JP2010073655A - Temperature adjustment mechanism and plasma treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature adjustment mechanism capable of attaining suitable plasma treatment characteristics by controlling a temperature of a dielectric window used for plasma treatment and safely working while efficiently performing the temperature control of the whole system, and a plasma treatment device using the temperature adjustment mechanism. <P>SOLUTION: The plasma treatment device 1 includes a cooling passage 21 for cooling the dielectric window 3, and an external cooling passage 27 for cooling an external mechanism 10. A chiller 20 sets up the external mechanism 10 at a temperature of cooling a heat medium. The heat medium is supplied from the chiller 20 to an outward passage 27a, and returned to the chiller 20 through a return passage 27b by taking the heat of the external mechanism 10 via the external cooling passage 27. The heat medium is simultaneously supplied from the chiller 20 to an outward passage 21a in order to heat up at a designated temperature by a heater 25, and returned to the chiller 20 through a return passage 21b by taking the heat of the dielectric window 3 via a cooling passage 21. It is preferable that heat exchangers 26a, 26b are provided between the return passage 21b and the outward passage 21a, and between the return passage 27b and the outward passage 21a, respectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a temperature adjustment mechanism and a plasma processing apparatus using the temperature adjustment mechanism.

  Plasma technology is widely used in the manufacture of many semiconductor devices such as integrated circuits, liquid crystals, and solar cells. Plasma technology is used in thin film deposition and etching processes in the semiconductor manufacturing process, but advanced plasma processing such as ultra-fine processing technology is required for higher performance and higher performance products. In particular, a microwave plasma processing apparatus is often used that can stably generate a high-density plasma even in a high vacuum state where the pressure is relatively low.

  The plasma processing apparatus has a dielectric window (which may function as a shower plate for supplying plasma processing gas) that propagates microwaves, etc., which tends to be relatively hot and generates plasma stably. Temperature control is required. For stable plasma generation, the plasma processing equipment may be directly controlled or adjusted, but the temperature of the processing equipment is also high, so the necessary parts are cooled in order to work safely. It is desirable.

  Patent Document 1 discloses that it is possible to keep energy consumption low when cooling a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus unit, and to reduce the size of the entire apparatus. It is described to reduce. Brine tank for storing the heat medium, brine flow path and circulation pump for circulating supply to the object to be cooled, a cooling unit for cooling the heat medium below the set temperature, and the heat medium rising to the set temperature Heating means for heating, heating medium supply means for supplying hot water discharged from the cooling unit to the heating means, and control means.

  Patent Document 2 describes that in a microwave plasma processing apparatus using a radial line slot antenna, the cooling efficiency of the shower plate is optimized and at the same time the microwave excitation efficiency is optimized. In the plasma processing apparatus of Patent Document 2, the radiation surface of the radial line slot antenna is a part of the outer wall of the processing chamber, is in close contact with the cover plate that is in close contact with the shower plate, and is further disposed on the radial line slot antenna. A cooler is provided so as to absorb the heat flow flowing through the inside in the thickness direction.

  Patent Document 3 describes that a waste heat utilization system that can achieve energy saving of semiconductor manufacturing equipment is constructed by reusing warmed cooling water discharged from a semiconductor manufacturing apparatus as a heating source. Has been. In the technique of Patent Document 3, intermediate temperature cooling water having a temperature higher than room temperature discharged from the semiconductor manufacturing apparatus is supplied to the semiconductor manufacturing apparatus via the intermediate temperature cooling water supply line, and from the intermediate temperature cooling water discharged from the semiconductor manufacturing apparatus. Further, high-temperature cooling water having a higher temperature is supplied as a heating source to the semiconductor manufacturing apparatus via the high-temperature cooling water supply line.

Utility Model Registration No. 3061067 JP 2002-299330 A International Publication No. 2002/066731 Pamphlet

  In the dielectric window of the plasma processing apparatus, heat gradually accumulates in the dielectric window due to the plasma processing, resulting in a very large temperature distribution and consequently thermal distortion, which changes the characteristics of the apparatus (plasma processing). May become non-uniform). In addition, when such overheating occurs, even if a gas having a low decomposition temperature is used as the plasma gas, there is a possibility that the gas cannot be used because it is decomposed before being introduced into the processing chamber.

