CN115116813A

CN115116813A - Plasma processing apparatus and plasma processing method

Info

Publication number: CN115116813A
Application number: CN202210151147.5A
Authority: CN
Inventors: 吉森大晃; 嘉瀬庆久; 中泽和辉
Original assignee: Shibaura Mechatronics Corp
Current assignee: Shibaura Mechatronics Corp
Priority date: 2021-03-23
Filing date: 2022-02-15
Publication date: 2022-09-27
Also published as: JP2022147006A; TW202238664A; KR20220132438A; JP7337868B2

Abstract

The invention provides a plasma processing apparatus and a plasma processing method capable of suppressing contamination caused by contaminants. The plasma processing apparatus of an embodiment includes: a first chamber; a first exhaust unit; a plasma generating section; a first gas supply section; a second chamber; a conveying part; a second exhaust section; a second gas supply unit; and a controller. The controller controls the second exhaust unit so that the pressure inside the second chamber is substantially equal to the pressure inside the first chamber when the transfer unit transfers the processing object, and controls the second gas supply unit so that the gas is supplied into the second chamber when the transfer unit finishes transferring the processing object.

Description

Plasma processing apparatus and plasma processing method

Technical Field

Embodiments of the present invention relate to a plasma processing apparatus and a plasma processing method.

Background

The drying process using plasma is used, for example, in the production of a microstructure. For example, in the manufacture of semiconductor devices, flat panel displays, photomasks, and the like, various plasma processes such as etching, ashing, and damage removal are performed.

A plasma processing apparatus for performing such a plasma process includes, for example, a process chamber for performing a plasma process on a processing object, a transfer chamber (transfer chamber) connected to the process chamber via a gate valve, and a transfer robot provided inside the transfer chamber and transferring the processing object to the process chamber.

Here, inside the transfer chamber, contaminants including organic matter may be generated. Since the processing object is transported inside the transfer chamber, if a contaminant is generated, the generated contaminant may adhere to the surface of the processing object. In this case, when the processing object to which the contaminants are attached is carried into the process chamber and plasma processing is performed, the quality of the product may be affected. Further, when the processing object to which the contaminants are attached is carried out from the transfer chamber to the outside, the processing in the subsequent step may be affected.

Therefore, a technique for suppressing contamination of a treatment object with contaminants has been proposed (for example, see patent documents 1 and 2).

However, in recent years, the materials of microstructures have been diversified and miniaturized, and the influence of contaminants on the quality may increase.

Therefore, it is desired to develop a technique that can further suppress contamination caused by contaminants.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open No. Hei 6-196540

[ patent document 2] Japanese patent laid-open No. 2003-17478

Disclosure of Invention

[ problems to be solved by the invention ]

The present invention has been made to solve the problem, and an object of the present invention is to provide a plasma processing apparatus and a plasma processing method capable of suppressing contamination caused by contaminants.

[ means for solving problems ]

The plasma processing apparatus of an embodiment includes: a first chamber capable of placing a processing object therein while maintaining a gas atmosphere having a reduced pressure at a relatively high pressure; a first exhaust unit capable of depressurizing the inside of the first chamber to a predetermined pressure; a plasma generating section capable of generating the plasma; a first gas supply unit capable of supplying a process gas to an inside of the first chamber and a region where the plasma is generated; a second chamber connected to the first chamber via a gate valve, the second chamber being capable of maintaining a gas atmosphere having a reduced pressure at a relatively high pressure; a transfer unit which is provided inside the second chamber and can transfer the processing object to the first chamber; a second exhaust unit capable of depressurizing the inside of the second chamber to a predetermined pressure; a second gas supply unit capable of supplying a gas into the second chamber; and a controller capable of controlling the conveying unit, the second exhaust unit, and the second gas supply unit. The controller controls the second exhaust unit so that the pressure inside the second chamber is substantially equal to the pressure inside the first chamber when the transfer unit transfers the processing object, and controls the second gas supply unit so that the gas is supplied into the second chamber when the transfer unit finishes transferring the processing object.

[ Effect of the invention ]

According to an embodiment of the present invention, there are provided a plasma processing apparatus and a plasma processing method capable of suppressing contamination caused by contaminants.

Drawings

Fig. 1 is a layout diagram illustrating a plasma processing apparatus according to the present embodiment.

Fig. 2 is a schematic cross-sectional view illustrating an example of the processing section.

Fig. 3 is a schematic cross-sectional view illustrating a treatment section according to another embodiment.

Fig. 4 is a schematic cross-sectional view for illustrating the interface.

FIG. 5 is C ₁₆ H ₃₀ O ₄ Vapor pressure curve of (a).

Fig. 6 is a timing chart for exemplifying the supply of gas.

[ description of symbols ]

1: plasma processing apparatus

2: controller

3: storage part

4. 72: conveying part

5: load interlock

6. 16: treatment section

7: delivery part

51. 61, 71, 164: chamber

51a, 61c, 164 b: gate valve

52. 66, 73, 162: exhaust part

53: gas supply unit

61 a: transmission window

61b, 164 a: opening of the container

62: placing part

63: antenna with a shield

64a, 64 b: high frequency power supply

64a1, 64b 1: matching device

65. 74, 166: gas supply unit

65a, 74 a: flow rate control unit

66a, 166 a: pressure control unit

100: treated article

161: plasma generating part

161 a: discharge tube

161 b: guide waveguide

161b 1: terminal matcher

161b 2: stub tuner

161b 3: trough

161 c: delivery pipe

163: microwave generating part

164 c: rectifying plate

165: placing part

B1, B2: dot

G: process gas

G1: gas (es)

M: microwave oven

P: plasma body

T1, T2: timing of

T1 a: during the carrying-in period

T2 a: during the carrying-out period

Detailed Description

Hereinafter, embodiments of the present invention will be described by way of example with reference to the accompanying drawings. In the drawings, the same constituent elements are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

Fig. 1 is a layout diagram illustrating a plasma processing apparatus 1 according to the present embodiment.

As shown in fig. 1, the plasma processing apparatus 1 includes, for example: a controller 2, a storage section 3, a conveying section 4, a load-lock section 5, a processing section 6, and a delivery section 7.

