JPH08330242A - Plasma vapor growth device, and method of removing film of adhesion-preventive shield in plasma vapor growth device - Google Patents

Abstract

PURPOSE: To effectively prevent the occurrence of dust generated by the exfoliation of a film by preventing the adhesion of a material to the inner face of a vacuum container. CONSTITUTION: An adhesion preventive shield 5 is arranged capably of replacement in condition that it is insulated from a vacuum container 1 such that it covers the inner face of the vacuum container 1. a bias voltage is applied to the shield 5 by a shield bias voltage application mechanism 51, charged particles in plasma collides against the adhesion preventive shield 5. The material having adhered to the adhesion preventive shield 5 is repelled by these charged particles, and a part reaches the board 40 on a substrate holder 4. The temperature of the adhesion preventive shield 5 is adjusted by temperature adjusting mechanism 54, and a discharge preventive member 55 is arranged in the behind space, and abnormal discharge is prevented. When etching off the the film of the adhesion preventive shield 5, a board bias voltage application mechanism 42 operates too, and the readhesion of film to the substrate holder 4 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma vapor phase growth apparatus used for forming various thin films on the surface of a substrate.

[0002]

2. Description of the Related Art When manufacturing a large scale integrated circuit (LSI), a liquid crystal display (LCD) or the like, a step of forming various thin films on the surface of a substrate is required. As a device for forming a thin film, a vacuum vapor deposition device, a sputtering device, etc. are known, but a plasma vapor phase growth device is often used because it can form a compound or amorphous thin film at a relatively low temperature. .

FIG. 3 is a schematic view of an example of a conventional plasma vapor deposition apparatus. The plasma vapor deposition apparatus shown in FIG. 3 includes a vacuum container 1 equipped with an exhaust system 11, a gas introduction mechanism 2 for introducing a predetermined gas into the vacuum container 1, and energy is supplied to the introduced gas to generate plasma. It is mainly configured by a power supply mechanism 3 for forming, a substrate holder 4 for mounting a substrate 40 for forming a thin film, and the like. In the apparatus of FIG. 3, the substrate 40 is loaded into the vacuum container 1 through a gate valve (not shown) and placed on the substrate holder 4. After exhausting the inside of the vacuum container 1 by the exhaust system 11, a predetermined gas is introduced by the gas introduction mechanism. Next, energy such as high frequency power is applied to the gas in the vacuum container 1 by the power supply mechanism 3 to form plasma. Then, a predetermined thin film is deposited on the surface of the substrate by the gas phase reaction generated by the plasma. For example, when a silane gas and an oxygen gas are introduced by the gas introduction mechanism 3, a decomposition reaction or the like is caused by plasma, and a thin film of silicon oxide is formed on the surface of the substrate 40.

In the above plasma vapor phase growth apparatus, an electric field may be set between the plasma and the surface of the substrate 40 so that charged particles in the plasma collide with the surface of the substrate 40. For example, in a film forming technique called an ion assist method, ions are made to collide with the surface of the substrate 40 with relatively weak acceleration energy during film formation, and the thin film is efficiently grown by utilizing the energy of the ions. .

To set an electric field between the plasma and the substrate 40, a bias voltage (hereinafter referred to as a substrate bias voltage) is applied so that the surface of the substrate 40 has a predetermined potential with respect to the plasma potential (≈0). . This substrate bias voltage is usually applied by the interaction of plasma and radio frequency. That is, as shown in FIG. 3, the substrate high frequency power supply 422 is connected to the substrate holder 4, and the high frequency power is applied to the substrate 40 through the substrate holder 4. In the positive half cycle of the applied high frequency, the electrons in the plasma are quickly collected on the surface of the substrate, but in the negative half cycle, the ions with low mobility are slowly collected. Due to such a difference in mobility, electrons are gathered on the surface of the substrate 40 and the same state as when a negative bias voltage is applied is obtained. As a result, an electric field is established between the plasma and the plasma.

Application of the substrate bias voltage as described above
Recently, a thin film is formed so that a hole or a groove formed on the surface of the substrate 40 is closed with a thin film. FIG. 4 is an explanatory diagram of an example of thin film formation in which holes or grooves formed on the surface of a substrate are closed with a thin film. As shown in FIG. 4A, a thin film pattern 400 made of, for example, metal is formed as wiring on the surface of the substrate 40, and holes or grooves 401 are present according to the shape of the pattern 400. When the pattern 400 is further formed on the upper layer of the pattern 400, the pattern 400 is formed on the insulating film 4.
It is covered with 02 to insulate the layers.

In this case, when a normal thin film is formed without applying the substrate bias voltage, particles used as a material of the thin film are hard to reach the bottom of the hole or groove 401 and easily gather on the upper surface of the pattern 400. pattern 40 as in b)
The thin film grows from the upper surface of 0 to the upper edge of the hole or groove 401 so as to bulge in a round shape. As a result, as shown in FIG. 4C, even if the hole or groove 401 is closed with a thin film, a cavity 403 called a void is formed in the thin film.
When such a cavity 403 is formed, the withstand voltage between the patterns 400, which are metal wirings, is significantly deteriorated due to moisture existing in the cavity 403, which causes a serious failure that short-circuits the integrated circuit. Becomes

Therefore, a substrate bias voltage is applied to set an electric field between the plasma and the surface of the substrate 40, and ions in the plasma are extracted and collided by this electric field. In the case as shown in FIG. 4A, the electric field becomes the steepest at the corner portion of the upper edge of the hole or groove 401, so that the ions collide most with this portion. As a result,
The thin film deposited on this portion is etched, and some of the etched material reaches the inside of the hole or groove 401. Therefore, the inside of the hole or groove 401 and the pattern 4 are
The difference in the deposition rate from the upper surface of No. 00 is improved, and FIG.
As shown in (c ′), the hole or groove 401 can be closed with a thin film without forming the cavity 403. In this case, since it is necessary to etch the thin film,
Generally, a higher acceleration electric field is set as compared with the ion assist method described above.