  For this reason, in order to suppress overheating of the dielectric window, a method of cooling the periphery of the dielectric window (for example, the upper part of the device) using a heat medium has been adopted. When the side surface of the dielectric window is cooled, the heat medium that has cooled the upper portion of the dielectric window cools the side surface as it is, so that there is a limit to the temperature control. In addition, the temperature control is often performed using a change in flow rate, and the responsiveness of the temperature change is not preferable.

  The present invention has been made in view of the above circumstances, and realizes good plasma processing characteristics by controlling the temperature of the dielectric window used for plasma processing, and safely while efficiently controlling the temperature of the entire apparatus. An object of the present invention is to provide a temperature control mechanism capable of working and a plasma processing apparatus including the temperature control mechanism.

In order to achieve the above object, a temperature adjustment mechanism according to the first aspect of the present invention includes:
A temperature control mechanism of a plasma processing apparatus having a processing chamber for generating plasma,
The plasma processing apparatus is at least partially in contact with the processing chamber, and is opposed to an object to be processed with the plasma sandwiched between an external apparatus outside the processing chamber through which heat of the processing chamber is conducted, A dielectric window for sealing plasma inside the processing chamber,
An external device cooling flow path for circulatingly supplying a heat medium to the external device;
A dielectric window cooling channel that circulates and supplies the heat medium in the vicinity of the dielectric window, the heat medium flowing out from the external device cooling channel does not directly flow into the channel;
A cooling device for adjusting the heat medium to a predetermined temperature;
Heating means for heating the heat medium to a predetermined temperature before flowing into the dielectric window cooling channel;
It is characterized by providing.

Preferably, the flow path from the cooling device to the dielectric window cooling flow path, the flow path before the heating means,
A flow path from one or both of the external device cooling flow path or the dielectric window cooling flow path to the cooling device;
It is characterized by providing the heat exchanger which performs heat exchange between.

Preferably, the dielectric window cooling channel is an upper surface cooling channel that circulates and supplies the heat medium to a side of the dielectric window that faces the outside of the processing chamber.
The side cooling channel that circulates and supplies the heat medium to the side surface in the extending direction of the main surface of the dielectric window, the heat medium flowing out from the upper surface cooling channel does not directly flow into the channel,
It is characterized by providing.

More preferably, the dielectric window cooling channel includes a first heating unit that heats the heat medium to a first temperature before flowing into the upper surface cooling channel.
A second heating means for heating the heat medium to a second temperature before flowing into the side surface cooling channel;
It is characterized by providing.

In order to achieve the above object, a plasma processing apparatus according to the second aspect of the present invention provides:
A temperature adjustment mechanism according to the first aspect is provided.

  According to the temperature control mechanism and the plasma processing apparatus using the temperature control mechanism of the present invention, the temperature of the dielectric window used for the plasma processing is controlled to achieve good plasma processing characteristics, and the temperature of the entire apparatus can be controlled efficiently. While working safely.

  Hereinafter, a plasma processing apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a schematic configuration diagram of a plasma processing apparatus according to an embodiment of the present invention. The plasma processing apparatus 1 includes a processing container (chamber) 2 that performs plasma processing therein, and a dielectric window 3, an antenna 4, a waveguide 5, and a cooling jacket 6 provided on the upper part of the processing container 2. .

  Inside the processing container 2, a space S for forming plasma and a stage 7 on which the substrate W to be processed is placed are provided. An exhaust chamber 8 having a cylindrical shape is provided directly below the stage 7. The stage support shaft 9 a passes through the center of the exhaust chamber 8 and supports the stage 7 at the end on the processing container 2 side. The exhaust chamber 8 forms a gap with the stage support shaft 9a, and exhausts from the gap (hereinafter referred to as the exhaust cylinder 8a).

  As a part constituting the wall of the processing container 2, a holding ring 2a is assembled to the upper part of the lower container 2b. The holding ring 2 a is configured to have a concentric step whose ring diameter (inner diameter) increases toward the ceiling side of the processing container 2, and holds the dielectric window 3 while covering the side surface of the dielectric window 3. The surface of 3 toward the processing container 2 side is locked. The holding ring 2a and the lower container 2b are made of, for example, aluminum (Al), and a protective film made of, for example, aluminum oxide is formed on the inner wall surface by, for example, oxidation treatment.

