Plasma processing apparatus and plasma processing method

Abstract

The present application provides a kind of plasma processing device that can inhibit pollution caused by pollutants, and plasma processing method. The plasma processing device of embodiment includes: first chamber;First exhaust part;Plasma generating part;First gas supply part;Second chamber;Conveying part;Second exhaust part;Second gas supply part;And controller. The controller carries out the conveying of the conveying part to the processing object when, control the second exhaust part, to make the pressure inside the second chamber be approximately equal to the pressure inside the first chamber, when the conveying of the conveying part to the processing object ends, control the second gas supply part, and supply the gas to the inside of the second chamber.

Description

Technical Field

[0001] The embodiments of the present invention relate to a plasma processing apparatus and a plasma processing method. Background Technology

[0002] Plasma drying processes are used, for example, in the manufacture of microstructures. In the manufacture of semiconductor devices, flat panel displays, photomasks, and other devices, various plasma treatments are performed, such as etching, ashing, and damage removal.

[0003] The plasma processing apparatus for performing this type of plasma processing includes, for example, a process chamber for performing plasma processing on the processed material, a transfer chamber connected to the process chamber via a gate valve, and a transport robot located inside the transfer chamber and transporting the processed material between the transfer chamber and the process chamber.

[0004] Here, inside the transfer chamber, contaminants containing organic matter may sometimes be generated. Since the processed items are transported inside the transfer chamber, there is a risk that these contaminants will adhere to the surface of the processed items. In this case, if the processed items with contaminants are moved into the process chamber and subjected to plasma treatment, the quality of the product may be affected. Furthermore, if the processed items with contaminants are removed from the transfer chamber to the outside, subsequent processing steps may be affected.

[0005] Therefore, a technology for inhibiting the contamination of treated materials by pollutants has been proposed (for example, see Patent Document 1 and Patent Document 2).

[0006] However, in recent years, the diversification and miniaturization of materials with fine structures have increased the risk of contaminants affecting quality.

[0007] Therefore, it is desirable to develop technologies that can further suppress pollution caused by pollutants.

[0008] [Existing technical documents]

[0009] [Patent Literature]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 6-196540

[0011] [Patent Document 2] Japanese Patent Application Publication No. 2003-17478 Summary of the Invention

[0012] [The problem the invention aims to solve]

[0013] The problem to be solved by the present invention is to provide a plasma treatment apparatus and a plasma treatment method that can suppress pollution caused by pollutants.

[0014] [Technical means to solve the problem]

[0015] The plasma processing apparatus of this embodiment includes: a first chamber for maintaining a high-pressure depressurized gas environment and capable of housing a workpiece; a first exhaust unit for depressurizing the interior of the first chamber to a predetermined pressure; a plasma generation unit for generating plasma; a first gas supply unit for supplying process gas to the interior of the first chamber and the region where the plasma is generated; a second chamber connected to the first chamber via a gate valve and capable of maintaining a high-pressure depressurized gas environment; a conveying unit disposed inside the second chamber for conveying the workpiece between the second chamber and the first chamber; a second exhaust unit for depressurizing the interior of the second chamber to a predetermined pressure; a second gas supply unit for supplying gas to the interior of the second chamber; and a controller for controlling the conveying unit, the second exhaust unit, and the second gas supply unit. When the conveying unit conveys the workpiece, the controller controls the second exhaust unit to make the pressure inside the second chamber approximately equal to the pressure inside the first chamber. When the conveying unit finishes conveying the workpiece, the controller controls the second gas supply unit to supply gas to the interior of the second chamber.

[0016] [The effects of the invention]

[0017] According to embodiments of the present invention, a plasma treatment apparatus and a plasma treatment method are provided that can suppress pollution caused by pollutants. Attached Figure Description

[0018] Figure 1 This is a layout diagram illustrating the plasma processing apparatus of this embodiment.

[0019] Figure 2 This is a schematic cross-sectional view used to illustrate an example of the processing unit.

[0020] Figure 3 This is a schematic cross-sectional view illustrating the processing unit in another embodiment.

[0021] Figure 4 It is a schematic cross-sectional view used to illustrate the junction.

[0022] Figure 5 It is C 16 H 30 Vapor pressure curve of O4.

[0023] Figure 6It is a timing diagram used to illustrate the gas supply.

[0024] [Explanation of Symbols]

[0025] 1: Plasma processing device

[0026] 2: Controller

[0027] 3: Storage Department

[0028] 4. 72: Transport Department

[0029] 5: Load the interlocking unit

[0030] 6, 16: Processing Department

[0031] 7: Handover Department

[0032] 51, 61, 71, 164: Chambers

[0033] 51a, 61c, 164b: Gate valves

[0034] 52, 66, 73, 162: Exhaust section

[0035] 53: Gas Supply Department

[0036] 61a: Transmission window

[0037] 61b, 164a: Opening

[0038] 62: Loading section

[0039] 63: Antenna

[0040] 64a, 64b: High-frequency power supply

[0041] 64a1, 64b1: Matchers

[0042] 65, 74, 166: Gas Supply Department

[0043] 65a, 74a: Flow Control Department

[0044] 66a, 166a: Pressure Control Section

[0045] 100: Items to be processed

[0046] 161: Plasma Generation Unit

[0047] 161a: Discharge tube

[0048] 161b: Introducing waveguide

[0049] 161b1: Terminal Matcher

[0050] 161b2: Short-circuit tuner

[0051] 161b3: slot

[0052] 161c: Delivery pipe

[0053] 163: Microwave Generating Unit

[0054] 164c: Rectifier board

[0055] 165: Loading section

[0056] B1, B2: Points

[0057] G: Process Gas

[0058] G1: Gas

[0059] M: Microwave

[0060] P: Plasma

[0061] T1, T2: Timing

[0062] T1a: During the move-in period

[0063] T2a: During the move-out period Detailed Implementation

[0064] Hereinafter, embodiments of the present invention will be illustrated with reference to the accompanying drawings. Furthermore, in each drawing, the same constituent elements are labeled with the same reference numerals, and detailed descriptions are appropriately omitted.

[0065] Figure 1 This is a layout diagram illustrating the plasma processing apparatus 1 of this embodiment.

[0066] like Figure 1 As shown, the plasma processing apparatus 1 includes, for example, a controller 2, a storage unit 3, a conveying unit 4, a loading interlock unit 5, a processing unit 6, and a transfer unit 7.

