JP2649330B2 - Plasma processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing method.

[0002]

2. Description of the Related Art Conventionally, an electrode for applying electric power provided in a reaction space is a pair of parallel flat plates, and one of the electrodes is used as a film forming surface. The film formation rate on the film forming surface in such a system is about 1% to 3%. In the conventional plasma gas phase reaction method,
A plasma discharge or a glow discharge is generated between the pair of parallel plate electrodes, and a semiconductor film or the like is formed on the substrate surface.
In the method using only such a pair of electrodes, the uniformity of the coating can be suppressed to a range of variation within ± 5%. But,
In the above method, the film formation surface cannot be made larger than the electrode area. For this reason, the above method has the disadvantage that it is completely unsuitable for mass production.

On the other hand, a substrate for film formation is provided between parallel plate electrodes, and a large number of substrates are separated from each other by a predetermined distance (2 cm to 6 cm) so that the electric field is substantially parallel to the surface on which the film is formed. There is known a method of vertically arranging and arranging them. An example is a patent application filed by the present applicant (plasma gas phase reactor, Japanese Patent Application No. 57-167280 filed on Sep. 25, 1982). That is,
Since a so-called floating plasma gas phase reaction method in which a substrate is released from any electrode in terms of potential and a gas phase reaction is carried out in a positive column is used, a film can be formed on a large number of substrates. . According to the above method, the productivity can be improved by 5 to 20 times as compared with a method of disposing a substrate on one electrode of a conventionally known parallel plate type electrode.

However, in such a floating plasma gas phase reaction method, the uniformity of the obtained film thickness is as shown in FIG. 1 as an example, as described later. Further, as another conventional example, the 40th Proceedings of the Japan Society for Response Science, (1979-9), P.S. No. 316 describes that a high-frequency electric field is applied to the substrate in a horizontal direction, and additionally, a DC electric field is applied to the substrate in a vertical direction.

[0005]

FIGS. 1A to 1E are diagrams for explaining the nonuniformity of the film thickness on a substrate obtained by a conventional plasma gas phase reaction method. FIG.
(A) shows the relative positional relationship between the substrate (5) and the electrodes (23) and (25). The substrate (5) has about 50
A silicon film is formed to a thickness of 00 °. As shown in FIG. 1C, the silicon film formed on the substrate (5) becomes thicker near the pair of electrodes (23) and (25). Further, as shown in FIG. 1 (B, D, E), the substrate (5)
3), the central portion of (25) becomes thicker, or the end portion of the substrate (5) becomes thinner. For this reason, the film thickness formed at the upper and lower ends (corners) of the substrate (5) is
It is 20% to 30% thinner than the thickness of the upper and lower ends of the center.

That is, in the floating plasma gas phase reaction method proposed by the present applicant, since the surface on which the film is formed is floating in terms of potential, the electric charge charged up on the substrate (5) and the electric charge in the plasma Ions repel each other. Therefore, the active particles in flight are less likely to sputter on the surface on which the film is formed. Further, in order to promote this, the high-frequency electric field used for the plasma reaction is supplied in a laminar flow so as to flow along the film formation surface. That is, the high-frequency electric field is disposed so as to be substantially parallel to the film formation surface.

[0007] The present invention is intended to solve the above problems, and an object thereof is to provide a plasma processing method for performing a plasma treatment.

[0008]

Means for Solving the Problems (First invention) In order to achieve the above object, a plasma processing method according to the present invention comprises: a plurality of electrodes arranged orthogonally to a film forming surface of a substrate; of electrical energy and a oscillator for supplying, in a plane parallel with respect to the film forming surface of the substrate
The film is formed while oscillating an electric field from the plurality of oscillators for supplying electric energy at the same frequency having different phases for generating a Lissajous pattern.

(Second Invention) A plasma processing method according to the present invention includes a plurality of electrodes arranged perpendicular to a film formation surface of a substrate, and a plurality of oscillators for supplying electric energy. in a plane parallel to the film forming surface of, characterized in that the electric field to form a film while oscillating the different <br/> comprising frequency to generate a Lissajous pattern from said plurality of oscillators of electrical energy for supplying .