The dielectric window 3 is formed of a dielectric material that propagates microwaves, such as SiO ₂ or Al ₂ O ₃ . The dielectric window 3 is held at the periphery by the holding ring 2 a and can cover the opening of the processing container 2. The dielectric window 3 has a function of a shower plate, and the gas introduced into the dielectric window 3 is uniformly supplied into the space S immediately below the dielectric window 3.

The antenna 4 includes a waveguide 4a, a slot plate 4b, and a slow wave plate 4c. Examples of the slot plate 4b include RLSA (radial line slot antenna). The waveguide 4a is made of a shield member, and the slow wave plate 4c is made of a dielectric material such as SiO ₂ or Al ₂ O ₃ . The slow wave plate 4c is located between the waveguide 4a and the slot plate 4b and compresses the microwave wavelength. The waveguide 5 is a coaxial waveguide composed of an outer waveguide 5a and an inner waveguide 5b.

  An antenna 4 is coupled on the dielectric window 3. More specifically, the slot plate 4 b of the antenna 4 is in close contact with the dielectric window 3. A waveguide 5 is connected to the antenna 4. The waveguide 4a is connected to the outer waveguide 5a, and the slot plate 4b is coupled to the inner waveguide 5b.

  A cooling jacket 6 is provided on the antenna 4 as means for cooling the dielectric window 3 from above. The cooling jacket 6 can be installed on the antenna 4 in the vicinity of the heat generating part in the plasma processing apparatus 1, can be efficiently cooled, and hardly affects the temperature of other parts of the plasma processing apparatus 1. The cooling jacket 6 is made of a material having a high thermal diffusivity, such as aluminum (Al), and includes a cooling flow path 21 for the heat medium so as to reach the entire interior. The temperature of the heat medium flowing through the cooling channel 21 is set in advance in the chiller 20 in accordance with the temperature at which the upper part of the dielectric window 3 is desired to be cooled. Since the heat medium supplied from the chiller 20 circulates in the cooling flow path 21, the heat accumulated in the dielectric window 3, the antenna 4, and the like can be released, and has a role of preventing overheating. As the heat medium used for cooling, a liquid heat exchange medium such as silicon oil, fluorine-based liquid, or ethylene glycol can be used.

  The holding ring 2a for locking the dielectric window 3 includes means for cooling the dielectric window 3 from the side. Specifically, a cooling flow path 22 capable of circulating a heat medium is provided inside the holding ring 2a. The temperature of the chiller 20 is set in advance for the heat medium flowing through the cooling flow path 22 in accordance with the temperature at which the side of the dielectric window 3 is desired to be cooled. The heat medium supplied from the chiller 20 flows through the cooling flow path 22 to cool the side of the dielectric window 3 and suppress the temperature rise of the dielectric window 3.

  The dielectric window 3 can be efficiently cooled by the cooling flow path 21 of the cooling jacket 6 on the upper side and the cooling flow path 22 of the holding ring 2a on the side. By setting the heat medium flowing through the cooling flow path 21 and the cooling flow path 22 at different temperatures, it is possible to perform cooling according to each part. The chiller 20 can also be used by equalizing the heat medium that circulates inside the cooling flow path 21 and the cooling flow path 22. When temperature control is performed precisely, a heater 25 is attached between the chiller 20 and the supply side of the cooling flow path 21 or between the chiller 20 and the supply side of the cooling flow path 22. When supplying the cooling flow path 21 or the cooling flow path 22 to the cooling flow path 21, the heater 25 is heated up to a predetermined temperature immediately before, so that precise temperature control is possible.

  When controlling both the upper side and the side temperature, heaters 25a and 25b are provided in the stage before supplying the heat medium to the respective cooling flow paths 21 and 22 respectively. Alternatively, a structure in which only the cooling flow paths 21 and 22 at the corresponding positions on either the upper side or the side of the dielectric window 3 are provided to cool the dielectric window 3 may be used. Even in that case, it is desirable to provide the heater 25. The temperature control can be performed more precisely and the responsiveness is improved, so the time required for the temperature control can be shortened.

  The exhaust chamber 8 and the stage support 9 outside the processing container 2 are at a high temperature because the heat of the processing container 2 is transmitted. In particular, the stage support shaft 9a that supports the stage 7 having a heating mechanism for heating the substrate to be processed W is likely to be high temperature, and the stage support base 9 that is directly connected to the stage support shaft 9a is also high temperature.

