JP2012169552A - Cooling mechanism, processing chamber, component in processing chamber, and cooling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling mechanism and a cooling method which allow the cutting of heat medium required for vacuum evaporation cooling, and the efficient cooling of a member to be cooled.SOLUTION: The cooling mechanism 6 for cooling a member to be cooled to a target temperature comprises: a decompression chamber 60 thermally connected with the member to be cooled; a spray part 64 for spraying an interior surface of the decompression chamber 60 with a liquid-phase heat medium having a temperature equal to or lower than the target temperature; a power source 68 for electric field generation for generating an electric field for depositing the heat medium sprayed from the spray part 64 on the interior surface of the decompression chamber 60; and an evacuation part for evacuating the decompression chamber 60 so that the internal pressure of the decompression chamber 60 is equal to or lower than a saturation vapor pressure of the heat medium at the target temperature.

Description

  The present invention relates to a cooling mechanism and a cooling method for controlling to cool and maintain a temperature of a member to be cooled to a target temperature, and a processing chamber and processing chamber components constituting the cooling mechanism.

  In a semiconductor manufacturing apparatus, plasma is often used to perform processing such as etching on a semiconductor wafer as an object to be processed. This plasma may unnecessarily heat the semiconductor wafer or the processing chamber wall surface, resulting in a high temperature. . Also, a semiconductor manufacturing apparatus that requires a high temperature when processing a semiconductor wafer is used, but even such an apparatus needs to be cooled for other processing such as conveyance after processing. . Therefore, the semiconductor manufacturing apparatus includes a cooling mechanism for cooling the semiconductor wafer, the processing chamber wall surface, the high temperature member, and the like. The cooling mechanism performs cooling by, for example, circulating a cooling liquid (hereinafter referred to as a heat medium) through a flow path formed inside a mounting table on which a semiconductor wafer is mounted (for example, patent document). 1, 2). A cooling system that circulates the heat medium is called a forced convection heat transfer system.

  However, in forced convection heat transfer type cooling, there is a certain limit to the flow path heat transfer characteristics, so that there is a problem that uniform cooling of a semiconductor wafer or the like is difficult and temperature control response is poor. Of course, in order to increase the amount of heat exchange between the heat medium and the cooling unit, it may be possible to increase the heat transfer characteristics of the flow path by providing fins or the like in the flow path. Since there is a contradictory relationship with the loss, if the heat transfer characteristic of the flow path is increased, the pressure loss of the flow path increases, and there is a problem that the energy consumption of the pump that sends out the heat medium increases. Conversely, if the pressure loss is reduced to save energy, the temperature difference between the inlet side and outlet side of the heat medium increases, the heat transfer characteristics of the flow path deteriorate, and it becomes difficult to uniformly cool the semiconductor wafer. .

JP 2001-44176 A JP 7-235588 A

  In order to solve the above-mentioned problems, the present inventor applied a liquid phase heat medium to a portion to be cooled among the inner surfaces (inner side wall surface, inner top surface, inner bottom surface) of the decompression chamber formed on the mounting table. By controlling the pressure in the decompression chamber so that the phase change of the heat medium is induced on the inner surface by spraying, compared with the conventional cooling method, uniform cooling of the semiconductor wafer, high heat transfer, high response, energy saving We have devised a cooling mechanism that can be realized. Such a cooling method using the phase change of the heat medium is called a phase change heat transfer method or a vacuum vaporization cooling method.

However, when an experiment was attempted, in the configuration in which the heat medium is simply sprayed on the inner surface of the low pressure decompression chamber, there is no mechanism that actively guides the heat medium to the inner surface of the decompression chamber, so that it accidentally adheres to the inner surface. Therefore, the liquid phase heat medium is difficult to adhere to the inner surface, and a new problem has been faced in that it is necessary to supply a larger amount of heat medium than the theoretically required amount of the heat medium.
Further, if the amount of the heat medium is increased, it is possible to attach a liquid phase heat medium to the inner surface of the decompression chamber, but the large amount of heat medium supplied into the decompression chamber cannot be evacuated sufficiently. When it falls, there is a problem that the heat medium attached to the inner surface of the decompression chamber is less likely to cause a phase change, and the mounting table cannot be effectively cooled.

  The present invention has been made in view of such circumstances, and an object thereof is to draw a heat medium sprayed into a decompression chamber thermally connected to a member to be cooled into the inner surface of the decompression chamber by an electric field. Accordingly, there are provided a cooling mechanism and a cooling method capable of reducing the amount of a heat medium necessary for vacuum vaporization cooling and cooling a member to be cooled with high efficiency, and a processing chamber and a processing chamber member constituting the cooling mechanism. There is.

  The cooling mechanism according to the present invention is a cooling mechanism that cools the temperature of a member to be cooled to a target temperature, a decompression chamber that is thermally connected to the member to be cooled, and an inner surface of the decompression chamber that is equal to or lower than the target temperature. A spray section for spraying a liquid phase heat medium, an electric field generating section for generating an electric field for attaching the heat medium sprayed from the spray section to the inner surface of the decompression chamber, and an internal pressure of the decompression chamber is the target And an exhaust section that exhausts the decompression chamber so as to be equal to or lower than a saturated vapor pressure of the heat medium at a temperature.

  In the cooling mechanism according to the present invention, the spray unit has a nozzle for spraying the heat medium onto the decompression chamber, and the heat medium is charged by friction between the nozzle and the heat medium. It is characterized by being.

  The cooling mechanism according to the present invention includes a voltage application unit that applies a voltage to the spray unit.

  The cooling mechanism according to the present invention is characterized in that the decompression chamber is formed inside the member to be cooled.

  The cooling mechanism according to the present invention is characterized in that the decompression chamber is disposed outside the member to be cooled, and the decompression chamber and the member to be cooled are in contact with each other.