[0009]

In the above plasma vapor deposition apparatus, it is inevitable that a thin film will be deposited on the inner surface of the vacuum container while the thin film formation is continued. This thin film deposition occurs because particles floating in the vacuum container adhere to the inner surface of the vacuum container. The thin film deposited on the inner surface becomes dust when it reaches a certain thickness. If this dust adheres to the substrate, it may cause a disconnection or short circuit of the wiring pattern, resulting in a serious circuit defect. The invention of the present application is made in order to solve the above problems, and prevents the adhesion of the material to the inner surface of the vacuum container, it is possible to effectively suppress the generation of dust caused by thin film peeling plasma plasma The purpose is to provide a phase growth apparatus.

[0010]

In order to achieve the above object, the invention according to claim 1 of the present application comprises a vacuum container having an exhaust system, and a gas introducing mechanism for introducing a predetermined gas into the vacuum container. In a plasma vapor phase growth apparatus comprising a power supply mechanism for applying energy to the introduced gas to form plasma, and using a gas phase reaction generated by the plasma to form a predetermined thin film on the surface of the substrate, The vacuum container is arranged so as to cover the inner surface of the vacuum container and is insulated from the vacuum container. The material floating in the vacuum container is prevented from adhering to the inner surface of the vacuum container to prevent the deposition of a thin film on the inner surface. A shield bias voltage for applying a shield bias voltage for causing charged particles in plasma to collide with the deposition shield by setting an electric field between the deposition shield and the plasma. Is a configuration that has a pressurizing mechanism. Similarly, in order to achieve the above object, the invention according to claim 2 is the high frequency power supply according to the structure of claim 1, wherein the shield bias voltage applying mechanism applies the shield bias voltage by interaction with plasma. Is included. Similarly, in order to achieve the above object, the invention according to claim 3 is the structure according to claim 1 or 2, wherein a predetermined voltage is applied to the substrate to cause charged particles in the plasma to collide with the surface of the substrate. It has a substrate bias voltage applying mechanism for applying a substrate bias voltage. Similarly, in order to achieve the above object, the invention according to claim 4 is the structure according to claim 2 or 3, wherein the substrate bias voltage applying mechanism etches a corner portion of a hole or groove formed on the surface of the substrate. However, the substrate bias voltage is applied so that the hole or groove is closed by the thin film deposition. Similarly, in order to achieve the above-mentioned object, the invention according to claim 5 provides the above-mentioned claim 1,
In the configurations 2, 3, or 4, the deposition shield is provided so as to be replaceable. Similarly, in order to achieve the above purpose,
According to a sixth aspect of the invention, in the structure of the first, second, third, fourth or fifth aspect, a temperature adjusting mechanism for controlling the temperature of the deposition shield is provided. Similarly, in order to achieve the above-mentioned object, the invention according to claim 7 is the above-mentioned claim 1, 2, 3,
In the configuration of 4, 5, or 6, a discharge prevention member that prevents discharge in the space is provided in the space between the deposition shield and the inner surface of the vacuum container. Similarly, in order to achieve the above object, the invention according to claim 8 is the same as claim 1, 2, 3,
In the thin film removal method for removing a thin film deposited on the deposition shield of the plasma vapor deposition apparatus of 4, 5, 6 or 7, a predetermined gas is introduced by a gas introduction mechanism, and a power supply mechanism is applied to the introduced gas. Energy is applied to form a plasma, and the thin film deposited on the deposition shield is etched and removed by the material generated in the plasma, and at the time of this etching removal, the deposition bias is applied by the shield bias voltage application mechanism. Has a configuration in which a predetermined shield bias voltage is applied to. Similarly, in order to achieve the above object, the invention according to claim 9 is
The thin film removal method for removing the thin film deposited on the deposition shield of the plasma vapor deposition apparatus according to claim 3 or 4, wherein a predetermined gas is introduced by the gas introduction mechanism, and the power supply mechanism is applied to the introduced gas. Energy is applied to form a plasma, and the thin film deposited on the deposition shield is removed by etching by the material generated in the plasma.At the time of this etching removal, the shield bias voltage applying mechanism prevents the thin film. A predetermined shield bias voltage is applied to the attachment shield, and the substrate bias voltage applying mechanism applies a substrate bias voltage to a substrate holder on which the substrate is placed. Operates the bias voltage application mechanism to apply the substrate bias voltage to the substrate holder It has a configuration that performed while.