[0010]

[Operation] A plasma is generated to introduce a reactive gas into a reaction space and form a film on a substrate. The plasma is generated by an electric field applied from a plurality of electrodes and a plurality of oscillators for supplying electric energy in a plane parallel to a film formation surface of a substrate provided in the reaction space and orthogonally arranged. . Also, the electric field generated from the plurality of electrodes and the oscillator, by a Lissajous pattern, the density of the electric field with respect to the film forming surface of the substrate is made uniform, preventing to become also the field density decreases at the substrate end, Note The thickness is made more uniform.

An electric field generated from a plurality of oscillators for supplying electric energy can have a Lissajous pattern drawn by using the same frequency having different phases or different frequencies. In addition, since the surface of the substrate on which the film was formed was set at a potential that was electrically floating (floating) from the plurality of electrodes, the extent to which plasma energy sputtered the surface of the substrate on which the film was formed could be reduced. In addition, film type
The surface is averaged by sputtering using the Lissajous waveform.
Therefore, the film quality and thickness can be made uniform. In addition, film type
Placed in a plane parallel to and perpendicular to the formed surface
The electric field density applied to the film-forming surface of the substrate from the plurality of electrodes is not only made uniform, but also larger than the electric field generated only by the pair of electrodes, so that the film-forming speed can be improved.

[0012]

[Embodiment] One embodiment of the present invention is a plasma gas phase reaction apparatus for preventing a reactive gas from being dispersed all over a reaction chamber, wherein the reaction chamber has a cylindrical shape utilizing the outer shape of a substrate. It is shaped like a space. In this cylindrical space, the substrate is disposed in parallel with the back surfaces thereof in close contact with each other, and the film-forming surface of the front surface is separated by a certain distance, for example, 2 cm to 10 cm, typically 4 cm to 6 cm. I have.
In addition, the reactive gas is selectively guided into the cylindrical space where the substrate is formed, and the plasma discharge is selectively performed only in the cylindrical space. As a result, the collection efficiency of the reactive gas was increased from 20% to 50%, which is 10 to 30 times that of the conventional 1% to 3%. Further, in one embodiment of the present invention, when a film is formed repeatedly a number of times, the flakes adhered and formed on the upper part of the reaction chamber at that time fall on the film forming surface of the substrate and induce the generation of binholes. In order to prevent this, the film forming surface of the substrate is vertically oriented along with gravity.

One embodiment of the present invention is a method for manufacturing a semiconductor device, comprising the steps of:
In order to promote uniformity of film thickness in the lower part, central part and peripheral part, and uniformity of film quality, rod-shaped infrared lamps are arranged perpendicular to each other from above and below, so that the entire cylindrical space is heated uniformly. Was planned. That is, the rod-shaped infrared lamp is
Its cross-sectional area is 10 cm ² and its length is 10 cm in the electrode direction.
cm to 60cm, width 15cm to 100c
m substrate, for example, a substrate of 20 cm × 60 cm, has a temperature distribution of 100 ° C. to 650 ° C.
It is characterized in that the temperature is within 00 ° C. ± 5 ° C.

In one embodiment of the present invention, a continuous production system is used as a basic condition, and in addition to improving the properties of the coating in the reaction chamber, unnecessary reaction products are prevented from adhering to the inner wall of the reaction chamber.
In one embodiment of the present invention, an apparent inner wall of the reaction chamber is formed as a side surface of the cylindrical space, so that a new inner wall is created each time a coating is formed, that is, each time a holder is newly installed in the reaction chamber. Therefore, even when the film is repeatedly formed, unnecessary reaction products can be prevented from being layered on the inner wall. That is, the embodiment of the present invention has a great feature that generation of flakes formed in the reaction chamber can be prevented.