[0067] The controller 2 includes, for example, 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. The controller 2 controls the operation of each component installed in the plasma processing device 1 based on a control program stored in the storage unit.

[0068] The storage unit 3 may, for example, store the processed item 100 in a stacked (multi-level) manner. The storage unit 3 may be, for example, a so-called pod or a front-opening unified pod (FOUP) that serves as a front-opening carrier. However, the storage unit 3 is not limited to the example shown, as long as it can store the processed item 100. At least one storage unit 3 may be provided.

[0069] A conveying unit 4 is disposed between the storage unit 3 and the loading interlocking unit 5. The conveying unit 4 performs the conveying and transfer of the processed item 100 between the storage unit 3 and the loading interlocking unit 5. In this case, the conveying unit 4 performs the conveying and transfer of the processed item 100 at a pressure (e.g., atmospheric pressure) higher than the pressure during plasma treatment. The conveying unit 4 is, for example, a conveying robot with an arm that holds the processed item 100.

[0070] A loading interlock unit 5 is disposed between the conveying unit 4 and the transfer unit 7. The loading interlock unit 5 transfers the processed material 100 between the conveying unit 4 and the transfer unit 7, which have different gas environment pressures. Therefore, the loading interlock unit 5 includes a chamber 51, an exhaust unit 52, and a gas supply unit 53.

[0071] Chamber 51 has an airtight structure capable of maintaining a high-pressure, depressurized gas environment. An opening for loading and unloading the processed material 100 is provided on the side wall of chamber 51. Additionally, a gate valve 51a is provided to open and close the opening. Chamber 51 is connected to chamber 71 (an example of a second chamber) of the junction 7 via the gate valve 51a.

[0072] The exhaust section 52 exhausts gas from the interior of the chamber 51 so that the pressure inside the chamber 51 is approximately equal to the pressure inside the chamber 71 of the junction section 7. The exhaust section 52 may include, for example, a turbomolecular pump (TMP) and a pressure control section (auto pressure controller (APC)).

[0073] The gas supply unit 53 supplies gas to the interior of the chamber 51 so that the pressure inside the chamber 51 is approximately equal to the pressure of the conveying unit 4. The supplied gas may be, for example, air or nitrogen.

[0074] The processing unit 6 performs plasma treatment on the workpiece 100 in a gas environment with high pressure and reduced pressure.

[0075] The processing unit 6 can be configured as a plasma processing device such as a plasma etching device, a plasma ashing device, a sputtering device, or a plasma chemical vapor deposition (CVD) device.

[0076] In this case, there are no particular limitations on the method of plasma generation; for example, it can be set to generate plasma using high frequency or microwaves.

[0077] However, the type of plasma processing apparatus or the plasma generation method is not limited to the examples shown. That is, the processing unit 6 can perform plasma processing on the workpiece 100 in a gas environment with a relatively high pressure and reduced pressure.

[0078] Furthermore, there is no particular limitation on the number of processing units 6. At least one processing unit 6 is sufficient. When multiple processing units 6 are provided, they can be of the same type or different types. Additionally, when multiple plasma processing devices of the same type are provided, the processing conditions can be different or the processing conditions can be the same for each device.

[0079] Figure 2 This is a schematic cross-sectional view used to illustrate an example of the processing unit 6.

[0080] Figure 2 The processing unit 6 shown in the example is an inductively coupled plasma processing apparatus. That is, it is an example of a plasma processing apparatus that uses plasma P generated by high-frequency energy to generate plasma products from process gas G and processes the processed material 100.

[0081] like Figure 2 As shown, the processing unit 6 includes, for example, a chamber 61 (equivalent to an example of a first chamber), a mounting unit 62, an antenna 63, a high-frequency power supply 64a, a high-frequency power supply 64b, a gas supply unit 65 (equivalent to an example of a first gas supply unit), and an exhaust unit 66 (equivalent to an example of a first exhaust unit).

[0082] The chamber 61 is, for example, a generally cylindrical shape with a bottom, and has an airtight structure capable of maintaining a high-pressure, depressurized gas environment. A transmission window 61a is provided in an airtight manner at the upper part of the chamber 61. The transmission window 61a is plate-shaped and can be formed of a material with high transmittance to high-frequency energy and that is not easily etched during plasma processing. For example, the transmission window 61a can be formed of a dielectric material such as quartz.

[0083] An opening 61b for loading and unloading the processed item 100 is provided on the side wall of the chamber 61. A gate valve 61c is also provided to open and close the opening 61b. The chamber 61 is connected to the chamber 71 of the junction 7 via the gate valve 61c.

[0084] The mounting section 62 is provided inside the chamber 61. The workpiece 100 is mounted on the upper surface of the mounting section 62. In this case, the workpiece 100 can be directly mounted on the upper surface of the mounting section 62, or it can be mounted on the mounting section 62 via a support member (not shown). In addition, a holding device such as an electrostatic chuck can be provided in the mounting section 62.

[0085] Antenna 63 supplies high-frequency energy (electromagnetic energy) to the region inside cavity 61 where plasma P is generated. Plasma P is generated using the high-frequency energy supplied to the interior of cavity 61. For example, antenna 63 supplies high-frequency energy to the interior of cavity 61 through transmission window 61a.

[0086] The high-frequency power supply 64a is electrically connected to the antenna 63 via a matching adapter 64a1. The matching adapter 64a1 includes a matching circuit for achieving impedance matching between the high-frequency power supply 64a and the plasma P. The high-frequency power supply 64a is used to generate plasma P. That is, the high-frequency power supply 64a is provided to generate plasma P by generating a high-frequency discharge inside the chamber 61. The high-frequency power supply 64a applies high-frequency power with a frequency of approximately 100 kHz to 100 MHz to the antenna 63.

[0087] In this embodiment, the antenna 63 and the high-frequency power supply 64a constitute the plasma generation unit that generates plasma P.

[0088] The high-frequency power supply 64b is electrically connected to the mounting section 62 via a matching adapter 64b1. The matching adapter 64b1 includes a matching circuit for achieving impedance matching between the high-frequency power supply 64b side and the plasma P side. The high-frequency power supply 64b controls the energy of the ions introduced into the processed material 100 mounted in the mounting section 62. The high-frequency power supply 64b applies high-frequency power with a relatively low frequency (e.g., below 13.56 MHz) suitable for ion introduction to the mounting section 62.