  The cooling mechanism according to the present invention is characterized in that the member to be cooled is a processing chamber of a substrate processing apparatus that performs predetermined processing on a substrate.

  The cooling mechanism according to the present invention is characterized in that the member to be cooled is a processing chamber part disposed in a processing chamber of a substrate processing apparatus that performs a predetermined process on a substrate.

  The cooling mechanism according to the present invention is characterized in that the processing chamber component is a mounting table for mounting a substrate in the processing chamber.

  The cooling mechanism according to the present invention is a cooling mechanism that cools the temperature of a member to be cooled to a target temperature, a decompression chamber that is thermally connected to the member to be cooled, and an inner surface of the decompression chamber that is equal to or lower than the target temperature. A spray part for spraying a liquid phase heat medium, an electric field generator for generating an electric field for attaching the heat medium sprayed from the spray part to the inner surface of the decompression chamber, and detecting the temperature of the member to be cooled A cooled member temperature detecting unit, and an exhaust unit that exhausts the decompression chamber so that the temperature detected by the cooled member temperature detecting unit becomes a target temperature.

  The processing chamber according to the present invention is a processing chamber for performing predetermined processing on a substrate, and a spray chamber for spraying a decompression chamber formed in a wall and a liquid phase heat medium having a target temperature or lower on the inner surface of the decompression chamber. And an electric field generation unit that generates an electric field for attaching the heat medium sprayed from the spray unit to the inner surface of the decompression chamber.

  A processing chamber component according to the present invention is a processing chamber component to be disposed in a processing chamber of a substrate processing apparatus that performs predetermined processing on a substrate, and a decompression chamber formed therein, and an inner surface of the decompression chamber at a target temperature or lower. A spraying section for spraying the liquid phase heat medium, and an electric field generating section for generating an electric field for attaching the heat medium sprayed from the spraying section to the inner surface of the decompression chamber.

  The cooling method according to the present invention is the cooling method in which the temperature of the member to be cooled is cooled to the target temperature by using the decompression chamber thermally connected to the member to be cooled. Spraying a liquid phase heat medium having a temperature equal to or lower than the temperature; generating an electric field for attaching the sprayed heat medium to the inner surface of the decompression chamber; and the heat medium having an internal pressure in the decompression chamber at the target temperature. And evacuating the decompression chamber so as to be equal to or lower than the saturated vapor pressure.

  The cooling method according to the present invention is characterized in that, in the step of exhausting the decompression chamber, the decompression chamber is exhausted so that an internal pressure of the decompression chamber becomes equal to a saturated vapor pressure of the heat medium at the target temperature. To do.

  The cooling method according to the present invention is the cooling method in which the temperature of the member to be cooled is cooled to the target temperature by using the decompression chamber thermally connected to the member to be cooled. Spraying a liquid phase heat medium below temperature, generating an electric field for attaching the sprayed heat medium to the inner surface of the decompression chamber, detecting the temperature of the member to be cooled, and detecting Evacuating the decompression chamber so that the measured temperature becomes a target temperature.

In the present invention, the decompression chamber for cooling is thermally connected to the member to be cooled. The liquid phase heat medium below the target temperature is sprayed on the inner surface of the decompression chamber, that is, the surface to be cooled. The sprayed heat medium is attracted to and adhered to the inner surface of the decompression chamber by the electric field generated by the electric field generation unit. The exhaust unit exhausts the decompression chamber so that the internal pressure of the decompression chamber is equal to or lower than the saturated vapor pressure of the heat medium at the target temperature. For this reason, the heat medium before adhering to the inner surface of the decompression chamber is in a liquid phase, and the heat medium adhering to the inner surface rises above the target temperature, so that the phase changes to the gas phase.
Therefore, the member to be cooled can be cooled by the latent heat of the heat medium. In addition, the heat medium can be effectively attached to the inner surface of the decompression chamber by the Coulomb force. Therefore, it is possible to reduce the heat medium required for vacuum vaporization cooling as compared with the configuration in which the heat medium is simply sprayed. Furthermore, since it is not necessary to spray an excessive heat medium as compared with the configuration in which the heat medium is simply sprayed, the decompression chamber can be sufficiently decompressed, and the member to be cooled can be effectively cooled. Furthermore, since the amount of heat medium delivered can be reduced, the energy consumption of the pump that delivers the heat medium can also be reduced.
The cooling method according to the present invention includes a step of spraying a liquid phase heat medium, a step of generating an electric field, and a step of exhausting the decompression chamber, but each step may be executed by an arbitrary procedure. And may be executed substantially simultaneously.

  In the present invention, the heat medium is charged by friction between the nozzle of the spray section and the heat medium. Since the sprayed and charged particles of the heat medium repel each other by the Coulomb force, they are attracted and adhered to the inner surface of the decompression chamber in the form of fine particles. That is, when the sprayed heat medium is not charged, the particles of the heat medium are aggregated due to surface tension and are difficult to reach the inner surface of the decompression chamber, but if the heat medium is charged, the heat medium particles Can be prevented. Therefore, it is possible to effectively adhere the heat medium to the inner surface of the decompression chamber.

  In the present invention, the heating medium can be charged by applying a voltage to the spraying section by the voltage applying section. The action obtained by charging the heat medium is as described above.

  In the present invention, the decompression chamber is formed inside the member to be cooled. Therefore, the member to be cooled can be effectively cooled. In addition, the cooling mechanism can be reduced in size.

  In the present invention, the decompression chamber is disposed outside the member to be cooled, and is thermally connected by contacting the decompression chamber and the member to be cooled. Therefore, it is possible to cool the member to be cooled which is difficult to form the decompression chamber inside.

  In the present invention, the processing chamber of the substrate processing apparatus that performs a predetermined process on the substrate is cooled.

  In the present invention, the processing chamber components arranged in the processing chamber of the substrate processing apparatus that performs predetermined processing on the substrate are cooled.