  Since the exhaust chamber 8 and the stage support 9 are outside the processing container 2, they are in a position where they can be easily touched from the outside of the plasma processing apparatus 1. However, the temperature is high and it is dangerous to touch it with bare hands. In consideration of safety during work, it is necessary to lower the temperature to some extent by cooling. However, if the temperature is too low, the process gas passes through the exhaust pipe 8a, and deposits adhere to the plasma processing apparatus 1.

  The exhaust chamber 8 and the stage support 9 are provided with cooling channels 23 and 24 through which a heat medium can flow. The heat medium is circulated through the cooling channels 23 and 24 to release heat. The cooling channels 23 and 24 can be cooled to a temperature at which safety can be maintained even if they are touched. Further, since the temperature can be lowered in a short time and the temperature at that time can be controlled, the temperature can be kept constant as compared with the case where the cooling channels 23 and 24 are not provided. As a result, the work can be performed safely, the deposits can be prevented from being adhered, and the plasma generation conditions can be set to a more stable state. As the heat medium used for cooling at this time, a liquid heat exchange medium such as silicon oil, fluorine-based liquid, or ethylene glycol can be used.

  As the heat medium supplied to the cooling flow paths 23 and 24, the same heat medium as the cooling flow paths 21 and 22 for cooling the upper side or the side of the dielectric window 3 can be used. Furthermore, since the working space is limited, it is preferable that the plasma processing apparatus 1 is not large, and considering the environment and the like, it is desirable that the chiller 20 is also used.

  When the chiller 20 is also used, first, the temperature of the chiller 20 is set in accordance with the cooling channels 23 and 24 having the lowest cooling temperature. The cooling channels 21 and 22 used for cooling the dielectric window 3 are respectively provided with heaters 25a and 25b, and the heating medium is heated to a predetermined temperature before the heating medium is supplied to the cooling channels 21 and 22. Heat. Even when the chiller 20 is also used, by providing the heaters 25a and 25b, the cooling channels 21, 22, 23, and 24 can each circulate the heat medium at a predetermined temperature, and the cooling channels 21, 22 can be precisely temperature-controlled.

  The heat medium discharged from the cooling channels 21, 22, 23, 24 has a high temperature, and the heat medium to be heated by the heaters 25a, 25b before being supplied from the chiller 20 to the cooling channels 21, 22 has a temperature. Is low. You may provide a heat exchanger between the flow path which flows into heater 25a, 25b, and the return path of each cooling flow path. By providing the heat exchanger, the burden on the chiller 20 and the heaters 25a and 25b can be reduced, and the energy efficiency of cooling can be improved.

  Hereinafter, a plasma processing method will be briefly described. The processing container 2 of the plasma processing apparatus 1 is closed by a dielectric window 3. At this time, the inside of the processing container 2 is evacuated and decompressed by the exhaust cylinder 8a and the vacuum pump 8b of the exhaust chamber 8 to be in a vacuum state.

  A microwave is supplied from the microwave source through the waveguide 5. The microwave propagates in the radial direction between the waveguide 4a and the slot plate 4b and is radiated from the slot of the slot plate 4b. The microwave propagates through the dielectric window 3 and has a plane of polarization, and forms a circularly polarized wave as a whole.

When microwaves are fed into the processing vessel 2 to form plasma, an inert gas such as argon (Ar) or xenon (Xe) and nitrogen (N ₂ ), and a process gas such as hydrogen as necessary. And supply to the gas flow path. The gas is introduced into the processing container 2 so as to be uniform immediately below the dielectric window 3. A voltage is applied to the high-frequency power source 13 to generate argon (Ar) or xenon (Xe) plasma formed in the space S, and the substrate to be processed W placed on the stage 7 can be subjected to plasma processing. For example, the film on the substrate W to be processed is etched, so-called RIE (reactive ion etching). A series of processes of carrying in the substrate W to be processed and carrying it out after the plasma processing is repeated, and a predetermined substrate processing is performed on a predetermined number of substrates.

