JP4777790B2 - Structure for plasma processing chamber, plasma processing chamber, and plasma processing apparatus - Google Patents

Description

  The present invention relates to a plasma processing chamber structure, a plasma processing chamber, and a plasma processing apparatus, and more particularly to a plasma processing chamber structure that is exposed to plasma.

  Conventionally, there has been known a plasma processing chamber including a cylindrical container and an electrode disposed in the container and connected to a high-frequency power source. In the plasma processing chamber, a processing gas is introduced into the container, and the electrode applies high-frequency power to the space in the container. Further, when a semiconductor wafer as a substrate is accommodated in a container, the introduced processing gas is converted into plasma by high frequency power to generate ions and the like, and the semiconductor wafer is subjected to plasma processing, for example, etching processing by the ions and the like. .

In the above-described plasma processing chamber, when a reactive gas, for example, a mixed gas of C ₄ F ₈ gas and argon (Ar) gas is used as a processing gas, depot active species (radicals) generated from the reactive gas are used. ) Adheres as a polymer to the inner side wall of the container (hereinafter simply referred to as “side wall”). If the amount of polymer attached is too large, when the plasma treatment is performed on the semiconductor wafer, the polymer may peel from the side wall and adhere to the surface of the semiconductor wafer as a deposit, so it is necessary to remove the polymer attached to the side wall. There is.

  The polymer adhering to the side wall is preferably removed by colliding the cation generated when the processing gas becomes plasma with the side wall, and the number of times the cation collides with the side wall depends on the potential of the side wall. The Specifically, when the potential of the side wall is low and the potential difference between the side wall and the plasma formed from the processing gas in the processing space is large, the number of collisions of the cation with the side wall increases and the attached polymer is removed. .

However, in a process in which no active species such as O ₂ gas is generated as a processing gas (depotless process), if the potential difference between the side wall and the plasma is too large, the number of times the cation collides with the side wall increases. The side walls as well as the attached polymer may be scraped off. Therefore, it is necessary to appropriately adjust the number of collisions of cations on the side wall by controlling the potential of the side wall.

  As a technique for controlling the potential of the side wall of the plasma processing chamber, a method of adjusting the anode / cathode ratio of the container in the plasma processing chamber is known. The anode / cathode ratio of the container changes depending on the distance (gap) between the upper electrode and the lower electrode disposed in the container and the position of the baffle plate disposed in the container. Therefore, in order to adjust the anode / cathode ratio, it is necessary to change the position of the gap or the baffle plate, and as a result, the plasma density distribution in the container cannot be set to a preferable distribution for the etching process. There is.

  Therefore, as a technique for controlling the potential of the side wall of the plasma processing chamber without adjusting the anode / cathode ratio of the vessel, a potential control circuit including an impedance adjusting means such as a variable capacitor or coil is disposed between the side wall and the ground potential. A technique for controlling the potential of the sidewall by adjusting the impedance of the potential control circuit is known (see, for example, Patent Documents 1 and 2).

In addition, the polymer may adhere not only to the side wall but also to the electrode surface, or the electrode may be scraped by cations. Therefore, a potential control circuit having an impedance adjusting means is arranged between the electrode and the ground potential, and the potential of the electrode Is also preferably controlled.
JP-A-10-275694 Japanese Patent Laid-Open No. 11-176821

  However, the above-described technology for controlling the potential requires a potential control circuit including an impedance adjusting unit, which causes a problem that the structure of the plasma processing chamber is complicated. This also increases the manufacturing cost of the plasma processing chamber.

  In the above-described technique for controlling the potential, the side wall potential can be controlled only uniformly. However, since the amount of polymer adhering is not uniform in the plasma processing chamber, the polymer cannot be removed properly.

  SUMMARY OF THE INVENTION A first object of the present invention is to provide a plasma processing chamber structure, a plasma processing chamber, and a plasma processing apparatus capable of controlling the potential and simplifying the structure of the plasma processing chamber. is there.

  A second object of the present invention is to provide a plasma processing chamber part, a plasma processing chamber, and a plasma processing apparatus that can control the potential and appropriately remove the deposits.

In order to achieve the first object, a plasma processing chamber structure according to claim 1 is provided with a container having a processing space for storing a substrate, and a substrate disposed in the container and placed in the container. A plasma processing chamber having a mounting table that is electrically conductively grounded in a plasma processing chamber structure disposed in the plasma processing chamber connected to at least one high-frequency power source. and member, interposed between the conductive cooling member and the processing space has a surface exposed to the processing space, and a plate-shaped electrode electrically floating, the conductive cooling member and the plate At least one insulating member made of a dielectric material and a support having a buffer chamber inside, the plate-like electrode, the at least one insulating member, and the conductive member. A cooling member, and The support constitutes a shower head that supplies gas to the processing space, and the shower head linearly penetrates the conductive cooling member, the at least one insulating member, and the plate electrode. Gas holes, and the plurality of gas holes communicate with a buffer chamber of the support .

The plasma processing chamber structure according to claim 2 is the plasma processing chamber structure according to claim 1, wherein the plate electrode is connected to a DC power source.

The plasma processing chamber structure according to claim 3 is the plasma processing chamber structure according to claim 1 or 2, wherein the electric capacity of the shower head that changes in accordance with the physical properties of the at least one insulating member. It is 1000 pF or more.

  The plasma processing chamber structure according to claim 4 is the plasma processing chamber structure according to claim 3, wherein the electric capacity is 50000 pF or more.

  The plasma processing chamber structure according to claim 5 is the plasma processing chamber structure according to any one of claims 1 to 4, wherein the at least one insulating member is made of metal oxide and metal nitride. It consists of at least 1 material selected from the group which consists of.

  The plasma processing chamber structure according to claim 6 is the plasma processing chamber structure according to any one of claims 1 to 4, wherein the at least one insulating member is made of an organosilicon compound. And

  The structure for a plasma processing chamber according to claim 7 is the structure for a plasma processing chamber according to any one of claims 1 to 4, wherein the at least one insulating member is made of an organic material. .

  The plasma processing chamber structure according to claim 8 is the plasma processing chamber structure according to any one of claims 1 to 7, wherein a thickness of the at least one insulating member varies depending on a part. It is characterized by doing.

  The plasma processing chamber structure according to claim 9 is the plasma processing chamber structure according to claim 8, wherein the thickness of the at least one insulating member decreases toward the central portion of the container. And

  The plasma processing chamber structure according to claim 10 is the plasma processing chamber structure according to any one of claims 1 to 7, wherein the at least one insulating member is formed of a different material depending on a portion. It is characterized by being.

The plasma processing chamber structure according to claim 11 is the plasma processing chamber structure according to claim 10, wherein a relative dielectric constant of a material disposed in the at least one insulating member is directed toward a central portion of the container. It is characterized by becoming larger.

In order to achieve the first object, a structure for a plasma processing chamber according to claim 12 is provided with a container having a processing space for storing a substrate, and a substrate disposed in the container and placed in the container. A plasma processing chamber having a mounting table that is electrically conductively grounded in a plasma processing chamber structure disposed in the plasma processing chamber connected to at least one high-frequency power source. and member, interposed between the conductive cooling member and the processing space has a surface exposed to the processing space, and a plate-shaped electrode electrically floating, the conductive cooling member and the plate A vacuum layer interposed between the electrode-like electrodes and a support having a buffer chamber therein, and the plate-like electrode, the vacuum layer, the conductive cooling member, and the support are gasses in the processing space. Supplying shower head The shower head includes a plurality of gas holes that linearly penetrate the conductive cooling member, the vacuum layer, and the plate electrode, and the plurality of gas holes communicate with a buffer chamber of the support. and wherein the Rukoto through.

In order to achieve the first object, a plasma processing chamber according to claim 13 includes a container having a processing space for storing a substrate, and a mounting table disposed in the container and mounting the stored substrate. a plasma processing chamber having bets, in the mounting table plasma processing chamber connected to at least one high frequency power source, a cooling member of a conductive electrically grounded, the cooling member and the processing space of the conductive A plate-like electrode having a surface exposed to the processing space and interposed between them, and an electrically floating plate , and a dielectric disposed between the conductive cooling member and the plate-like electrode. At least one insulating member and a support having a buffer chamber therein, the plate electrode, the at least one insulating member, the conductive cooling member, and the support in the processing space. Gas supply The shower head comprises a plurality of gas holes that linearly penetrate the conductive cooling member, the at least one insulating member, and the plate electrode, and the plurality of gas holes are supported by the support head. A plasma processing chamber structure communicating with a body buffer chamber is provided.