  In the present invention, the mounting table for mounting the substrate in the processing chamber of the substrate processing apparatus is cooled.

In the present invention, the temperature of the member to be cooled is detected by the member to be cooled temperature detection unit, and the exhaust unit exhausts the decompression chamber so that the detected temperature is equal to or lower than the target temperature.
The cooling method according to the present invention includes a step of spraying a liquid phase heat medium, a step of generating an electric field, a step of detecting temperature, and a step of exhausting the decompression chamber. May be executed in an arbitrary procedure, and may be executed almost simultaneously.

  According to the present invention, the heat medium sprayed in the decompression chamber thermally connected to the member to be cooled is drawn into the inner surface of the decompression chamber by an electric field, thereby reducing the heat medium necessary for vacuum vaporization cooling. In addition, the member to be cooled can be cooled with high efficiency.

It is a mimetic diagram showing one composition of a semiconductor manufacturing device which has a cooling mechanism concerning an embodiment of the invention. It is a schematic diagram which shows the structure of an exhaust part and a cold water manufacturing device. It is a flowchart which shows the process sequence of the control part which concerns on cooling. It is a state figure which shows vacuum evaporation cooling conditions notionally. FIG. 10 is a schematic diagram illustrating a configuration example of a semiconductor manufacturing apparatus having a cooling mechanism according to Modification 1; FIG. 10 is a schematic diagram illustrating a configuration example of a semiconductor manufacturing apparatus having a cooling mechanism according to Modification 2. FIG. 10 is a schematic diagram illustrating a configuration example of a semiconductor manufacturing apparatus having a cooling mechanism according to Modification 3. FIG. 10 is a schematic diagram illustrating a configuration example of a semiconductor manufacturing apparatus having a cooling mechanism according to Modification Example 4.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
FIG. 1 is a schematic diagram showing one configuration of a semiconductor manufacturing apparatus having a cooling mechanism 6 according to an embodiment of the present invention. The semiconductor manufacturing apparatus according to the present embodiment is, for example, a parallel plate type plasma etching apparatus. The parallel plate type plasma etching apparatus is an example of a plasma processing apparatus, and is not limited thereto. The semiconductor manufacturing apparatus includes a hollow cylindrical processing chamber 1. The processing chamber 1 is made of, for example, aluminum and is grounded.

  A disk-shaped mounting table 2 that functions as a lower electrode and is provided with a disk-shaped insulator 21 on the bottom surface of the processing chamber 1 at a substantially central portion. The mounting table 2 is made of aluminum, for example, and has a decompression chamber 60 inside. The decompression chamber 60 is connected to each component of the cooling mechanism 6 that cools the mounting table 2 that is a member to be cooled to a target temperature, and constitutes a part of the cooling mechanism 6. By cooling the mounting table 2 by the cooling mechanism 6, the semiconductor wafer W mounted on the mounting table 2 is cooled to the process temperature. The mounting table 2 is connected to a high frequency power source 4 that applies a high frequency for generating a bias voltage. Here, the target temperature is a temperature that is a target of control of the mounting table 2 that is a member to be cooled, and ideally matches the process temperature to be controlled for the semiconductor wafer W. In consideration of the thermal resistance with the wafer W, the temperature may be set lower than the process temperature.

  In addition, an upper electrode 3 is provided at a substantially central portion of the top surface of the processing chamber 1 so as to face the mounting table 2. An annular insulator 14 is interposed between the processing chamber 1 and the upper electrode 3. A high frequency power source 5 for generating plasma is connected to the upper electrode 3. The upper electrode 3 is formed in a hollow shape, and constitutes a gas shower head having a plurality of process gas supply holes (not shown) on the surface facing the mounting table 2. A process gas supply pipe 31 for supplying a process gas to the upper electrode 3 is provided at the center of the upper surface of the upper electrode 3. The upper electrode 3 supplies a process gas into the processing chamber 1 by a function as a gas shower head. .

Further, as an exhaust mechanism, for example, an exhaust pipe 12 is connected to a side surface near the bottom surface of the processing chamber 1, and the inside of the processing chamber 1 is evacuated by a vacuum pump (not shown) provided downstream of the exhaust pipe 12. Is configured to do. The exhaust mechanism may be structured to exhaust from the bottom of the processing chamber 1.
Furthermore, a transfer port 11 for the semiconductor wafer W is formed on the side surface of the processing chamber 1, and the transfer port 11 can be opened and closed by a gate valve 13.

  The decompression chamber 60 formed on the mounting table 2 has a cylindrical shape having a circular bottom surface portion, a peripheral surface portion, and a circular top surface portion. The bottom surface portion has a discharge port for discharging the gas and water inside the decompression chamber 60 where appropriate.

  The cooling mechanism 6 includes a controller 61 that controls the operation of each component. The control unit 61 is, for example, a microcomputer including a CPU. The CPU stores a computer program necessary for the operation of the control unit 61, a storage unit that stores various information such as a process temperature necessary for a semiconductor manufacturing process, An input / output unit for inputting / outputting information and control signals is connected.

  The cooling mechanism 6 includes a temperature controller 62, a spray unit 64, an exhaust unit 65, a cold water producing device 651, a water supply pump 66, a flow control valve 67, and an electric field necessary for cooling the mounting table 2 that is a member to be cooled. A power supply 68 for generation is provided. In the following embodiment, an example of using an ejector vacuum pump will be mainly described as the exhaust unit 65. However, as will be described later, a separator for separating water and a rotary pump may be combined, and an equivalent function is provided. Other exhaust devices may be used as long as they are appropriate.