[0089] The gas supply unit 65 supplies process gas G to the region inside the chamber 61 where plasma P is generated via the flow control unit 65a. The flow control unit 65a may be, for example, a mass flow controller (MFC). The gas supply unit 65 may be connected to the side wall of the chamber 61 and be located near the transmission window 61a.

[0090] The process gas G is appropriately selected based on the type of processing or the material of the surface to be processed on the workpiece 100. For example, in the case of etching, a process gas G containing fluorine atoms, such as CF4 or CF3, can be used to generate highly reactive free radicals. In this case, the process gas G can be, for example, a gas containing only fluorine atoms, or a mixture of a gas containing fluorine atoms and a rare gas.

[0091] The exhaust unit 66 depressurizes the interior of chamber 61 to a predetermined pressure. The exhaust unit 66 may be, for example, a turbomolecular pump (TMP). The exhaust unit 66 may be connected to the bottom surface of chamber 61 via a pressure control unit 66a. The pressure control unit 66a controls the pressure based on the output of a pressure gauge (not shown) that detects the pressure inside chamber 61, so that the interior of chamber 61 reaches the predetermined pressure. The pressure control unit 66a may be, for example, an automatic pressure controller (APC).

[0092] When plasma treatment is performed on the workpiece 100, the internal pressure of the chamber 61 is reduced to a predetermined pressure using the exhaust section 66, and a predetermined amount of process gas G (e.g., CF4, etc.) is supplied from the gas supply section 65 to the region inside the chamber 61 where plasma P is generated. Meanwhile, high-frequency power of a predetermined power is applied to the antenna 63 from the high-frequency power supply 64a, and electromagnetic energy is radiated into the interior of the chamber 61 through the transmission window 61a. Additionally, high-frequency power of a predetermined power is applied to the mounting section 62 where the workpiece 100 is mounted from the high-frequency power supply 64b, forming an electric field that accelerates ions from plasma P toward the workpiece 100.

[0093] Electromagnetic energy is radiated into the interior of chamber 61 to generate plasma P. Through the generated plasma P, the process gas G is excited and activated to generate plasma products such as neutral active species and ions. Then, the generated plasma products are supplied to the processed item 100 to perform plasma treatment on the processed item 100.

[0094] Figure 3 This is a schematic cross-sectional view illustrating the processing unit 16 of another embodiment.

[0095] Processing unit 16 is generally a microwave-excited plasma processing apparatus, also known as a "chemical dry etching (CDE) apparatus" or a "remote plasma apparatus". Processing unit 16 uses plasma P to generate plasma products from process gas G, and mainly uses the free radicals contained in the plasma products to process the workpiece 100.

[0096] like Figure 3 As shown, the processing unit 16 includes, for example, a plasma generating unit 161, an exhaust unit 162 (equivalent to an example of a first exhaust unit), a microwave generating unit 163, a chamber 164 (equivalent to an example of a first chamber), a mounting unit 165, and a gas supply unit 166 (equivalent to an example of a first gas supply unit).

[0097] The plasma generating unit 161 includes, for example, a discharge tube 161a, an inlet waveguide 161b, and a delivery tube 161c.

[0098] The discharge tube 161a has an internal region for generating plasma P and is located away from the chamber 164. The discharge tube 161a is tubular and can be formed of a material with high transmittance to microwaves M and that is not easily etched. For example, the discharge tube 161a can be formed of a dielectric such as alumina or quartz.

[0099] The inlet waveguide 161b is connected to the outside of the discharge tube 161a in a manner approximately orthogonal to it. A termination matcher 161b1 is provided at the end of the inlet waveguide 161b. In addition, a stub tuner 161b2 is provided on the inlet side (the inlet side of microwave M) of the inlet waveguide 161b.

[0100] An annular groove 161b3 is provided at the connection between the waveguide 161b and the discharge tube 161a. Microwaves M propagating inside the waveguide 161b are radiated into the discharge tube 161a via the groove 161b3.

[0101] One end of the delivery tube 161c is connected to the end of the discharge tube 161a opposite to the gas supply section 166. The other end of the delivery tube 161c is connected to the chamber 164. The delivery tube 161c is formed of a material resistant to free radicals contained in the plasma generator. The delivery tube 161c is formed, for example, of quartz, stainless steel, ceramic, fluoropolymer, etc.

[0102] The exhaust section 162 reduces the internal pressure of the chamber 164 to a predetermined pressure. The exhaust section 162 may, for example, be connected to the bottom surface of the chamber 164 via a pressure control section 66a. The exhaust section 162 may, for example, be the same as the exhaust section 66 described above.

[0103] A microwave generating unit 163 is disposed at the end of the inlet waveguide 161b opposite to the discharge tube 161a side. The microwave generating unit 163 generates microwaves M at a predetermined frequency (e.g., 2.75 GHz) and radiates them toward the inlet waveguide 161b.

[0104] The chamber 164 has an airtight structure capable of maintaining a high-pressure, depressurized gas environment. An opening 164a for loading and unloading the processed material 100 is provided on the side wall of the chamber 164. Additionally, a gate valve 164b is provided to open and close the opening 164a. The chamber 164 is connected to the chamber 71 of the junction 7 via the gate valve 164b.

[0105] Additionally, a flow rectifier 164c can be installed inside the chamber 164. The flow rectifier 164c can be installed on the inner wall of the chamber 164 in a manner substantially parallel to the mounting surface of the mounting section 165. Gas containing free radicals is introduced into the space between the flow rectifier 164c and the ceiling of the chamber 164 via the delivery pipe 161c. If the flow rectifier 164c is provided, it becomes easier to make the amount of free radicals in the processing surface of the processed product 100 substantially uniform.

[0106] The mounting section 165 is disposed inside the chamber 164. The workpiece 100 is mounted on the upper surface of the mounting section 165. In this case, the workpiece 100 can be placed directly on the top of the mounting section 165, or it can be placed on the mounting section 165 via a support member (not shown). In addition, a holding device such as an electrostatic chuck can be provided in the mounting section 165.