In order to achieve the first object, a plasma processing apparatus according to claim 14 includes a container having a processing space for storing a substrate, and a mounting table disposed in the container and mounting the stored substrate. A plasma processing chamber having a plasma processing chamber connected to at least one high frequency power source, wherein the plasma processing chamber includes an electrically conductive cooling member that is electrically grounded; has a surface exposed to the processing space interposed between the conductive cooling member and the processing space, and a plate-shaped electrode electrically floating, the cooling member and the plate-like electrodes of the conductive is disposed between the at least one insulating member made of a dielectric, possess a support having a buffer chamber therein, said plate-shaped electrodes, the at least one insulating member, the cooling of the conductive Part And the support constitutes a shower head for supplying gas to the processing space, and the shower head linearly penetrates the conductive cooling member, the at least one insulating member, and the plate electrode. A plurality of gas holes are provided, and the plurality of gas holes include a structure for a plasma processing chamber that communicates with a buffer chamber of the support .

According to the plasma processing chamber structure according to claim 1, the plasma processing chamber according to claim 13, and the plasma processing apparatus according to claim 14, the conductive cooling for electrically grounding the plasma processing chamber structure. between member and has a surface exposed to an intervening the processing space between the conductive cooling member and the processing space, and electrically and plate electrode floating, conductive cooling member and the plate-shaped electrode And at least one insulating member made of a dielectric and a support having a buffer chamber therein . A structure including a conductive cooling member and a plate electrode, which are two conductive members, and a dielectric interposed between the conductive cooling member and the plate electrode has a predetermined electric capacity. In this structure, the potential of the conductive cooling member is fixed to the ground potential. In addition, when high-frequency power is applied to the space of the container to generate plasma, a sheath that is a region with very few electrons is generated in the vicinity of the structure. In addition, the structure has an impedance ((capacitance) reactance) having a magnitude commensurate with the size of its electric capacity. When an alternating current corresponding to high-frequency power passes through the sheath and the structure, a voltage drop from the space to the ground potential occurs. The voltage drop is shared by the sheath and the structure. The voltage drop sharing ratio of the sheath and the structure changes according to the magnitude of the (capacitance) reactance of the structure. Further, a potential corresponding to the voltage drop shared by the structure is generated on the surface of the plate electrode exposed to the processing space. Therefore, the potential can be controlled without using the potential control circuit by controlling the electric capacity of the structure. As a result, the potential can be controlled and the structure of the plasma processing chamber can be simplified.

According to the plasma processing chamber structure of the second aspect, the plate electrode is connected to the DC power source. When a DC power source is connected to a conductive member and DC power is supplied to the conductive member, it is not necessary to use a matching unit necessary for supplying high-frequency power, and only ions are drawn into the structure. since being able to maintain a state in which electrons are not drawn, it is not free electrons is reduced in the space in the container. Therefore, the structure of the plasma processing chamber can be further simplified, and the efficiency of the plasma processing can be improved.

According to the plasma processing chamber structure of the third aspect, since the electric capacity of the shower head that changes according to the physical property of at least one insulating member is 1000 pF or more, the (capacitance) reactance of the structure is reduced. The voltage drop amount shared by the structure can be reduced. Thereby, the electric potential which generate | occur | produces in the surface exposed to the space of a plate-shaped electrode can be made lower, and the polymer adhering to a structure can be removed efficiently.

  According to the plasma processing chamber structure of the fourth aspect, since the electric capacity is 50000 pF or more, the (capacitance) reactance of the structure can be further reduced.

  According to the structure for a plasma processing chamber according to claim 5, since the at least one insulating member is made of at least one material selected from the group consisting of metal oxide and metal nitride, the first conductive member is used. And the heat transfer efficiency between 2nd electroconductive members can be improved, and, thereby, temperature control of a structure can be performed easily.

  According to the plasma processing chamber structure of the sixth aspect, since at least one insulating member is made of an organic silicon compound, both high heat transfer properties and high insulating properties can be achieved.

  According to the structure for a plasma processing chamber of the seventh aspect, since at least one insulating member is made of an organic material, high insulation can be secured and the electrical capacity of the structure can be easily increased.

  According to the structure for a plasma processing chamber according to claim 8, since the thickness of at least one insulating member varies depending on the site, the potential generated at each site according to the amount of polymer adhering to each site. The amount of polymer deposited at each site can be controlled to be constant.

  According to the plasma processing chamber structure of the ninth aspect, the thickness of at least one insulating member decreases toward the center of the container. When the thickness of the insulating member is reduced, the electric capacity is increased (capacitance) and the reactance is decreased, so that the voltage drop amount shared by the structure is decreased. In addition, the amount of polymer generated in the plasma treatment may increase toward the center of the container. In this case, an appropriate potential can be easily generated on the surface exposed to the space of the second conductive member in accordance with the amount of polymer generated.

  According to the structure for a plasma processing chamber according to claim 10, since at least one insulating member is formed of a different material depending on the part, it is generated at each part according to the amount of polymer adhering to each part. The potential can be changed, which allows the amount of polymer deposited at each site to be controlled constant.

According to the plasma processing chamber structure of the eleventh aspect, the relative dielectric constant of the material disposed in the at least one insulating member increases toward the central portion of the container. When the relative dielectric constant of the insulating member increases, the electric capacity is increased (capacitive) reactance decreases, the amount of voltage drop structures share decreases. Further, the amount of polymer in a plasma processing may become more towards the center of the container. In this case, an appropriate potential can be easily generated on the surface exposed to the space of the second conductive member in accordance with the amount of polymer generated.

According to claim 12 the plasma processing chamber for Structure according, organic conductive cooling member electrically grounded, the surface exposed to the intervening the processing space between the conductive cooling member and the processing space And an electrically floating plate electrode , a conductive cooling member and a vacuum layer interposed between the plate electrode , and a support having a buffer chamber therein . A structure having two conductive members , a conductive cooling member and a plate-like electrode, and a vacuum layer interposed between the conductive cooling member and the plate-like electrode has a predetermined electric capacity. In this structure, the potential of the conductive cooling member is fixed to the ground potential. In addition, when high-frequency power is applied to the space of the container to generate plasma, a sheath that is a region with very few electrons is generated in the vicinity of the structure. In addition, the structure has an impedance ((capacitance) reactance) having a magnitude commensurate with the size of its electric capacity. When an alternating current corresponding to high-frequency power passes through the sheath and the structure, a voltage drop from the space to the ground potential occurs. The voltage drop is shared by the sheath and the structure. The voltage drop sharing ratio of the sheath and the structure changes according to the magnitude of the (capacitance) reactance of the structure. Further, a potential corresponding to the voltage drop shared by the structure is generated on the surface of the plate electrode exposed to the processing space. Therefore, the potential can be controlled without using the potential control circuit by controlling the electric capacity of the structure. As a result, the potential can be controlled and the structure of the plasma processing chamber can be simplified.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, a plasma processing chamber including the plasma processing chamber structure according to the first embodiment of the present invention will be described.

Figure 1 is a sectional view showing a schematic configuration of a plasma processing chamber comprises a plasma processing chamber for structures according to the shape condition of the present embodiment. This plasma processing chamber is configured to perform RIE (Reactive Ion Etching) processing or ashing processing on a semiconductor wafer W as a substrate.

In FIG. 1, a plasma processing chamber 10 has a cylindrical container 11, and the container 11 has a processing space S inside. Further, in the container 11, for example, a cylindrical susceptor 12 is disposed as a mounting table on which a semiconductor wafer W having a diameter of 300 mm (hereinafter simply referred to as “wafer W”) is mounted. The inner wall surface of the container 11 is covered with a container side wall member 45. The container side wall member 45 is made of aluminum, and the surface facing the processing space S is coated with yttria (Y ₂ O ₃ ). The container 11 is electrically grounded, and the susceptor 12 is installed on the bottom of the container 11 via an insulating member 29. The side surface of the susceptor 12 is covered with a susceptor side surface covering member 60.