  The temperature controller 62 controls the temperature of the cold water supplied from the cold water producer 651 described later to the spray temperature according to the control signal from the control unit 61, and the temperature-controlled water is supplied to the spray unit 64 through the pipe 63a. Supply. Here, the spraying temperature must be higher than the temperature at which the sprayed mist water freezes and lower than the temperature at which it evaporates before reaching the inner surface of the decompression chamber. Since the lower limit temperature at which the mist of water evaporates is the target temperature, in other words, the spray temperature must be higher than the freezing temperature and lower than the target temperature. In addition, since the inner wall of the mounting table which is a member to be cooled is cooled by the heat of vaporization when the mist is vaporized, the cooling effect does not depend on the temperature of the mist itself.

  The spray part 64 is provided in the peripheral surface part of the decompression chamber 60, and is connected to the temperature controller 62 through the piping 63a. The spray unit 64 includes a mist nozzle (nozzle) 64a for spraying liquid phase water (heat medium) supplied from the temperature controller 62 onto the inner surface of the decompression chamber 60, for example, the top surface portion. The heat medium is charged by friction between the nozzle 64a and water. For example, the sprayed water can be charged by forming the mist nozzle 64a from stainless steel or resin. The magnitude and polarity of the charge to be charged depends on the positional relationship between the material forming the mist nozzle 64a and water in the charge train, and the charge amount increases as the position in the charge train increases. In addition, when water is located on the negative side of the charging column with respect to the material of the mist nozzle, it is negatively charged, and when it is located on the positive side, it is positively charged. Further, since the electric charge is generated not only in the water but also in the mist nozzle due to the friction between the mist nozzle and water, the spray unit 64 is grounded to prevent the mist nozzle from continuing to be charged.

The electric field generating power source (electric field generating unit) 68 is a DC power source that generates an electric field for attaching water sprayed from the spray unit 64 to the inner surface of the decompression chamber 60, for example, the top surface. For example, a linear or sheet-like conductive member (electric field generating portion) 68a in a non-grounded state is provided on the top side of the decompression chamber 60, and by applying a voltage to the conductive member 68a, An electric field directed from the inside of the decompression chamber 60 toward the top surface portion or an electric field directed from the top surface portion of the decompression chamber 60 toward the inside can be generated. As a method of installing the conductive member 68a, the conductive member 68a is installed on the top side of the decompression chamber 60, which is used as a ceiling portion of the decompression chamber 60, and the ceiling portion and other portions are insulated from each other. You may comprise so that a voltage may be applied to 60 ceiling parts. At this time, the inner surface on the top side of the decompression chamber 60 in which the conductive member 68a is installed is DC-insulated by an insulating member 68b such as an insulating film so that no direct current is conducted between the conductive member 68a and the mounting table 2. It is necessary to keep. When it is desired to avoid the conductive member 68a from being exposed to the sprayed water, the surface of the conductive member 68a facing the decompression chamber 60 is covered with a film made of a dielectric, and the decompression chamber. An electric field may be generated by providing a ground electrode paired therewith on the bottom side of the interior of 60 or the like. In this case, it is preferable to have a structure in which the ground electrode is sandwiched between dielectric materials, so that the grounding electrode 2 is not exposed to the sprayed water and can be insulated from the mounting table 2 in a direct current manner.
The electric field is generated so that the water sprayed from the spraying part 64 is attracted to the top surface part of the decompression chamber 60. When water is positively charged, an electric field is generated such that the electrostatic potential inside the decompression chamber 60 is higher than the electrostatic potential of the top surface, and when water is negatively charged, the pressure is reduced. An electric field may be generated so that the electrostatic potential inside the chamber 60 is lower than the electrostatic potential of the top surface portion.

  FIG. 2 is a schematic diagram illustrating the configuration of the exhaust unit 65 and the cold water producer 651. The exhaust unit 65 generally vaporizes a liquid to form a vapor, and sucks and exhausts the gas present in the container to be evacuated by a suction force generated when the vapor is ejected at a high speed. In this case, water is used as the liquid. The exhaust unit 65 serving as an ejector vacuum pump includes a water storage tank 65d that stores water supplied through the pipe 63d, a pumping pump 65h that pumps water from the water storage tank 65d through the pipes 65g and 65i, and steam from the pumped water. A vacuum chamber 65j to be generated, an ejector nozzle 65b for injecting water vapor supplied from the vacuum vessel 65j through the pipe 65k, a suction chamber 65a in which the ejector nozzle 65b is disposed, and a diffuser 65c are connected to each other, and the suction chamber 65a communicates with the pipe 63b. In particular, the water storage tank 65d is provided with a condenser 65e for condensing the water vapor discharged from the decompression chamber 60 of the mounting table 2. In addition, an overflow pipe 65f is provided at an appropriate location of the water storage tank 65d.

  The exhaust part 65 configured as described above obtains a vacuum suction force in the suction chamber 65a by supplying water from the water storage tank 65d to the ejector nozzle 65b by the pressure feed pump 65h and circulating it through the diffuser 65c and the water storage tank 65d. Is. The exhaust unit 65 discharges the gas in the decompression chamber 60 and the liquid temperature control medium remaining in the decompression chamber 60, that is, water, from the decompression chamber 60 by the vacuum suction force. More specifically, when cooling the mounting table 2, the exhaust unit 65 discharges not only vaporized water vapor but also liquid water that has not been vaporized from the decompression chamber 60. Further, when heating the mounting table 2, the exhaust unit 65 discharges not only water vapor but also condensed liquid water from the decompression chamber 60.

The cold water producer 651 includes a cold water storage tank 651a communicating with the suction chamber 65a, a pipe 651f for supplying water from the water storage tank 65d to the cold water storage tank 651a, a float valve 651g provided in the pipe 651f, and a pipe 651b. A chilled water production pump 651c for pumping the water in the cold water storage tank 651a, a freezing chamber 651d for cooling the pumped water, and an evaporator 651e disposed in the cold water storage tank 651a. A part of the water jetted from the evaporator 651e evaporates as water vapor, and the water is cooled by removing the latent heat necessary for the evaporation from the remaining water.
The cold water storage tank 651a communicates with the pipe 63c, and is configured such that cold water is sent from the cold water storage tank 651a to the temperature controller 62 through the pipe 63c.

