JP2009218324A - Plasma treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately control the temperature of a protective shield even in a plasma treatment device of, for instance, dry etching of a high aspect ratio or the like which processes a substrate by keeping the substrate at a relatively low temperature close to room temperature. <P>SOLUTION: This plasma treatment device 11 is used for treating an object 29 in a vessel 13 by using plasma by discharge between a pair of electrodes 21 and 23 facing each other, and provided with: the vessel 13 having thermally-conductive sidewalls 19; a flowing water pipe 37 arranged outside the sidewalls 19, providing heat to the sidewalls 19, and drawing heat from the sidewalls 19; protective shields 33a and 33b formed of a thermally-conductive material, and changed in contact areas to the sidewalls 19 by being deformed by temperature; and mounting parts 31 for thermally-conductively mounting the protective shields 33a and 33b to the insides of the sidewalls 19. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus that uses plasma to process an object in a container by a method such as dry etching, CVD, or sputtering.

  Plasma processing apparatuses used for manufacturing electronic devices and the like include sputtering apparatuses for forming thin films on semiconductor substrates, glass substrates, etc., film forming apparatuses such as plasma CVD, and dry etching apparatuses for processing the substrate surface. is there.

  For example, a dry etching apparatus that performs reactive ion etching includes a container into which a process gas such as sulfur hexafluoride or nitrogen trifluoride is introduced at a predetermined pressure, and a pair of faces provided in the container. And parallel electrodes. A high frequency power source is connected to one of the electrodes. A board | substrate is arrange | positioned in the vicinity of the parallel electrode to which the power supply was connected among a pair of parallel electrodes. When electric power is supplied to the electrodes, process gas ions and radicals are generated by discharge between the electrodes. The ions and radicals collide with the substrate and etch the substrate surface.

  In such a process using plasma, a product generated by a reaction accompanying the process is deposited on the inner wall of the container to become a deposited film. The deposited film will eventually peel and become fine particles. The particles scatter in the container and adhere to the substrate surface. In recent years, since the integration of electronic devices is increasing, even if very small particles adhere to the substrate surface, the electronic device including the substrate surface becomes a defective product.

  In order to improve the manufacturing yield of electronic devices, it is necessary to suppress adhesion of particles to the substrate surface. Therefore, a protective shield is provided in the container to prevent the product from accumulating on the inner wall of the container. This deposits the product on the protective shield rather than on the inner wall of the container. By replacing the protective shield before the thickness of the deposited film on the protective shield exceeds a predetermined value, peeling or particle formation of the deposited film can be prevented.

  Considering the labor and cost for replacing the protective shield, the replacement cycle should be long. In view of this, a plasma processing apparatus has been proposed in which the replacement cycle of the protective shield (protection shield) is increased (see, for example, Patent Document 1). The thin film deposition apparatus described in Patent Document 1 includes a deposition shield temperature control unit using a deposition shield heating unit and a temperature sensor that measures the temperature of the deposition shield. Hold the deposition shield at a constant temperature above the temperature of the deposition shield during the process.

The main cause of particle formation due to the peeling of the deposited film is a temperature change during and before and after the process. That is, it is heated from before the start of the process to during the process, and cooled after the end of the process. By repeating this heating and cooling, the thermal stress applied to the deposited film changes, and particle formation occurs due to peeling of the deposited film. As described above, in the thin film deposition apparatus described in Patent Document 1, the deposition shield film is peeled off due to a temperature change of the deposition shield in order to keep the deposition shield temperature at a temperature higher than a certain temperature.・ Suppressing particles and scattering.
JP-A-5-179436

  In the case of thin film formation such as sputtering using plasma and plasma CVD, the substrate is maintained at a relatively high temperature of 100 to 400 ° C. Therefore, even if the deposition shield is held at a high temperature as described in Patent Document 1 above, The influence on processes such as deposition and film quality is small. In contrast, in the case of dry etching with a high aspect ratio, for example, the substrate is maintained at a relatively low temperature near room temperature. There are strong concerns about the negative impact on

  Furthermore, the thin film deposition apparatus described in Patent Document 1 only includes a heating unit and does not include a cooling unit. Therefore, there is a problem that an apparatus that maintains and processes a substrate at a relatively low temperature near room temperature, such as the above-described high aspect ratio dry etching process, cannot be applied without adversely affecting the process.