  In the plasma processing chamber 10, an exhaust path 13 that functions as a flow path for discharging gas molecules above the susceptor 12 to the outside of the container 11 is formed by the inner wall of the container 11 and the side surface of the susceptor 12. An annular baffle plate 14 is disposed in the middle of the exhaust passage 13 to prevent plasma leakage. In addition, the space downstream of the baffle plate 14 in the exhaust passage 13 wraps around the susceptor 12, and enters an automatic pressure control valve (hereinafter referred to as “APC valve”) 15 that is a variable butterfly valve. Communicate. The APC valve 15 is connected to a turbo molecular pump (hereinafter referred to as “TMP”) 17 which is an exhaust pump for evacuation through an isolator 16, and the TMP 17 is connected to the valve V 1. Are connected to a dry pump (hereinafter referred to as “DP”) 18 which is an exhaust pump. The exhaust flow path constituted by the APC valve 15, isolator 16, TMP 17, valves V 1 and DP 18 controls the pressure in the container 11 by the APC valve 15, and further until the inside of the container 11 is almost vacuumed by the TMP 17 and DP 18. Reduce pressure.

  A pipe 19 is connected between the isolator 16 and the APC valve 15 to the DP 18 via the valve V2. The pipe 19 and the valve V2 bypass the TMP 17 and roughen the inside of the container 11 with the DP 18.

A high frequency power supply 20 is connected to the susceptor 12 via a power supply rod 21 and a matcher 22, and the high frequency power supply 20 supplies a high frequency power of a relatively high frequency, for example, 40 MHz, to the susceptor 12. Thereby, the susceptor 12 functions as a lower electrode. The matching unit 22 reduces the reflection of the high frequency power from the susceptor 12 to maximize the supply efficiency of the high frequency power to the susceptor 12. The susceptor 12 applies high frequency power of 40 MHz supplied from the high frequency power supply 20 to the processing space S. At this time, a potential (potential) due to the applied high frequency power is generated in the processing space S.

  Further, another high-frequency power source 46 is connected to the susceptor 12 via a feeding rod 35 and a matching unit 36. The other high-frequency power source 46 applies a relatively low frequency, for example, a high-frequency power of 2 MHz to the susceptor. 12 is supplied. The matching unit 36 has the same function as the matching unit 22.

  A high frequency (2 MHz) potential is generated on the susceptor 12, particularly on the surface thereof, due to the supplied 2 MHz high frequency power. Further, a potential is generated on the surface due to the supplied high frequency power of 40 MHz.

  Accordingly, since potentials are generated in the processing space S and the susceptor 12, among the cations generated in the processing space S, the number of cations corresponding to the difference between the potential of the processing space S and the potential of the susceptor 12 is increased. Collide with 12 surfaces. The cations that collide with the surface of the susceptor 12 remove the polymer attached to the surface of the susceptor 12 by impact force or the like.

  A disc-shaped ESC electrode plate 23 made of a conductive film is disposed above the susceptor 12. An ESC DC power source 24 is electrically connected to the ESC electrode plate 23. The wafer W is attracted and held on the upper surface of the susceptor 12 by a Coulomb force or a Johnson-Rahbek force generated by a DC voltage applied to the ESC electrode plate 23 from the ESC DC power source 24. In addition, an annular focus ring 25 is disposed above the susceptor 12 so as to surround the wafer W attracted and held on the upper surface of the susceptor 12. The focus ring 25 is exposed to the processing space S and converges the plasma toward the surface of the wafer W in the processing space S, thereby improving the efficiency of RIE processing and ashing processing.

  Further, for example, an annular refrigerant chamber 26 extending in the circumferential direction is provided inside the susceptor 12. A refrigerant having a predetermined temperature, for example, cooling water or a Galden (registered trademark) liquid, is circulated and supplied to the refrigerant chamber 26 via a refrigerant pipe 27 from a chiller unit (not shown), and the susceptor 12 is supplied depending on the temperature of the refrigerant. The processing temperature of the wafer W attracted and held on the upper surface is controlled.

Further, a plurality of heat transfer gas supply holes 28 are opened in a portion of the upper surface of the susceptor 12 where the wafer W is adsorbed and held (hereinafter referred to as “adsorption surface”). The plurality of heat transfer gas supply holes 28 are connected to a heat transfer gas supply unit 32 via a heat transfer gas supply line 30 disposed inside the susceptor 12, and the heat transfer gas supply unit 32 serves as a heat transfer gas. Helium gas is supplied to the gap between the adsorption surface and the back surface of the wafer W through the heat transfer gas supply hole 28.

  A plurality of pusher pins 33 as lift pins that can protrude from the upper surface of the susceptor 12 are arranged on the suction surface of the susceptor 12. These pusher pins 33 are connected via a motor (not shown) and a ball screw (not shown), and freely protrude from the suction surface due to the rotational motion of the motor converted into a linear motion by the ball screw. To do. When the wafer W is sucked and held on the suction surface in order to perform the RIE process or the ashing process on the wafer W, the pusher pin 33 is accommodated in the susceptor 12 and the wafer W subjected to the RIE process or the ashing process is unloaded from the container 11. Sometimes, the pusher pin 33 protrudes from the upper surface of the susceptor 12 to lift the wafer W away from the susceptor 12 and lift it upward.

  A gas introduction shower head 34 is arranged on the ceiling of the container 11 so as to face the susceptor 12. A buffer chamber 40 is provided in the gas introduction shower head 34, and a processing gas introduction pipe 41 from a processing gas supply unit (not shown) is connected to the buffer chamber 40. A pipe insulator 42 is disposed in the middle of the processing gas introduction pipe 41. Further, the gas introduction shower head 34 has a plurality of gas holes 37 that allow the buffer chamber 40 to conduct to the processing space S. The gas introduction shower head 34 supplies the processing gas supplied from the processing gas introduction pipe 41 to the buffer chamber 40 into the container 11 through the gas hole 37.

  Further, on the side wall of the container 11, a wafer W loading / unloading port 43 is provided at a position corresponding to the height of the wafer W lifted upward from the susceptor 12 by the pusher pin 33, and the loading / unloading port 43 includes the loading / unloading port 43. A gate valve 44 for opening and closing 43 is attached.

In the container 11 of the plasma processing chamber 10, as described above, the susceptor 12 applies high-frequency power to the processing space S that is a space between the susceptor 12 and a later-described ceiling electrode plate 38 included in the gas introduction shower head 34. As a result, the processing gas supplied from the gas introduction shower head 34 in the processing space S is converted into high-density plasma to generate cations and radicals, and the wafer W is subjected to RIE processing and ashing processing by the cations and radicals. .

  Specifically, in the plasma processing chamber 10, when the RIE process or the ashing process is performed on the wafer W, the gate valve 44 is first opened, and the wafer W to be processed is loaded into the container 11. Is applied to the ESC electrode plate 23, and the loaded wafer W is sucked and held on the suction surface of the susceptor 12. Further, the processing gas is supplied from the gas introduction shower head 34 into the container 11 at a predetermined flow rate and flow ratio, and the pressure in the container 11 is controlled to a predetermined value by the APC valve 15 or the like. Further, high frequency power is applied to the processing space S by the susceptor 12, and DC power is applied to the processing space S by the ceiling electrode plate 38. As a result, the processing gas introduced from the gas introduction shower head 34 is converted into plasma in the processing space S, and the plasma is converged on the surface of the wafer W by the focus ring 25 to physically or chemically etch the surface of the wafer W. .

  The operation of each component of the plasma processing chamber 10 described above is controlled by a CPU of a control unit (not shown) provided in the plasma processing chamber 10 according to a program corresponding to RIE processing and ashing processing.

By the way, in the same manner as the removal of the polymer adhering to the side wall described above, the polymer adhering to the ceiling electrode plate 38 is appropriately adjusted by appropriately adjusting the number of cations colliding with the ceiling electrode plate 38 in the container 11. In order to remove, it is necessary to control the potential of the ceiling electrode plate 38.