Further, in one embodiment of the present invention, the outside of the electrode is covered with a supply hood, an exhaust hood, and an insulating hood (quartz or the like) at the inlet and outlet of the reactive gas, and the electrode is connected to the reaction chamber wall. Parasitic discharge was prevented, and a floating grid was provided between the electrode and the reaction space to prevent the anode dark area and the cathode dark area from extending in the reaction space. That is, a positive column region in which the electric field intensity in this reaction space was extremely small could be obtained. As a result, it was possible to prevent the sputter (reactive substance) having strong kinetic energy accelerated in the dark portion of the strong electric field in the reaction space from being sputtered on the film-formed surface and to improve the film quality.

Such a plasma gas phase reaction apparatus eliminates mixing of impurities of a lower (layer on which a film is formed) semiconductor layer already formed into another semiconductor layer to be formed thereon. The thickness of the mixture at the lamination interface of the semiconductor layers is 200Å to 300Å, which is about 1/10 to 1/5 of the conventional thickness, and the variation in film thickness within the substrate and between substrates of the same batch is ± 5%. Within (for example, 5000 $)
(The variation is within ± 250 °).

Hereinafter, a plasma gas phase reaction apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a view for explaining an apparatus capable of continuously performing a plasma gas phase reaction according to an embodiment of the present invention. FIG. 3 is a diagram for explaining an electric field generated by a plurality of pairs of electrodes according to an embodiment of the present invention. Specific Example 1 In FIG. 2, the plasma gas phase reaction apparatus includes a first preliminary chamber (1) for loading a substrate (5) from one side, and a reaction chamber (2) for performing a plasma gas phase reaction process. And a second preliminary chamber (3) for taking out the substrate (5) after the plasma gas phase reaction processing.

A gate valve () is connected to a connecting portion between the first preliminary chamber (1) and the reaction chamber (2) and a connecting portion between the reaction chamber (2) and the second preliminary chamber (3). 43) and (44) are provided. The gate valves (43), (44) are used to move the substrates (4), (5) and the holders (6), (7) from the first preliminary chamber (1) into the reaction chamber (2), and , Is opened for movement from the reaction chamber (2) to the second preliminary chamber (3). The gate valves (43) and (44) are used when the substrate (4) and the holder (6) are mounted from the door (11) in the first preliminary chamber (1) during the plasma gas phase reaction, When the substrate (5) and the holder (6) are taken out of the door (12) in the second spare room (3), the substrate (5) is closed. When mounting the substrate (4) in the first preliminary chamber (1) and taking out the substrate (4) from the second preliminary chamber (3), the first preliminary chamber (1) and the second preliminary chamber are used. Nitrogen is supplied to the chamber (3) from the inlets (20) and (32) to bring the pressure to atmospheric pressure.

The first preliminary chamber (1) has a guide (9) for mounting a substrate (4) and a holder (6) from the outside, and a door that can be opened and closed between the atmosphere and the first preliminary chamber (1). (11)
To heat and deaerate the adsorbate on the substrate (4) under vacuum
It comprises infrared lamps (15) and (15 '), and vacuum exhaust means (29) for exhausting the first preliminary chamber (1). After the gate valve (43) is opened, the substrate (5) and the holder (6) are moved from the first preliminary chamber (1) into the reaction chamber (2) which has been evacuated in advance. This move
Step motor (8) provided in the first spare room (1)
Done by

First, a holder (6) including a guide (9)
Is lifted about 1.5 cm above and then moved by extending a guide (9) into the reaction chamber (2). Further, after reaching the center of the reaction chamber (2), the holder (6) is lowered by stopping the guide (9) and lowering the guide (9) downward by about 1.5 cm. Then, a fin shaft (39) for receiving a disc-shaped disk above the holder (7) is provided at a position at an intermediate height thereof, where the holder (7) is held, and the cylindrical space (1) is held.
00) is formed.