  In order to perform plasma processing stably, it is necessary to keep the dielectric window 3 at a predetermined temperature. By supplying a heat medium from the chiller 20 to the cooling passages 21 and 22, it is possible to cool by taking away the heat accumulated in the dielectric window 3. Since the heat medium is heated to a predetermined temperature by the heaters 25a and 25b before being supplied to the cooling channels 21 and 22, it is possible to cool the heat medium at a temperature according to each location. Based on the temperature detection result of the temperature sensor 11 provided in the vicinity of the antenna 4, the control unit (not shown) instructs the heating of the heaters 25 a and 25 b. The temperature of the dielectric window 3 can be controlled more precisely in a short time, and plasma can be stably formed.

  In addition to cooling the dielectric window 3, a heat medium is circulated inside the cooling flow paths 23, 24 to cool the exhaust chamber 8 and the stage support 9, thereby maintaining a predetermined temperature. The exhaust chamber 8 and the stage support 9 are cooled to a temperature within a range where safety can be maintained even if they are touched, and work near the plasma processing apparatus 1 can be performed safely. The cooling is performed in a temperature range where deposits do not adhere, and there is no risk of quality deterioration. By maintaining the temperature at a constant temperature, it contributes to maintaining good process conditions.

  Hereinafter, the temperature adjustment mechanism according to the first aspect of the present invention will be described. FIG. 2 is a block diagram showing a temperature adjustment mechanism of the plasma processing apparatus according to the embodiment of the present invention. As the plasma processing apparatus, the plasma processing apparatus 1 shown in FIG. 1 is used. In FIG. 2 and subsequent figures, the exhaust chamber 8 and the stage support 9 in the plasma processing apparatus 1 are collectively referred to as an external mechanism 10. Also, the cooling channels 23 and 24 corresponding to each are collectively described as an external cooling channel 27.

  The dotted line encircled portions in the figure indicate portions (objects to be cooled) cooled by the cooling flow paths 21 and 27. The objects to be cooled are the dielectric window 3 and the external mechanism 10. The dielectric window 3 may be cooled from above or from the side, but either case may be used here. The arrows in the figure indicate the moving direction of the heat medium. A flow path indicated by a straight arrow indicates a flow path from the chiller 20 to the object to be cooled via the cooling flow paths 21 and 27. Hereinafter, the flow path from the chiller 20 to the object to be cooled is referred to as the forward paths 21a, 27a and the like. A flow path indicated by a one-dot chain line arrow indicates a flow path from the object to be cooled to the chiller 20 via the cooling flow paths 21 and 27. Hereinafter, the flow path from the object to be cooled to the chiller 20 is referred to as a return path 21b, 27b or the like. Since the temperature of the heat medium flowing through the return paths 21b and 27b is after taking heat from the object to be cooled, the temperature is higher than the temperature of the heat medium flowing through the corresponding forward paths 21a and 27a.

  The plasma processing apparatus 1 includes a cooling channel 21 that cools the top of the dielectric window 3. Further, an external cooling channel 27 for cooling the external mechanism 10 is also provided. Since the chiller 20 is used as both the cooling flow path 21 and the external cooling flow path 27, the temperature of the heat medium is set to a temperature at which the external mechanism 10 is cooled, for example, about 80 ° C., where the temperature of the object to be cooled is low. Keep it.

  It is desirable that the external mechanism 10 be cooled by the external cooling flow path 27 and be kept at a temperature that can maintain safety even if it is touched. Since the external mechanism 10 is outside the sealed processing container 2, there is a risk of touching it by mistake. For example, in a factory, when it is not possible to secure a sufficient space between devices, it is dangerous to get burned by touching the adjacent device during operation. If the external mechanism 10 is cooled, an accident may occur. Can be prevented. Furthermore, by cooling the external mechanism 10 at a predetermined temperature, it can be maintained at a constant temperature unlike when no cooling is performed. The plasma generation conditions can be kept constant by stabilizing the temperature. Furthermore, since there is no sudden temperature change and the temperature does not become lower than a predetermined temperature, the occurrence of problems in which deposits adhere due to the process gas passing through the external mechanism 10 can be reduced.

  Since the temperature of the dielectric window 3 greatly affects the plasma generation conditions, it is necessary to strictly control the temperature. The temperature of the heat medium is set to 100 ° C. until the plasma is stabilized from the idling state when the apparatus is started and the state ready for operation is maintained. Since the temperature of the heat medium output from the chiller 20 is set to 80 ° C., temperature control from 80 ° C. to 100 ° C. can be performed only by the heater 25. After that, when the plasma is stabilized, the heat from the plasma is also transmitted to the dielectric window 3, so that the temperature of the dielectric window exceeds 150 ° C. when the temperature of the heat medium remains at 100 ° C. The temperature of the dielectric window 3 can be stabilized by controlling the heating to the heat medium with the heater 25 in consideration of the change in the amount of heat from the plasma.