Generally, a structure comprising a conductive member that is electrically grounded, a conductive member that faces a space to which high-frequency power is applied, and that is electrically floating, and a dielectric sandwiched between these two conductive members Has a predetermined electrical capacity. When plasma is generated in a space facing an electrically floating conductive member, a sheath is generated in the vicinity of the structure. In addition, the structure has an impedance ((capacitance) reactance) having a magnitude commensurate with the size of its electric capacity. When an alternating current corresponding to high-frequency power passes through the sheath and the structure, a voltage drop from the space to the ground potential occurs. The voltage drop is shared by the sheath and the structure. The voltage drop sharing ratio of the sheath and the structure changes according to the magnitude of the (capacitance) reactance of the structure. In addition, a potential corresponding to the voltage drop shared by the structure is generated on the surface exposed to the space of the electrically floating conductive member.

  The gas introduction shower head 34 as the plasma processing chamber structure according to the present embodiment has a configuration described below in order to control the potential of the ceiling electrode plate 38 using the above-described potential generation principle. .

  FIG. 2 is an enlarged cross-sectional view of the gas introduction shower head in FIG.

  In FIG. 2, the gas introduction shower head 34 has a disk-like ceiling electrode plate (CEL) 38 (second conductive property) having a surface exposed to the processing space S (hereinafter referred to as “processing space S side surface”). Member), an electrode support (CEL body) 39 (first conductive member) that supports the ceiling electrode plate 38 in a detachable manner and has the above-described buffer chamber 40, and the ceiling electrode plate 38 and the electrode support 39, a cooling plate 47 that cools the ceiling electrode plate 38 to a predetermined temperature during plasma processing, and an insulating film 48 (insulation) interposed between the cooling plate 47 and the ceiling electrode plate 38. Sex member).

  The electrode support 39 is electrically connected to the container 11, the cooling plate 47 is electrically connected to the container 11 via the electrode support 39, and the periphery of the ceiling electrode plate 38 is covered by the annular insulating member 50. Yes. Therefore, the electrode support 39 and the cooling plate 47 are grounded via the container 11, while the ceiling electrode plate 38 is electrically floating.

  In the gas introduction shower head 34, the electrode support 39 is made of a conductive member, for example, anodized aluminum, the cooling plate 47 is also made of a conductive material, for example, aluminum, and the ceiling electrode plate 38 is also made of a conductive material, for example, Made of low resistance silicon. The insulating film 48 interposed between the cooling plate 47 and the ceiling electrode plate 38 is made of a dielectric (insulating material), for example, polyimide, and the alumite film 51 (insulating) is formed on the surface of the cooling plate 47 on the insulating film 48 side. Sex member) is formed. That is, the gas introduction shower head 34 has a sandwich structure composed of a conductive member (electrode support 39, cooling plate 47), an insulating member (insulating film 48, anodized film 51), and a conductive member (ceiling electrode plate 38). Have A structure having a sandwich structure composed of a conductive member, an insulating member, and a conductive member has an electric capacity corresponding to the dielectric constant, thickness, and surface area of the insulating member, as will be described later. Therefore, the gas introduction shower head 34 has a predetermined electric capacity corresponding to the dielectric constant, thickness, and surface area of the insulating film 48 and the alumite film 51.

  In the gas introduction shower head 34, the voltages of the electrode support 39 and the cooling plate 47 are fixed to the ground potential. Further, when high-frequency power is applied to the processing space S from the high-frequency power source 20 or another high-frequency power source 46 to generate plasma, a sheath that is a region with very few electrons is generated in the vicinity of the gas introduction shower head 34. Further, the gas introduction shower head 34 has an impedance ((capacity) reactance) having a magnitude corresponding to the magnitude of its electric capacity. When an alternating current corresponding to the high frequency power passes through the sheath and the gas introduction shower head 34, a voltage drop from the processing space S to the ground potential (the electrode support 39 and the cooling plate 47) occurs. Each of the gas introduction shower heads 34 is shared. The voltage drop sharing ratio of the sheath and the gas introduction shower head 34 changes in accordance with the (capacity) reactance of the gas introduction shower head 34. In addition, a potential corresponding to the voltage drop shared by the gas introduction shower head 34 is generated on the ceiling electrode plate 38. Therefore, the potential of the ceiling electrode plate 38 can be controlled by controlling the magnitude of the electric capacity of the gas introduction shower head 34.

Further, the relationship between the electrical capacity of the structure, the thickness of the insulating member, and the relative dielectric constant is expressed by the following formula (1).
C = ε × S / d (1)
Here, C is an electric capacity, ε is a relative dielectric constant, S is a surface area of the insulating member, and d is a thickness of the insulating member.

  Therefore, the electric capacity of the gas introduction shower head 34 can be controlled by changing the relative dielectric constant and thickness of the insulating film 48, the thickness of the anodized film 51, and the like.

The relationship between (capacitance) reactance and electrical capacitance is expressed by the following equation (2).
Xc = 1 / (2π × f × C) (2)
Here, Xc is the (capacitance) reactance, and f is the frequency of the high-frequency potential.

  According to the above formula (2), as the electric capacity increases, the (capacitance) reactance decreases (see Table 1 below). Here, in order to remove a large amount of the polymer adhering to the ceiling electrode plate 38, the voltage drop shared by the gas introduction shower head 34 is reduced to lower the potential of the ceiling electrode plate 38, and the ceiling electrode plate 38 and the processing are performed. Although it is necessary to increase the potential difference in the space S, in order to reduce the voltage drop shared by the gas introduction shower head 34, it is necessary to reduce the (capacitance) reactance. For this purpose, the electric capacity is set to be large. It is good.

  Here, in order to set the target value of the electric capacity of the gas introduction shower head 34, the present inventors set the electric capacity of the gas introduction shower head 34 to 150 pF using the plasma processing chamber of FIG. When the amount of the polymer adhering to the ceiling electrode plate 38 after the plasma treatment for a predetermined time was examined, it was confirmed that a lot of polymer was adhered to the ceiling electrode plate 38. On the other hand, when the electric capacity of the gas introduction shower head 34 was set to 1000 pF, it was confirmed that almost no polymer adhered to the ceiling electrode plate 38, and the electric capacity of the gas introduction shower head 34 was set to 50,000 pF. However, it was confirmed that the polymer was completely removed from the ceiling electrode plate 38. From the above, if the electric capacity of the gas introduction shower head 34 is at least 1000 pF or more, the (capacity) reactance of the gas introduction shower head 34 can be made sufficiently small, and the gas introduction shower head 34 is shared accordingly. The amount of voltage drop can be made sufficiently small. As a result, the potential of the ceiling electrode plate 38 can be made sufficiently low, the potential difference between the ceiling electrode plate 38 and the processing space S can be made sufficiently large, and the polymer adhering to the gas introduction shower head 34 can be efficiently removed. I understood. From the above, the electric capacity of the gas introduction shower head 34 is at least 1000 pF or more, preferably 50000 pF or more.

Further, in order to increase the electric capacity of the gas introduction shower head 34, it is preferable to reduce the thickness of the insulating film 48 from the above equation (1). When the thickness of the insulating film 48 is reduced, the thickness of the ceiling electrode plate 38, the cooling plate 47, etc. can be increased. As a result, these heat capacities increase, which is preferable from the viewpoint of temperature controllability. In order to increase the electric capacity of the gas introduction shower head 34, a dielectric having a large relative dielectric constant may be set as the insulating film 48 from the above equation (1). The materials shown in the following Table 2 correspond to the dielectric constituting the insulating film 48. In the plasma processing chamber according to the present embodiment, the insulating film 48 is made of polyimide from the viewpoint of ease of processing.

  When the insulating film 48 is made of polyimide, the thickness of the insulating film 48 (polyimide film) and the single electric capacity (C2) of the insulating film 48, and the combined thickness of the insulating film 48 and the insulating film 48 and the alumite film 51 are combined. Table 3 below shows the relationship between the static capacity (C1 + C2), that is, the electrical capacity of the gas introduction shower head 34.

  Here, as described above, the electric capacity of the gas introduction shower head 34 is preferably at least 1000 pF, and the thickness of the insulating film 48 is preferably reduced from the viewpoint of the temperature controllability of the ceiling electrode plate 38. Therefore, in the plasma processing chamber according to the present embodiment, the thickness of the insulating film 48 is set to 25 μm.