The controller 2 includes an arithmetic Unit such as a Central Processing Unit (CPU) and a storage Unit such as a memory. The controller 2 is, for example, a computer or the like. The controller 2 controls the operation of each element provided in the plasma processing apparatus 1, for example, based on a control program stored in the storage unit.

The housing section 3 houses the processing object 100 in a stacked state (multi-stage state), for example. The storage unit 3 is, for example, a so-called Pod or a Front-Opening Unified Pod (FOUP) as a Front-Opening carrier. However, the storage unit 3 is not limited to the illustrated example, and may store the processing object 100. At least one receiving portion 3 may be provided.

The conveying section 4 is provided between the storage section 3 and the load interlock section 5. The conveying section 4 conveys and delivers the processed object 100 between the storage section 3 and the load lock section 5. In this case, the conveying unit 4 conveys and delivers the processing object 100 under an environment of a pressure (for example, atmospheric pressure) higher than the pressure at the time of performing the plasma processing. The conveying unit 4 is, for example, a conveying robot having an arm that holds the processed object 100.

The load-lock section 5 is provided between the conveying section 4 and the transfer section 7. The load lock section 5 transfers the processing object 100 between the transfer section 4 and the transfer section 7, which have different pressures in the gas atmosphere. Therefore, the load interlock 5 includes a chamber 51, an exhaust portion 52, and a gas supply portion 53.

The chamber 51 has a gas-tight structure capable of maintaining a gas atmosphere with a large gas pressure reduced. An opening for carrying in and carrying out the processing object 100 is provided in a side wall of the chamber 51. Further, a gate valve 51a for opening and closing the opening is provided. The chamber 51 is connected to a chamber 71 (corresponding to an example of a second chamber) of the delivery unit 7 via a gate valve 51 a.

The exhaust unit 52 exhausts the inside of the chamber 51 so that the pressure inside the chamber 51 becomes substantially equal to the pressure inside the chamber 71 of the delivery unit 7. The exhaust unit 52 may include, for example, a Turbo Molecular Pump (TMP), A Pressure Controller (APC), and the like.

The gas supply unit 53 supplies gas into the chamber 51 so that the pressure inside the chamber 51 is substantially equal to the pressure of the conveying unit 4. The gas to be supplied may be, for example, air or nitrogen.

The processing unit 6 performs plasma processing on the processing object 100 in a gas atmosphere having a relatively high pressure and a reduced pressure.

The processing unit 6 may be a plasma processing apparatus such as a plasma etching apparatus, a plasma ashing apparatus, a sputtering apparatus, or a plasma Chemical Vapor Deposition (CVD) apparatus.

In this case, the method of generating plasma is not particularly limited, and plasma may be generated using, for example, high frequency or microwave.

However, the type of the plasma processing apparatus and the plasma generating method are not limited to the examples. That is, the processing unit 6 may perform plasma processing on the processing object 100 in a gas atmosphere in which a large gas pressure is reduced.

The number of processing units 6 is not particularly limited. At least one processing unit 6 may be provided. When a plurality of processing units 6 are provided, the same type of plasma processing apparatus may be provided, or different types of plasma processing apparatuses may be provided. In the case where a plurality of plasma processing apparatuses of the same type are provided, the processing conditions may be different from one another, or may be the same.

Fig. 2 is a schematic cross-sectional view illustrating an example of the processing unit 6.

The processing unit 6 illustrated in fig. 2 is an inductively coupled plasma processing apparatus. That is, the plasma processing apparatus is an example of a plasma processing apparatus that generates a plasma product from a process gas G using a plasma P excited and generated by high-frequency energy, and processes a processing object 100.

As shown in fig. 2, the processing unit 6 includes, for example: a chamber 61 (corresponding to an example of a first chamber), a mounting portion 62, an antenna 63, a high-frequency power supply 64a, a high-frequency power supply 64b, a gas supply portion 65 (corresponding to an example of a first gas supply portion), an exhaust portion 66 (corresponding to an example of a first exhaust portion), and the like.

The chamber 61 has, for example, a substantially cylindrical shape with a bottom, and has an airtight structure capable of maintaining a gas atmosphere with a large gas pressure and a reduced pressure. A transmission window 61a is provided in an upper portion of the chamber 61 so as to be airtight. The transmission window 61a has a plate shape, and may be formed of a material having high transmittance for high frequency energy and being not easily etched when plasma processing is performed. The transmission window 61a may be formed of a dielectric material such as quartz.

An opening 61b for carrying in and out the processing object 100 is provided in a side wall of the chamber 61. Further, a gate valve 61c for opening and closing the opening 61b is provided. The chamber 61 is connected to the chamber 71 of the interface 7 via the gate valve 61 c.

The mounting portion 62 is disposed inside the chamber 61. The treatment object 100 is placed on the upper surface of the placement portion 62. In this case, the treatment object 100 may be placed on the upper surface of the placement portion 62 as it is, or may be placed on the placement portion 62 via a support member or the like, not shown. In addition, a holding device such as an electrostatic chuck may be provided on the mounting portion 62.

The antenna 63 supplies high-frequency energy (electromagnetic energy) to a region where plasma P is generated inside the chamber 61. The plasma P is generated by high-frequency energy supplied to the inside of the chamber 61. For example, the antenna 63 supplies high-frequency energy to the inside of the chamber 61 through the transmission window 61 a.

The high-frequency power supply 64a is electrically connected to the antenna 63 via the matching unit 64a 1. The matching unit 64a1 is provided with a matching circuit or the like for matching the impedance on the high-frequency power supply 64a side and the impedance on the plasma P side. The high-frequency power supply 64a is a power supply for generating the plasma P. That is, the high-frequency power supply 64a is provided to generate a high-frequency discharge in the chamber 61 and generate plasma P. The high-frequency power supply 64a supplies high-frequency power having a frequency of about 100KHz to 100MHz to the antenna 63.

In the present embodiment, the antenna 63 and the high-frequency power supply 64a serve as a plasma generating portion that generates plasma P.

The high-frequency power source 64b is electrically connected to the mounting portion 62 via a matching unit 64b 1. The matching unit 64b1 is provided with a matching circuit or the like for matching the impedance on the high-frequency power supply 64b side with the impedance on the plasma P side. The high-frequency power source 64b controls the energy of ions introduced into the processing object 100 placed on the placing unit 62. The high-frequency power supply 64b applies high-frequency power having a relatively low frequency (for example, 13.56MHz or less) suitable for drawing ions to the placement unit 62.