  At this time, the amount of the heat medium flowing through the cooling channel 21 is kept constant, and the temperature of the heat medium is strictly controlled by the intensity of the heating of the heater 25. Compared with the temperature control by the flow rate, the temperature control by the intensity of heating of the heater 25 has high responsiveness and can be controlled to a predetermined temperature in a short time.

  The heat medium supplied from the chiller 20 circulates in respective circulation paths of the cooling flow path 21 that cools the dielectric window 3 and the external cooling flow path 27 that cools the external mechanism 10.

  In the cooling of the external mechanism 10, the heat medium flows through the forward path 27 a, takes the heat of the external mechanism 10 through the external cooling flow path 27, passes through the return path 27 b, and is returned to the chiller 20.

  In cooling the dielectric window 3, the heat medium is heated to a predetermined temperature by the heater 25 provided in the middle of the forward path 21a. For example, the heat medium supplied from the chiller 20 to the forward path 21 a at 80 ° C. is heated to 110 ° C. by the heater 25. Then, the heat of the dielectric window 3 is taken through the cooling flow path 21, passes through the return path 21 b, and is returned to the chiller 20.

  When the heat medium flowing through the external cooling flow path 27 is returned to the chiller 20 from the return path 27b, it is necessary to lower the temperature of the heat medium to nearly 80 ° C. before being supplied from the chiller 20 again. Further, the heat medium flowing through the cooling flow path 21 is heated by the heater 25 to about 20 ° C. in the forward path 21 a before being heated by the heater 25. Therefore, by providing the heat exchanger 26a between the return path 21b and the forward path 21a of the cooling flow path 21, it is not necessary to heat the heat medium by the heater 25. A similar result can be obtained by providing a heat exchanger 26b between the return path 27b of the external cooling flow path 27 and the forward path 21a of the cooling flow path 21. At this time, when the temperature of the heat medium flowing through the return path 21b is compared with the temperature of the heat medium flowing through the return path 27b, the temperature of the heat medium flowing through the return path 21b is higher. By arranging the higher temperature so as to be closer to the heater 25, heat can be exchanged more efficiently.

  The temperature managed by the dielectric window 3 is higher, and the temperature of the heat medium passing through the forward path 21a is set higher than that of the heat medium passing through the forward path 27a. Furthermore, in order to take heat away from the object to be cooled, the heat medium passing through the return path 21b has a higher temperature than the heat medium passing through the return path 27b. Therefore, the heat exchanger 26a may include not only the forward path 21a and the return path 21b but also the heat exchanger 26b between the forward path 21a and the return path 27b. You may provide the heat exchanger 26a, 26b in either one, without providing two. As a result, the plasma processing apparatus 1 has improved heat exchange efficiency, leading to energy saving.

  FIG. 3 is a block diagram showing a temperature adjustment mechanism of the plasma processing apparatus according to the first modification of the embodiment of the present invention. A dotted line encircled portion in the figure indicates a portion (object to be cooled) cooled by the cooling flow paths 21, 22, and 27. The objects to be cooled are the dielectric window 3 and the external mechanism 10. The dielectric window 3 has cooling from above and cooling from the side. The basic structure is the same as the temperature adjustment mechanism of the plasma processing apparatus according to the embodiment of the present invention shown in FIG.

  Around the dielectric window 3, a cooling channel 21 for cooling the upper side and a cooling channel 22 for cooling the side are provided. The cooling flow path 21 includes a heater 25 a in the middle of the forward path 21 a and can supply a heat medium having a predetermined temperature to the cooling flow path 21. In addition, a heat exchanger 26a is provided between the forward path 21a and the return path 21b to perform efficient cooling. Similarly, the cooling flow path 22 includes a heater 25b in the forward path 22a, and a heat exchanger 26b between the forward path 22a and the return path 22b. By doing in this way, the temperature of the cooling flow path 21 for cooling the upper side of the dielectric window 3 and the cooling flow path 22 for cooling the side of the dielectric window 3 can be strictly controlled. The upper part of the dielectric window 3 is more susceptible to heat from the plasma than the side. In this case, the heater 25b may be set at a higher temperature than the heater 25a.