[0011]

EXAMPLES Examples of the present invention will be described below. FIG.
FIG. 1 is a schematic diagram of a plasma vapor phase growth apparatus according to an embodiment of the present invention. The plasma vapor phase growth apparatus shown in FIG. 1 is similar to the apparatus of FIG. 3, and includes a vacuum container 1 having an exhaust system 11, a gas introduction mechanism 2 for introducing a predetermined gas into the vacuum container 1, and the introduced gas. It has a power supply mechanism 3 for applying energy to the substrate to form plasma, and a substrate holder 4 for mounting a substrate on which a thin film is to be formed.

Further, the apparatus of FIG. 1 is arranged in a state of being insulated from the vacuum container 1 so as to cover the inner surface of the vacuum container 1, and the material floating in the vacuum container 1 is transferred to the inner surface of the vacuum container 1. A deposition shield 5 that prevents adhesion and prevents deposition of a thin film on the inner surface, and an electric field is set between the deposition shield 5 and the plasma to cause charged particles in the plasma to collide with the deposition shield 5. And a shield bias voltage applying mechanism 51 for applying a shield bias voltage.

First, the vacuum container 1 comprises a film forming chamber 101 and a vacuum exhaust chamber 102 located below the film forming chamber 101 and having a slightly larger space. Then, the portion forming the film forming chamber 101 and the portion forming the vacuum exhaust chamber 102 are configured to be separable. This is for replacing the deposition shield 5 described later. Further, a gate valve (not shown) is provided on the wall of the vacuum chamber 1 in the film forming chamber 101, and an exhaust pipe 13 connected to the exhaust system 11 is provided on the wall of the vacuum exhaust chamber 102. There is. The exhaust system 11 includes a roughing pump 111, a main pump 112 arranged in front of the roughing pump 111, a main valve 113 and a variable conductance valve 114 arranged on an exhaust path exhausted by these pumps 111, 112. It is mainly composed of and. The vacuum container 1 has a bell jar 12 on the upper side. A circular opening is provided in the center of the upper vessel wall of the vacuum container 1, and the bell jar 12 is hermetically connected to this opening. The bell jar 12 has a cylindrical shape with a diameter of about 100 mm having a hemispherical end and an opening at the lower end, and is made of a dielectric material such as quartz glass.

In the example shown in FIG. 1, the gas introduction mechanism 2 is composed of two gas introduction systems 21 and 22 so that two different gases can be introduced simultaneously. Each of the gas introduction systems 21 and 22 is mainly composed of pipes 211 and 221 connected to a gas cylinder (not shown) and gas introduction bodies 212 and 222 connected to the ends of the pipes 211 and 221. FIG. 2 is a diagram illustrating the configuration of the gas introduction body. As shown in FIG. 2, the gas introduction bodies 212, 2
22 is composed of an annular pipe having a circular cross section. The gas introduction bodies 212 and 222 are supported by a support rod 23 provided in the vacuum container 1, and are horizontally arranged along the inner surface of the vacuum container 1. The vacuum container 1
May have a cylindrical shape or a rectangular tube shape.

A transport pipe 24 is provided so as to penetrate the wall of the vacuum container 1 in an airtight manner, and one end of the transport pipe 24 is connected to the gas introduction bodies 212 and 222. The other ends of the gas introduction bodies 212 and 222 are the pipes 211 and 22 of FIG.
Connected to 1. Then, the gas introduction bodies 212, 22
As shown in FIG. 2, 2 has a gas outlet 25 on its inner surface. The gas outlet 25 is an opening having a diameter of about 0.5 mm and is provided on the circumference with an interval of about 25 mm.

On the other hand, returning to FIG. 1, the power supply mechanism 3 includes a high-frequency coil 31 arranged around the bell jar 12, and a high-frequency power source 33 for supplying high-frequency power to the high-frequency coil 31 via a matching unit 32. It is mainly composed of and. For the high frequency power supply 33, for example, 13.56 MH
A device for generating high frequency power of z is adopted, and the high frequency power is supplied from the high frequency coil 31 into the bell jar 12.

A substrate holder 4 is provided below the bell jar 12 in the vacuum container 1. The substrate holder 4 mounts a substrate 40 for forming a thin film on the upper surface thereof, and has a built-in temperature adjusting mechanism 41 for heating or cooling the substrate 40 as necessary. The substrate holder 4 is provided with a substrate bias voltage applying mechanism 42 for applying a predetermined substrate bias voltage to the substrate 40 by the interaction between generated plasma and high frequency. The substrate bias voltage applying mechanism 42 is used for the substrate matching box 4
21 and a substrate high-frequency power source 422 that generates a predetermined high-frequency power to be applied via the substrate matching device 421. The “bias voltage due to interaction between plasma and high frequency” requires that a considerable capacitance exists between the high frequency power supplies 33 and 422 and the plasma. Therefore, when the substrate holder 4 and the substrate 40 are all made of metal, the substrate holder 4
A predetermined capacitor is connected on the power feeding circuit to 0.

The deposition shield 5, which is one of the major features of the apparatus of this embodiment, is a sheet holder 52 attached to the vacuum container 1 in an insulated state, and a front surface of the sheet holder 52. It is mainly configured by the held shield sheet 53. The sheet holder 52 is a substantially cylindrical member, and has a shape in which the inner diameter gradually decreases as it goes upward as shown in FIG. The curved portion of the inner surface of the sheet holder 52 is configured to form a substantially spherical surface with respect to the center point of the substrate on the substrate holder 4.