Thereafter, the guide (9) passes under the disk and is retracted and stored in the original first spare room (1). Further, the gate valve (43) is closed. After this,
The first preliminary chamber (1) is brought to atmospheric pressure by supplying nitrogen from the inlet (20). During this time, the substrate (4)
Is mounted on a holder (6) attached to a guide (9). This operation is sequentially repeated. Next, a mechanism in the reaction chamber (2) will be described. The reaction chamber (2) includes a system (97) for supplying a reactive gas, a system (98) for evacuating, and electrodes (23) and (25) to be described later.
A first oscillator (21) for supplying high-frequency power to the power supply and a second oscillator (85) are also provided.

The system (97) for supplying the reactive gas is
A valve (51), a flow meter (52) as a ping system,
It is connected to a cylinder (not shown) via an inlet (33) for introducing a carrier gas and also inlets (34), (35) and (37) for introducing a reactive gas.
The inlets (34, 35, 37) are gaseous at room temperature, such as silicide gas, germanium gas, and doping gas for P-type or N-type (for example,
Cylinders such as diborane and phosphine are connected.
Liquids at room temperature, such as tin chloride, aluminum chloride and antimony chloride, are supplied from a bubbler via (36). Since these gases become gas under reduced pressure, they can be sufficiently controlled by the flow meter (52). The temperature of the bubbler (36) was controlled by an electronic thermostat for vapor deposition.

These reactive gases (34, 35, 37)
Is supplied from the supply port (27) to the nozzle (2) of the supply means (46).
Injected downward through 4). This nozzle (24)
Are formed with a large number of holes (42) of 1 mm to 2 mm, and are blown out uniformly over the whole. The back surface of the nozzle (24) is made of an insulating material to prevent a parasitic discharge from being generated on the inner wall of the reaction chamber (2). Further, a negative electrode (23) for plasma discharge is provided between the holes (42) of the nozzle (24). The negative electrode (23) is connected to a first oscillator (21) (10 KHz to 50M) for supplying electric energy via a lead (49).
Hz, for example 13.56 MHz or 30 KHz, 1
0W to 1KW). The other positive terminal (22) is connected to the nozzle (2) of the exhaust means (47).
4) A mesh or porous positive electrode (2
5).

Further, the second oscillator (85) (10 KHz)
To 50 MHz, for example 13.56 MHz or 3
0 KHz (10 W to 1 KW) is provided such that a second electric field is generated in the front-rear direction in the drawing. Also, changing the phase at the same frequency the frequency generated from the first oscillator (21) a second oscillator (85), or when the different frequency, the electric field becomes a Lissajous pattern, whereas the electric field only to a direction in addition, compared with the electric field pattern Deki by, we have become possible to produce a uniform coating to the periphery of the substrate surface.

Further, a pair of electrodes (23) and (25)
And a cylindrical space (100), a mesh (hole diameter is 1 cm to 3 cm) or a porous (hole diameter is 1c).
m to 3 cm) of stainless steel, and the floating grids (40) and (41) are used to form a cylindrical space (10) in which a dark portion generated by discharge is disposed in a positive column.
The surface of the substrate (5) is not sputtered. Due to the floating grids (40) and (41), the pressure in the reaction chamber (2) is from 0.01 torr to 5 torr.
Even if the pressure changes in the range of torr, the low pressure (for example, 0.05 torr) causes the dark part to have a cylindrical space (10 torr).
0) extended to, it reduces the spa <br/> jitter against the coating surface of the substrate (5). And, on the film formation surface, the spatter is light.
As a result, a good quality film can be formed.

The exhaust means (47) has substantially the same shape as the nozzle (24) for supplying a reactive gas, and both are made of transparent quartz (insulating film). The reaction product from (100), carrier gas, and unnecessary gas are made into a laminar flow and exhausted from an exhaust port (28) to a vacuum pump (30). At the time of film formation, the fin shaft (39) rotates while being vacuum-blocked from the external step motor (19). Therefore, the substrate (5) and the holder (7) held by the fin shaft (39) rotate at 3 to 10 rotations / minute to uniformly coat the film formed on the substrate (5). Let me.