[0107] A gas supply unit 166 is connected to the end of the discharge tube 161a opposite to the chamber 164 side. The gas supply unit 166 supplies process gas G into the discharge tube 161a. Additionally, a pressure control unit 166a may be provided between the gas supply unit 166 and the discharge tube 161a. The pressure control unit 166a controls the pressure of the process gas G supplied to the interior of the discharge tube 161a.

[0108] When plasma treatment is performed on the workpiece 100, the pressure inside the chamber 164 is reduced to a predetermined pressure using the exhaust section 162. At this time, the pressure inside the discharge tube 161a, which communicates with the chamber 164, is also reduced. Next, process gas G at a predetermined pressure is supplied to the discharge tube 161a from the gas supply section 166 via the pressure control section 166a. Additionally, microwaves M of a predetermined power are emitted from the microwave generation section 163 into the waveguide 161b. The emitted microwaves M propagate inside the waveguide 161b and are emitted into the discharge tube 161a via the groove 161b3.

[0109] Plasma P is generated by the energy of microwave M radiated into the interior of discharge tube 161a. The process gas G is excited and activated by the generated plasma P to generate plasma products containing free radicals or ions.

[0110] A gas containing plasma generators is supplied to the interior of chamber 164 via delivery pipe 161c. At this time, short-lived ions cannot reach the interior of chamber 164, while long-lived free radicals do. The free radical-containing gas supplied to the interior of chamber 164 is rectified by rectifier plate 164c and reaches the processing surface of workpiece 100 for plasma treatment such as etching. In this case, chemical treatment utilizing free radicals is primarily performed. Furthermore, since ions used for physical treatment are not supplied to the interior of chamber 164, the processing surface of workpiece 100 is not damaged by ions. Therefore, processing unit 16 is suitable, for example, for removing damage caused by etching treatment using ions.

[0111] Furthermore, while the above description, as an example of a processing unit, illustrates inductively coupled plasma (ICP) processing apparatus and CDE (remote plasma device), the processing unit is not limited to these plasma processing apparatuses. For example, the processing unit may also be a capacitively coupled plasma (CCP) processing apparatus (e.g., a parallel-plate type reactive ion etching (RIE) apparatus), or other microwave-excited plasma processing apparatuses (e.g., surface wave plasma (SWP) apparatuses). Moreover, known techniques can be applied to the basic structure of other plasma processing apparatuses; therefore, detailed descriptions are omitted.

[0112] Next, return to Figure 1 The handover section 7 will be explained.

[0113] like Figure 1 As shown, the transfer unit 7 is located between the processing unit 6 (16) and the loading interlock unit 5. The transfer unit 7 performs the transfer of the processed item 100 between the processing unit 6 (16) and the loading interlock unit 5.

[0114] Figure 4 This is a schematic cross-sectional view used to illustrate the junction 7.

[0115] also, Figure 4 yes Figure 1 A cross-sectional view of the junction 7 along line AA.

[0116] like Figure 4 As shown, the transfer section 7 includes: a chamber 71, a conveying section 72, an exhaust section 73 (equivalent to an example of a second exhaust section), and a gas supply section 74 (equivalent to an example of a second gas supply section).

[0117] Chamber 71 has an airtight structure capable of maintaining a high-pressure depressurized gas environment. Chamber 71 is connected to chamber 61 (164) via gate valve 61c (164b).

[0118] The conveying unit 72 is disposed inside the chamber 71. The conveying unit 72 performs the transfer of the processed item 100 between the processing unit 6 (16) and the loading interlocking unit 5. For example, the conveying unit 72 conveys (carries in and out) the processed item 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) with an arm that holds the processed item 100.

[0119] The exhaust section 73 reduces the internal pressure of the chamber 71 to a specified pressure. The exhaust section 73 may be connected to the bottom surface of the chamber 71, for example, via a pressure control section 66a.

[0120] The exhaust section 73 may be configured to be the same as the exhaust section 66 described above.

[0121] The pressure control unit 66a controls the pressure inside the chamber 71 based on the output of a pressure gauge (not shown) that detects the pressure inside the chamber 71, so that the pressure inside the chamber 71 becomes a specified pressure.

[0122] Here, as described above, the process gas G used in plasma processing may contain highly reactive gases, such as those containing fluorine atoms. If the highly reactive gas flows from the interior of the chamber 61 (164) of the processing section 6 (16) to the interior of the chamber 71 of the transfer section 7, there is a risk that the highly reactive gas may react with the components exposed inside the chamber 71, generating contaminants.

[0123] Furthermore, byproducts generated during plasma processing sometimes adhere to the inner wall of the chamber 61 (164) of the processing section 6 (16) or to components exposed inside the chamber 61 (164). Therefore, if an airflow is formed from the interior of the chamber 61 (164) of the processing section 6 (16) toward the interior of the chamber 71 of the junction section 7, there is a risk that byproducts detached from the inner wall of the chamber 61 (164) of the processing section 6 (16) may enter the interior of the chamber 71 of the junction section 7 along with the airflow. Byproducts that enter the interior of the chamber 71 of the junction section 7 become contaminants to the processed product 100.

[0124] Therefore, when the processed item 100 is moved into or out of the chamber 61(164) of the processing unit 6(16), the exhaust unit 73 and the pressure control unit 66a installed in the chamber 71 cooperate to make the pressure inside the chamber 71 approximately equal to the pressure inside the chamber 61(164) of the processing unit 6(16). For example, the pressure inside the chamber 61(164) of the processing unit 6(16) can be set to 1×10 -3 Pa ~ 1×10 -2 Approximately Pa.

[0125] In this case, the pressure inside chamber 71 of the so-called junction 7 being approximately equal to the pressure inside chamber 61 (164) of the processing section 6 (16) means that the pressure inside chamber 71 is between the same as the pressure inside chamber 61 and 5 × 10⁻⁶ higher than the same as the pressure inside chamber 61. -2 The pressure range of Pa. If so, it can effectively prevent highly reactive gases or byproducts from entering the interior of the chamber 71 of the junction 7.

[0126] In order to suppress the inflow of particles into the processing unit 6 (16), the inventors also attempted to make the pressure inside the chamber 71 of the transfer section 7 approximately equal to the pressure inside the chamber 61 (164) of the processing unit 6 (16). Specifically, by venting the chamber 71 of the transfer section 7 using the exhaust section 73, the pressure inside the chamber 71 was maintained at 1×10⁻⁶. -3 Pa ~ 5 × 10 -3 Pa.