  The water supply pump 66 is interposed in the pipe 63c. The water supply pump 66 is, for example, a diaphragm pump, is driven according to a control signal from the control unit 61, and sends the water cooled by the cold water maker 651 to the temperature controller 62.

  The flow rate control valve 67 is interposed in the pipe 63 c closer to the temperature controller 62 than the water supply pump 66. The flow control valve 67 controls the flow rate of water sent from the water supply pump 66 in accordance with a control signal from the control unit 61, and sends the flow-controlled water to the temperature controller 62.

  The cooling mechanism 6 further includes a member-to-be-cooled temperature detector 69a, a pressure detector 69b, a flow rate detector 69c, and a water temperature detector 69d. The member-to-be-cooled temperature detection unit 69a is a thermocouple thermometer buried in an appropriate location of the mounting table 2 that is a member to be cooled, for example, detects the temperature of the mounting table 2, and sends information on the detected temperature to the control unit 61. Output. The pressure detection unit 69 b is connected to the pipe 63 b, detects the pressure inside the decompression chamber 60, and outputs information on the detected pressure to the control unit 61. The flow rate detection unit 69 c detects the flow rate of the water flowing through the pipe 63 c and outputs information on the detected flow rate to the control unit 61. The water temperature detection unit 69d detects the temperature of the water that is flown through the pipe 63c and is temperature-controlled by the temperature controller 62 and ejected from the nozzle, and outputs the detected water temperature information to the control unit 61. The control unit 61 takes in information on the mounting table temperature, pressure, flow rate, and water temperature via the input / output unit, executes a process related to cooling based on the taken-in information, and performs an exhaust unit 65, a water supply pump 66, and a flow rate control. A control signal for controlling the operation of the valve 67 is output to each part. The semiconductor wafer W is mounted on the mounting table 2 with high heat transfer efficiency, and temperature control is performed via the mounting table 2.

  FIG. 3 is a flowchart showing a processing procedure of the control unit 61 related to cooling. Here, as an ideal case, it is assumed that the target temperature is equal to the process temperature. The control unit 61 drives the exhaust unit 65, the water supply pump 66, and the like. Further, an electric field for drawing mist is generated in the decompression chamber 60 by the electric field generating power source 68 (step S11). And the control part 61 reads process temperature required for the semiconductor manufacturing process which is the objective of temperature control from the memory | storage part which is not shown in figure (step S12). Next, the controller 61 detects the temperature of the mounting table 2 at the member-to-be-cooled temperature detector 69a (step S13).

  Then, the control unit 61 sets the process temperature as a target temperature, and determines whether or not the temperature of the mounting table 2 detected by the member-to-be-cooled temperature detecting unit 69a exceeds the process temperature (step S14). Hereinafter, the temperature of the mounting table 2 (cooled member) detected by the cooled member temperature detection unit 69a is referred to as a detected temperature. When the detected temperature is equal to or lower than the process temperature (step S14: NO), that is, when the detected temperature is equal to or lower than the target temperature, there is no need to cool the mounting table 2 any more, so the control unit 61 closes the flow control valve 67. The state is controlled (step S15).

  When it is determined that the detected temperature is higher than the process temperature (step S14: YES), the control unit 61 determines a set water temperature and a set flow rate of water to be injected to the top surface (step S16), and the inside of the decompression chamber 60 Is determined (step S17). Here, the set water temperature, the set flow rate, and the set pressure will be described.

FIG. 4 is a state diagram conceptually showing vacuum vaporization cooling conditions. The horizontal axis is temperature, and the vertical axis is pressure. The curve in the graph shows the saturated vapor pressure Psv (T) of water. Psv (T) is a function of temperature T. When the detected temperature is higher than the process temperature T1, it is necessary to lower the temperature of the mounting table 2. Therefore, the control unit 61 has a process temperature within the temperature and pressure range indicated by hatching in a temperature region lower than the process temperature T1. A set pressure corresponding to a set temperature set below T1 (= target temperature) is determined. The set temperature may be set equal to the process temperature T1, but may be set slightly lower than the process temperature T1 in order to speed up the stage to converge to the target temperature (= process temperature T1). The set water temperature of the water ejected from the nozzle is controlled to the spray temperature described above. At this time, the set water temperature (= spray temperature) is higher than the water temperature when the set pressure is the saturated vapor pressure, that is, the set water temperature so that the jetted water does not completely evaporate in the middle. Must be low. However, if it is too low, it will freeze, so it must be at a temperature that will not freeze. After the water ejected from the nozzle reaches the top surface in the target decompression chamber 60, the temperature rises by the top surface and vaporizes because it is higher than the set water temperature. During vaporization, heat is removed from the top surface as the heat of vaporization, and the temperature of the top surface is lowered. Thus, a series of flow from spraying to vaporization is repeated until the top surface is cooled to the process temperature T1. Note that if the mounting table 2 reaches the target temperature, it is not necessary to further cool it, so ideally the pressure in the decompression chamber 60 does not need to be set lower than the saturated vapor pressure at the process temperature. Specifically, since it is considered that a thermal resistance exists in the heat transfer between the semiconductor wafer W and the temperature-controlled mounting table 2 and a temperature gradient is generated, the target temperature is set lower than the process temperature, The set pressure may be set lower than the saturated vapor pressure at the process temperature and equal to the saturated vapor pressure at the target temperature. Also, in temperature control using feedback, the set pressure may be lower than the saturated vapor pressure at the target temperature because it may converge to the target temperature while vibrating in the vicinity of the target temperature. Also good. About the flow volume of water, what is necessary is just to determine so that the pressure in the decompression chamber 60 may not remove | deviate from the said temperature-pressure range by vaporization of the water injected to the top | upper surface part. That is, the set flow rate may be determined so that less water than the amount of water vapor that can be exhausted by the vacuum pump is injected.
Specifically, the control unit 61 stores in advance a table in which the process temperature (= set temperature), the set water temperature, the set flow rate, and the set pressure are associated, and the process temperature read in step S12 The set water temperature, the set flow rate, and the set pressure may be determined based on the table.