Further, in such an apparatus, after forming a film by a predetermined plasma gas phase reaction, the substrate (5) and the holder (7) are moved to the second preliminary chamber (3) which has been evacuated. I let it. That is, the substrate (5) and the holder (7) are moved by opening the gate valve (44) after evacuating the gas in the reaction chamber (2) and the second preliminary chamber (3). For the movement of the substrate (5) and the holder (7), the guide (10) is extended from the right direction, reaches the reaction chamber (2), lifts the holder (7) about 1 cm, and then moves the guide (10). Again and taken out to the second spare room (3). Thereafter, the gate valve (44) was closed in the second preliminary chamber (3), and nitrogen was supplied from the inlet (32) to atmospheric pressure. Thus, a reaction chamber (2) as shown in FIG. 2, a first preparatory chamber (1), a second preparatory chamber (3)
In between, the plasma gas phase reaction is continuously processed. Needless to say, the substrate (5) and the holder (7) on which the film is formed are drawn into the first preliminary chamber (1) after the plasma gas phase reaction processing, so that the second preliminary chamber (1) is formed. It goes without saying that 3) may be omitted.

FIG. 3 is a longitudinal sectional view of one embodiment of the present invention as viewed from the side of the second preliminary chamber of the reaction chamber of FIG. In FIG.
A coating surface of the substrate (5), a first electric field (90) and a second electric field (90);
The direction of the electric field (91) is clearly shown. FIG.
, Halogen heaters are used for the heaters (18) and (18 '). Cylindrical space (100)
Was heated to 100 to 650 ° C, for example 250 ° C, by heaters (18), (18 '). The reactive gas decomposed, for example, silane. Furthermore, a first electric field (90) is supplied to the substrate (5) by a pair of electrodes (23) and (25) substantially parallel to the surface on which the film is formed, and at the same time, the first electric field (90) is supplied. 90) the second orthogonal to
A pair of electrodes (72), (8)
2), and a plasma gas phase reaction was performed. Each electrode (23), (25), (72), (82)
Is a first oscillator (21) and a second oscillator (85)
It is connected to.

In the cylindrical space (100), the reactive gas is supplied from the inlets (33), (34) and (38) to the supply means (4).
It is supplied in parallel to the substrate (5) via 6) and is evacuated by the vacuum pump (30) of the vacuum exhaust system (98) by the exhaust means (47). When amorphous silicon is produced from silane as a film to be formed on the substrate (5), the thickness of 5000 mm is 300 cc / min of SiH, the film formation speed is 20 mm / sec, and the substrate (20 cm × 60 cm is 20 cm).
Sheets, total area 24000cm ² ) and pressure 0.08torr
r. According to the plasma gas phase reaction of this specific example, in the conventional method, the central portion of the substrate (5) is 5000 ° (variation).
(± 20%), the peripheral portion in the vertical direction was 3000 ° (variation ± 20%) . In contrast, in this embodiment,
Is equal to 4500 ° (bath) in any part of the substrate (5).
(Fluctuation ± 5%), and the uniformity was extremely improved.

FIGS. 4 (A), (B), (C), (D),
FIG. 4E is a diagram for explaining the distribution when non-single-crystal silicon is formed to a thickness of 0.5 μm in FIG. In the cylindrical space (100), the substrate (5), the first electrode (23), (2)
5), the second electrodes (72) and (82) are arranged as shown in FIG. 4, and (A)-(A ') of the cylindrical space (100);
(B)-(B '), (C)-(C'), (D)-
FIG. 4 shows the thickness distribution of the coating in the cross section at (D ′).
(B), (C), (D) and (E) show. It was found that all of the cross-sectional views of the coating had extremely uniformity as compared with those of FIG. 1 and had a variation within ± 10% which was sufficiently practical.

Further, instead of neutralizing unpaired bonds of silicon or carbon with Si—H or C—H by hydrogen, instead of using Si—F, C—F and a halide, particularly a fluoride gas, Needless to say, this concentration may be less than 40 at%, for example, 2 to 5 at%. Regarding the type of semiconductor to be formed, as described above, it is not a single layer but a group 4 Si, Ge, SixC _1-x (0 <x <
1), Six Ge _1-x (0 <x <1), SixSn _1-x (0 <x <
1) or a plurality of layers in which junctions are provided by changing their conductivity types, and in addition, GaAs, GaAlAs,
It goes without saying that other semiconductors such as BP may be used.