The gas supply unit 65 supplies the process gas G to the region in the chamber 61 where the plasma P is generated through the flow rate control unit 65 a. The Flow rate control unit 65a may be, for example, a Mass Flow Controller (MFC). The gas supply part 65 may be connected to a sidewall of the chamber 61, for example, in the vicinity of the transmission window 61 a.

The process gas G is appropriately selected according to the type of the process, the material of the processing surface of the processing object 100, and the like. For example, in the case of etching treatment, CF may be used ₄ Or CF ₃ And the process gas G containing fluorine atoms so as to generate highly reactive radicals. In this case, the process gas G may be a gas containing only fluorine atoms, or may be a mixed gas of a gas containing fluorine atoms and a rare gas.

The exhaust unit 66 reduces the pressure inside the chamber 61 to a predetermined pressure. The exhaust section 66 may be a Turbo Molecular Pump (TMP), for example. The exhaust portion 66 may be connected to the bottom surface of the chamber 61 via a pressure control portion 66 a. The pressure control unit 66a performs control so that the inside of the chamber 61 becomes a predetermined pressure based on an output of a pressure gauge, not shown, that detects the pressure inside the chamber 61. The Pressure control unit 66a may be, for example, an Automatic Pressure Controller (APC).

When the plasma processing is performed on the processing object 100, the inside of the chamber 61 is depressurized to a predetermined pressure by the exhaust unit 66, and a predetermined amount of the process gas G (for example, CF) is supplied from the gas supply unit 65 to a region in the chamber 61 where the plasma P is generated ₄ Etc.). On the other hand, a high-frequency power of a predetermined power is applied from the high-frequency power supply 64a to the antenna 63, and electromagnetic energy is radiated into the chamber 61 through the transmission window 61 a. Further, a high-frequency power of a predetermined power is applied from the high-frequency power source 64b to the mounting portion 62 on which the processing object 100 is mounted, and an electric field for accelerating ions from the plasma P toward the processing object 100 is formed.

The process gas G is excited and activated by the generated plasma P to generate plasma products of neutral reactive species, ions, and the like by electromagnetic energy radiated to the inside of the chamber 61. Then, the plasma treatment is performed on the treatment object 100 by supplying the generated plasma product to the treatment object 100.

Fig. 3 is a schematic sectional view illustrating the processing unit 16 according to another embodiment.

The processing unit 16 is generally referred to as a "Chemical Dry Etching (CDE) apparatus" or a microwave excitation type plasma processing apparatus called a "remote plasma apparatus". The processing unit 16 generates a plasma product from the process gas G using the plasma P, and performs processing of the processing object 100 mainly using radicals contained in the plasma product.

As shown in fig. 3, the processing unit 16 includes, for example: a plasma generating section 161, an exhaust section 162 (corresponding to an example of a first exhaust section), a microwave generating section 163, a chamber 164 (corresponding to an example of a first chamber), a mounting section 165, and a gas supplying section 166 (corresponding to an example of a first gas supplying section).

The plasma generating section 161 includes, for example, a discharge tube 161a, an introduction waveguide 161b, and a delivery tube 161 c.

The discharge tube 161a has a region in which plasma P is generated, and is disposed at a position away from the chamber 164. The discharge tube 161a has a tubular shape and can be formed of a material that has high transmittance for the microwave M and is not easily etched. For example, the discharge tube 161a may be formed of a dielectric such as alumina or quartz.

The introduction waveguide 161b is connected to the outside of the discharge tube 161a so as to be substantially orthogonal to the discharge tube 161 a. A termination adapter 161b1 is provided at the end of the introduction waveguide 161 b. Further, a stub tuner 161b2 is provided on the inlet side of the introduction waveguide 161b (the introduction side of the microwave M).

An annular groove 161b3 is provided at the connection portion between the introduction waveguide 161b and the discharge tube 161 a. The microwave M propagating through the interior of the introduction waveguide 161b is radiated into the discharge tube 161a through the groove 161b 3.

One end of the duct 161c is connected to an end of the discharge tube 161a opposite to the gas supply unit 166. The other end of the delivery pipe 161c is connected to the chamber 164. The transport pipe 161c is made of a material having resistance to radicals contained in plasma products. The delivery pipe 161c is formed of, for example, quartz, stainless steel, ceramics, fluorine resin, or the like.

The exhaust unit 162 reduces the pressure inside the chamber 164 to a predetermined pressure. The exhaust portion 162 may be connected to the bottom surface of the chamber 164 via the pressure control portion 66a, for example. The exhaust portion 162 may be the same as the exhaust portion 66 described above, for example.

The microwave generating unit 163 is provided at an end of the introduction waveguide 161b opposite to the discharge tube 161 a. The microwave generator 163 generates a microwave M having a predetermined frequency (e.g., 2.75GHz) and radiates the microwave M toward the introduction waveguide 161 b.

The chamber 164 has a gas-tight structure capable of maintaining a gas environment at a reduced pressure of a greater gas pressure. An opening 164a for carrying in and out the processing object 100 is provided in a side wall of the chamber 164. Further, a gate valve 164b for opening and closing the opening 164a is provided. The chamber 164 is connected to the chamber 71 of the interface 7 via a gate valve 164 b.

In addition, a rectification plate 164c may be provided inside the chamber 164. The flow regulating plate 164c may be provided on the inner wall of the chamber 164 so as to be substantially parallel to the mounting surface of the mounting portion 165. Gas containing radicals is introduced into a space between the rectifying plate 164c and the ceiling of the chamber 164 through the duct 161 c. If the rectifying plate 164c is provided, it is easy to make the amount of radicals substantially uniform in the processed surface of the processed object 100.

The mounting portion 165 is disposed inside the chamber 164. The treatment object 100 is placed on the upper surface of the placement section 165. In this case, the processing object 100 may be placed directly on the upper surface of the placement unit 165, or may be placed on the placement unit 165 via a support member or the like, not shown. In addition, a holding device such as an electrostatic chuck may be provided in the mounting portion 165.