  Also, aluminum alloy is widely used as the material of the container, and the inner wall of the container is covered with a protective film having high corrosion resistance and plasma resistance such as alumite. However, when exposed to plasma for a long time, the protective film on the inner wall of the container deteriorates and cracks occur. The plasma enters the inside of the container wall from the crack and reacts with a low plasma resistance material such as an aluminum alloy which is a material of the container wall. As a result, the product of the reaction between the material of the container wall and the plasma may become a new particle source that adheres to the substrate surface. The technique described in Patent Document 1 also has a problem that such deterioration of the inner wall of the container itself cannot be suppressed.

  Furthermore, in the technique described in Patent Document 1, when replacing the protective shield, it is necessary to replace not only the protective shield but also the heating means attached to the protective shield. There is also a problem that the burden is large.

  In order to solve the above-mentioned problems, the present invention 1) Maintains the substrate at a relatively low temperature near room temperature, for example, even in the case of processing such as dry etching with a high aspect ratio, the temperature of the protective shield is appropriate. It is an object of the present invention to provide a plasma processing apparatus capable of controlling the above, 2) suppressing deterioration of the inner wall of the container in which plasma is generated, and 3) reducing the cost required for replacing the protective shield.

In order to achieve the above object, a plasma processing apparatus of the present invention is a plasma processing apparatus for processing an object in a container using plasma generated by discharge between a pair of opposing electrodes,
A container having a thermally conductive wall;
A heat source provided on the outside of the wall, for applying heat to the wall, and for taking heat away from the wall;
A protective shield that is provided on the inner side of the wall portion, a part of which is always capable of transferring heat to the wall portion, and is deformed by heat transmitted through the wall portion, thereby changing a contact area with the wall portion; Is provided.

  According to the present invention, the temperature of the protective shield can be appropriately controlled even in processing such as dry etching with a high aspect ratio, for example, by processing while maintaining the substrate at a relatively low temperature near room temperature. In addition, it is possible to suppress deterioration of the inner wall of the container where plasma is generated. Furthermore, it is possible to reduce the cost for replacing the protective shield.

Embodiment 1 FIG.
FIG. 1 is a perspective view in which a part of the plasma processing apparatus according to Embodiment 1 of the present invention is cut away. The plasma processing apparatus 11 includes a container 13 and a temperature adjustment unit 35.

  The container 13 is a container whose external appearance and internal hollow are both rectangular parallelepiped. The container 13 is formed by an upper portion 15, a bottom portion 17, and a side wall (wall portion) 19. At least the side wall 19 of the container 13 is made of a heat conductive material. Specific examples of such materials include metals having high thermal conductivity such as aluminum, alloys thereof, and graphite. A process gas having a predetermined pressure is introduced into the container 13. Therefore, the plasma processing apparatus 11 further includes a device (not shown) that maintains a predetermined type and configuration of gas at a predetermined pressure.

  The container 13 includes an upper electrode 21 and a lower electrode 23 that are a pair of parallel electrodes disposed in the upper and lower sides, a susceptor 27 on which a substrate 29 as a processing target is placed, and an attachment portion 31. And protective shields 33 a and 33 b for protecting the inside of the side wall 13. As shown in the figure, the upper electrode 21 is installed, and the lower electrode 23 is connected to a high-frequency power source 25. The upper and lower electrodes 21 and 23 are arranged apart from each other by a predetermined distance. The susceptor 27 is disposed on the lower electrode 23 and supports the substrate 29 while maintaining a predetermined temperature.

  The attachment portion 31 is a member that attaches the protective shields 33 a and 33 b to the inside of the side wall 13, and engages with a portion (not shown) provided inside the side wall 13, for example. The attachment portion 31 is made of a heat conductive material. Thus, the attachment portion 31 forms a contact portion where the side wall 19 and the protective shields 33a and 33b are in thermal contact with each other in a straight band shape.

  As shown in FIG. 2, the protective shields 33a and 33b are bimetallic plates obtained by joining two kinds of metals 33a and 33b. The joint surfaces of the two types of metals 33 a and 33 b are generally arranged in parallel with the side wall 19. The first metal 33 a is disposed on the center side of the container 13. The second metal 33 b is disposed on the side wall inside the container 13. The linear expansion coefficient of the first metal 33a is larger than the linear expansion coefficient of the second metal 33b.

