface for reaction products and to reduce the actual amount of reactive gas used by half. I made it.

Thereafter, the reactive gases 40, 41, and 42 already described in Example 1 are introduced into the excitation chamber 32 by opening and closing the valve 38 to this substrate.
to be introduced. In this 32, high frequency induced energy 3
3, the reactive gas and the carrier gas are chemically excited, activated or reacted, and then introduced into the container 45 via the homogenizer 34. A substrate 31 is inserted into this container, and if necessary, this is rotated at 3 to 30 revolutions per minute, for example, 6 times per minute, in a direction such as 50.50' in FIG. 32 side of the introduction part and the exhaust part 36
This effectively eliminates variations in the film growth rate from side to side and makes it uniform. This is to improve the uniformity of the formed film.

Furthermore, this substrate reacts with high frequency induction energy 35,
Excited, unnecessary reaction products and carrier gas are exhausted by a vacuum pump 36.

This exhaust gas 37 is configured with the same loop in which impurities and residual reaction products are then removed by a filter and a trap, and a carrier gas such as helium is purified by a purifier and is again introduced into the carrier gas 40. This also applies to the exhaust gases 37', 37'', and 37'''.

In the above manner, a film mainly composed of silicon of a predetermined thickness, for example, 10 to 10 μm, is formed under light weight.
In this case, an impurity exhibiting I2, P-type or N-type conductivity is deposited on the substrate at the same time as the film is formed and mixed into the film.

After the treatment of system (1) was completed, reactive gases and flying reaction products from this system were exhausted and removed.

After this, move the boat with the substrate planted on the thread (■).

During this movement, the pressures in the containers of system (1) and system (2) must be the same. Similarly to system (2), a film containing silicon as a main component is formed in the second yarn (2) according to the design. At this time, the board in the system (■) moves to the system (2), the board in the system (2) moves to the system (2), and the board in the system (2) moves to the exit 59.

The respective light weights ~■ indicate the system of P-type film formation, I-type film formation (in a state where impurities are not artificially mixed), N-type film formation, and induction annealing. However, the junction is P
If junctions such as PNl, Pll 12N, PNPN, etc. are made instead of IN, with their planes approximately parallel to the substrate surface, the number of systems will be increased or decreased accordingly.

In the present invention, a film is formed parallel to the surface of the substrate according to the same chemical proviso, and the impurity m is also Ge regardless of its type.

Additives such as Sn, Pb, N, O, and C are also uniform in the surface direction. However, it is possible to control the EQ (energy band gap) in the direction in which the film is formed by changing the m1 types of In, Qe, C, NSO, and this is also a major feature of the present invention. . Also in this case, the energy bandgap can be varied continuously by varying the amount of additive via valves 38, 38'.

As described above, in the present invention, when silicon carbide is formed on the surface of the substrate, a reactive gas is chemically activated, excited or reacted at a position away from the substrate, and at this remote position, Silicon, impurities, and additives were chemically thoroughly mixed. As a result, a specific material was present throughout the resulting film, and a film was formed in which so-called massive clusters were not present. This is also a feature of the present invention.

In the embodiments of the present invention, silicon was mainly used. However, by adding nitrogen to this silicon, Si N (
0<x<4), germanium 4-x was added to form SiGe (0<x<1), sx
1−x Sn (Q<x<1), x
1-x Si Pb with the addition of lead (0<x<1), x
1-X Add oxygen to 3i Q2-x (Q<x <2>
, carbon may be added to prepare a mixture such as s+c (0<X<1). Also, depending on the value of these X, not only 3i but also Ge, S
n, etc. may also be formed. Depending on the purpose, it is also possible to simultaneously mix P- or N-type impurities into these semiconductors. In particular, conductive impurities such as In and zn are added in addition to B as P-type impurities, and N
Sb, Te, or Se in addition to P as type impurities
may be added to improve the activity of impurities.

In the present invention, the inert gas used as a carrier gas is limited to helium or neon. The ionization voltage of helium is 24.57 eV, and that of neon is 21.59 eV.
V and other inert gases such as Ar, Kr, N2
is 10 to 158V, which is smaller than the first two. As a result, this He or Ne maintains its ionized state for a long time and has a large active energy. As a result, He or Ne
It is presumed that when the reaction product is formed into a film on the surface to be formed, a uniform film is formed and the substantial mean free path of the reactive gas is increased. These were obtained from experimental facts, and in particular, when trying to uniformly produce a semiconductor film on a large 10 to 30 cI11 square substrate like the device of the present invention, helium becomes active at a position far away from the reactive gas. It has the great feature that a highly uniform coating can be obtained even if the necessary chamber is made as small as practical.

Furthermore, in the embodiments of the present invention, it is mainly stated that the film is a semiconductor. However, this coating is also effective for forming a single or multiple layer of tin, indium or antimony oxide or nitride constituting a conductor, particularly a transparent electrode. Then those halides, such as tin chloride (SnC14)
The liquid of indium chloride (■n2C13×H20) is bubbled in helium, and the vaporized and atomized reactive gas is chemically activated in a high-frequency induction furnace, and then the coating surface located further away from it is chemically activated. It may also be produced as a coating on top.

In particular, when producing one or both electrodes of a semiconductor device that uses light such as a solar cell, a transparent conductive film is applied before or after forming a semiconductor layer according to the present invention. It is possible to make the electrode by continuous formation, which allows for an engineering-consistent flow of the electrode.

Further, as the transparent conductive film, nitrides such as titanium nitride, tantalum nitride, tin nitride, etc. may be used instead of oxides. At this time, chlorides such as titanium, tantalum, tin, etc. may be reacted with a nitride gas such as ammonia as a reactive gas.

The substrate may be GaAs or GaA other than those mentioned in Example 1.
It goes without saying that it may be made of a compound semiconductor such as IAs, sp, or CdS.

P- or N-type impurities are selectively implanted or diffused into the semiconductor or conductor coating formed by the present invention, particularly the semiconductor coating mainly composed of silicon, using photoetching technology.
A transistor, a diode, a visible light laser, a light emitting element, or a photoelectric conversion element using this junction may be fabricated by partially forming an N junction and further performing laser annealing partially as necessary. In particular, a PI with an energy bandgap of W-N (WIDE TONALLOW) configuration (2 to 3 c on the W side and 1 to 1.5 eV on the N side)
A N1MINPN junction, a PNPN junction, or a MIPN junction type structure may be used, and a transparent conductive electrode according to the present invention may be formed on the upper surface thereof to serve as an antireflection film. In this way, the photoelectric conversion efficiency can be improved to 15 to 30%, which is industrially useful.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of a manufacturing apparatus for forming a semiconductor film, particularly a silicon film, according to the present invention. FIG. 2 shows the characteristics of the coating obtained by the method of the present invention. FIG. 3 is an example of another manufacturing apparatus for implementing the present invention.

Claims (1)

[Scope of Claims] A plurality of reaction chambers; a transport means for moving substrates to be processed between the plurality of reaction chambers without exposing them to the atmosphere; and means for introducing a reaction gas into the reaction chambers; means for evacuating gas from the reaction chamber; means for heating the substrate to be processed in the reaction chamber; and induction for decomposing and activating the reaction gas at a position away from the substrate to be processed in the reaction chamber. 1. A film forming apparatus comprising: means for supplying energy.