The upper end portion of the sheet holding body 52 reaches up to the vicinity of the upper wall portion of the vacuum container 11, and although not apparent from the figure, its upper edge is in contact with the lower end of the bell jar 12. ing. Further, the lower end portion of the sheet holder 52 is positioned so as to surround the outside of the substrate holder 4, and the lower edge thereof is located slightly lower than the upper surface of the substrate holder 4. An upper end portion and a lower end portion of the sheet holding body 52 are respectively bent inward, and a shield sheet 53 is arranged so as to be sandwiched between the bent portions. The shield sheet 53 is a thin sheet made of a material such as pure aluminum and having a thickness of about 3 mm.

A temperature adjusting mechanism 54 is provided on the deposition shield 5 having the above-described structure. This temperature adjustment mechanism 54
Temperature control block 54 disposed behind the sheet holder 52
1, a pipe 542 connected to a medium passage provided penetrating the temperature control block 541, and a temperature control unit 54 for sending a temperature control medium to the temperature control block 541 through the pipe 542.
It is mainly composed of 3 and 3. The temperature control block 541 is
It is made of a material having good thermal conductivity such as an aluminum alloy, and is arranged in contact with the sheet holder 52 with good thermal conductivity. The temperature control unit 543 sends liquid or gas into the temperature control block 541 to control the temperature. For example, the deposition shield 5 may be prevented from being deposited on the deposition shield 5 by maintaining the deposition shield 5 at a predetermined high temperature. In such a case, the temperature adjusting mechanism 54 operates and the deposition shield 5 is protected. Adjust to the desired temperature. Also, at some temperature,
In some cases, peeling of the deposited thin film may be suppressed, and by maintaining the deposition shield 5 at this temperature, it is possible to prevent the thin film from peeling and generating dust even if the thin film is deposited.

A discharge prevention member 55 is arranged between the temperature control block 541 and the vacuum container 1. The discharge prevention member 55 has a shape that fills the space formed by the temperature control block 541 and the vacuum container 1 in accordance with the shape of the space. Discharge prevention member 55 of this embodiment
Has a shape such that a plate having an L-shaped cross section is rolled into a circumferential shape, and is made of a dielectric material such as quartz glass. By thus filling the space formed between the deposition shield 5 and the vacuum container 1 with the discharge prevention member 55 made of a dielectric material, it is possible to prevent plasma from entering the space and causing discharge. When a discharge is generated in such a portion, the component is damaged by the discharge, and the component is sputtered to become a source of releasing foreign matter.

Next, the shield bias voltage applying mechanism 51, which is one of the other features of the apparatus of this embodiment, will be described. The shield bias voltage applying mechanism 51 of the present embodiment
Is a matching device for shield 511 and a matching device for shield 51
1 and a shield high frequency power source 512 for generating a predetermined high frequency power to be applied to the deposition shield 5 via That is, the shield bias voltage applying mechanism 51 of the present embodiment employs a mechanism for generating a “bias voltage due to interaction between plasma and high frequency waves” similarly to the substrate bias voltage applying mechanism 42. In addition, the power feeding line from the matching device for shield 511 is the sheet holding member 52.
Connected to. The shield sheet 53 is held by the sheet holder 52 as described above, and both of them keep good electrical contact. Further, similarly to the substrate bias voltage applying mechanism 42, a capacitor is arranged on the power supply line as needed.

Next, the operation of the plasma vapor deposition apparatus of the present embodiment having the above-mentioned structure will be described. First, the substrate 40 is passed through a gate valve (not shown) provided in the vacuum container 1.
Are loaded into the vacuum container 1 and placed on the substrate holder 4. The gate valve is closed and the exhaust system 11 is operated to exhaust the inside of the vacuum container 1 to, for example, about 5 mTorr. Next, the gas introduction mechanism 2 is operated to introduce a predetermined gas into the vacuum container 1 at a predetermined flow rate. At this time, the gas is pipe 2
Gas introduction body 21 from 11, 221 via transport pipe 24
2, 222, and is introduced into the vacuum container 1 so as to be blown inward from the gas outlets 25 of the gas introduction bodies 212, 222. The introduced gas diffuses in the vacuum container 1 and reaches the bell jar 12.

In this state, the power supply mechanism 3 is operated,
High-frequency coil 3 from high-frequency power supply 33 through matching device 32
1 is applied with high frequency power of 13.56 MHz 2500 W. At the same time, the substrate bias voltage applying mechanism 4242 and the shield bias voltage applying mechanism 51 also operate, and the substrate 4
A predetermined bias voltage is applied to each of 0 and the deposition shield 5. The high frequency power supplied by the power supply mechanism 3 is
It is introduced into the bell jar 12 through the high frequency coil 31 and gives energy to the gas existing in the bell jar 12 to generate plasma. The generated plasma diffuses from the bell jar 12 toward the lower substrate 40. A predetermined product is generated in the plasma, and this product is generated on the substrate 4
A predetermined thin film is formed by reaching 0. For example, when forming a silicon oxide thin film, the first gas introduction system 21
The monosilane gas is introduced by the second gas introduction system 2
Oxygen gas is introduced by 2. The monosilane / oxygen plasma decomposes the monosilane and reacts with oxygen to form a silicon oxide thin film.