  As shown in FIG. 2, the protection shields 33 a and 33 b are curved so as to be separated from the side wall 19 as they move upward or downward from the attachment portion 31, respectively, as shown in FIG. 2. Since the protective shields 33a and 33b are bimetals having a larger coefficient of linear expansion inside than the outside as described above, the curvature decreases when the temperature becomes high due to discharge, and the protective shields 33a and 33b are as shown in FIG. It approaches a flat plate shape. As a result, the contact area between the protective shields 33a and 33b and the side wall 19 is increased. Therefore, the protective shields 33 a and 33 b are deprived of much heat by the flowing water pipe 37 through the attachment portion 31 and / or the side wall 19. As described above, the protective shields 33a and 33b are deformed by changing the curvature by transferring heat to and from the flowing water pipe 37 via the attachment portion 31 and / or the side wall 19.

  The temperature adjustment unit 35 includes a flowing water pipe 37 as a heat source that applies heat to the side wall 19 of the container 13 or takes heat away from the side wall 19. In the flowing water pipe 37, cold water, hot water, or water vapor (collectively referred to as “water”) flows through the inside thereof according to the temperature to be controlled. The flowing water pipe 37 is provided in contact with the side wall 19 of the container 13. The temperature and amount of water flowing through the water flow pipe 37 are controlled by a temperature control unit (not shown). The temperature control unit includes, for example, a sensor that detects each of the temperature of the side wall 19 and the temperature of the medium flowing through the water pipe 37, a heater that gives heat to the medium in the water pipe 37, or a cooler that takes heat away from the medium. And a control unit for controlling the heater or the cooler based on information obtained from the sensor. With such a configuration, the temperature of the side wall 19 of the container 13 can be controlled within a desired range. The heat source is not limited to the flowing water pipe 37, and any heat source may be used as long as it transfers the heat of the heater to the side wall 19 or transfers the heat of the side wall 19 to the cooler.

  Next, the operation of the plasma processing apparatus 11 when performing dry etching with a high aspect ratio using the plasma processing apparatus 11 will be described. In the dry etching process with a high aspect ratio, the substrate 29 is maintained at a relatively low temperature near room temperature. During the etching, the protective shields 33a and 33b are heated by the discharge between the electrodes 21 and 23. Therefore, it is necessary to cool the protective shields 33a and 33b in order to maintain the protective shields 33a and 33b at about room temperature according to the temperature of the substrate 29. Here, an example in which the protective shields 33a and 33b are cooled and maintained at 60 ° C. to 65 ° C. will be described.

  About 60 ° C. water flows through the water flow pipe 37. Prior to etching, the protective shields 33a and 33b are maintained at about 60 ° C. by the flowing water pipe 37. When the etching starts, the protective shields 33a and 33b are heated by the discharge. Therefore, the protective shields 33a and 33b approach a flat plate shape as described above (for example, see FIG. 3). Then, the contact area between the protective shields 33a and 33b and the side wall 19 increases. As a result, more heat from the protective shields 33a and 33b is taken away by the flowing water pipe 37, and as a result, the temperature of the protective shields 33a and 33b decreases. When the temperature of the protective shields 33a and 33b is lowered, the protective shields 33a and 33b are gradually curved to reduce the curvature when the protective shields 33a and 33b are viewed from the side. As shown in FIG. 1, the protective shields 33a and 33b eventually bend to such a degree that heat is transmitted to the side wall 19 only through the attachment portion 31. Thereafter, when the temperature of the protective shields 33a and 33b rises again due to the discharge for etching, the protective shields 33a and 33b approach a flat plate shape, and the processes described so far are repeated. Thereby, the protective shields 33a and 33b are kept at 60 ° C to 65 ° C.

  In the protective shield, contrary to the present embodiment, the linear expansion coefficient of the outer metal may be larger than the linear expansion coefficient of the inner metal. In this case, as the temperature becomes higher, the curvature becomes smaller and the portion in contact with the inside of the wall portion increases. Therefore, it can be applied to the case where the temperature of the protective shield is maintained by heating with the flowing water pipe 37. In addition, the material which comprises a protective shield, and the ratio of each material are good to adjust suitably according to the temperature which should be maintained. In addition, although the longitudinal direction of the attachment portion 31 is the horizontal direction, the direction may be a vertical direction or an oblique direction. In addition, although the protective shield is assumed to be a separate upper and lower body, it may be integrated. In this case, the protective shield is preferably fixed to the side wall 19 by an attachment portion such as a pin or a screw. Further, in this case, the contact portion where the side wall 19 and the protective shield are always in thermal contact is the portion where the side wall 19 and the protective shield are in direct contact.