The gas supply unit 166 is connected to an end portion of the discharge tube 161a opposite to the chamber 164. The gas supply unit 166 supplies the process gas G to the inside of the discharge tube 161 a. Further, a pressure control section 166a may be provided between the gas supply section 166 and the discharge tube 161 a. The pressure controller 166a controls the pressure of the process gas G supplied to the inside of the discharge tube 161 a.

When the plasma processing is performed on the processing object 100, the inside of the chamber 164 is depressurized to a predetermined pressure by the exhaust unit 162. At this time, the inside of the discharge tube 161a communicating with the chamber 164 is also decompressed. Next, the process gas G of a predetermined pressure is supplied from the gas supply unit 166 to the inside of the discharge tube 161a via the pressure control unit 166 a. The microwave M having a predetermined power is radiated from the microwave generating unit 163 into the introduction waveguide 161 b. The radiated microwave M propagates inside the introduction waveguide 161b, and is radiated into the discharge tube 161a through the groove 161b 3.

The plasma P is generated by the energy of the microwave M radiated into the discharge tube 161 a. The process gas G is excited and activated by the generated plasma P to generate a plasma product containing radicals, ions, or the like.

The gas containing the plasma product is supplied to the inside of the chamber 164 via the delivery pipe 161 c. At this time, ions and the like having a short lifetime cannot reach the inside of the chamber 164, and radicals having a long lifetime reach the inside of the chamber 164. The gas containing radicals supplied into the chamber 164 is rectified by the rectifying plate 164c to reach the processing surface of the processing object 100, and plasma processing such as etching processing is performed. In this case, chemical treatment using radicals is mainly performed. Further, since the ions for the physical processing are not supplied to the inside of the chamber 164, the processing surface of the processing object 100 is not damaged by the ions. Therefore, the processing unit 16 is suitable for removing damage caused by etching using ions, for example.

In the above, the Inductively Coupled Plasma (ICP) processing apparatus and the CDE apparatus (remote Plasma apparatus) have been described as examples of the processing unit, but the processing unit is not limited to these Plasma processing apparatuses. For example, the processing unit may be a Capacitively Coupled Plasma (CCP) processing apparatus (e.g., a parallel plate (Reactive Ion Etching) apparatus), another microwave excitation type Plasma processing apparatus (e.g., a Surface Wave Plasma (SWP) apparatus, or the like.

Next, returning to fig. 1, the delivery unit 7 will be described.

As shown in fig. 1, the interface 7 is provided between the

processing units

6 and 16 and the load interlock 5. The transfer unit 7 transfers the processed object 100 between the processing unit 6(16) and the load interlock unit 5.

Fig. 4 is a schematic sectional view for illustrating the interface 7.

Fig. 4 is a sectional view of the interface 7 of fig. 1 taken along line a-a.

As shown in fig. 4, the interface 7 includes: a chamber 71, a conveying section 72, an exhaust section 73 (corresponding to an example of a second exhaust section), and a gas supply section 74 (corresponding to an example of a second gas supply section).

The chamber 71 has a gas-tight structure capable of maintaining a gas atmosphere with a large gas pressure reduced. The chamber 71 is connected to the chamber 61(164) via the gate valve 61c (164 b).

The conveying unit 72 is provided inside the chamber 71. The conveyance unit 72 transfers the processed object 100 between the

processing units

6 and 16 and the load lock unit 5. For example, the transfer unit 72 transfers (carries in and out) the processing object 100 between the chamber 61(164) of the processing unit 6 (16). The conveying unit 72 may be, for example, a conveying robot (e.g., a multi-joint robot) having an arm that holds the processing object 100.

The exhaust unit 73 reduces the pressure inside the chamber 71 to a predetermined pressure. The exhaust unit 73 may be connected to the bottom surface of the chamber 71 via the pressure control unit 66a, for example.

The exhaust section 73 may be the same as the exhaust section 66 described above, for example.

The pressure control unit 66a performs control so that the pressure inside the chamber 71 becomes a predetermined pressure based on an output of a pressure gauge, not shown, that detects the pressure inside the chamber 71.

As described above, the process gas G used for the plasma treatment is, for example, a highly reactive gas such as a gas containing fluorine atoms. When the highly reactive gas flows from the inside of the

chambers

61 and 164 of the

processing units

6 and 16 to the inside of the chamber 71 of the delivery unit 7, the highly reactive gas reacts with the elements exposed to the inside of the chamber 71, and contaminants may be generated.

By-products generated during the plasma treatment may adhere to the inner wall of the chamber 61(164) of the processing unit 6(16) or elements exposed to the inside of the chamber 61 (164). Therefore, when the gas flow is formed from the inside of the chamber 61(164) of the processing unit 6(16) toward the inside of the chamber 71 of the interface unit 7, by-products peeled from the inner wall of the chamber 61(164) of the processing unit 6(16) may enter the inside of the chamber 71 of the interface unit 7 along with the gas flow. The by-products intruding into the chamber 71 of the interface 7 become contaminants into the processing object 100.

Therefore, when the processed object 100 is carried into the chamber 61(164) of the processing section 6(16) or the processed object 100 is carried out from the chamber 61(164) of the processing section 6(16), the exhaust section 73 and the pressure attached to the chamber 71 are usedThe force control unit 66a cooperates with each other to make the pressure inside the chamber 71 substantially equal to the pressure inside the

chambers

61 and 164 of the

processing units

6 and 16. For example, the pressure inside the chamber 61(164) of the processing section 6(16) may be set to 1 × 10 ^-3 Pa～1×10 ^-2 Pa or so.

In this case, the pressure inside the chamber 71 of the transfer unit 7 is substantially equal to the pressure inside the chamber 61(164) of the processing unit 6(16), and means that the pressure inside the chamber 71 is set to be from the same pressure as the pressure inside the chamber 61 to a pressure 5 × 10 higher than the same pressure as the pressure inside the chamber 61 ^-2 Range of pressure of Pa. In this way, the intrusion of highly reactive gases or by-products into the chamber 71 of the transfer unit 7 can be effectively suppressed.