[0127] As described above, even if the contaminants move from the chamber 61 (164) of the processing section 6 (16) to the chamber 71 of the transfer section 7, considering that as long as the exhaust volume of the exhaust section 73 is large enough relative to the capacity of the chamber 71, the contaminants will be discharged from the chamber 71 by the exhaust section 73 before adhering to the processed item 100, so it can be considered that the pollution caused by the contaminants can be eliminated.

[0128] However, it has been found that contaminants sometimes adhere to the processed item 100 inside chamber 71. If the processed item 100 with contaminants is moved into the chamber 61 (164) of the processing unit 6 (16) and subjected to plasma treatment, the quality of the product may be affected. In addition, if the processed item 100 with contaminants is moved out of the plasma treatment device 1, the processing of subsequent processes may be affected.

[0129] The inventors and others have obtained the following insight from their research: when the workpiece 100 is moved into or out of the chamber 61 (164) of the processing unit 6 (16), if the pressure inside the chamber 71 is made approximately equal to the pressure inside the chamber 61 (164) of the processing unit 6 (16), contaminants are generated inside the chamber 71. That is, it has been determined that if the pressure inside the chamber 71 is reduced, contaminants are generated from components that are exposed inside the chamber 71 and contain organic matter.

[0130] As described above, chamber 71 has an airtight structure capable of maintaining a high-pressure, depressurized gas environment. Therefore, in order to constitute an airtight structure, sealing members such as O-rings are used in chamber 71. The inventors have conducted intensive investigations and obtained the following insights.

[0131] It was determined that the sealing member contains, for example, C. 16 H 30Organic compounds such as O4. Furthermore, if the sealing component containing organic matter is exposed to a high-pressure, depressurized gas environment, the organic components of the sealing component may sometimes evaporate and be released into the interior of chamber 71. Additionally, heat from plasma processing is transferred to chamber 71, causing its temperature to sometimes reach around 50°C. In this situation, the temperature of the sealing component increases, making it easier for its components to be released. The components of the sealing component released into the interior of chamber 71 become contaminants.

[0132] Further research by the inventors yielded the following insights: controlling the pressure inside chamber 71 can suppress the release of components from the sealing member, thereby preventing contamination of the processed material 100 inside chamber 71.

[0133] Figure 5 It is C 16 H 30 Vapor pressure curve of O4.

[0134] C 16 H 30 O4 is a component that is frequently found in sealing components such as O-rings.

[0135] in addition, Figure 5 Points B1 and B2 in the diagram are measured values. Figure 5 The dashed line in the diagram is an approximate curve based on points B1 and B2.

[0136] In the region below the vapor pressure curve, C 16 H 30 O4 components are easily evaporated; in the upper region of the vapor pressure curve, C... 16 H 30 The components of O4 are difficult to evaporate. For example, after the processed material 100 is transported to the chamber 61 (164) of the processing unit 6 (16), if the pressure inside the chamber 71 is placed in the region above the vapor pressure curve, the release of the components of the sealing member can be suppressed.

[0137] Furthermore, since the chamber 61 of the processing unit 6 is exposed to plasma, it is sometimes heated from 80°C to about 100°C. In addition, the processed item 100 is sometimes subjected to plasma treatment in the chamber 164 of the processing unit 16 while being heated from 150°C to about 300°C. Therefore, the chamber 164 of the processing unit 16 is sometimes also heated from 80°C to about 100°C.

[0138] In the case described above, chamber 71 is connected to chamber 61 (164) via gate valve 61c (164b), so the temperature of chamber 71 also rises to about 50°C to 70°C.

[0139] For example, after the processed item 100 is transferred to the chamber 61 (164) of the processing unit 6 (16), if the pressure inside the chamber 71 is set to 5 × 10⁻⁶, -3 If the temperature is above Pa, then even if the temperature in chamber 71 is around 50°C, C can still be suppressed. 16 H 30 The components of O4 evaporate.

[0140] However, depending on the type of plasma treatment or the treatment conditions, the temperature of chamber 71 may increase further.

[0141] The inventors and others obtained the following insights from their research: After the processing item 100 is transferred to the chamber 61 (164) of the processing unit 6 (16), if the pressure inside the chamber 71 is set to 1×10 -1 Above Pa, even if the type of plasma treatment or the treatment conditions change, C can be almost eliminated. 16 H 30 The evaporation of O4 components.

[0142] Furthermore, if the pressure inside chamber 71 is too high, the airflow from chamber 71 towards chamber 61 (164) of processing unit 6 (16) may cause byproducts adhering to the inner wall of chamber 61 (164) to detach, or byproducts to float inside chamber 61 (164). Therefore, when the processed item 100 is moved in and out of processing unit 6, the pressure inside chamber 71 is preferably set to 8 × 10⁻⁶. -3 Pa ~ 5 × 10 -2 Approximately Pa. Furthermore, the pressure inside chamber 71 of the junction 7 is determined to be slightly higher than the pressure inside chamber 61 (164) of the processing section 6 (16) within the pressure range mentioned above.

[0143] Pressure control of chamber 71 can be achieved using exhaust section 73 and pressure control section 66a, but it is difficult to quickly increase the reduced pressure.

[0144] Therefore, as Figure 4 As shown, a gas supply unit 74 is provided in the junction 7 of this embodiment.

[0145] The gas supply unit 74 supplies gas G1 to the interior of the chamber 71 via the flow control unit 74a. The flow control unit 74a may be, for example, a mass flow controller (MFC).

[0146] Gas G1 may be a gas that does not readily react with the processed material 100 or components exposed inside the chamber 71. For example, gas G1 may be a rare gas such as nitrogen or argon, or a mixture thereof.

[0147] In addition, gas G1 is supplied to control the pressure inside chamber 71, and the pressure control amount is small, so the amount of gas G1 supplied to the inside of chamber 71 is small. For example, the flow rate of gas G1 is more than 10 sccm and less than 1000 sccm.

[0148] Therefore, the gas that reacts with pollutants containing organic matter can be supplied as gas G1, or the gas that reacts with pollutants containing organic matter can be added to nitrogen or the like described above. The gas that reacts with pollutants containing organic matter can be, for example, ozone gas. If gas G1 is ozone gas, or contains ozone gas, then even if pollutants containing organic matter are generated, at least a portion of the generated pollutants can be decomposed.