  The control part 61 which finished the process of step S17 controls the opening degree of the flow control valve 67 based on the set flow rate, and controls the flow rate to be the set flow rate (step S18).

  Next, the control unit 61 feedback-controls the operation of the temperature controller 62 while detecting the water temperature by the water temperature detection unit 69d based on the set water temperature so that the water temperature matches the set water temperature (= spray temperature). The water temperature is controlled to be the set water temperature (step S19). Then, the control unit 61 feedback-controls the operation of the exhaust unit 65 while detecting the pressure by the pressure detection unit 69b based on the set pressure so that the pressure in the decompression chamber 60 matches the set pressure, and the pressure is set. Control is performed so that the pressure is reached (step S20). After reaching the set flow rate, the set water temperature, and the set pressure by the control in step S18 and the feedback control in step S19 and step S20, the mounting table 2 is cooled to the process temperature by using the set flow rate, the set water temperature, and the set pressure. Accordingly, the cooling process is set to a steady state, and the process temperature is continuously maintained while the semiconductor wafer W is subjected to the semiconductor manufacturing process. When the cooling proceeds and the temperature of the mounting table 2 is about to fall below the target temperature, the water below the target temperature does not evaporate at the set pressure, so that the cooling does not proceed any further and the subcooling does not occur.

  When the plasma processing such as a semiconductor manufacturing process on the semiconductor wafer W under a predetermined process condition, for example, an etching process is completed, and the processing in step S20 or step S15 related to cooling is completed, the control unit 61 It is determined whether or not to proceed to the next process in which the semiconductor manufacturing process is performed based on the process temperature (step S21). When it determines with transfering to the next process (step S21: YES), the control part 61 returns a process to step S12, acquires a new process temperature, and repeats said cooling process.

  When it determines with not transfering to the next process (step S21: NO), the control part 61 determines whether plasma processing is complete | finished (step S22). When it is determined that the plasma processing is not to be ended, such as when processing of another new semiconductor wafer W is continued under the same process conditions (step S22: NO), the control unit 61 returns the processing to step S13. When it determines with complete | finishing a plasma process (step S22: YES), the control part 61 complete | finishes the process which concerns on cooling. When the process returns to step S13 in the above, it is clear that the temperature of the mounting table 2 has not changed, and when it is not necessary to determine the set water temperature, the set flow rate, and the set pressure, the process goes to step S18 instead of step S13. Processing may be returned.

  In the cooling mechanism 6 and the cooling method according to the embodiment, and the mounting table 2 constituting the cooling mechanism 6, water sprayed on the top surface of the decompression chamber 60 is evaporated at a low temperature, and the mounting table 2 is cooled by latent heat of evaporation. Therefore, compared with the conventional cooling method, uniform cooling and high responsiveness of the semiconductor wafer W can be realized.

  Moreover, the water sprayed in the decompression chamber 60 can be efficiently drawn into the top surface portion by the electric field, the water required for vacuum vaporization cooling can be reduced, and the mounting table 2 can be cooled with high efficiency. It is possible to save energy by reducing the amount of water required for vacuum vaporization cooling.

  Furthermore, since it is not necessary to spray excess water as compared with a configuration in which a heat medium is simply sprayed without using an electric field, the decompression chamber 60 can be sufficiently decompressed, and the mounting table 2 can be effectively cooled. Is possible.

  Furthermore, since the water sprayed from the spray part 64 is charged by friction with the mist nozzle 64a, the mist-like water particles repel each other by the Coulomb force. For this reason, the sprayed water is attracted and adhered to the top surface portion of the decompression chamber 60 in the form of fine particles. Therefore, water can be effectively adhered to the inner surface of the decompression chamber 60 and the mounting table 2 can be cooled.

  Furthermore, since the decompression chamber 60 is configured inside the mounting table 2, the mounting table 2 can be efficiently cooled, and the space for the cooling mechanism 6 can be saved.

  In the embodiment, the example in which the decompression chamber 60 is provided in the mounting table 2 has been described. However, the decompression chamber is provided in another processing chamber part to be arranged in the processing chamber 1, and the present embodiment is used. Such a cooling mechanism may be configured. An example of providing a decompression chamber in the wall of the processing chamber will be described later.

(Modification 1)
FIG. 5 is a schematic diagram illustrating a configuration example of a semiconductor manufacturing apparatus having the cooling mechanism 106 according to the first modification. The semiconductor manufacturing apparatus and cooling mechanism 106 according to Modification 1 have the same configuration as that of the embodiment, and further include a voltage application unit 164b that applies a voltage to the spray unit 64. The voltage application unit 164b is a direct current power source for charging water sprayed from the spray unit 64. When the electric field generating power supply 68 generates an electric field from the inside of the decompression chamber 60 toward the top surface, a positive potential is applied to the spraying portion 64 to generate an electric field from the top surface of the decompression chamber 60 to the inside. If so, a negative potential is applied to the spray section 64.

  In the first modification, by applying a voltage to the spray unit 64, the water sprayed from the spray unit 64 can be effectively charged, and the water can be drawn into and attached to the top surface of the decompression chamber 60. .