The present inventors have attempted to make the pressure in the chamber 71 of the interface section 7 substantially equal to the pressure in the chamber 61(164) of the processing section 6(16) in order to suppress the inflow of particles into the processing section 6 (16). Specifically, the inside of the chamber 71 of the delivery part 7 is exhausted by the exhaust part 73 so that the pressure inside the chamber 71 is maintained at 1 × 10 ^-3 Pa～5×10 ^-3 Pa。

As described above, even if contaminants move from the chamber 61(164) of the processing section 6(16) to the chamber 71 of the transfer section 7, it is considered that the contaminants are discharged from the chamber 71 by the exhaust section 73 before adhering to the processing object 100 if the exhaust amount of the exhaust section 73 is sufficiently large relative to the capacity of the chamber 71, and therefore the contamination due to the contaminants can be eliminated.

However, it is actually found that contaminants may adhere to the processing object 100 inside the chamber 71. When the processing object 100 to which the contaminants are attached is carried into the chamber 61(164) of the processing unit 6(16) and plasma processing is performed, the quality of the product may be affected. When the processed object 100 to which the contaminants have adhered is carried out from the plasma processing apparatus 1 to the outside, the processing in the subsequent steps may be affected.

The present inventors have conducted studies and, as a result, have obtained the following findings: when the pressure inside the chamber 71 is made substantially equal to the pressure inside the chamber 61(164) of the processing section 6(16) at the time of carrying in and carrying out the processing object 100 to and from the chamber 61(164) of the processing section 6(16), contamination occurs inside the chamber 71. That is, it was found that when the pressure inside the chamber 71 is reduced, contaminants are generated from the elements including organic substances exposed to the inside of the chamber 71.

As described above, the chamber 71 has a gas-tight structure capable of maintaining a gas environment in which a large gas pressure is reduced. Therefore, in order to form an airtight structure, a sealing member such as an O-ring is used for the chamber 71. The present inventors have made extensive investigations and, as a result, have obtained the following findings.

It is judged that the sealing member contains, for example, C ₁₆ H ₃₀ O ₄ And the like. When the sealing member containing organic substances is exposed to a gas atmosphere having a relatively high pressure and a reduced pressure, the organic substances in the sealing member may evaporate and be released into the chamber 71. Further, heat generated during the plasma processing is transferred to the chamber 71, and the temperature of the chamber 71 may be about 50 ℃. In this case, the temperature of the sealing member becomes high, and the components of the sealing member are more easily released. The components of the sealing member released to the inside of the chamber 71 become contaminants.

The inventors further conducted studies and obtained the following findings: by controlling the pressure inside the chamber 71, the release of the components of the sealing member can be suppressed, and the contamination of the processing object 100 inside the chamber 71 can be suppressed.

FIG. 5 is C ₁₆ H ₃₀ O ₄ Vapor pressure curve of (a).

C ₁₆ H ₃₀ O ₄ Is a component that is contained in a large amount in a seal member such as an O-ring.

Note that points B1 and B2 in fig. 5 are measured values, and the broken line in fig. 5 is an approximate curve based on points B1 and B2.

In the region of the lower side of the vapor pressure curve, C ₁₆ H ₃₀ O ₄ Is easily evaporated, and in the upper region of the vapor pressure curve, C ₁₆ H ₃₀ O ₄ The components (a) are difficult to evaporate. For example, in a chamber in which the processed object 100 is processed with respect to the processing units 6(16)61(164), when the pressure inside the chamber 71 is set to the upper region of the vapor pressure curve after the conveyance, the release of the components of the sealing member can be suppressed.

In addition, the chamber 61 of the processing unit 6 may be heated from 80 ℃ to about 100 ℃ because it is exposed to plasma. The processing object 100 may be plasma-processed while being heated from 150 ℃ to about 300 ℃ in the chamber 164 of the processing unit 16. Therefore, the chamber 164 of the processing unit 16 may be heated from 80 ℃ to about 100 ℃.

In the case described above, since the chamber 71 is connected to the chamber 61(164) via the gate valve 61c (164b), the temperature of the chamber 71 also rises to about 50 to 70 ℃.

For example, after the processed object 100 is transferred to the

chambers

61 and 164 of the

processing units

6 and 16, the pressure inside the chamber 71 is set to 5 × 10 ^-3 Pa or more, C can be suppressed even if the temperature of the chamber 71 is about 50 DEG C ₁₆ H ₃₀ O ₄ The components of (a) are evaporated.

However, depending on the type of plasma processing, the processing conditions, and the like, the temperature of the chamber 71 may become higher.

The present inventors have conducted studies and, as a result, have obtained the following findings: after the processed object 100 is transferred to the

chambers

61 and 164 of the

processing units

6 and 16, the pressure inside the chamber 71 is set to 1 × 10 ^-1 Pa or more, C can be almost eliminated even if the kind of plasma treatment, the treatment conditions, or the like are changed ₁₆ H ₃₀ O ₄ Evaporation of the components of (a).

When the pressure in the chamber 71 is excessively high, by-products adhering to the inner wall of the chamber 61(164) may be peeled off or by-products may float in the chamber 61(164) by the gas flow from the chamber 71 to the chamber 61(164) of the processing unit 6 (16). Therefore, when the processing object 100 is carried in and out from the processing unit 6, the pressure inside the chamber 71 is preferably set to 8 × 10 ^-3 Pa～5×10 ^-2 Pa or so. The pressure inside the chamber 71 of the interface 7 is determined to be within the pressure range, as compared with that of the processing section 6(16)The pressure inside chamber 61(164) is slightly higher.

The pressure of the chamber 71 can be controlled by the exhaust unit 73 and the pressure control unit 66a, but it is difficult to quickly increase the low pressure.

Therefore, as shown in fig. 4, the gas supply unit 74 is provided in the delivery unit 7 of the present embodiment.

The gas supply unit 74 supplies the gas G1 to the chamber 71 through the flow rate control unit 74 a. The flow rate control unit 74a may be, for example, a Mass Flow Controller (MFC).

The gas G1 may be, for example, a gas that is less likely to react with the processing object 100 or the elements exposed to the inside of the chamber 71. For example, the gas G1 may be a rare gas such as nitrogen or argon, or a mixed gas thereof.