  Note that the appropriate value of the electric capacity of the gas introduction shower head 34 varies depending on the type of plasma processing and the type of processing gas. Specifically, in plasma processing (depot process) with a large amount of polymer adhesion, the potential of the ceiling electrode plate 38 is reduced by reducing the (capacity) reactance and reducing the voltage drop amount shared by the gas introduction shower head 34. Since it is necessary to reduce the potential difference between the ceiling electrode plate 38 and the processing space S, it is preferable that the electric capacity of the gas introduction shower head 34 is large. In the depotless process, the potential of the ceiling electrode plate 38 is increased by increasing the (capacity) reactance and increasing the voltage drop amount shared by the gas introduction shower head 34, so that the ceiling electrode plate 38 and the processing space S Since it is necessary to reduce the potential difference, the electric capacity of the gas introduction shower head 34 is preferably small. The material and thickness of the insulating film 48 are not limited to those described above (polyimide, 25 μm), and are set according to the desired electric capacity of the gas introduction shower head 34.

In addition, the material of the insulating film 48 may be selected based on not only the ease of processing but also other viewpoints. For example, in order to improve the heat transfer efficiency between the ceiling electrode plate 38 and the cooling plate 47 (or the electrode support 39), an insulating material having a high heat transfer efficiency may be selected. Yttria, alumina (Al ₂ O ₃ ), A metal oxide such as silica (SiO ₂ ), or a metal nitride such as aluminum nitride (AlN) is preferably selected. In order to achieve both high heat transfer and high insulation between the ceiling electrode plate 38 and the cooling plate 47 (or electrode support 39), SiC, a silicon (Si) compound, and a methyl group polymer compound ( It is preferable to select an organosilicon compound) (silicon oil). Furthermore, in order to achieve both a large electric capacity and high insulation, it is preferable to select an organic functional material (organic substance) such as polyimide, PTFE, or fluororubber described above. If a vacuum layer is provided between the two conductive members, the vacuum layer insulates the two conductive members from each other, so that a vacuum is provided between the cooling plate 47 and the ceiling electrode plate 38 instead of the insulating film 48. A layer may be provided. In addition, an air layer may be provided between the cooling plate 47 and the ceiling electrode plate 38, and a liquid such as a Galden (registered trademark) liquid or a Fluorinert (registered trademark) liquid is filled between the cooling plate 47 and the ceiling electrode plate 38. May be.

By the way, conventionally, in the plasma processing chamber, a high frequency power source has been connected to the ceiling electrode plate of the gas introduction shower head. When supplying high-frequency power from a high-frequency power source to the ceiling electrode plate, even if a polymer adheres to the surface facing the processing space of the ceiling electrode plate and an insulating film is formed on the surface of the ceiling electrode plate, the high-frequency power Through the ceiling electrode plate, the supplied high-frequency power can be applied to the processing space.

However, since the high frequency power supply requires a matching unit to supply high frequency power to the ceiling electrode plate, the structure of the plasma processing chamber becomes complicated. In addition, since a high-frequency potential is generated in the ceiling electrode plate due to the supplied high-frequency power, the potential of the ceiling electrode plate changes periodically, and the ceiling electrode plate draws cations and draws electrons. Repeatedly occurs . Accordingly , a predetermined amount of electrons are lost from the processing space, and the efficiency of the plasma processing is reduced.

On the other hand, when DC power is supplied to the ceiling electrode plate from a DC power source, a matching unit is not necessary. Furthermore, since the potential of the ceiling electrode plate does not change, it is possible to maintain a state in which only cations are attracted, electrons are not lost from the processing space, and plasma processing efficiency can be improved. However, if a polymer adheres to the surface of the ceiling electrode plate that faces the processing space, direct current power cannot pass through the insulating film made of the polymer, so the ceiling electrode plate cannot apply the supplied direct current power to the processing space. Further, when the ceiling electrode plate is not electrically floating, DC power cannot be supplied to the ceiling electrode plate.

  Corresponding to these, the gas introduction shower head 34 as the plasma processing chamber structure according to the present embodiment has a predetermined value in order to appropriately remove the polymer adhering to the ceiling electrode plate 38 as described above. By having the electric capacity and electrically floating the ceiling electrode plate 38, DC power can be supplied to the ceiling electrode plate 38. Specifically, a CEL DC power source 49 is electrically connected to the electrically floating ceiling electrode plate 38. The ceiling electrode plate 38 applies DC power supplied from the CEL DC power source 49 to the processing space S.

  According to the gas introduction shower head 34 according to the present embodiment, the gas introduction shower head 34 is interposed between the electrode support 39 and the cooling plate 47 that are electrically grounded, and the electrode support 39 and the processing space S. A ceiling electrode plate 38 having a surface exposed to the processing space S and electrically floating; an insulating film 48 made of polyimide and an alumite film 51 disposed between the electrode support 39 and the ceiling electrode plate 38; Is provided.

A gas introduction shower head 34 having a sandwich structure composed of a conductive member (electrode support 39, cooling plate 47), an insulating member (insulating film 48, anodized film 51), and a conductive member (ceiling electrode plate 38) has a predetermined structure. Having a value electrical capacity. In the gas introduction shower head 34, the voltages of the electrode support 39 and the cooling plate 47 are fixed to the ground potential. Further, when high-frequency power is applied to the processing space S from the high-frequency power source 20 or another high-frequency power source 46 to generate plasma, a sheath that is a region with very few electrons is generated in the vicinity of the gas introduction shower head 34. Further, the gas introduction shower head 34 has an impedance ((capacity) reactance) having a magnitude corresponding to the magnitude of its electric capacity. When an alternating current corresponding to the high frequency power passes through the sheath and the gas introduction shower head 34, a voltage drop from the processing space S to the ground potential (the electrode support 39 and the cooling plate 47) occurs. Each of the gas introduction shower heads 34 is shared. The voltage drop sharing ratio of the sheath and the gas introduction shower head 34 changes in accordance with the (capacity) reactance of the gas introduction shower head 34. In addition, a potential corresponding to the voltage drop shared by the gas introduction shower head 34 is generated on the ceiling electrode plate 38. Therefore, by controlling the magnitude of the electric capacity of the gas introduction shower head 34, the potential of the ceiling electrode plate 38 (the potential of the surface on the processing space S side) can be controlled without using the potential control circuit. As a result, the potential on the surface of the processing space S can be controlled, and the structure of the plasma processing chamber can be simplified. Further, by controlling the potential on the surface on the processing space S side, it is possible to appropriately control the removal amount of the polymer adhering to the ceiling electrode plate 38 in the deposition process, and the ceiling electrode plate 38 is scraped in the deposition process. Can be prevented.

  In the gas introduction shower head 34, the ceiling electrode plate 38 is electrically connected to a CEL DC power source 49. When the CEL DC power source 49 is connected to the ceiling electrode plate 38 and DC power is supplied to the ceiling electrode plate 38, it is not necessary to use a matching unit, and only ions are drawn into the ceiling electrode plate 38 so that electrons are not Since they are not drawn in, electrons do not decrease in the processing space S. Therefore, the structure of the plasma processing chamber can be further simplified, and the efficiency of the plasma processing can be improved.

  In the gas introduction shower head 34, as the material of the insulating film 48, at least one of metal oxides such as yttria, alumina, and silica, and metal nitrides such as aluminum nitride may be selected. 38 and the cooling plate 47 (or the electrode support 39) can be improved, and as a result, the temperature control of the gas introduction shower head 34 can be easily performed.

  Further, in the gas introduction shower head 34, an organic silicon compound may be selected as the material of the insulating film 48, whereby a high heat transfer property between the ceiling electrode plate 38 and the cooling plate 47 (or electrode support 39). And high insulation properties.

  Further, in the gas introduction shower head 34, an organic functional material may be selected as the material of the insulating film 48, thereby ensuring high insulation and easily increasing the electric capacity of the gas introduction shower head 34. can do.

  Although the high frequency power supply 20 and the other high frequency power supply 46 are connected to the susceptor 12 of the plasma processing chamber 10 described above, only one high frequency power supply may be connected to the susceptor 12.

  The gas introduction shower head 34 may be connected to a high-frequency power source that supplies high-frequency power with a weak output that does not generate a potential on the surface of the ceiling electrode plate 38 on the processing space S side.