(Modification 2)
FIG. 6 is a schematic diagram illustrating a configuration example of a semiconductor manufacturing apparatus having the cooling mechanism 206 according to the second modification. The semiconductor manufacturing apparatus and cooling mechanism 206 according to Modification 2 have the same configuration as that of the embodiment, and a decompression chamber 260 and a spray unit 264 are also provided inside the processing chamber (cooled member) 201, and the processing chamber The point which is comprised so that the desired location of the inner wall of 201 may be cooled differs from embodiment. A desired place on the inner wall of the processing chamber 201 to be cooled may be a part of the inner wall or all of the inner wall. Below, the said difference is mainly demonstrated.

  The processing chamber 201 of the semiconductor manufacturing apparatus according to Modification 2 has a decompression chamber 260 for cooling the processing chamber 201 inside the wall. For convenience of drawing, the decompression chamber 260 is partially formed in the processing chamber 201. However, the decompression chamber 260 is only an example, and the decompression chamber 260 may be provided over the entire circumference of the processing chamber 201. The decompression chamber 260 may be provided in some or other portions. In other words, the decompression chamber 260 may be provided in a portion corresponding to a location where cooling is required on the inner wall of the processing chamber 201. Further, the decompression chamber 260 does not necessarily need to be housed inside the wall of the processing chamber 201, and may be structured to protrude outward. At the bottom of the decompression chamber 260, a discharge port for discharging the gas and water inside the decompression chamber 260 is formed at appropriate places, and the discharge port is connected to the exhaust unit 65 through a pipe 263b.

  The spray unit 264 is provided on the outer peripheral side of the decompression chamber 260 and is connected to the temperature controller 62 through the pipe 63a. The spray unit 264 has a mist nozzle 264a, and the specific configuration is the same as in the embodiment.

The electric field generating power source 268 is a DC power source that generates an electric field for attaching water sprayed from the spraying section 264 to the inner surface of the decompression chamber 260, for example, the inner peripheral surface. A linear or sheet-like conductive member 268c in an ungrounded state is provided in the inner peripheral wall of the decompression chamber 260. By applying a voltage to the conductive member 268c, a high potential can be obtained. The electric field directed from the outer peripheral side to the inner peripheral side of the decompression chamber 260 or the electric field directed from the inner peripheral side to the outer peripheral side of the decompression chamber 260 can be generated with the direction toward the lower potential as the direction of the electric field. An insulating member 268d such as an insulating film is provided in the wall of the decompression chamber 260 where the conductive member 268c is installed so that a direct current does not flow between the conductive member 268c and the mounting table 2.
Similarly to the embodiment, the electric field generating power source 268 includes a conductive member 268a and an insulating member 268b, and generates an electric field that draws water as a heat medium into the top surface portion of the decompression chamber 60.

In the second modification, a portion where the inner wall of the processing chamber 201 needs to be cooled can be cooled, the plasma processing can prevent the processing chamber wall from becoming high temperature, and film formation is performed at a high temperature. When using a gas for CVD, it is possible to prevent deposits from growing on the inner surface of the processing chamber by lowering the temperature, and in an etching process in which reaction products are likely to deposit at low temperature sites, the inner wall Further, by providing a protective wall that can be removed with good heat transfer with the inner wall, the reaction product can be positively deposited on the protective wall to suppress the deposition on other places.
In the modification 2, the inner wall part to cool may be a top plate. In general, when cooling susceptors and side walls, the mist should be prevented from accumulating as a liquid at the bottom of the decompression chamber as much as possible in order to prevent unnecessary cooling of the area other than the intended location and reduction in cooling efficiency. I must. However, when the top plate is cooled, the target location for cooling is exactly the bottom of the decompression chamber. Therefore, the mist may be sprayed toward the bottom, or the mist may be dropped by gravity.

(Modification 3)
FIG. 7 is a schematic diagram illustrating a configuration example of a semiconductor manufacturing apparatus having the cooling mechanism 306 according to the third modification. The cooling mechanism 306 according to Modification 3 includes first and second decompression chambers 360 and 370 for cooling the mounting table 2 and the processing chamber (cooled member) 301 as the cooled members.

  The first decompression chamber 360 has a hollow cylindrical shape, and is fixed to a substantially central portion of the bottom surface of the processing chamber 301, and the mounting table 2 is fixed to the top side via a disk-shaped insulator 21. The first decompression chamber 360 has the same configuration as that of the decompression chamber 60 described in the embodiment, and a first spray unit 364 is provided on the peripheral surface portion of the first decompression chamber 360. In addition, a first conductive member 368a that is insulated by a first insulating member 368b and is not grounded is provided on the top side of the first decompression chamber 360, and the first conductive member 368a is provided for generating an electric field. A voltage is applied by a power source 368. Furthermore, a discharge port for discharging the gas and water inside the first pressure reduction chamber 360 is formed in the bottom surface portion of the first pressure reduction chamber 360, and the gas and water discharged from the discharge port pass through the pipe 363b. It is supplied to the exhaust part 65.

  The second decompression chamber 370 has a configuration in which the decompression chamber 260 according to Modification 2 is provided on the outer peripheral side of the processing chamber 301, and a second spray unit 371 is provided. In addition, a second conductive member 368c that is insulated by the second insulating member 368d and is in a non-contact state is provided in the inner peripheral wall of the second decompression chamber 370, and the second conductive member 368c is provided with the second conductive member 368c. The voltage is applied by the electric field generating power source 368. Furthermore, a discharge port for discharging the gas and water inside the second pressure reduction chamber 370 is formed in the bottom surface portion of the second pressure reduction chamber 370, and the gas and water discharged from the discharge port pass through the pipe 363b. It is supplied to the exhaust part 65.

  In the third modification, the same effect as in the embodiment can be obtained.