The gas G1 is supplied for controlling the pressure inside the chamber 71, and the amount of the gas G1 supplied into the chamber 71 is small because the amount of the pressure to be controlled is also small. For example, the flow rate of the gas G1 is 10sccm or more and 1000sccm or less.

Therefore, the gas that reacts with the contaminants including organic substances may be supplied as gas G1, or the gas that reacts with the contaminants including organic substances may be supplied by adding it to the nitrogen gas or the like described above. The gas that reacts with contaminants including organic substances may be, for example, ozone gas. If the gas G1 is ozone gas or contains ozone gas, even if contaminants including organic substances are generated, at least a part of the generated contaminants can be decomposed.

The sealing member used in the processing unit 6 is the same as that used in the delivery unit 7. The pressure inside the chamber 61(164) is maintained at a pressure at which the components of the sealing member may evaporate during the period other than the period of performing the plasma processing. Therefore, the components of the sealing member are evaporated and released into the

chambers

61 and 164, and may adhere to the processing object 100. However, the inventors made an effort to investigate that the probability of the contaminants adhering to the inside of the chamber 71 is higher than the probability of the contaminants adhering to the inside of the chamber 61 (164).

The reason is considered to be presumably that: since the process gas is introduced into the chamber 61(164) to perform the plasma treatment, the contaminants (the evaporated components of the sealing member) are discharged from the chamber 61(164) together with the process gas. That is, it is considered that the adhesion of contaminants to the processing object 100 can be suppressed by increasing the pressure in the chamber by the introduction of the gas.

Fig. 6 is a timing chart for exemplifying the supply of the gas G1.

T1 in fig. 6 is a timing at which the transfer unit 7 starts to transfer the processing object 100 from the chamber 71 to the chamber 61(164) of the processing unit 6 (16).

T2 in fig. 6 is a timing when the processing object 100 starts to be carried out from the chamber 61(164) of the processing unit 6(16) to the chamber 71 of the delivery unit 7.

When there is no processing object 100 to be processed, the plasma processing apparatus 1 is in a standby state. When the plasma processing apparatus 1 is in the standby state, the inside of the chamber 51 of the load lock 5 is exhausted by the exhaust unit 52 and maintained at 1 × 10 ^-2 Pa～1×10 ^-1 Pressure around Pa. In the present embodiment, the value is, for example, 5 × 10 ^-2 Pa。

The pressure inside the chamber 71 of the interconnecting section 7 is maintained to suppress C ₁₆ H ₃₀ O ₄ 5X 10 of evaporated components ^-3 A pressure of Pa or more. Specifically, the controller 2 controls the pressure control unit 66a attached to the chamber 71 so that the pressure inside the chamber 71 becomes 5 × 10 based on the output of a not-shown pressure gauge for detecting the pressure inside the chamber 71 ^-3 A pressure of Pa or more.

The inside of the chamber 61 of the processing unit 6 is exhausted by the exhaust unit 66 to be maintained at 1 × 10 ^-3 Pa～1×10 ^-2 Pressure of Pa. In the present embodiment, the value is, for example, 1 × 10 ^-3 Pa。

When the processing object 100 is processed, the inside of the chamber 51 in which the interlock 5 is loaded is exhausted, so that the pressure inside the chamber 51 becomes the same as the atmospheric pressure. The conveying unit 4 takes out the processing object 100 located inside the housing unit 3 and conveys it into the chamber 51 of the loading interlock unit 5 ((1) of fig. 6).

When the processed object 100 is carried into the chamber 51After the inside, the inside of the chamber 51 is depressurized. After the pressure inside the chamber 51 was reduced to a predetermined pressure, the gas G1 was supplied from the gas supply unit 74 into the chamber 71 so that the pressure inside the chamber 71 became 1 × 10 ^-1 Pa or above. The predetermined pressure is 1X 10 ^-2 Pa or more and less than 1X 10 ^-1 Pressure of Pa. In the present embodiment, the value is, for example, 5 × 10 ^-2 Pa。

When the pressure inside the chamber 51 and the pressure inside the chamber 71 reach the above pressures, the gate valve 51a is opened. Then, the processing object 100 is carried into the chamber 71 by the carrying section 72 ((2) of fig. 6).

The chamber 51 communicates with a space outside the plasma processing apparatus 1. Therefore, when the processing object 100 is transported, air in the external space is taken into the chamber 51. The air in the external space may contain water vapor or particles. By setting the pressure inside the chamber 71 to a pressure higher than the pressure inside the chamber 51, the inflow of water vapor or particles from the chamber 51 to the chamber 71 can be suppressed.

After the processing object 100 is conveyed into the chamber 71, the gate valve 51a is closed. When the gate valve 51a is closed, the supply of the gas G1 into the chamber 71 is stopped. Further, the decompression inside the chamber 51 is maintained.

When the pressure inside the chamber 71 becomes, for example, 5X 10 ^-2 After Pa, the gate valve 61c is opened. Then, the processing object 100 is carried into the chamber 61(164) by the carrying section 72 (T1 in fig. 6).

Inside the chamber 61(164) of the processing unit 6(16), a plasma product is generated from a highly reactive gas by using plasma, and the processing of the processing object 100 is performed. Therefore, there are cases where highly reactive gases remain inside the chamber 61(164) and by-products generated during plasma processing adhere to the inner wall of the chamber 61(164) of the processing section 6 (16). When the pressure inside the chamber 71 is made substantially equal to the pressure inside the

chambers

61 and 164 of the

processing units

6 and 16, the intrusion of the highly reactive gas or by-product into the chamber 71 of the transfer unit 7 can be suppressed.

When the processing object 100 is carried into the chamber 61(164), the gate valve 61c is closed. Will be selected fromThe period from the opening of the gate valve 61c to the closing of the gate valve 61c is a carrying-in period T1a of the processing object 100. When the gate valve 61c is closed, the gas G1 is supplied from the gas supply unit 74 into the chamber 71. Thereby, the pressure inside the chamber 71 is maintained at 1 × 10 ^-1 Pa or above.