  The temperature of the heat medium in the chiller 20 is set according to the external cooling flow path 27 that cools the external mechanism 10, and the cooling flow paths 21 and 22 around the dielectric window 3 having a temperature higher than that of the external mechanism 10 are set. The heaters 25a and 25b are heated to a predetermined temperature. The heat medium can be circulated at a temperature matched to each of the cooling flow paths 21, 22, and 27, and the plasma processing operation is performed safely while maintaining the temperature of the dielectric window 3 at a temperature matched to the plasma generation conditions. be able to.

  FIG. 4 is a block diagram showing a temperature adjustment mechanism of the plasma processing apparatus according to the second modification of the embodiment of the present invention. A heat exchanger 26 is provided between the forward path portion before the forward paths 21a and 22a of the cooling flow paths 21 and 22 are branched and the return path portion after the return paths 21b and 22b merge. The temperature of the dielectric window 3 is higher than the temperature of the external mechanism 10, and the upper side and the side of the dielectric window 3 are controlled at the same temperature, so that one flow path is provided before and after the object to be cooled is cooled. Can be summarized. Thereby, the heat exchanger 26 can be made one. Further, one end of the heat exchanger 26 may be provided in the return path 27b instead of the return path portion after the return paths 21b and 22b merge.

  FIG. 5 is a block diagram showing a temperature adjustment mechanism of the plasma processing apparatus according to the third modification of the embodiment of the present invention. A return path is formed so that the return paths 21b and 22b of the cooling flow paths 21, 22 and 27 merge and immediately return to the chiller 20 to merge the return path 27b. A heat exchanger 26 is provided between the return path after the return paths 21b and 22b returned at a higher temperature merge and the forward paths 21a and 21b where the temperature of the heat medium needs to be higher than that of the forward path 27a. At this time, by providing the heat exchanger 26 before the forward paths 21a and 21b are diverted, only one heat exchanger 26 is required.

  Regarding the temperature adjustment mechanism of the plasma processing apparatus 1 according to the embodiment, various ways of taking flow paths are conceivable. The number and arrangement of heaters 25 and heat exchangers 26 can be arbitrarily set according to the flow path. It is desirable to design the temperature adjustment mechanism in accordance with the shape and size of the plasma processing apparatus 1. By adjusting the temperature of the chiller 20 to the external mechanism 10 having a low set temperature and providing the heaters 25a and 25b on the forward paths 21a and 22a supplied to the cooling flow paths 21 and 22 of the dielectric window 3, the chiller 20 is provided. In addition, the temperature of the heat medium flowing through the cooling channels 21, 22, and 27 can be set to a predetermined temperature, and the temperatures of the dielectric window 3 and the external mechanism 10 can be controlled. Furthermore, the heaters 25a and 25b can control the temperature more precisely in a short time. Further, by providing the heat exchanger 26 between the forward paths 21a, 22a before being heated by the heaters 25a, 25b and the return paths 21b, 22b, 27b of the cooling flow paths 21, 22, 27, the heater 25 Heating of the heat medium can be reduced. Further, the burden on the chiller 20 can be reduced. As a result, the plasma processing apparatus 1 has improved heat exchange efficiency, leading to energy saving. The return path including the heat exchanger 26 may be any of the return paths 21b, 22b, and 27b, or a combination thereof (that is, a merged portion).

  In the plasma processing apparatus 1 according to the embodiment, the shape of the cooling flow path 21 for cooling the dielectric window 3 is preferably a shape corresponding to the antenna 4. The shape of the cooling flow path 22 is preferably a shape that covers the side surface of the dielectric window 3. By cooling so as to cover the dielectric window 3, the cooling efficiency of the dielectric window 3 can be increased. Further, by arranging the heaters 25a and 25b as close to the cooling flow paths 21 and 22 as possible, the heaters 25a and 25b can be cooled at a predetermined temperature, and the responsiveness by temperature control is increased.

  In forming the plasma, the upper and side of the dielectric window 3 of the plasma processing apparatus 1 are managed separately at different temperatures, so that the plasma processing can be controlled within a desired range. In order to perform separate temperature management on the upper side and the side of the dielectric window 3 while preventing overheating in the vicinity of the dielectric window 3 that is at a high temperature, cooling channels 21 and 22 are provided. It is desirable to include heaters 25a and 25b. By controlling the temperature more precisely, the plasma generation conditions can be maintained in a good state.