  As described above, according to the present embodiment, even when a substrate is processed while being maintained at a relatively low temperature near room temperature, such as dry etching with a high aspect ratio, the substrate to be processed It becomes possible to appropriately control the protective shield in a temperature range that does not affect the temperature of the shield. It is also possible to keep the protective shield at a high temperature by modifying the configuration of the protective shield. Therefore, even when products generated by reactions associated with the plasma process are deposited on the protective shield used in various modes, the deposited products are prevented from peeling off and becoming particles. it can.

  Further, the protective shields 33a and 33b are disposed relatively near the side wall 19 of the container. Therefore, a gap in which a product resulting from a reaction accompanying the plasma process flows into the inside of the side wall 19 of the container is reduced. Accordingly, it is possible to suppress the deterioration of the inner wall of the container where plasma is generated. Furthermore, according to the plasma processing apparatus 11 of the present embodiment, when the product is deposited on the protective shield, it is only necessary to replace the protective shield while leaving the water pipe and the like. Accordingly, it is possible to reduce labor and cost for maintenance such as replacement of the protective shield.

Embodiment 2. FIG.
The plasma processing apparatus of the present embodiment has a feature different from that of the first embodiment in the mechanism in which the protective shield changes the contact area with the side wall of the container. The mechanism is embodied by the shape of the container sidewall and the protective shield. FIG. 4 is an enlarged side sectional view showing characteristic portions of the protective shield and the side wall of the container provided in the plasma processing apparatus according to Embodiment 2 of the present invention. Except for the part shown in FIG. 4, the plasma processing apparatus of the present embodiment includes the same parts as those of the plasma processing apparatus of the first embodiment shown in FIG. 1, and the corresponding parts will be described using the same reference numerals.

  As shown in FIG. 4, the side wall 119 of the container 13 gradually protrudes toward the inside of the container and becomes thicker as the distance from an engaging portion to which a mounting portion 131 to be described later is attached. The side wall 119 has five step portions on the upper and lower sides. The side wall 119 includes a plurality of inner wall portions facing in the vertical direction, that is, the first inner wall portions 155a and 155b, the second inner wall portions 159a and 159b, the third inner wall portions 163a and 163b, and the fourth inner wall from the side closer to the engaging portion. It has parts 167a and 167b and fifth inner wall parts 171a and 171b. The side wall 119 has a plurality of wall step portions facing the thickness direction, that is, first wall step portions 157a and 157b, second wall step portions 161a and 161b, third wall step portions 165a and 165b, and a fourth wall step portion. Portions 169a and 169b and fifth wall step portions 173a and 173b. Each step portion of the side wall 119 includes first to fifth inner wall portions and first to fifth wall step portions.

  The upper and lower protective shields 133a and 133b are attached to the side wall 119 by the attachment portion 131 similar to the attachment portion 31 of the first embodiment so as to form a contact portion that is in thermal contact with the side wall 19 in a straight strip shape. Each of the upper and lower protective shields 133a and 133b is recessed corresponding to the stepped portion of the side wall 119 as the distance from the mounting portion 131 is decreased, and the opposing surface facing the side wall 119 is recessed, whereby the plate-like members are gradually thinned. It is. Each of the protective shields 133a and 133b includes a plurality of facing surface portions facing in the vertical direction, that is, a first facing surface portion 135a and 135b, a second facing surface portion 139a and 139b, a third facing surface portion 143a and 143b, a fourth facing surface portion 147a, 147b, and fifth opposing surface portions 151a and 151b. Further, the protective shields 133a and 133b are respectively a plurality of shield step portions facing the thickness direction, that is, the first shield step portions 137a and 137b, the second shield step portions 141a and 141b, and the third shield step portions 145a and 145b. , Fourth shield stepped portions 149a and 149b and fifth shield stepped portions 153a and 153b. The step portions of the protective shields 133a and 133b have first to fifth opposing surface portions and first to fifth shield step portions, respectively.

  The step portion group of the side wall 119 and the step portion group of the protective shields 133a and 133b are associated with each other in a predetermined relationship.