Example 2 In Example 2, the plasma gas phase reactor of Example 1 was used.
A silane is supplied from the inlet (34) as a reactive gas to form a silicon semiconductor film. The temperature of the substrate (5) at the time of producing the silicon semiconductor film was 250 ° C. The silicon semiconductor film has a growth rate of 8 ° / sec and a high frequency (13.
56MHz) Electric field is 500W, silane is 300c
c / min, and could be obtained when the pressure during the plasma gas phase reaction was set to 0.1 torr. As a result, in the conventional plasma gas phase reaction apparatus, an electric field is applied by a pair of parallel plate type electrodes, and the film formation rate is 1Å / sec to 3Å.
/ Sec in the reaction vessel, for example, 60 cm × 60 cm
While the film was formed on one sheet, the plasma gas phase reaction apparatus of this example was 20 cm × 60 c
The total area was 8 times as large as 20 m, and a film was formed at a rate of 10 ° to 25 ° / sec, and a growth rate of 6 times was obtained. As a result, the productivity increased by a total of 48 times.

More importantly, when using a conventional plasma gas phase reaction apparatus, once or twice the plasma gas phase reaction operation is performed, the inner wall of the reaction vessel has a thickness of 3 μm to 10 μm.
μm silicon flakes were deposited. However, in the plasma gas phase reaction apparatus of this specific example, a film having a thickness of 0.5 μm is repeatedly formed, and even when the number of times reaches 100, flakes are slightly observed on the inner wall of the reaction vessel. Was only done. Thus, since the formed semiconductor layer has a long plasma state distance, the photoconductivity is also 2 × 1.
0 ^-4 to 7 × 10 ^-3 (ohm cm) ^-1 , dark conductivity 3 ×
It had a ^value between 10 ^-9 and 1 × 10 ^-11 (ohm cm) ^-1 .

This is because the conventional method in which the direction of the electric field of the plasma is perpendicular to the surface on which the film is formed has a photoconductivity of 3 ×.
10 ^-5 to 3 × 10 ^-4 (ohm cm) ^-1 , dark conductivity 5
Considering that it is from × 10 ^-8 to 1 × 10 ^-9 (ohm cm) ^-1 , the semiconductor film shows an improvement in characteristics with a photophotosensitivity (photoconductivity / dark conductivity) of 10 ⁶ times or more. Was done. Although a specific example of the present invention is a case where an impurity is not positively added, a P-type or N-type semiconductor film having the same high electrical conductivity can be formed even when an impurity for a P-type or an N-type is added. Can be. It is also possible to form PI, NI, PIN, and PN junctions by stacking P, I, and N-type semiconductors.

Embodiment 3 In this embodiment, a conductive metal is produced using the plasma gas phase reactor of Embodiment 1. Hereinafter, a case in which metal aluminum is formed by a plasma gas phase reaction method will be described. In FIG. 2, the bubbler (36) has
Aluminum chloride was filled. Aluminum chloride
Was heated to 40 ° C. to 60 ° C. by an electronic thermostat. Further, as for the carrier gas, an inert gas helium was introduced into the reaction chamber (2) at a flow rate of 100 cc / min from the inlet (33). That is, a gas containing helium and aluminum chloride mixed therein was introduced into the reaction chamber (2).

Further, hydrogen is supplied from the inlet (33) through 60.
It was introduced at a flow rate of cc / min to 100 cc / min. The substrate temperature is 200 ° C. to 550 ° C., for example, 300 ° C.
Was chosen. The high frequency electric field was supplied at a frequency of 30 KHz to the first electrodes (23), (25) and the second electrodes (72), (82) at 100 W to 300 W, for example, 200 W. Thus, 20cm x 60c
20 substrates (5) having a size of m were mounted on the holder (6), and a film having a thickness of 0.5 μm to 1 μm was formed at a growth rate of 5 ° / sec. And the thickness of the coating is
The uniformity could be formed to ± 5% or less.