At this time, the charged particles in the plasma collide with the surface of the substrate 40 by the substrate bias voltage applied by the substrate bias voltage applying mechanism 42. For example, when a thin film is formed in the hole or groove as described above, the substrate high frequency power source 422 to 13.56 MHz
High frequency power of about 2400 W is applied to the substrate. As a result, as shown in FIGS. 4B 'and 4C', it becomes possible to close the hole or groove with a thin film without forming a cavity.

On the other hand, when the plasma vapor deposition apparatus of this embodiment is operating as described above, a material having a thin film deposition action on the deposition shield 5 floats inside the vacuum container 1. . That is, a material that adheres to the surface of the substrate 40 to form a thin film may simultaneously adhere to the deposition shield 5 and deposit a thin film. Further, in particular, when the thin film is formed in the hole or groove while operating the substrate bias voltage applying mechanism 42 as described above, the film deposited on the upper edge of the hole or groove is sputtered by the ions, and It is re-emitted to and floats. This floating material is the shield sheet 5
3 adheres to the surface of the No. 3 and stays, and when the amount of adhering and staying reaches a considerable amount and time, the attached material grows into a thin film on the surface of the shield sheet 53. However, since the shield bias voltage applying mechanism 51 operates and the predetermined shield bias voltage is applied to the deposition shield 5 as described above, the growth of the thin film on the surface of the shield sheet 53 is suppressed. That is, a predetermined electric field is formed between the deposition shield 5 and the plasma by the shield bias voltage applied by the shield bias voltage.
Ions in the plasma accelerated by this electric field sputter the thin film that is being deposited on the surface of No. 3. As a result,
Deposition of thin films is suppressed.

It should be further noted that when the shield bias voltage applying mechanism 51 is operated as described above, the thin film deposited on the shield sheet 53 is sputtered by the ions in the plasma and is again discharged into the vacuum container 1. It A part of this re-emitted material reaches the surface of the substrate 40 and contributes to the formation of a thin film on the surface of the substrate. Therefore, when the shield bias voltage applying mechanism 51 is operated, thin film deposition on the shield sheet 53 is suppressed,
An important side effect of improving the film formation rate on the surface of the substrate 40 is obtained.

The substrate bias voltage applied to the substrate 40 by the substrate bias voltage applying mechanism 42 is smaller than the shield bias voltage applied to the deposition shield 5 by the shield bias voltage applying mechanism 51. This is because the shield bias voltage 5 completely suppresses the thin film deposition, while the substrate bias voltage does not correspond to the hole or groove 4 as shown in FIG.
The thin film deposited on the corner portion of the upper edge of 01 is sputtered to promote the thin film deposition in the hole or groove 401.
This is because the thin film deposition on the substrate 4 is not completely suppressed.

Even if the shield bias voltage applying mechanism 51 is operated as described above, if the thin film forming process is continued for a very long time, it is inevitable that a certain amount of thin film is deposited on the surface of the shield sheet 53. In this case, plasma etching is performed to remove the thin film, or the shield sheet 53 is replaced with another one.

When plasma etching is performed, a fluorine-based gas such as carbon tetrafluoride is introduced into the vacuum chamber 1 by the gas introduction mechanism 2 to form plasma in the same manner as described above. Fluorine active species are generated in the plasma, and the fluorine active species reach the surface of the shield sheet 53 and react with the thin film, whereby the thin film is removed by etching. That is, the fluorine active species reacts with the thin film to form a compound having a high vapor pressure, which is removed by being discharged by the exhaust system. During the plasma etching, it is more preferable to operate the substrate bias voltage applying mechanism 42 to apply the substrate bias voltage. That is, even if the material released from the deposition shield 5 adheres to the substrate holder 4, it is possible to prevent the charged particles accelerated by the substrate bias voltage from ejecting the adhered substance and growing into a thin film on the substrate holder 4. .

When replacing the shield sheet 53, the upper part of the vacuum vessel 1 is lifted and separated from the lower part, and the old shield sheet 53 is replaced with the sheet holder 5.
Remove from 2. Then, a new shield sheet 53 is similarly set and held on the sheet holder 52, and thereafter, the upper portion of the vacuum container 1 is airtightly connected to the lower portion.

Next, the results of an experiment confirming the effects of the plasma vapor phase growth apparatus of this embodiment will be described. Tables 1 and 2 show the results of an experiment confirming the effect of the plasma vapor phase growth apparatus of this example. Explaining the conditions of this experiment, the introduced gas was monosilane 100s.
The oxygen is 300 sccm in ccm. The sccm is a standard cubic centimeter.
It is an abbreviation for er per minute, and is represented by the amount (volume) of gas flowing at 0 ° C. and 1 atmosphere per minute. The high frequency provided by the power supply mechanism 3 is 13.56 MHz.
The high frequency applied by the substrate bias voltage applying mechanism 42 was 2.5 kW, and the high frequency applied by the shield bias voltage applying mechanism 51 was 400 kHz, 2 kW.

Further, after continuously treating 25 substrates under these conditions, in order to remove the thin film deposited on the deposition shield 5, the gas introduction mechanism 2 was used to add 200 carbon tetrafluoride gas.
Sccm and oxygen gas of 100 sccm were introduced, and high frequency of 2 kW was supplied by the power supply mechanism 3 to perform plasma etching. At this time, the deposition shield 5 has a 2.
A high frequency of 5 kW was applied. Further, the time point when the plasma etching was completed was measured by detecting a change in impedance of the deposition shield 5. That is, when the thin film deposited on the deposition shield 5 is completely removed, the impedance of the deposition shield 5 as the load of the high-frequency circuit returns to the original state before the start of the process. The removal can be ended.