  In order to save energy, it is desirable to provide heat exchangers 26a and 26b between the forward paths 21a and 22a before being heated by the heaters 25a and 25b and the return paths 21b and 22b. Depending on the downsizing of the apparatus and the problem of the installation location, not only the chiller 20 but also the heat exchanger 26 may be used. Use of the heat exchanger 26 not only enables energy saving, but also reduces the burden on the heater 25 and the chiller 20 and shortens the time until the temperature becomes constant.

  Furthermore, by providing the external cooling channel 27 in the external mechanism 10 of the plasma processing apparatus 1, the safety of the apparatus is increased and an unexpected accident can be prevented. Furthermore, a rapid temperature drop or temperature change to the process gas passing through the external mechanism 10 can be prevented, and deposit adhesion can be reduced.

  Note that the plasma processing apparatus and the temperature adjustment mechanism described in the embodiment are merely examples, and the present invention is not limited to these. The plasma processing method, the gas used for the plasma processing, the substrate to be processed, the number of temperature sensors, and the like can be arbitrarily selected. The arrangement of the heater, the heat exchanger, the cooling channel, and the like are not limited to the example of the embodiment, and various implementations are possible.

1 is a schematic configuration diagram of a plasma processing apparatus according to an embodiment of the present invention. It is a block diagram which shows the temperature control mechanism of the plasma processing apparatus which concerns on embodiment of this invention. It is a block diagram which shows the temperature control mechanism of the plasma processing apparatus which concerns on the modification 1 of embodiment of this invention. It is a block diagram which shows the temperature control mechanism of the plasma processing apparatus which concerns on the modification 2 of embodiment of this invention. It is a block diagram which shows the temperature control mechanism of the plasma processing apparatus which concerns on the modification 3 of embodiment of this invention.

Explanation of symbols

1 Plasma processing equipment
2 Processing container (chamber)
2a Retaining ring
3 Dielectric window
4 Antenna
5 Waveguide
6 Cooling jacket
8 Exhaust chamber
9 Stage support stand
10 External mechanism
20 Chillers 21, 22, 23, 24 Cooling channel
21a, 22a Outbound
21b, 22b Return path 25, 25a, 25b Heater 26, 26a, 26b Heat exchanger
27 External cooling flow path
27a Outbound
27b Return

Claims (5)

A temperature control mechanism of a plasma processing apparatus having a processing chamber for generating plasma,
The plasma processing apparatus is at least partially in contact with the processing chamber, and is opposed to an object to be processed with the plasma sandwiched between an external apparatus outside the processing chamber through which heat of the processing chamber is conducted, A dielectric window for sealing plasma inside the processing chamber,
An external device cooling flow path for circulatingly supplying a heat medium to the external device;
A dielectric window cooling channel that circulates and supplies the heat medium in the vicinity of the dielectric window, the heat medium flowing out from the external device cooling channel does not directly flow into the channel;
A cooling device for adjusting the heat medium to a predetermined temperature;
Heating means for heating the heat medium to a predetermined temperature before flowing into the dielectric window cooling channel;
A temperature control mechanism comprising: A flow path from the cooling device to the dielectric window cooling flow path, the flow path before the heating means,
A flow path from one or both of the external device cooling flow path or the dielectric window cooling flow path to the cooling device;
The temperature control mechanism according to claim 1, further comprising a heat exchanger that performs heat exchange between the two. The dielectric window cooling channel is an upper surface cooling channel that circulates and supplies the heat medium to a side of the dielectric window that faces the outside of the processing chamber.
The side cooling channel that circulates and supplies the heat medium to the side surface in the extending direction of the main surface of the dielectric window, the heat medium flowing out from the upper surface cooling channel does not directly flow into the channel,
The temperature control mechanism according to claim 1, further comprising: The dielectric window cooling channel includes a first heating unit that heats the heat medium to a first temperature before flowing into the upper surface cooling channel;
A second heating means for heating the heat medium to a second temperature before flowing into the side surface cooling channel;
The temperature adjusting mechanism according to claim 3, further comprising:   A plasma processing apparatus comprising the temperature adjusting mechanism according to claim 1.

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