  The inner wall portion and the opposing surface portion, that is, the portions facing the up and down direction of the respective stepped portion groups of the side wall 119 and the protective shields 133a and 133b are in close contact with each other or arranged to face each other at a predetermined interval. Specifically, the first inner wall portions 155a and 155b and the first facing surface portions 135a and 135b are in close contact with each other. Further, for example, the second to fifth inner wall portions 159a, 159b, 163a, 163b, 167a, 167b, 171a, 171b are respectively the first to fifth opposing surface portions 139a, 139b, 143a, 143b, 147a, 147b, 151a. , 151b and parallel to each other at a constant interval.

  Next, the wall step portion and the shield step portion, that is, the portion facing the thickness direction of the side wall 119 of each step portion group of the side wall 119 and the protective shields 133a and 133b, the interval gradually increases as the distance from the mounting portion 131 increases. It arrange | positions so that it may become parallel. Specifically, in the low temperature state in which the protective shields 133a and 133b are contracted, each of the first to fifth wall step portions and the first to fifth shield step portions are all separated, for example, the second wall The interval between the stepped portion 161a and the second shield stepped portion 141a is larger than the interval between the first wall stepped portion 157a and the first shield stepped portion 137a. Further, for example, the interval between the third wall step portion 165a and the third shield step portion 145a is larger than the interval between the second wall step portion 161a and the second shield step portion 141a. Similarly, the third to fifth wall stepped portions 165a, 169a, and 173a and the third to fifth shield stepped portions 145a, 149a, and 153a are also arranged so that the distance gradually increases as the distance from the mounting portion 131 increases. The same applies to the lower wall step portions 157b, 161b, 165b, 169b, 173b and the shield step portions 137b, 141b, 145b, 149b, 153b.

  In this way, the stepped portion group of the side wall 119 and the stepped portion group of the protective shields 133a and 133b, in particular, the wall stepped portion and the shield stepped portion are arranged so that the distance gradually increases as the distance from the mounting portion 131 increases. As a result, when the protective shields 133a and 133b are heated and expanded, as shown in FIG. FIG. 5 shows a state in which the first wall stepped portion 157a and the first shield stepped portion 137a are in contact with the second wall stepped portion 161a and the second shield stepped portion 141a. When the temperature becomes high, the contact area between the side wall 119 and the protective shields 133a and 133b increases, so that the protective shields 133a and 133b are passed from the protective shields 133a and 133b to the flowing water pipe 37 through the attachment portion 113 and / or the side walls 119 more than at low temperatures. As a result, the temperature of the protective shields 133a and 133b decreases. Therefore, similarly to the first embodiment, it is possible to appropriately control the protective shield within a temperature range of about room temperature. Therefore, even when a product generated by a reaction associated with the plasma process is deposited on the protective shield, the deposited compound can be prevented from peeling off or becoming particles and scattering.

  Further, the protective shields 133a and 133b are disposed in the vicinity of the side wall 119 of the container. Therefore, a gap through which a product resulting from a reaction accompanying the plasma process flows into the inside of the side wall 119 of the container is reduced. Accordingly, it is possible to suppress the deterioration of the inner wall of the container where plasma is generated. Furthermore, according to this embodiment, when the product is deposited on the protective shield, it is only necessary to replace the protective shield while leaving the water pipe and the like intact. Accordingly, it is possible to reduce labor and cost for maintenance such as replacement of the protective shield.

  Although the side wall 119 and the protective shields 133a and 133b have five stepped portions, the number of the stepped portions and the recessed portions is as long as they are in the relation as described above. It is not limited to.

Embodiment 3 FIG.
The plasma processing apparatus of the present embodiment has a feature different from that of the first and second embodiments in the mechanism in which the protective shield changes the contact area with the side wall of the container. The mechanism is embodied by the shape of the container and the protective shield. FIG. 4 is a plan view showing a cross section from above of the plasma processing apparatus according to Embodiment 3 of the present invention.

  The plasma processing apparatus 211 includes a container 213 and a temperature adjustment unit 235.

  The container 13 is cylindrical in appearance and hollow inside. The container 13 is formed by a cylindrical side wall 219, a bottom 217, and an upper portion (not shown). At least the side wall 19 of the container 13 is made of a heat conductive material as in the first embodiment. In addition, a predetermined gas is introduced into the container 13 at a predetermined pressure by a device (not shown) similar to that of the first embodiment.

  The container 213 has a pair of parallel electrodes (not shown) arranged in the vertical direction facing each other and a susceptor 227 on which a substrate 229 as a processing object is placed, as in the first embodiment. The mounting portion 231 and protective shields 233a and 233b for protecting the inside of the side wall 213 are provided.