[0034]

[Table 1] First, as shown in Table 1, in forming a silicon oxide thin film under the above conditions, the deposition rate on the substrate when the shield bias voltage was applied to the deposition shield 5 was 525 nm / min, and when it was not applied, it was 480 nm / min. The film formation rate was improved by about 10% as compared with the above. Further, the time until the plasma etching is completed is 30 minutes when the shield bias voltage is applied when the thin film is formed on the substrate, but it takes 45 minutes when the shield bias voltage is not applied. did. This means that the thin film deposition on the deposition shield 5 can be suppressed to 2/3 by applying the shield bias voltage.

Further, the thin film was removed by the above plasma etching every time 25 substrates were processed, and the adhesion state of particles to the substrates after processing 1850 substrates in total was measured. That is, after processing the 1850th substrate, thin film removal by plasma etching as described above is performed,
After that, a new substrate was loaded into the vacuum container 1 and processed. Then, after the treatment, the number of particles attached to the surface of the substrate was measured by a laser light scattering method.
Table 2 shows the scattering cross section by laser light scattering method 0.28 μm
The measurement results of ^two or more particles are shown.

[0036]

[Table 2] As shown in Table 2, when the thin film was formed without applying the shield bias voltage, it was found by visual observation that the silicon oxide thin film deposited on the deposition shield 5 was peeled off, and the number of particles was 1,000. It turns out that there are many above. On the other hand, when the thin film was formed without applying the shield bias voltage, the number of particles was drastically reduced to 20 or less. When the substrate bias voltage was applied, the number was 20 or less as well. This is because when the thin film is removed by plasma etching, the material that has come out of the deposition shield 5 and adheres to the substrate holder 4 is also removed at the same time, so that the thin film deposition that causes particles is completely included in the substrate holder 4 as well. This is the effect that could be removed.

It was also observed that the surface state of the oxide film attached to the substrate holder 4 was different when the substrate bias voltage was applied to the substrate holder 4 and when it was not applied. It was presumed that the surface was opaque and powdery when not applied, whereas it was colorless and transparent when applied, and that the substrate could be continuously processed without fear of particle generation thereafter. When the shield bias voltage is not applied to the deposition shield 5 when the thin film is removed by plasma etching, the flow rate of the carbon tetrafluoride gas / oxygen gas is 400.
It was found that even if the film thickness was increased to sccm / 200 sccm or the thin film removal by plasma etching was continued for 24 hours, the thin film on the deposition shield 5 could not be removed and the etching rate was extremely low. From this, it was confirmed that applying a bias voltage to the deposited portion of the thin film is very effective in shortening the time required to remove the deposited thin film by etching.

In the description of the above embodiments, the substrate bias voltage and the shield bias voltage are explained as being applied by "interaction between plasma and high frequency", but when the thin film to be deposited or formed is a conductor. It is also possible to apply these by a DC power supply. However,
It is preferable to apply these by a high-frequency power source from the viewpoint of versatility, since there are less restrictions on the thin film material and the like.

Further, the plasma vapor phase growth apparatus of the above-mentioned embodiment can be modified in structure so as to utilize helicon wave plasma. The helicon wave plasma utilizes the fact that an electromagnetic wave with a frequency lower than the plasma frequency propagates in the plasma without being attenuated when a strong magnetic field is applied, and has recently attracted attention as a technology that can generate high-density plasma at low pressure. There is something. When the propagation direction of the electromagnetic wave in the plasma and the direction of the magnetic field are parallel, the electromagnetic wave becomes circularly polarized light in a certain fixed direction and travels spirally. For this reason, it is called helicon wave plasma. In the case of forming a helicon wave plasma, a loop-shaped antenna formed by bending a single rod-shaped member into two round upper and lower loops is shown in FIG.
Instead of the high frequency coil 31, the bell jar 11 is arranged so as to surround the outside thereof, and a DC electromagnet as a helicon wave magnetic field setting means is arranged concentrically with the bell jar 12 outside the bell jar 11. When a high frequency of 13.56 MHz is supplied to the bell jar 12 from the high frequency power supply 23 via the matching unit 22, the helicon wave plasma is formed by the action of the magnetic field.

[0040]