  Next, a plasma processing chamber provided with the plasma processing chamber structure according to the second embodiment of the present invention will be described.

  The present embodiment is basically the same in configuration and operation as the first embodiment described above, and the thickness of the insulating film is not constant, but decreases toward the center of the ceiling electrode plate. Only the first embodiment described above is different. Therefore, the description of the same configuration is omitted, and only the operation different from that of the first embodiment will be described below.

  FIG. 3 is an enlarged cross-sectional view of a gas introduction shower head as the plasma processing chamber structure according to the present embodiment.

In FIG. 3, a gas introduction shower head 52 detachably supports a disk-shaped ceiling electrode plate 53 (second conductive member) having a surface exposed to the processing space S, and the ceiling electrode plate 53, In addition, the electrode support 39 (first conductive member) having the buffer chamber 40 described above is interposed between the ceiling electrode plate 53 and the electrode support 39, and the ceiling electrode plate 53 is brought to a predetermined temperature during the plasma processing. A cooling plate 47 to be cooled and an insulating film 54 (insulating member) interposed between the cooling plate 47 and the ceiling electrode plate 53 are provided.

Central portion of the density container of the plasma generated between the processing air in the plasma processing chamber, i.e., may be higher toward the center portion of the ceiling electrode plate, a polymer that adheres to the ceiling electrode plate in depot process the ceiling electrode In some cases, the amount of non-uniform adhesion to the plate increases more toward the center of the ceiling electrode plate. At this time, in order to appropriately remove the polymer that adheres unevenly to the ceiling electrode plate, the potential generated on the processing space side surface of the ceiling electrode plate is preferably lowered toward the center of the ceiling electrode plate.

In the gas introduction shower head 52 as the plasma processing chamber structure according to the present embodiment, the thickness of the insulating film 54 varies depending on the site in order to cope with this, specifically, the ceiling electrode plate 53. Toward the center of the container 11, that is, toward the center of the container 11. As shown in Table 3 described above, the electric capacity smaller the thickness of the insulating film is increased. Accordingly, in the gas introduction shower head 52, the partial electric capacity increases toward the center of the ceiling electrode plate 53 and the reactance decreases. Therefore, the gas introduction shower heads toward the center of the ceiling electrode plate 53. The amount of voltage drop shared by the head 52 can be reduced, and the potential generated on the surface of the ceiling electrode plate 53 on the processing space S side can be lowered toward the center.

  According to the gas introduction shower head 52 according to the present embodiment, since the thickness of the insulating film 54 changes depending on the part, it occurs in each part according to the amount of polymer adhering to each part of the ceiling electrode plate 53. The potential to be applied can be appropriately changed, and thereby the amount of polymer attached at each site can be controlled to be constant. More specifically, since the thickness of the insulating film 54 decreases toward the central portion of the container, an appropriate potential can be easily generated according to the amount of the polymer that increases toward the central portion.

In the gas introduction shower head 52 described above, the thickness of the insulating film 54 changes depending on the site, but instead, the insulating film may be made of a different material depending on the site. Specifically, the dielectric constant of the material constituting the insulating film, for example, may be increased toward the center portion of the ceiling electrode plate 53. Thereby, in the gas introduction shower head 52, since the (capacity) reactance decreases toward the center of the ceiling electrode plate 53, the amount of voltage drop shared by the gas introduction shower head 34 toward the center of the ceiling electrode plate 53 is reduced. The potential generated on the surface of the ceiling electrode plate 53 on the processing space S side can be reduced toward the center.

  In each of the embodiments described above, the gas introduction shower head has the insulating film 48 (54) and the alumite film 51 as insulating members. However, the gas introduction shower head may have only the insulating film as an insulating member. .

  Moreover, in each embodiment mentioned above, although the gas introduction shower head was comprised as a different structure from the container 11, a part of container 11 may comprise a part of gas introduction shower head, for example, an electrode The lid member of the support 39 may be constituted by a part of the container 11.

In the gas introduction shower head in each embodiment described above, an insulating film as an insulating member is disposed between the ceiling electrode plate and the cooling plate, but the position where the insulating member is disposed is not limited thereto, The insulating film may be disposed between the electrically conductive member that is electrically grounded and the electrically conductive member that is electrically floating.

  For example, the present invention can be applied to a plasma processing chamber structure as shown in FIG.

  A plasma processing chamber structure 55 shown in FIG. 4 includes a chamber lid 57 that covers an upper portion of the gas introduction shower head 56 including a ceiling electrode plate 38, a cooling plate 47, and an electrode support 39. The chamber lid 57 is made of a conductive member such as aluminum and is electrically grounded. The plasma processing chamber structure 55 includes an insulating film 58 made of polyimide and interposed between the electrode support 39 and the chamber lid 57.

  The gas introduction shower head 56 does not include the insulating film 48 and the alumite film 51, and further, the gas introduction shower head 34 is covered with an annular insulating member 59 around the electrode support 39 and the cooling plate 47. And different. In the gas introduction shower head 56, not only the ceiling electrode plate 38 but also the cooling plate 47 and the electrode support 39 are electrically floated.

  The plasma processing chamber structure 55 described above includes an electrically grounded conductive member (chamber lid 57), an insulating member (insulating film 58), and an electrically floating conductive member (electrode support 39, cooling). It has a sandwich structure comprising a plate 47 and a ceiling electrode plate 38). Therefore, also in this plasma processing chamber structure 55, it is possible to obtain the same effect as the effect of the gas introduction shower head 34 in the first embodiment described above.

Note that the material of the insulating film 58 is not limited to polyimide, but metal oxides such as yttria, alumina, and silica, metal nitrides such as aluminum nitride, SiC, a silicon compound and a high molecular compound of a methyl group, PTFE, Any organic functional material such as fluororubber may be used. Also, it may be provided the air layer between the chamber lid 57及beauty electrodes support 39, instead of the insulating film 58, further, Galden between chamber lid 57及beauty electrodes support 39 (registered trademark) solution Or a liquid such as Fluorinert (registered trademark) liquid.

  Further, the gas introduction shower head 56 described above does not include the insulating film 48 and the alumite film 51, but the cooling plate 47 includes the alumite film 51 as in the first embodiment described above. Also good.

  In each of the above-described embodiments, the gas introduction shower head has been described as the plasma processing chamber structure to which the present invention is applied. However, the plasma processing chamber structure to which the present invention is applicable is not limited to the gas introduction shower head. For example, the structure provided in the inner wall in a container also corresponds. Further, the plasma processing chamber structure to which the present invention is applied is not limited to one, and the plasma processing chamber may have a plurality of plasma processing chamber structures to which the present invention is applied. Good.

  Furthermore, since the plasma density distribution in the container can be changed by controlling the electrical capacity of the structure for the plasma processing chamber to which the present invention is applied, the removal amount of the polymer adhering to the structure is controlled. In addition, the removal amount of the polymer adhering to other structures can be controlled together.

  Next, a plasma processing chamber including a plasma processing chamber component according to the third embodiment of the present invention will be described.

  This embodiment is basically the same in configuration and operation as the first embodiment described above, and has a thermal spray film in which the plasma processing chamber component facing the processing space in the container is made of an insulating material. And the thickness of the sprayed film is different from the first embodiment described above in that the thickness of the sprayed film is set according to the amount of polymer adhering to the component. Therefore, the description of the same configuration is omitted, and only the operation different from that of the first embodiment will be described below.

  Also on the surface of the container side wall member 45 facing the processing space S in the container 11 in FIG. 1, the baffle plate 14 facing the exhaust passage 13 which is a part of the space in the container 11, and the surface of the susceptor side surface covering member 60. Similar to the electrode plate 38, a polymer (attachment) adheres.

  Since the polymer is activated and decomposes when heat is applied, conventionally, a heater is embedded in the side wall of the container, and the polymer attached to the side wall is heated by the heater to remove the polymer. It was. However, it may be difficult to dispose a heater on the baffle plate and the susceptor side surface covering member, and in this case, the attached polymer cannot be removed.

  Certainly, the polymer can be removed by colliding cations by controlling the potential of the container side wall member, baffle plate and susceptor side surface covering member, but it adheres to the container side wall member, baffle plate and susceptor side surface covering member. The amount of polymer is not uniform.