(Modification 4)
FIG. 8 is a schematic diagram illustrating a configuration example of a semiconductor manufacturing apparatus having a cooling mechanism according to the fourth modification. In the above embodiment, the case where the ejector pump is used as the exhaust part has been described. However, instead of the ejector pump, a rotary pump 465 may be used as shown in FIG. In this case, a separator 465 a that separates the water that has become liquid is installed upstream of the rotary pump 465. The water separated by the separator 465a may be temporarily stored in the drain tank 465b and then circulated again to the spray nozzle through the water supply pump 66 or may be discharged as it is. Alternatively, it may be discharged directly without using the drain tank 465b. Even when recirculation is performed through the water supply pump 66, if there is no need to adjust the flow rate, it may be directly circulated without passing through the drain tank 465b. However, if the drain tank 465b is used, excessive water is discharged. There is an advantage that you can. In addition to the water from the separator 465a, a deficient amount of water may be supplied to the water supply pump 66 through the pipe 63d. Alternatively, when it is sufficient to circulate only the water from the separator 465a, it is not necessary to constantly supply water through the pipe 63d. The pump used on the downstream side of the separator 465a is not limited to the rotary pump, and may be any pump that can be used from the atmosphere at a low vacuum pressure.

  The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Processing chamber 2 Mounting stand 3 Upper electrode 4,5 High frequency power supply 6 Cooling mechanism 60,260 Decompression chamber 360 1st decompression chamber 370 2nd decompression chamber 61 Control part 62 Temperature controller 64 Spray part 64a Mist nozzle 364 1st spray part 371 Second spraying part 65 Exhaust part 68 Electric field generating power source (electric field generating part)
68a Conductive member (electric field generator)
368a First conductive member 368c Second conductive member 164b Voltage application unit 69a Cooled member temperature detection unit 69b Pressure detection unit 69c Flow rate detection unit W Semiconductor wafer

Claims (14)

In the cooling mechanism that cools the temperature of the member to be cooled to the target temperature,
A decompression chamber thermally connected to the member to be cooled;
A spraying section for spraying a liquid phase heat medium having a temperature equal to or lower than the target temperature onto the inner surface of the decompression chamber;
An electric field generator for generating an electric field for attaching the heat medium sprayed from the spray section to the inner surface of the decompression chamber;
A cooling mechanism, comprising: an exhaust unit that exhausts the decompression chamber so that an internal pressure of the decompression chamber is equal to or lower than a saturated vapor pressure of the heat medium at the target temperature. The spray section is
The cooling according to claim 1, further comprising a nozzle for spraying the heat medium to the decompression chamber, wherein the heat medium is charged by friction between the nozzle and the heat medium. mechanism. The cooling mechanism according to claim 1, further comprising: a voltage applying unit that applies a voltage to the spraying unit. The decompression chamber is
The cooling mechanism according to any one of claims 1 to 3, wherein the cooling mechanism is formed inside the member to be cooled. The decompression chamber is
The cooling mechanism according to any one of claims 1 to 3, wherein the cooling mechanism is arranged outside the member to be cooled, and the decompression chamber and the member to be cooled are in contact with each other. The member to be cooled is
The cooling mechanism according to any one of claims 1 to 5, wherein the cooling mechanism is a processing chamber of a substrate processing apparatus that performs predetermined processing on a substrate. The member to be cooled is
The cooling mechanism according to any one of claims 1 to 5, wherein the cooling mechanism is a processing chamber component disposed in a processing chamber of a substrate processing apparatus that performs predetermined processing on a substrate. The processing chamber parts are:
The cooling mechanism according to claim 7, wherein the cooling mechanism is a mounting table for mounting a substrate in the processing chamber. In the cooling mechanism that cools the temperature of the member to be cooled to the target temperature,
A decompression chamber thermally connected to the member to be cooled;
A spraying section for spraying a liquid phase heat medium having a temperature equal to or lower than the target temperature onto the inner surface of the decompression chamber;
An electric field generator for generating an electric field for attaching the heat medium sprayed from the spray section to the inner surface of the decompression chamber;
A member-to-be-cooled temperature detector that detects the temperature of the member to be cooled;
A cooling mechanism comprising: an exhaust unit that exhausts the decompression chamber so that the temperature detected by the member-to-be-cooled temperature detection unit becomes a target temperature. In a processing chamber for performing predetermined processing on a substrate,
A decompression chamber formed in the wall;
A spray section for spraying a liquid phase heat medium having a target temperature or lower onto the inner surface of the decompression chamber;
An electric field generating unit that generates an electric field for causing the heat medium sprayed from the spraying unit to adhere to the inner surface of the decompression chamber. In processing chamber components to be placed in a processing chamber of a substrate processing apparatus that performs predetermined processing on a substrate,
A decompression chamber formed inside,
A spray section for spraying a liquid phase heat medium having a target temperature or lower onto the inner surface of the decompression chamber;
A processing chamber component comprising: an electric field generating unit that generates an electric field for attaching the heat medium sprayed from the spraying unit to the inner surface of the decompression chamber. In a cooling method for cooling the temperature of the member to be cooled to a target temperature using a decompression chamber thermally connected to the member to be cooled,
Spraying a liquid phase heat medium below the target temperature on the inner surface of the decompression chamber;
Generating an electric field for attaching the sprayed heat medium to the inner surface of the decompression chamber;
Evacuating the decompression chamber so that the internal pressure of the decompression chamber is equal to or lower than the saturated vapor pressure of the heat medium at the target temperature. In the step of exhausting the decompression chamber,
The cooling method according to claim 12, wherein the decompression chamber is exhausted so that an internal pressure of the decompression chamber becomes equal to a saturated vapor pressure of the heat medium at the target temperature. In a cooling method for cooling the temperature of the member to be cooled to a target temperature using a decompression chamber thermally connected to the member to be cooled,
Spraying a liquid phase heat medium below the target temperature on the inner surface of the decompression chamber;
Generating an electric field for attaching the sprayed heat medium to the inner surface of the decompression chamber;
Detecting the temperature of the member to be cooled;
Evacuating the decompression chamber so that the detected temperature becomes a target temperature.

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