As described above, according to the invention of claim 1 of the present application, the adhesion of the material to the inner surface of the vacuum container is prevented, and the generation of dust caused by the thin film peeling can be effectively suppressed. It will be possible. Further, since the shield bias voltage is applied to the deposition shield, the material adhering to the deposition shield is released again and contributes to the formation of a thin film on the substrate. As a result, the deposition rate on the substrate is also improved. Furthermore, as a result of the deposition shield being insulated from the vacuum container, no shield bias voltage is applied to the vacuum container, which is safe in this respect. According to the invention of claim 2, in addition to the effect of claim 1, a shield bias voltage is applied by interaction between plasma and high frequency, so that there are few restrictions in terms of thin film material and high versatility. There is an advantage. According to the third aspect of the present invention, since the substrate bias voltage applying mechanism is provided, it is possible to form a thin film while causing charged particles to collide with the surface of the substrate. According to the invention of claim 4, in addition to the effect of claim 2 or 3,
When closing the holes or grooves formed on the substrate surface by thin film deposition, it is possible to obtain the effect that no cavity is formed in the thin film. Further, according to the invention of claim 5, in addition to the effect of claim 1, 2, 3 or 4, generation of dust can be prevented by exchanging the deposition shield, which is more preferable in this respect. is there. According to the invention of claim 6, in addition to the effect of claim 1, 2, 3, 4 or 5, the temperature of the deposition shield is adjusted to an optimum value, so that the deposition shield is not deposited in a thin film. It is possible to set the temperature to the temperature or, conversely, to the temperature at which the thin film is not separated even if it is deposited. According to the invention of claim 7, in addition to the effect of claim 1, 2, 3, 4, 5 or 6, the discharge in the space between the deposition shield and the vacuum container is suppressed, It is possible to prevent damage to members due to electric discharge and release of foreign matter due to sputtering. Furthermore, according to the invention of claim 8, since the shield bias voltage is applied when removing the thin film by etching the deposition shield, the efficiency of etching is improved and the time until completion of thin film removal can be shortened. it can. Further, according to the invention of claim 9, the shield bias voltage is applied at the time of thin film removal by etching of the deposition shield as in the case of the eighth aspect, so that the etching efficiency is improved and the time until completion of thin film removal is improved. Can be shortened. Further, at this time, it is possible to suppress the material that is etched and released from the deposition shield from re-adhering to the substrate holder and depositing a thin film, which can contribute to the production of a further preferable high-quality thin film.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a plasma vapor deposition apparatus of an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of gas introduction bodies 212 and 222 in FIG.

FIG. 3 is a schematic view of an example of a conventional plasma vapor deposition apparatus.

FIG. 4 is an explanatory diagram of an example of forming a thin film in which a hole or a groove formed on the surface of a substrate is closed with a thin film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 11 Exhaust system 2 Gas introduction mechanism 3 Electric power supply mechanism 4 Substrate holder 42 Substrate bias voltage application mechanism 5 Adhesion shield 51 Shield bias voltage application mechanism 52 Sheet holder 53 Shield sheet 54 Temperature control mechanism 55 Discharge prevention member

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[Procedure amendment]

[Submission date] September 20, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

FIG. 3 is a schematic view of an example of a conventional plasma vapor deposition apparatus. The plasma vapor deposition apparatus shown in FIG. 3 includes a vacuum container 1 equipped with an exhaust system 11, a gas introduction mechanism 2 for introducing a predetermined gas into the vacuum container 1, and energy is supplied to the introduced gas to generate plasma. It is mainly configured by a power supply mechanism 3 for forming, a substrate holder 4 for mounting a substrate 40 for forming a thin film, and the like. In the apparatus of FIG. 3, the substrate 40 is loaded into the vacuum container 1 through a gate valve (not shown) and placed on the substrate holder 4. After exhausting the inside of the vacuum container 1 by the exhaust system 11, introducing gas
A predetermined gas is introduced by the mechanism 2 . Next, the power supply mechanism 3 supplies energy such as high frequency power to the vacuum container 1.
A gas is applied to form a plasma. Then, a predetermined thin film is deposited on the surface of the substrate by the gas phase reaction generated by the plasma. For example, when a silane gas and an oxygen gas are introduced by the gas introduction mechanism 2 , a decomposition reaction or the like is caused by plasma, and a thin film of silicon oxide is formed on the surface of the substrate 40.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

To set an electric field between the plasma and the substrate 40, a bias voltage (hereinafter referred to as a substrate bias voltage) is applied so that the surface of the substrate 40 has a predetermined potential with respect to the plasma potential (≈0). . This substrate bias voltage is usually applied by the interaction of plasma and radio frequency. That is, as shown in FIG. 3, the substrate high frequency power supply 422 is connected to the substrate holder 4, and the high frequency power is applied to the substrate 40 through the substrate holder 4. In the positive half cycle of the applied high frequency, the electrons in the plasma are quickly collected on the surface of the substrate 40 , but in the negative half cycle, the ions with low mobility are slowly collected. Due to such a difference in mobility, electrons are gathered on the surface of the substrate 40 and the same state as when a negative bias voltage is applied is obtained. As a result, an electric field is established between the plasma and the plasma.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

Application of the substrate bias voltage as described above
Recently, a thin film is formed so that a hole or a groove formed on the surface of the substrate 40 is closed with a thin film. FIG. 4 is an explanatory diagram of an example of thin film formation in which holes or grooves formed on the surface of a substrate are closed with a thin film. As shown in FIG. 4A, a thin film pattern 400 made of, for example, metal is formed as wiring on the surface of the substrate 40, and holes or grooves 401 are present according to the shape of the pattern 400. Another pattern on the upper layer of this pattern 400
When forming a pattern, the pattern 400 is formed on the insulating film 40.
2 to insulate the layers.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

In this case, when a normal thin film is formed without applying the substrate bias voltage, particles used as a material of the thin film are hard to reach the bottom of the hole or groove 401 and easily gather on the upper surface of the pattern 400. pattern 40 as in b)
The thin film grows so as to bulge in a round shape from the upper surface of 0 to the upper edge of the hole or the full 401. As a result, as shown in FIG. 4C, even if the hole or groove 401 is closed with a thin film, a cavity 403 called a void is formed in the thin film.
When such a cavity 403 is formed, the withstand voltage between the patterns 400, which are metal wirings, is significantly deteriorated due to moisture or the like entering the cavity 403, which may cause a serious failure that short-circuits the integrated circuit. Become.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

The deposition shield 5, which is one of the major features of the apparatus of this embodiment, is a sheet holder 52 attached to the vacuum container 1 in an insulated state, and a front surface of the sheet holder 52. It is mainly configured by the held shield sheet 53. The sheet holder 52 is a substantially cylindrical member, and has a shape in which the inner diameter gradually decreases as it goes upward as shown in FIG. The curved portion of the inner surface of the sheet holder 52 is the base on the substrate holder 4.
It is configured to form a substantially spherical surface with respect to the center point of the plate 40 .