  For example, when a heater is embedded in the container side wall member, the polymer that should adhere to the surface of the container side wall member is thermally decomposed into gas molecules, and the gas molecules reach the baffle plate and the susceptor side surface covering member. As a result, the amount of polymer adhering to the surface of the baffle plate and the susceptor side surface covering member may be larger than the amount of polymer adhering to the surface of the container side wall member. .

  When the heater is not embedded in the container side wall member, the amount of polymer adhering to the surface of the container side wall member may be larger than the amount of polymer adhering to the surface of the baffle plate and the susceptor side surface covering member. Further, the surface of the baffle plate and the susceptor side surface covering member may not be covered (exposed) by the polymer, and at this time, the baffle plate and the susceptor side surface covering member may be scraped by the collision of cations.

  Further, when a corrosive gas is used as the processing gas, the container side wall member is covered with quartz, but in this case as well, the amount of the polymer adhering to the surface of the container side wall member is not covered with quartz, and the side surface coating of the susceptor is not covered with quartz. More than the amount of polymer adhering to the surface of the member.

  Therefore, even if the potentials of the container side wall member, the baffle plate, and the susceptor side surface covering member are uniformly controlled, the polymers attached to the surfaces of the container side wall member, the baffle plate, and the susceptor side surface covering member cannot be removed appropriately. .

  Here, the container side wall member, the baffle plate, and the susceptor side surface covering member as the plasma processing chamber component according to the present embodiment have the configuration shown in FIG.

FIG. 5 is a diagram showing a schematic configuration of the plasma processing chamber component according to the present embodiment, (A) is a diagram showing the positional relationship between the sheath and the plasma processing chamber component, and (B) is a diagram showing the positional relationship between the sheath and the plasma processing chamber component. It is a circuit diagram which shows typically the components for plasma processing chambers as an electric circuit.

In FIG. 5 (A), the plasma processing chamber parts (container sidewall member, the baffle plate and the susceptor side surface covering member) 61, electrically grounded, electrically conductive material, for example, a base 6 2 made of aluminum, the base portion And a sprayed film 63 (insulating portion) made of an insulating material such as yttria, alumina, silica, or aluminum nitride, which covers the processing space S and faces the processing space S.

  Further, when plasma is generated in the processing space S, a sheath 64 is generated in the vicinity of the plasma processing chamber component 61 so as to face the sprayed film 63. Since the sheath 64 is a region with very few electrons, it has the same properties as the insulating film. Accordingly, the sheath 64 and the sprayed film 63 of the plasma processing chamber component 61 function as two capacitors (capacitors) connected in series as shown in FIG. Each of the sheath 64 and the sprayed film 63 has an electric capacity corresponding to the thickness and relative dielectric constant (see the above formula (1)), and further, a (capacitance) reactance corresponding to the electric capacity. (See the above formula (2).) When a current flows through two capacitors connected in series, a voltage drop occurs. The voltage drop sharing ratio of each capacitor is determined according to the magnitude of the (capacitance) reactance. Therefore, the amount of voltage drop shared by the plasma processing chamber component 61 can be controlled by controlling the magnitude of the electric capacity of the sprayed film 63, whereby the surface of the sprayed film 63 facing the processing space S is controlled. The potential (potential potential) generated at 63a can be controlled. In addition, since the magnitude of the electric capacity of the sprayed film 63 can be changed by changing the thickness of the sprayed film 63, the potential potential of the sprayed film 63 is controlled by changing the thickness of the sprayed film 63. can do.

  In order to confirm the above principle, the inventor measured the potential potential of the sprayed film 63 when the thickness of the sprayed film 63 and the magnitude of the high frequency power applied to the processing space S were changed, and FIG. This is shown in the graph of (B).

  FIG. 6 is a graph showing changes in the potential potential of the yttria film when the thickness of the yttria film as the thermal spray film and the magnitude of the high-frequency power in the plasma processing chamber component are changed. It is a graph at the time of applying high frequency power of 27 MHz, and (B) is a graph at the time of applying high frequency power of 3 MHz to processing space. In the figure, “■” indicates the case where the film thickness of the yttria film is 200 μm, and “♦” indicates the case where the film thickness of the yttria film is 100 μm.

  As shown in FIGS. 6A and 6B, even when the magnitude or frequency of the high frequency power is changed, the potential potential when the yttria film thickness is 100 μm is the same as that when the yttria film thickness is 200 μm. It was found that it was always lower than the potential potential, and it was confirmed that the potential potential of the sprayed film 63 can be controlled by changing the thickness of the sprayed film 63. In addition, since the (capacitance) reactance can be reduced as the thickness of the sprayed film 63 is reduced (see the above formulas (1) and (2)), the voltage drop amount shared by the plasma processing chamber component 61 is reduced. It was also found that the potential potential of the sprayed film 63 can be lowered as a result.

  In addition, as described above, the amount of polymer adhering to the surfaces of the container side wall member, the baffle plate, and the susceptor side surface covering member is not uniform, but the container side wall member and baffle as the plasma processing chamber component according to the present embodiment. In view of this, the plate and the susceptor side surface covering member each have a thermal sprayed film made of an insulating material having a thickness set in accordance with the amount of polymer adhering thereto.

  Specifically, when the amount of polymer adhering to the surface of the baffle plate and the susceptor side surface covering member is larger than the amount of polymer adhering to the surface of the container side wall member, the sprayed film of the baffle plate and susceptor side surface covering member Is made smaller than the thickness of the sprayed film of the container side wall member. At this time, the potential potential of the baffle plate and the susceptor side surface covering member becomes lower than the potential potential of the container side wall member, and the potential difference between the processing space S and the baffle plate or susceptor side surface covering member is determined between the processing space S and the container side wall member. The potential difference can be larger. That is, the potential potential of the container side wall member, the baffle plate, and the susceptor side surface covering member can be set to a potential corresponding to the amount of attached polymer. As a result, more polymer can be removed on the surface of the baffle plate and the susceptor side surface covering member than on the surface of the container side wall member, and as a result, the container side wall member, baffle plate and susceptor side surface coating with different polymer adhesion amounts can be removed. The polymer can be appropriately removed from the member.

  Further, when the amount of polymer adhering to the surface of the container side wall member is larger than the amount of polymer adhering to the surface of the baffle plate and the susceptor side surface covering member, the thickness of the sprayed film on the container side wall member is set to the baffle plate and It is made smaller than the thickness of the thermal spray film of the susceptor side surface covering member. At this time, the potential potential of the container side wall member becomes lower than the potential potential of the baffle plate and the susceptor side surface covering member, and the potential difference between the processing space S and the container side wall member is changed to the processing space S, the baffle plate, and the susceptor side surface covering member. The potential difference can be larger. That is, the potential potentials of the baffle plate, the susceptor side surface covering member, and the container side wall member can be set to potentials corresponding to the amount of attached polymer. As a result, more polymer can be removed on the surface of the container side wall member than on the surface of the baffle plate and the susceptor side surface covering member, and as a result, the baffle plate, susceptor side surface covering member, and container side wall having different polymer adhesion amounts. The polymer can be appropriately removed from the member. Furthermore, it is possible to prevent the surfaces of the baffle plate and the susceptor side surface covering member from being exposed, and it is possible to prevent the baffle plate and the susceptor side surface covering member from being scraped by cations.

  According to the plasma processing chamber component according to the present embodiment, a base 62 made of a conductive material that is electrically grounded, and a sprayed film made of an insulating material that covers the base 62 and faces the processing space S 63, and the thickness of the sprayed film 63 is set in accordance with the amount of polymer adhering to the surface 63a of the sprayed film 63, so that the potential potential of the sprayed film 63 is set to a potential corresponding to the amount of polymer to be removed. Therefore, removal of the polymer can be appropriately performed.

  In the plasma processing chamber component 61 described above, since the sprayed film 63 is made of sprayed yttria, alumina, silica, or aluminum nitride, the thickness of the sprayed film 63 can be easily set to a desired value. The polymer can be easily removed.

  Further, in the plasma processing chamber component 61 described above, the sprayed film 63 is provided as the insulating portion, but a plate-like insulating member, for example, a quartz plate may be attached to the base portion 62 as the insulating portion. As a result, the structure of the plasma processing chamber component 61 can be simplified, and the structure of the plasma processing chamber 10 can be simplified.