  The attachment portion 231 is a member that attaches the protective shields 233a and 233b to the inside of the side wall 213, and engages with a portion (not shown) provided inside the side wall 213, for example. The attachment portion 231 is made of a heat conductive material. As a result, the attachment portion 31 forms a contact portion where the wall portion 219 and the protective shields 233a and 233b are in thermal contact with each other in a straight strip shape in the vertical direction (the central axis direction of the container 213).

  As shown in FIG. 6, the protective shields 233 a and 233 b are curved so as to be further away from the side wall 219 as they are away from the attachment portion 231. The protective shields 233a and 233b are, for example, portions formed by cutting out a small cylinder having a radius smaller than the radius of the container 213 in parallel with the central axis. The protective shields 233a and 233b are arranged so that the central axis of the small cylinder and the central axis of the container 213 are parallel to each other and in a direction protruding outward from the container 213. When the temperature becomes high, the protective shields 233a and 233b expand. Therefore, as shown by the dotted lines in FIG. 6, the curvatures of the protective shields 233a and 233b increase, and the contact area between the protective shields 233a and 233b and the side wall 219 increases. FIG. 3 shows an example in which three protective shields 233a and 233b are provided in the container 213, but the number of protective shields 233a and 233b is not limited to this. The number of the protective shields 233a and 233b may be determined so that the protective shields 233a and 233b substantially cover the inner wall of the container 213 in consideration of the radius of curvature of the protective shields 233a and 233b, the amount of deformation with respect to temperature change, and the like.

  Similar to the first embodiment, the temperature adjustment unit 235 includes a water pipe 237 as a heat source that applies heat to the side wall 219 of the container 213 or removes heat from the side wall 219. The flowing water pipe 237 is provided in contact with the side wall 19 of the container 213 and is controlled by a temperature control unit (not shown).

  Next, the operation of the plasma processing apparatus 11 when performing dry etching processing with a high aspect ratio using the plasma processing apparatus 211 will be described. As in the first embodiment, an example in which the protective shields 233a and 233b are cooled and maintained at 75 ° C. to 80 ° C. will be described.

  In the flowing water pipe 237, water at about 60 ° C. flows. Prior to the etching, the protective shields 233a and 233b are maintained at about 60 ° C. by the flowing water pipe 237. When etching starts, the protective shields 233a and 233b are heated by the discharge. Therefore, the curvature of the protective shields 233a and 233b is increased as described above, and the contact area between the protective shields 233a and 233b and the side wall 219 is increased. As a result, more heat from the protective shields 233a and 233b is taken away by the flowing water pipe 237. As a result, the temperature of the protective shields 233a and 233b is lowered, and the protective shields 233a and 233b gradually bend and become larger. The curvature when 233a and 233b are viewed from above increases (a protective shield indicated by a dotted line in FIG. 6). The protection shields 233a and 233b eventually bend to such a degree that heat is transmitted to the side wall 219 only through the attachment portion 231 as shown by the solid line in FIG. Thereafter, when the temperature of the protective shields 233a and 233b rises again due to the discharge for etching, the curvature of the protective shields 233a and 233b increases, and the process described so far is repeated. As a result, the side wall 219 is kept at 60 to 65 ° C., and the protective shields 233a and 233b are kept at 75 to 80 ° C.

  As described above, according to the present embodiment, it is possible to appropriately control the protective shield within a temperature range of about room temperature. Therefore, even when a product generated by a reaction associated with the plasma process is deposited on the protective shield, the deposited product can be prevented from being peeled off or dispersed into particles.

  Further, the protective shields 233a and 233b are disposed relatively near the side wall 219 of the container. Therefore, a gap in which a product resulting from a reaction accompanying the plasma process flows into the inside of the side wall 219 of the container is reduced. Accordingly, it is possible to suppress the deterioration of the inner wall of the container where plasma is generated. Furthermore, according to the present embodiment, when the product is deposited on the protective shields 233a and 233b, it is only necessary to replace the protective shield while leaving the water pipe and the like intact. Accordingly, it is possible to reduce labor and cost for maintenance such as replacement of the protective shield.