[0149] Furthermore, the sealing member used in the processing section 6 is the same as the sealing member used in the transfer section 7. Additionally, the pressure inside chamber 61 (164) remains at a level that could cause the components of the sealing member to evaporate during periods other than plasma treatment. Therefore, the components of the sealing member evaporate and are released into the interior of chamber 61 (164), potentially adhering to the processed item 100. However, the inventors conducted a thorough investigation and found that the probability of contaminant adhesion inside chamber 71 is higher than the probability of contaminant adhesion inside chamber 61 (164).

[0150] The reason is believed to be that process gas is introduced into the interior of chamber 61 (164) for plasma treatment, so contaminants (components of the evaporated sealing components) are discharged from the interior of chamber 61 (164) along with the process gas. That is, it is believed that the pressure inside the chamber is increased by introducing gas, thereby inhibiting the adhesion of contaminants to the processed material 100.

[0151] Figure 6 This is a timing diagram used to illustrate the supply of gas G1.

[0152] Figure 6 T1 in the text is the timing at which the process 100 begins to be moved from the chamber 71 of the transfer section 7 into the chamber 61 (164) of the processing section 6 (16).

[0153] Figure 6 T2 in the text is the timing at which the process 100 begins to be moved from the chamber 61 (164) of the processing section 6 (16) to the chamber 71 of the transfer section 7.

[0154] When there is no workpiece 100 to be processed, the plasma processing apparatus 1 is in standby mode. When the plasma processing apparatus 1 is in standby mode, the interior of the chamber 51 of the loading interlock unit 5 is vented by the exhaust unit 52, maintaining a temperature of 1×10⁻⁶. -2 Pa ~ 1×10 -1The pressure is approximately 5 Pa. In this embodiment, it is, for example, 5 × 10 Pa. -2 Pa.

[0155] The pressure inside chamber 71 of the junction 7 is maintained at a level that can suppress C. 16 H 30 The components of O4 evaporated at 5×10 -3 The pressure is above Pa. Specifically, the controller 2 controls the pressure control unit 66a installed in the chamber 71 based on the output of a pressure gauge (not shown) that detects the pressure inside the chamber 71, so that the pressure inside the chamber 71 is 5 × 10 Pa. -3 Pressures above Pa.

[0156] The interior of chamber 61 of processing unit 6 is maintained at 1×10 by exhaust from exhaust unit 66. -3 Pa ~ 1×10 -2 The pressure is Pa. In this embodiment, it is, for example, 1 × 10⁻⁶ Pa. -3 Pa.

[0157] When processing the workpiece 100, the pressure inside the chamber 51 of the loading interlock unit 5 is reduced to atmospheric pressure by discharging the contents of the chamber 51. The conveying unit 4 removes the workpiece 100 from the storage unit 3 and moves it into the chamber 51 of the loading interlock unit 5. Figure 6 (1)).

[0158] After the processed material 100 is moved into the chamber 51, the pressure inside the chamber 51 is reduced. Once the pressure inside the chamber 51 is reduced to a predetermined pressure, gas G1 is supplied into the chamber 71 from the gas supply unit 74, making the pressure inside the chamber 71 1×10⁻⁶. -1 Above Pa. Furthermore, the so-called specified pressure is 1 × 10⁻⁶ Pa. -2 Pa or higher, less than 1×10 -1 The pressure is Pa. In this embodiment, it is, for example, 5 × 10 Pa. -2 Pa.

[0159] When the pressure inside chamber 51 and the pressure inside chamber 71 reach the stated pressure, gate valve 51a opens. Then, the conveying unit 72 transports the processed item 100 into the interior of chamber 71. Figure 6 (2)).

[0160] Chamber 51 is in communication with the external space of plasma processing apparatus 1. Therefore, during the transport of the processed item 100, air from the external space is drawn into chamber 51. There is a risk that the air from the external space may contain water vapor or particles. By setting the pressure inside chamber 71 to a pressure higher than that inside chamber 51, the inflow of water vapor or particles from chamber 51 into chamber 71 can be suppressed.

[0161] After the processed material 100 is transported into the interior of chamber 71, gate valve 51a is closed. With gate valve 51a closed, the supply of gas G1 to the interior of chamber 71 ceases. Furthermore, the pressure reduction inside chamber 51 is maintained.

[0162] When the pressure inside chamber 71 becomes, for example, 5 × 10 -2 After Pa, open the gate valve 61c. Then, use the conveying unit 72 to move the processed item 100 into the interior of chamber 61 (164). Figure 6 (T1).

[0163] Inside the chamber 61 (164) of the processing unit 6 (16), plasma is used to generate plasma products from highly reactive gases, and the processed product 100 is processed. Therefore, highly reactive gases may sometimes remain inside the chamber 61 (164), or byproducts generated during plasma processing may sometimes adhere to the inner wall of the chamber 61 (164) of the processing unit 6 (16). If the pressure inside the chamber 71 is made approximately equal to the pressure inside the chamber 61 (164) of the processing unit 6 (16), the intrusion of highly reactive gases or byproducts into the chamber 71 of the transfer unit 7 can be suppressed.

[0164] After the workpiece 100 is moved into the chamber 61 (164), the gate valve 61c is closed. The period from opening the gate valve 61c to closing the gate valve 61c is defined as the workpiece moving period T1a. After the gate valve 61c is closed, gas G1 is supplied into the chamber 71 from the gas supply unit 74. As a result, the pressure inside the chamber 71 is maintained at 1×10⁻⁶. -1 Pa or above.

[0165] After the pressure inside chamber 61 (164) is reduced to a specified pressure, the gas supply unit 65 (166) supplies process gas G until the pressure inside chamber 61 (164) becomes the pressure required for plasma treatment. The pressure required for plasma treatment is 1 × 10⁻⁶. -1 The pressure is approximately 1 Pa to 10 Pa. In this embodiment, it is, for example, 1 Pa. Furthermore, the specified pressure is 1 × 10⁻⁶ Pa. -3 Pa ~ 1×10 -2 Pa.

[0166] Once the pressure inside chamber 61 (164) reaches the pressure required for plasma treatment, a high-frequency voltage is applied from high-frequency power supply 64a to antenna 63 to generate plasma P. Then, plasma P is used to generate plasma products from process gas G, and the free radicals contained in the plasma products are used to treat the processed material 100.