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

The upper end portion of the sheet holding body 52 reaches up to the vicinity of the upper wall portion of the vacuum container 11, and although not apparent from the figure, its upper edge is in contact with the lower end of the bell jar 12. ing. Further, the lower end portion of the sheet holder 52 is positioned so as to surround the outside of the substrate holder 4, and the lower edge thereof is located slightly lower than the upper surface of the substrate holder 4. Sheet holding member 52 has an upper end portion and lower end portion being bent inwardly, respectively, shielding sheet 5 so as to be sandwiched the bent portion
3 are arranged. The shield sheet 53 is a thin sheet made of a material such as pure aluminum and having a thickness of about 3 mm.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

[0036]

[Table 2] As shown in Table 2, when the thin film was formed without applying the shield bias voltage, it was found by visual observation that the silicon oxide thin film deposited on the deposition shield 5 was peeled off, and the number of particles was 1,000. It turns out that there are many above. On the other hand, when a thin film was formed by applying a shield bias voltage, the number of particles was drastically reduced to 20 or less. When a substrate bias voltage is applied,
Similarly, the number was 20 or less. This is because when the thin film is removed by plasma etching, the material that has come out of the deposition shield 5 and adheres to the substrate holder 4 is also removed at the same time, so that the thin film deposition that causes particles is completely included in the substrate holder 4 as well. This is the effect that could be removed.

Claims (9)

[Claims] 1. A vacuum container having an exhaust system, a gas introduction mechanism for introducing a predetermined gas into the vacuum container, and a power supply mechanism for applying energy to the introduced gas to form plasma. Then, in a plasma vapor phase growth apparatus that creates a predetermined thin film on the surface of the substrate using the gas phase reaction generated by plasma, it is placed so as to cover the inner surface of the vacuum vessel and insulated from the vacuum vessel. , A deposition shield that prevents the material floating in the vacuum vessel from adhering to the inner surface of the vacuum vessel to prevent the deposition of a thin film on the inner surface, and an electric field is set between the deposition shield and the plasma. And a shield bias voltage application mechanism for applying a shield bias voltage for causing charged particles in plasma to collide with the deposition shield. 2. The shield bias voltage applying mechanism comprises:
2. The plasma vapor phase growth apparatus according to claim 1, further comprising a high frequency power source that applies a shield bias voltage by interaction with plasma. 3. A substrate bias voltage application mechanism for applying a predetermined voltage to the substrate to apply a substrate bias voltage for causing charged particles in plasma to collide with the surface of the substrate. Or the plasma vapor phase growth apparatus according to 2. 4. The substrate bias voltage applying mechanism applies a substrate bias voltage so that the hole or groove formed in the surface of the substrate is etched while the hole or groove is blocked by thin film deposition. The plasma vapor phase growth apparatus according to claim 2 or 3, wherein 5. The plasma vapor phase growth apparatus according to claim 1, wherein the deposition shield is provided so as to be replaceable. 6. A temperature adjusting mechanism for controlling the temperature of the deposition shield is provided.
The plasma vapor phase growth apparatus according to 2, 3, 4 or 5. 7. A discharge prevention member for preventing discharge in the space is provided in the space between the deposition shield and the inner surface of the vacuum container.
The plasma vapor phase growth apparatus according to 2, 3, 4, 5 or 6. 8. A thin film removing method for removing a thin film deposited on the deposition shield of the plasma vapor deposition apparatus according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the gas introduction mechanism is used Gas is introduced, energy is applied to the introduced gas by the power supply mechanism to form plasma, and the thin film deposited on the deposition shield is etched and removed by the material generated in the plasma, A method of removing a thin film of an adhesion-preventing shield, characterized in that a predetermined shield bias voltage is applied to the adhesion-preventing shield by the shield bias voltage applying mechanism during the etching removal. 9. A thin film removing method for removing a thin film deposited on the deposition shield of the plasma vapor deposition apparatus according to claim 3, wherein a predetermined gas is introduced by the gas introducing mechanism, and the introduced gas is introduced. Energy is applied by the power supply mechanism to form plasma, and the thin film deposited on the deposition shield is removed by etching by the material generated in the plasma, and at the time of this etching removal, the shield bias is applied. A predetermined shield bias voltage is applied to the deposition shield by a voltage applying mechanism, and the substrate bias voltage applying mechanism applies a substrate bias voltage to a substrate holder on which a substrate is placed. This substrate bias voltage application mechanism is operated together with the application mechanism to attach the substrate via to the substrate holder. A method for removing a thin film of an adhesion-preventing shield, which is carried out while applying a scanning voltage.