In the plasma processing chamber component 61 described above, the sprayed film 63 as an insulating portion faces the processing space S, but the insulating portion does not need to face the processing space S, and the insulating portion faces the processing space S. and it may be disposed between the conductive portion for electrically grounding floating conductive portion and electrical manner that. That is, the plasma processing chamber component 61 may have a sandwich structure similar to that of the gas introduction shower head 34 described above. Also in this case, the potential potential of the conductive part facing the processing space S can be controlled by changing the thickness of the insulating part. Further, the thickness of the insulating part is the surface of the conductive part facing the processing space S. It may be set according to the amount of the polymer adhering to the resin, whereby the adhering polymer can be appropriately removed.

  Further, the container side wall member, the baffle plate, and the susceptor side surface covering member described above each have a sprayed film made of an insulating material. However, if the amount of the adhering polymer is excessive, it is not necessary to have the sprayed film. Good. As a result, the potential difference between the processing space S and the surface of the container side wall member, the baffle plate, or the susceptor side surface covering member can be further increased, and a large amount of polymer can be removed.

  In each of the above-described embodiments, the plasma processing chamber in which the RIE process or the ashing process is performed on the semiconductor wafer is described as the plasma processing chamber to which the present invention is applied. However, the plasma processing chamber to which the present invention can be applied is described here. However, the present invention is not limited thereto, and the present invention can be applied as long as the semiconductor wafer is subjected to plasma treatment.

  In the plasma processing chamber according to each of the above-described embodiments, the substrate to be processed is a semiconductor wafer. However, the substrate to be processed is not limited to this, for example, an LCD (Liquid Crystal Display) or an FPD (Flat Panel Display). It may be a glass substrate such as.

It is sectional drawing which shows schematic structure of the plasma processing chamber provided with the structure for plasma processing chambers concerning the 1st Embodiment of this invention. It is an expanded sectional view of the gas introduction shower head in FIG. It is an expanded sectional view of the gas introduction shower head as a structure for plasma processing rooms concerning a 2nd embodiment of the present invention. It is an expanded sectional view which shows the modification of the structure for plasma processing chambers concerning the 1st Embodiment of this invention. It is a figure which shows schematic structure of the components for plasma processing chambers concerning the 3rd this Embodiment of this invention, (A) is a figure which shows the positional relationship of the components for sheaths and plasma processing chambers, (B) It is a circuit diagram which shows typically a sheath and components for plasma processing chambers as an electric circuit. It is a graph which shows the change of the potential potential of a yttria film when the thickness of the yttria film as a sprayed film and the magnitude of the high frequency power in the plasma processing chamber parts are changed. (A) is a high frequency power of 27 MHz in the processing space. (B) is a graph when high frequency power of 3 MHz is applied to the processing space.

Explanation of symbols

W Wafer S Processing space 10 Plasma processing chamber 11 Container 12 Susceptor 20 High frequency power supply 34, 52, 56 Gas introduction shower head 38, 53 Ceiling electrode plate 39 Electrode support 46 Other high frequency power supply 47 Cooling plates 48, 54, 58 Insulating film 49 CEL DC power supply 51 Anodized coating 55 Plasma processing chamber structure 57 Chamber lid 60 Susceptor side surface covering member 61 Plasma processing chamber component 62 Base 63 Sprayed film 63a Surface 64 Sheath

Claims (14)

A plasma processing chamber having a container having a processing space for storing a substrate and a mounting table disposed in the container and mounting the stored substrate, wherein the mounting table is connected to at least one high-frequency power source In the plasma processing chamber structure disposed in the plasma processing chamber,
A conductive cooling member that is electrically grounded;
A plate-like electrode having a surface exposed to the processing space interposed between the conductive cooling member and the processing space, and electrically floating,
At least one insulating member made of a dielectric material disposed between the conductive cooling member and the plate electrode ;
A support body having a buffer chamber inside ,
The plate electrode, the at least one insulating member, the conductive cooling member, and the support constitute a shower head that supplies gas to the processing space, and the shower head includes the conductive cooling member, A plurality of gas holes linearly penetrating the at least one insulating member and the plate electrode;
The structure for a plasma processing chamber, wherein the plurality of gas holes communicate with a buffer chamber of the support . The plasma processing chamber structure according to claim 1, wherein the plate electrode is connected to a DC power source. 3. The plasma processing chamber structure according to claim 1, wherein an electric capacity of the shower head that changes in accordance with a physical property of the at least one insulating member is 1000 pF or more.   4. The structure for a plasma processing chamber according to claim 3, wherein the electric capacity is 50000 pF or more.   5. The plasma processing chamber according to claim 1, wherein the at least one insulating member is made of at least one material selected from the group consisting of a metal oxide and a metal nitride. Structure.   The plasma processing chamber structure according to any one of claims 1 to 4, wherein the at least one insulating member is made of an organosilicon compound.   The plasma processing chamber structure according to any one of claims 1 to 4, wherein the at least one insulating member is made of an organic substance.   The structure for a plasma processing chamber according to any one of claims 1 to 7, wherein the thickness of the at least one insulating member varies depending on a part.   9. The plasma processing chamber structure according to claim 8, wherein a thickness of the at least one insulating member decreases toward a central portion of the container.   The plasma processing chamber structure according to any one of claims 1 to 7, wherein the at least one insulating member is formed of a different material depending on a portion.   The plasma processing chamber structure according to claim 10, wherein a relative dielectric constant of a material disposed in the at least one insulating member increases toward a central portion of the container. A plasma processing chamber having a container having a processing space for storing a substrate and a mounting table disposed in the container and mounting the stored substrate, wherein the mounting table is connected to at least one high-frequency power source In the plasma processing chamber structure disposed in the plasma processing chamber,
A conductive cooling member that is electrically grounded;
A plate-like electrode having a surface exposed to the processing space interposed between the conductive cooling member and the processing space, and electrically floating,
A vacuum layer interposed between the conductive cooling member and the plate electrode ;
A support body having a buffer chamber inside ,
The plate electrode, the vacuum layer, the conductive cooling member, and the support constitute a shower head that supplies gas to the processing space, and the shower head includes the conductive cooling member, the vacuum layer, and A plurality of gas holes linearly penetrating the plate electrode;
Wherein the plurality of gas holes plasma processing chamber for structures characterized Rukoto through with the buffer chamber of the support. A plasma processing chamber having a container having a processing space for storing a substrate and a mounting table disposed in the container and mounting the stored substrate, wherein the mounting table is connected to at least one high-frequency power source In the plasma processing chamber
A conductive cooling member that is electrically grounded;
A plate-like electrode having a surface exposed to the processing space interposed between the conductive cooling member and the processing space, and electrically floating,
At least one insulating member made of a dielectric material disposed between the conductive cooling member and the plate electrode ;
A support body having a buffer chamber inside ,
The plate electrode, the at least one insulating member, the conductive cooling member, and the support constitute a shower head that supplies gas to the processing space, and the shower head includes the conductive cooling member, A plurality of gas holes linearly penetrating the at least one insulating member and the plate electrode;
The plasma processing chamber, wherein the plurality of gas holes include a structure for a plasma processing chamber that communicates with a buffer chamber of the support . A plasma processing chamber having a container having a processing space for storing a substrate and a mounting table disposed in the container and mounting the stored substrate, wherein the mounting table is connected to at least one high-frequency power source In a plasma processing apparatus comprising a plasma processing chamber,
The plasma processing chamber is
A conductive cooling member that is electrically grounded;
A plate-like electrode having a surface exposed to the processing space interposed between the conductive cooling member and the processing space, and electrically floating,
At least one insulating member made of a dielectric material disposed between the conductive cooling member and the plate electrode ;
Possess a support having a buffer chamber therein,
The plate electrode, the at least one insulating member, the conductive cooling member, and the support constitute a shower head that supplies gas to the processing space, and the shower head includes the conductive cooling member, A plurality of gas holes linearly penetrating the at least one insulating member and the plate electrode;
The plasma processing apparatus, wherein the plurality of gas holes include a structure for a plasma processing chamber that communicates with a buffer chamber of the support .

Images