[0167] After plasma treatment is completed, the application of high-frequency voltage from high-frequency power supply 64a and the supply of process gas G are stopped. The interior of chamber 61 (164) is depressurized to 1 × 10⁻⁶. -3 Pa ~ 1×10 -2 The pressure is Pa. In this embodiment, the pressure inside chamber 61 (164) is, for example, reduced to 1 × 10 Pa. -3 Pa.

[0168] When the pressure inside chamber 61(164) becomes 1×10 -3 After Pa, the supply of gas G1 from the gas supply unit 74 is stopped. Then, when the pressure inside the chamber 71 becomes, for example, 5 × 10⁻⁶ Pa, the gas supply is stopped. -2 After Pa, open the gate valve 61c. Use the conveying unit 72 to remove the processed item 100 from inside the chamber 61 (164). Figure 6 (T2).

[0169] After the process item 100 is transported into the chamber 71 by the conveying unit 72, the gate valve 61c is closed. The period from opening the gate valve 61c to closing the gate valve 61c is defined as the process item 100 removal period T2a. After the removal period T2a, gas G1 is supplied into the chamber 71 from the gas supply unit 74.

[0170] When the pressure inside chamber 71 becomes 1×10 -1 After Pa reaches a certain value, the gate valve 51a is opened, and the processing unit 72 is used to transport the processed item 100 to the chamber 51. Figure 6 (4)).

[0171] After the processed material 100 is transferred into the interior of chamber 51, the gate valve 51a is closed. In the transfer section 7, the supply of gas G1 to the interior of chamber 71 is reduced. The supply of gas G1 is set such that the pressure inside chamber 71 becomes 1 × 10⁻⁶. -2 A supply of Pa or more. For example, the supply of gas G1 is set to 0.5 times. This can suppress the evaporation of the components of the sealing member and their release into the interior of the chamber 71. In addition, even if contaminants (the evaporated components of the sealing member) are generated when the processed item 100 is removed from the chamber 61 (164), the contaminants can be discharged to the outside of the chamber 71 together with the gas G1 by supplying gas G1.

[0172] Furthermore, not only can the amount of gas G1 supplied to the interior of chamber 71 be reduced, but the amount of gas discharged from exhaust section 73 can also be reduced by the pressure control unit 66a installed in chamber 71. That is, the gas supply unit 74 and the pressure control unit 66a can also make the pressure inside chamber 71 1×10⁻⁶. -2 The system maintains its operation in a coordinated manner at a pressure of Pa or higher. This allows for a reduction in the amount of gas G1 used.

[0173] In the loading interlocking unit 5, the interior of chamber 51 is vented to bring the pressure inside chamber 51 to atmospheric pressure. Once the pressure inside chamber 51 is equal to atmospheric pressure, the processing item 100 is removed from chamber 51 by the conveying unit 4 and stored in the storage unit 3. Figure 6 (5)). Then, the next processed item 100 is transferred to the loading interlock unit 5 ( Figure 6 (6)).

[0174] During the loading period T1a of the processed item 100 after T1 and the unloading period T2a of the processed item 100 after T2, the pressure of the transfer section 7 is temporarily set to include... Figure 5 The pressure in the region below the vapor pressure curve. Specifically, when the gate valve 61c is opened, the gas inside chamber 71 flows into the processing unit 6. Therefore, the pressure inside chamber 71 is reduced to the pressure inside chamber 61 (164) of the processing unit 6 (16) (e.g., the specified pressure before plasma treatment, i.e., 1×10). - 3 The components of the sealing member evaporate and are released into the interior of chamber 71 during the loading and unloading periods T1a and T2a, respectively.

[0175] However, after the loading-in period T1a and the unloading period T2a, the chamber 71 of the transfer section 7 and the chamber 61(164) of the processing section 6(16) are locked by a gate valve 61c(164b). Then, gas G1 is supplied to the interior of the chamber 71 of the transfer section 7 through the gas supply section 74, so that the pressure inside the chamber 71 is 5×10⁻⁶. -3 Pa or higher, preferably 1×10 -1 Pa or higher. Therefore, it can suppress the evaporation of components in the sealing member.

[0176] Furthermore, even if the pressure inside chamber 71 of the junction 7 and chamber 61 of the processing section 6 is set below the pressure at which the components of the sealing member can evaporate, contaminants (evaporated components of the sealing member) can be prevented from adhering to the processed item 100 by introducing gas into the interior of the junction 7. The interiors of chambers 71 and 61 are vented to maintain a prescribed reduced-pressure gas environment. The venting rates (L / min) of venting sections 73 and 66 have been determined. Then, when gas G1 is supplied into the interiors of chambers 71 and 61, the pressure inside chamber 71 increases, and the amount of gas G1 discharged per unit volume increases. As a result, it appears as if venting of the interior of the chambers is performed in accordance with the amount of gas G1 supplied. That is, through this venting, contaminants can be discharged along with gas G1.

[0177] In addition, as according to Figure 6It can be seen that in this way, the period during which the pressure inside chamber 71 is reduced to a pressure below the pressure at which the components that become sealing members can evaporate, i.e., the pressure inside chamber 61 (164) of processing unit 6 (16), can be shortened. Therefore, the evaporation of the components of the sealing member can be suppressed.

[0178] Furthermore, inside chamber 71, even if the components of the sealing member evaporate, by supplying gas G1, the contaminants (the evaporated components of the sealing member) can be discharged to the outside of chamber 71 along with gas G1, just like in chamber 61 (164).

[0179] Even when the chamber 71 remains empty of the processed material 100 for an extended period, the pressure control unit 66a installed in the chamber 71 can be controlled to reduce the exhaust volume of the exhaust unit 73. By reducing the exhaust volume of the exhaust unit 73, the pressure inside the chamber 71 can be reduced to 1×10⁻⁶. -2 The amount of gas G1 required above Pa. Furthermore, the duration of the state where the interior of chamber 71 is free of processed material 100 is, for example, from the cessation of gas G1 supply until the pressure inside chamber 71 reaches 1 × 10⁻⁶. -2 Pa is the time.

[0180] The above sequence can be controlled, for example, by the controller 2 to control the conveying unit 72, the exhaust unit 73, and the gas supply unit 74.