After the pressure inside the chamber 61(164) is reduced to a predetermined pressure, the process gas G is supplied by controlling the gas supply unit 65(166) until the pressure inside the chamber 61(164) reaches the pressure at which the plasma processing is performed. The pressure for performing the plasma treatment was 1X 10 ^-1 Pa-10 Pa. In the present embodiment, the pressure is, for example, 1 Pa. The predetermined pressure is 1X 10 ^-3 Pa～1×10 ^-2 Pa。

When the pressure inside the chamber 61(164) reaches a pressure at which the plasma processing is performed, a high-frequency voltage is applied from the high-frequency power supply 64a to the antenna 63, and plasma P is generated. Then, a plasma product is generated from the process gas G by using the plasma P, and the treatment of the treatment object 100 is performed by using radicals contained in the plasma product.

After the plasma processing is completed, the application of the high-frequency voltage from the high-frequency power supply 64a and the supply of the process gas G are stopped. The inside of the chamber 61(164) is depressurized to 1 × 10 ^-3 Pa～1×10 ^-2 Pressure of Pa. In the present embodiment, the pressure inside the chamber 61(164) is reduced to, for example, 1 × 10 ^-3 Pa。

When the pressure in the chamber 61(164) becomes 1X 10 ^-3 After Pa, the supply of the gas G1 from the gas supply unit 74 is stopped. Then, when the pressure inside the chamber 71 becomes, for example, 5 × 10 ^-2 After Pa, the gate valve 61c is opened. The processing object 100 is carried out from the chamber 61(164) by the transfer unit 72 (T2 in fig. 6).

After the processing object 100 is conveyed into the chamber 71 by the conveying unit 72, the gate valve 61c is closed. The period from the opening of the gate valve 61c to the closing of the gate valve 61c is defined as the carrying-out period T2a of the processing object 100. After the carrying-out period T2a, the gas G1 is supplied from the gas supply unit 74 into the chamber 71.

When the pressure inside the chamber 71 becomes 1X 10 ^-1 After Pa or more, the gate valve 51 is openeda, the processing object 100 is conveyed to the chamber 51 by the conveying unit 72 ((4) of fig. 6).

After the processing object 100 is conveyed into the chamber 51, the gate valve 51a is closed. In the delivery portion 7, the supply amount of the gas G1 to the inside of the chamber 71 is reduced. The supply amount of the gas G1 is set so that the pressure inside the chamber 71 becomes 1X 10 ^-2 A supply amount of Pa or more. For example, the supply amount of the gas G1 was set to 0.5 times. This can prevent the components of the sealing member from being evaporated and released into the chamber 71. Even if contaminants (components of the sealing member that have evaporated) are generated when the processing object 100 is carried out of the chamber 61(164), the contaminants can be discharged to the outside of the chamber 71 together with the gas G1 by supplying the gas G1.

Further, not only the supply amount of the gas G1 to the inside of the chamber 71 can be reduced, but also the exhaust amount of the exhaust portion 73 can be reduced by the pressure control portion 66a attached to the chamber 71. That is, the gas supply unit 74 and the pressure control unit 66a may be configured such that the pressure inside the chamber 71 is 1 × 10 ^-2 Pa or more is maintained in a cooperative manner. This can reduce the amount of gas G1 used.

In the load interlock 5, the inside of the chamber 51 is discharged so that the pressure inside the chamber 51 becomes atmospheric pressure. When the pressure inside the chamber 51 is about the same as the atmospheric pressure, the processing object 100 is taken out from the inside of the chamber 51 by the conveying unit 4 and stored in the storage unit 3 ((5) of fig. 6). Then, the next processing object 100 is conveyed to the load-lock unit 5 ((6) of fig. 6).

In the carrying-in period T1a of the processed object 100 after T1 and the carrying-out period T2a of the processed object 100 after T2, the pressure of the delivery portion 7 is temporarily set to a pressure included in a lower region of the vapor pressure curve in fig. 5. Specifically, when the gate valve 61c is opened, the gas inside the chamber 71 flows into the processing unit 6. Therefore, the pressure inside the chamber 71 is reduced to a pressure (for example, 1 × 10, which is a predetermined pressure immediately before the plasma processing) inside the chamber 61(164) of the processing unit 6(16) ^- ³ Pa) are substantially equal. Therefore, during the carrying-in period T1a and the carrying-out period T2a, the components of the sealing member are evaporated and released into the chamber 71.

However, after the carrying-in period T1a and the carrying-out period T2a have elapsed, the gate valve 61c (164b) closes the space between the chamber 71 of the interface 7 and the chamber 61(164) of the processing unit 6 (16). Then, the gas supply unit 74 supplies the gas G1 into the chamber 71 of the delivery unit 7 so that the pressure inside the chamber 71 becomes 5 × 10 ^-3 Pa or more, preferably 1X 10 ^-1 Pa or above. Therefore, evaporation of the components of the sealing member can be suppressed.

Even if the pressure inside the chamber 71 of the delivery part 7 and the chamber 61 of the processing part 6 is set to be equal to or lower than the pressure at which the components of the sealing member can be evaporated, by introducing a gas into the delivery part 7, it is possible to suppress the adhesion of contaminants (the evaporated components of the sealing member) to the processing object 100. The interiors of the chamber 71 and the chamber 61 are evacuated to maintain a predetermined reduced-pressure gas atmosphere. The exhaust speed (L/min) of the exhaust section 73 and the exhaust section 66 is determined. When the gas G1 is supplied into the chamber 71 and the chamber 61, the pressure in the chamber 71 rises, and the amount of the gas G1 discharged per unit volume increases. As a result, it appears that the inside of the chamber is exhausted in accordance with the amount of the supplied gas G1. That is, by the exhaust gas, the pollutants can be exhausted together with the gas G1.

As is apparent from fig. 6, the period during which the pressure inside the chamber 71 is reduced to a pressure equal to or lower than the pressure at which the component serving as the sealing member can evaporate, that is, the pressure inside the chamber 61(164) of the processing portion 6(16) can be shortened. Therefore, evaporation of the components of the sealing member can be suppressed.

In addition, even if the component of the sealing member is evaporated in the chamber 71, by supplying the gas G1, the contaminants (the evaporated component of the sealing member) can be discharged to the outside of the chamber 71 together with the gas G1, in the same manner as in the chambers 61 (164).