Further, triethylaluminum (TEA) as a starting material was filled in a bubbler (36) shown in FIG. In this case, further, the carrier gas did not need to be introduced from the inlet (33). Bubbles (36)
Is set to 60 ° C. so that the flow rate of the flow meter is 6 ° C.
0 cc / min. Further, hydrogen was introduced at a flow rate of 500 cc / min from the inlet (33) to perform a plasma gas phase reaction. Reaction pressure 0.1 torr to 0.3 t
orr, the frequency of the high frequency power supply is 100 KHz, the output is 1
By using KW, 5 inch silicon wafer can be
A total of 100 sheets were mounted. As a result, metal aluminum was formed on these substrates (5) at a growth rate of 7 ° / min.

At this time, even if the conductor was formed on the inner wall of the cylindrical space (100), the discharge did not become unstable, and the metal aluminum having a thickness of 1 μm to 2 μm could be deposited. At this time, hydrogen was introduced into the reaction chamber (2) from the external inlet (38) at a flow rate of 700 cc / min. Thus, the degree of flakes adhering to the inner wall of the reaction chamber (2) could be further reduced.
Therefore, even if the thickness is 1 μm to 2 μm by forming a film 30 times by the plasma gas phase reaction apparatus, the reaction chamber (2)
No particular fogging was observed on the inner wall and the viewing window.

Particularly, in this embodiment, since the two electrodes for plasma discharge are not connected to each other by the leak current, that is, the nozzle (24) and the holder (6) are electrically connected. The holder (6) and the lower nozzle (24) are similarly separated from each other. In addition, since the surrounding area has little adhesion to the inner wall of the reaction chamber (2), the discharge caused by the generation of the leak current did not become unstable in any of these electric circuits. In this specific example, aluminum was used. However, for example, metallic iron nickel or cobalt can be formed into a film using a carbonyl compound of iron, nickel or cobalt as a carbonyl compound.

Example 4 In this example, a silicon nitride film was formed using the plasma vapor reactor of Example 1. That is, in the case of FIG. 1, 200 cc / min of silane was introduced from the introduction port (34), and 800 cc / min of ammonia was introduced from the introduction port (35). The temperature of the substrate (5) is 300 ° C., the pressure of the cylindrical space (100) is 0.1 torr, and the substrate 2 of 1 cm × 60 cm is used.
1000Å on 100 zero or 5 inch wafers
A film was formed to a thickness of ~ 5000 mm. The above method
Since the uniformity of the film produced by the above method was improved , it was possible to obtain within ± 5% within and between lots.

Example 5 In this example, silicon oxide was formed. That is, silane (SiH 2) was set at 200 cc / min, and nitrogen peroxide (NO) was introduced through the inlet (34).
5) Introduce 200 cc / min from, and at the same time, the inlet (33)
More nitrogen was introduced at 200 cc / min. The high frequency power had a frequency of 30 KHz and an output of 500 W. 1st, 2nd
The frequency of the electric field is the same, and the phase shift is shifted by 90 degrees to recover.
The waveform was jute. Substrate temperature is 100 ° C to 400 ° C
However, if the coating is formed at 250 ° C., the uniformity of the coating is ± 3% and ± 3% when the coating is formed at 0.5 μm.
We were able to pay within 5%.

Example 6 In this example, a compound conductor such as tungsten silicide, molybdenum silicide or metallic tungsten, or molybdenum was prepared. That is, in the specific example 1, molybdenum chloride or tungsten fluoride is introduced from the bubbler (36), silane is further supplied from (35), and the ratio of tungsten or molybdenum to silicon is set to a predetermined ratio, for example, 1: 2, and plasma is applied. A gas phase reaction was performed. As a result, 250 ° C., 300 W, 13.56 MHz
In this case, a growth rate of 4 ° / sec to 6 ° / sec was obtained at a thickness of 0.4 μm. By adjusting the amount of the reactive gas, the compound metal and the refractory metal can be formed into a layered multilayer structure.