[0181] For example, when the conveying unit 72 is conveying (in and out) the processed item 100, the controller 2 controls the exhaust unit 73 to make the pressure inside the chamber 71 approximately equal to the pressure inside the chamber 61 (164). For example, when the conveying unit 72 finishes conveying the processed item 100, the controller 2 controls the gas supply unit 74 to supply gas G1 into the interior of the chamber 71.

[0182] For example, controller 2 supplies gas G1 to make the pressure inside chamber 71 higher than the pressure inside chamber 61 (164).

[0183] For example, controller 2 supplies gas G1 to make the pressure inside chamber 71 5 × 10⁻⁶. -3 Pa or higher, preferably 1×10 -1 Pa or above.

[0184] In addition, as explained above, the plasma processing method of this embodiment may include the following steps.

[0185] The process of plasma treatment of the workpiece 100 in a first region of a depressurized gas environment with a relatively high pressure. The first region is, for example, the interior of chamber 61 (164).

[0186] The process of transferring the processed item 100 between a second region, which is far from the first region, and the first region. The second region is, for example, the interior of a chamber 71.

[0187] Then, during the transport of the processed material 100, the pressure of the gas environment in the second region is made to be approximately equal to the pressure of the gas environment in the first region.

[0188] At the end of the transport of the processed material 100, gas G1 is supplied to the second area.

[0189] For example, after the process 100 is transported, gas G1 is supplied to make the pressure of the gas environment in the second region higher than the pressure of the gas environment in the first region when the process 100 was transported.

[0190] For example, by supplying gas G1, the pressure of the gas environment in the second region is made to be 5 × 10⁻⁶. -3 Pa or higher, preferably 1×10 -1 Pa or above.

[0191] Furthermore, since the contents of each process can be set to be the same as those described above, detailed explanations are omitted.

[0192] The above description illustrates this embodiment. However, the present invention is not limited to these descriptions.

[0193] Any implementation method that can be derived by making appropriate design changes to the above-described embodiments, as long as it possesses the features of the present invention, is included within the scope of the present invention.

[0194] For example, the shape, size, material, configuration, and quantity of each component included in the plasma processing device 1 are not limited to the examples shown and can be appropriately changed.

[0195] Furthermore, the components included in the various embodiments described above can be combined as much as possible, and any embodiments obtained by combining these components that possess the features of the present invention are included within the scope of the present invention.

[0196] In this embodiment, the pressure is controlled by a pressure control unit 66a installed in chamber 71 to maintain the pressure inside chamber 71 at 5 × 10⁻⁶. -3 Pa or higher. However, it is not limited to this. For example, the exhaust section 73 may be a combination of a turbomolecular pump and a dry pump, with an exhaust port connected to the dry pump provided at the bottom of the chamber 71. In cases where there is no processed material 100 inside the chamber 71 for an extended period, the dry pump may be used to exhaust the interior of the chamber 71. Alternatively, when the pressure reaches 5 × 10⁻⁶ Pa, the exhaust may be reduced to 10⁻⁶ Pa or higher. -3 After Pa, the exhaust section 73 is stopped.

Claims

1. A plasma processing apparatus, comprising: The first chamber maintains a high-pressure depressurized gas environment and is capable of housing a processable substance, which is then processed by plasma generated in the plasma generation area. The first exhaust section is capable of reducing the internal pressure of the first chamber to a specified pressure; A plasma generating unit capable of generating plasma in the region where the plasma is generated; The first gas supply unit supplies process gas to the area where the plasma is generated. The second chamber is connected to the first chamber via a gate valve. The sealing components containing organic matter are exposed inside, which can maintain a high-pressure depressurized gas environment. A conveying unit, located inside the second chamber, is capable of conveying the processed material between the second chamber and the first chamber; The second exhaust section is capable of reducing the pressure inside the second chamber to a specified pressure. The second gas supply unit is capable of supplying gas to the interior of the second chamber; as well as The controller is capable of controlling the conveying unit, the second exhaust unit, and the second gas supply unit. The controller is When the conveying unit conveys the processed item, the gate valve is opened to control the second exhaust unit, so that the pressure inside the second chamber is lower than the pressure inside the first chamber where the processing is performed, and approximately equal to the pressure inside the first chamber. When the conveying section finishes conveying the processed material, the gate valve is closed, and the second gas supply section is controlled to supply the interior of the second chamber with the gas at a flow rate increased compared to when the processed material was conveyed, thereby causing the internal pressure of the second chamber to reach or exceed the evaporation pressure of the organic matter.

2. The plasma processing apparatus according to claim 1, wherein, After the controller uses the conveying unit to move the processed item between the first chamber and the second chamber, it supplies gas to make the pressure inside the second chamber higher than the pressure inside the first chamber when the processed item was being moved.

3. The plasma processing apparatus according to claim 1 or 2, wherein, The controller supplies the gas to maintain a pressure of 5 × 10⁻⁶ inside the second chamber. -3 Pa or above.

4. The plasma processing apparatus according to claim 3, wherein, When the processed material is not present in the second chamber, the controller controls the second exhaust section to maintain a pressure of 5 × 10⁻⁶ ppm inside the second chamber. -3 Pa or above.

5. A plasma treatment method for treating an object with plasma, comprising: The process of plasma treatment of the workpiece is carried out in a first region with a high-pressure, depressurized gas environment. as well as The process of transferring the processed material between the first region and the second region, which is a sealed member containing organic matter and is located away from the first region, via a gate valve. During the transfer of the processed material, the gate valve is opened to make the pressure of the gas environment in the second region lower than the pressure at which the plasma treatment is performed in the first region, but approximately equal to the pressure of the gas environment in the first region. At the end of the transport of the processed material, the gate valve is closed, and gas with an increased flow rate compared to the transport of the processed material is supplied to the second region, thereby causing the internal pressure of the second region to reach above the evaporation pressure of the organic matter.

6. The plasma treatment method according to claim 5, wherein, After the material is transported, the gas is supplied to make the pressure of the gas environment in the second region higher than the pressure of the gas environment in the first region when the material was transported.

7. The plasma treatment method according to claim 5 or 6, wherein, By supplying the gas, the pressure of the gas environment in the second region is made to be 5 × 10⁻⁶. -3 Pa or above.

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