When the state in which the processing object 100 is not present in the chamber 71 continues for a long time, the exhaust amount of the exhaust unit 73 may be reduced by controlling the pressure control unit 66a attached to the chamber 71. By reducing the amount of exhaust gas from the exhaust section 73, the pressure in the chamber 71 can be reduced to 1 × 10 ^-2 Amount of gas G1 required above Pa. Furthermore, the interior of the chamber 71 is untreatedThe state of the object 100 continues for a time period from the time when the supply of the gas G1 is stopped to the time when the pressure inside the chamber 71 becomes 1 × 10 ^-2 Time in Pa.

The above procedure can be performed by controlling the conveying unit 72, the exhaust unit 73, and the gas supply unit 74 by the controller 2, for example.

For example, when the transfer (carrying in/out) of the processing object 100 by the transfer unit 72 is performed, the controller 2 controls the exhaust unit 73 so that the pressure inside the chamber 71 becomes substantially equal to the pressure inside the chambers 61 (164). For example, when the transfer of the processing object 100 by the transfer unit 72 is completed, the controller 2 controls the gas supply unit 74 to supply the gas G1 into the chamber 71.

For example, controller 2 supplies gas G1 to make the pressure inside chamber 71 higher than the pressure inside chamber 61 (164).

For example, the controller 2 supplies the gas G1 to make the pressure inside the chamber 71 5 × 10 ^-3 Pa or more, preferably 1X 10 ^-1 Pa or above.

As described above, the plasma processing method of the present embodiment may include the following steps.

And a step of performing plasma processing on the processing object 100 in a first region having a gas atmosphere with a relatively large gas pressure and a reduced pressure. The first region is, for example, the interior of chamber 61 (164).

And a step of conveying the processing object 100 between a second area distant from the first area and the first area. The second region is, for example, the interior of the chamber 71.

Then, when the processing object 100 is conveyed, the pressure of the gas atmosphere in the second region is set to be substantially equal to the pressure of the gas atmosphere in the first region.

When the conveyance of the processing object 100 is completed, the gas G1 is supplied to the second area.

For example, after the transfer of the processing object 100, the gas G1 is supplied so that the pressure of the gas atmosphere in the second region becomes higher than the pressure of the gas atmosphere in the first region when the processing object 100 is transferred.

For example, by supplying gas G1The pressure of the gas environment of the second area is 5 x 10 ^-3 Pa or more, preferably 1X 10 ^-1 Pa or above.

The contents of each step can be the same as those described above, and therefore, detailed description thereof is omitted.

The present embodiment has been described above as an example. However, the present invention is not limited to these descriptions.

The embodiment described above, to which design changes are appropriately made by those skilled in the art, is also included in the scope of the present invention as long as the embodiment has the features of the present invention.

For example, the shape, size, material, arrangement, number, and the like of each element included in the plasma processing apparatus 1 are not limited to the examples, and may be appropriately changed.

The elements included in the above-described embodiments may be combined as much as possible, and embodiments obtained by combining these embodiments are also included in the scope of the present invention as long as the features of the present invention are provided.

In the present embodiment, the pressure inside the chamber 71 is controlled by the pressure control unit 66a attached to the chamber 71 so as to be maintained at 5 × 10 ^-3 Pa or above. However, the present invention is not limited thereto. For example, the exhaust unit 73 may be a combination of a turbo molecular pump and a dry pump, and an exhaust port connected to the dry pump may be provided at the bottom of the chamber 71. When the inside of the chamber 71 is empty of the processing object 100 for a long time, the inside of the chamber 71 may be exhausted by the dry pump. Alternatively, it can be up to 5 × 10 ^-3 The exhaust unit 73 is stopped after Pa.

Claims

1. A plasma processing apparatus, comprising:

a first chamber capable of placing a processing object therein while maintaining a gas atmosphere having a reduced pressure at a relatively high pressure;

a first exhaust unit capable of depressurizing the inside of the first chamber to a predetermined pressure;

a plasma generating section capable of generating the plasma;

a first gas supply unit capable of supplying a process gas to an inside of the first chamber and a region where the plasma is generated;

a second chamber connected to the first chamber via a gate valve, the second chamber being capable of maintaining a gas atmosphere having a reduced pressure at a relatively high pressure;

a transfer unit which is provided inside the second chamber and can transfer the processing object to the first chamber;

a second exhaust unit capable of depressurizing the inside of the second chamber to a predetermined pressure;

a second gas supply unit capable of supplying a gas into the second chamber; and

a controller capable of controlling the conveying section, the second exhaust section, and the second gas supply section,

the controller is

Controlling the second exhaust unit so that a pressure inside the second chamber becomes substantially equal to a pressure inside the first chamber when the transfer unit transfers the processing object,

when the transfer of the processing object by the transfer unit is completed, the second gas supply unit is controlled to supply the gas into the second chamber.

2. The plasma processing apparatus according to claim 1, wherein the controller supplies the gas so that a pressure inside the second chamber is higher than a pressure inside the first chamber when the processing object is conveyed, after the processing object is conveyed by the conveying section between the first chamber and the second chamber.

3. The plasma processing apparatus according to claim 1 or 2, wherein the controller makes the pressure inside the second chamber 5 x 10 by supplying the gas ^-3 Pa or above.

4. The plasma processing apparatus of claim 3 wherein the controller is in the second chamberControlling the second exhaust part to make the pressure in the second chamber 5 × 10 when the processing object is not present in the chamber ^-3 Pa or above.

5. A plasma processing method for performing plasma processing on a processing object, comprising:

performing plasma treatment on the treatment object in a first region having a gas atmosphere with a relatively large gas pressure and a reduced pressure; and

a step of conveying the processed object between a second area far from the first area and the first area,

the pressure of the gas atmosphere in the second region is set to be substantially equal to the pressure of the gas atmosphere in the first region when the processing object is conveyed,

and supplying a gas to the second region when the transfer of the processing object is completed.

6. The plasma processing method according to claim 5, wherein after the transfer of the processing object is performed, the pressure of the gas atmosphere in the second region is made higher than the pressure of the gas atmosphere in the first region when the transfer of the processing object is performed by supplying the gas.

7. The plasma processing method according to claim 5 or 6, wherein the pressure of the gas atmosphere of the second region is made 5 x 10 by supplying the gas ^-3 Pa or above.