The inventors conducted an experiment in which a substrate was dry-etched using a plasma processing apparatus. The plasma processing apparatus used for the experiment includes four sets of divided protective shields having the same shape as that of the third embodiment. The etching gas was NF ₃ and the internal pressure was adjusted to about 10 Pa. The plasma processing apparatus used for the experiment includes a pipe inside the side wall of the cylindrical container. The temperature of the side wall was controlled to 60 ° C. to 65 ° C. by circulating water whose temperature was adjusted in the pipe. From the high frequency power source, 500 W of electric power was supplied to the electrode, plasma was generated in the container, and the substrate was etched. As a result of such an experiment, the protective shield was kept at 75 ° C. to 80 ° C., there was no particle adhesion due to the product, and good results were obtained that it was possible to prevent deterioration of the inner wall of the vacuum chamber due to plasma damage.

  The present invention can be applied to an apparatus or the like that performs processing using plasma, and can be used particularly to a plasma processing apparatus that forms a thin film on a substrate.

The perspective view which cuts and shows a part of plasma processing apparatus which concerns on Embodiment 1 of this invention. FIG. 3 is a side sectional view of the plasma processing apparatus according to the first embodiment. The side sectional view which expands and shows the high-temperature protective shield of the plasma processing apparatus which concerns on Embodiment 1. FIG. The side sectional view which expands and shows the low-temperature protective shield of the plasma processing apparatus concerning Embodiment 2. The side sectional view which expands and shows the high-temperature protective shield of the plasma processing apparatus concerning Embodiment 2. FIG. 6 is an upper cross-sectional view of a plasma processing apparatus according to a third embodiment.

Explanation of symbols

  11, 211 Plasma processing apparatus, 13/213 container, 19/119/219 side wall, 21/23 electrode, 25 high frequency power supply, 29/229 substrate, 31 mounting part, 33a / 33b / 133a / 133b / 233a / 233b Protective shield 37 ・ 237 Flowing waterway

Claims (5)

A plasma processing apparatus for processing an object in a container using plasma generated by discharge between a pair of opposing electrodes,
A container having a thermally conductive wall;
A heat source provided on the outside of the wall, for applying heat to the wall, and for taking heat away from the wall;
A protective shield made of a thermally conductive material, the contact area of which changes with the wall due to deformation due to temperature,
An attachment portion for attaching the protective shield to the inside of the wall portion so as to allow heat conduction;
A plasma processing apparatus comprising: The attachment portion is attached so as to form a contact portion in which the wall portion and the protective shield are in thermal contact with each other in a straight band shape,
The heat source takes heat from the wall,
The container includes a rectangular parallelepiped hollow,
The protective shield is a bimetal obtained by joining a metal plate on the wall side made of a metal having a low coefficient of thermal expansion and a metal plate on the container center side made of a metal having a high coefficient of thermal expansion. The plasma processing apparatus according to claim 1, wherein the metal plate is curved so as to be separated from the wall portion, and the curvature decreases as the temperature increases. The attachment portion is attached so as to form a contact portion in which the wall portion and the protective shield are in thermal contact with each other in a straight band shape,
The heat source is for applying heat to the wall,
The container includes a rectangular parallelepiped hollow,
The protective shield is a bimetal obtained by joining a metal plate on the wall side made of a metal having a high coefficient of thermal expansion and a metal plate on the container center side made of a metal having a low coefficient of thermal expansion. The plasma processing apparatus according to claim 1, wherein the metal plate is curved so as to be separated from the wall portion, and the curvature becomes smaller as the temperature becomes lower. The heat source takes heat from the wall,
The attachment portion is attached so as to form a contact portion in which the wall portion and the protective shield are in thermal contact with each other in a straight band shape,
The container includes a rectangular parallelepiped hollow,
The wall portion has a stepped portion that protrudes toward the center stepwise and becomes thicker as the distance from the contact portion increases.
The protective shield is disposed in close contact with or opposite to the wall portion, and a surface that is in close contact with or opposite to the wall portion is recessed corresponding to the step of the wall portion as the distance from the contact portion increases, thereby Is a plate-like member having a stepped portion that becomes thinner,
Of the step portions of the wall portion and the protective shield, the distance between the wall step portion and the shield step portion facing each other in the thickness direction of the wall portion increases as the distance from the contact portion increases. The plasma processing apparatus according to claim 1. The heat source takes heat from the wall,
The container is cylindrical,
The attachment portion is attached so that the wall portion and the protective shield form a contact portion that is in thermal contact with a linear strip in the central axis direction of the container,
The plasma processing apparatus according to claim 1, wherein the protective shield is curved so as to be further away from the wall portion as it is away from the contact portion.

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