As is clear from the above description, the plasma vapor reactor of the present invention can be formed on any of semiconductors, conductors, and insulators. In particular, an impurity was added to a structure-sensitive semiconductor or conductor, and a plurality of semiconductor layers to which a P-type or N-type impurity was added could be stacked. Although the floating grid in this specific example is provided on the first electrode side, the film quality can be improved by providing the floating grid on the second electrode side or both.
In this specific example, only the plasma gas phase reaction is shown. However, the light energy of ultraviolet light or infrared light may be simultaneously applied in addition to the electric energy to perform the light plasma gas phase reaction method.

[0044]

According to the present invention, a substrate provided in a reaction space is provided by providing a plurality of electrodes arranged orthogonally to a film formation surface and a plurality of oscillators for supplying electric energy. Since an electric field is applied in a plane parallel to the film formation surface, the film formation can be uniform and
The degree of sputtering on the film formation surface of the substrate can be reduced, and the film quality can be improved. According to the present invention,
In order to apply an electric field in a plane parallel to
Were averaged, and the film thickness became more uniform. In the present invention
According to the plurality of electrodes, by the same frequency different phases or different frequencies are applied, in a plane parallel to the coating surface of the substrate, for draw field as Lissajous waveform, film-forming The electric field applied to the surface can be made uniform, and a film having a uniform thickness can be formed. According to the present invention
For example, the electric field applied from multiple electrodes to the coating surface of the substrate
Since the degree is larger than the electric field density by a pair of electrodes,
The formation speed can be improved.

[Brief description of the drawings]

FIGS. 1A to 1E are diagrams for explaining non-uniformity of a film thickness on a substrate obtained by a conventional plasma gas phase reaction method.

FIG. 2 is a view for explaining an apparatus capable of continuously performing a plasma gas phase reaction in one embodiment of the present invention.

FIG. 3 is a diagram illustrating an electric field generated by a plurality of electrodes forming a pair according to an embodiment of the present invention.

4 (A), (B), (C), (D), and (E) are diagrams for explaining distribution when non-single-crystal silicon is formed to a thickness of 0.5 μm in FIG. It is.

[Explanation of symbols]

 (1) First preliminary chamber (2) Reaction chamber (3) Second preliminary chamber (4), (5) Substrate (6), (7) Holder (8), (13) Step motor (9), (10) Guide (11), (12) Door (15), (15 ') Infrared lamp (21) ... first oscillator (22) ... positive terminal (23) ... negative electrode (24) ... nozzle (25) ... positive electrode (27) ... supply port ( 28) Exhaust port (29) Vacuum exhaust means (30) Vacuum pump (43), (44) Gate valve (85) Second oscillator (90 ), (91) ... Indicates the direction of the electric field (97) ... Reactive gas supply system (98) ... Vacuum exhaust system (100) ... Cylindrical space

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-58-31532 (JP, A) JP-A-57-111055 (JP, A) JP-A-57-111056 (JP, A) JP-A-62-1 44576 (JP, A) US Patent 3,882,203 (US, A) US Patent 3,816,748 (US, A)

Claims (2)

(57) [Claims] 1. A plasma processing method comprising: a plurality of electrodes arranged orthogonal to a film forming surface of a substrate; and a plurality of oscillators for supplying electric energy, wherein the plurality of electrodes are parallel to the film forming surface of the substrate. such in a plane, the Lissajous pattern field from said plurality of oscillators of electrical energy for supplying
While oscillating the same frequency with different phases to generate
A plasma processing method comprising forming a coating . 2. A plasma processing method comprising: a plurality of electrodes arranged orthogonally to a film forming surface of a substrate; and a plurality of oscillators for supplying electric energy. such in a plane, the Lissajous pattern field from said plurality of oscillators of electrical energy for supplying
To form a film while oscillating a different frequency to generate
A plasma processing method comprising: