JP6304550B2 - Plasma processing equipment - Google Patents

Description

  The present invention relates to an inductively coupled plasma type plasma processing apparatus.

  In an inductively coupled plasma (ICP) type plasma processing apparatus, an inductive magnetic field is generated by applying high frequency power to a coil from a high frequency power source, and inductively coupled plasma is generated in a reaction chamber into which a process gas is introduced. The object to be processed is etched by a physicochemical reaction between ions or radicals in the plasma and the object to be processed.

  When the object to be processed includes a non-volatile material, a non-volatile substance generated by a reaction between ions or radicals in the plasma and the object to be processed protects the dielectric member and the dielectric member that block the opening of the reaction vessel from the plasma. For this reason, it may adhere to the cover provided. Since the non-volatile material attached to the dielectric member and / or the cover prevents the formation of the induction magnetic field, the generation of plasma is also prevented. Furthermore, the non-volatile substance attached to the dielectric member and / or the cover is easily peeled off during the plasma treatment process and may float in the reaction chamber. Thereby, a to-be-processed object may be contaminated.

  Incidentally, in order to stabilize the plasma processing process, the dielectric member is heated to a predetermined temperature range. The dielectric member is heated by arranging a heater or the like between the dielectric member and the coil (Patent Document 1). The heating of the dielectric member also contributes to the suppression of adhesion of the non-volatile substance to the dielectric member and / or the cover.

  In addition, a Faraday shield electrode (hereinafter referred to as FS electrode) is provided between the dielectric member and the coil, and the nonvolatile material adhering to the dielectric member and / or the cover is actively removed. (See Patent Documents 2 and 3).

JP 2008-226857 A JP 2008-130651 A JP 2013-33860 A

  As described above, since the heater is disposed between the dielectric member and the coil, the dielectric member is heated from the atmosphere side. When the adhesion of the non-volatile material is suppressed by heating the dielectric member, it is desirable that the surface on the reaction chamber side of the dielectric member is sufficiently heated. Therefore, in order to effectively suppress the adhesion of the non-volatile substance, it is necessary to increase the temperature of the heater by raising the temperature of the heater by applying high electric power to increase the temperature of the surface of the dielectric member on the reaction chamber side.

  Also in Patent Documents 1 and 2, an FS electrode is provided between the dielectric member and the coil, that is, outside the reaction chamber (atmosphere side). In this method, a high frequency is supplied from a high frequency power source to the FS electrode on the atmosphere side, and a bias voltage is generated inside the reaction chamber (vacuum side). Therefore, in order to obtain a bias effect that only removes the nonvolatile film, it is necessary to apply high power.

  An object of the present invention is to provide a plasma processing apparatus that effectively suppresses adhesion of a nonvolatile substance to a dielectric member, has a simple structure, and is excellent in maintainability.

One aspect of the present invention is a container having a reaction chamber that can be depressurized, a lower electrode that supports an object to be processed in the reaction chamber, a dielectric member that closes the opening of the container and faces the object to be processed, The dielectric member is disposed outside the reaction chamber, and is disposed between the coil for generating plasma in the reaction chamber, the lower electrode, and the dielectric member, and spaced apart from the dielectric member. It includes a cover that, the, the said surface of the reaction chamber side of the dielectric member, and the first electrode pattern, a first insulating film covering the first electrode pattern, are the form, the first insulating A second electrode pattern and a second insulating film covering the second electrode pattern are formed on the surface of the film, and the first electrode pattern is an electric heater for heating the dielectric member. Yes, the second electrode pattern is A plate electrode for coupling plasma capacitively said reaction chamber by applying high frequency power to the dielectric member, to a plasma processing apparatus.

  According to the plasma processing apparatus of the present invention, since the electrode pattern of the electric heater and / or the plate electrode is disposed on the reaction chamber side of the dielectric member, the adhesion of the nonvolatile substance is effectively suppressed.

It is sectional drawing which shows typically the structure of the plasma processing apparatus which concerns on 1st Embodiment of this invention. They are the longitudinal cross-sectional view (a) which shows typically the structure of the dielectric material material and electrode pattern which concern on 1st Embodiment, and the longitudinal cross-sectional view (b) which expanded this to the vertical direction. It is a top view of the 1st electrode pattern (electric heater) concerning a 1st embodiment. It is a top view of the 2nd electrode pattern (flat plate electrode) concerning a 1st embodiment. It is the longitudinal cross-sectional view (a) which shows typically the arrangement | positioning of the dielectric material member and coil which concern on 1st Embodiment, and the top view (b) of the same dielectric material material. It is a longitudinal cross-sectional view which shows typically the structure of the dielectric material material and electrode pattern which concern on 2nd Embodiment of this invention. It is the longitudinal cross-sectional view (a) which shows typically the arrangement | positioning of the dielectric material member and coil which concern on 3rd Embodiment of this invention, and the top view (b) of the dielectric material member. It is the longitudinal cross-sectional view (a) which shows typically the arrangement | positioning of the dielectric material member and coil which concern on 4th Embodiment of this invention, and the top view (b) of the same dielectric material material.

(First embodiment)
FIG. 1 shows the configuration of an inductively coupled plasma (ICP) type dry etching apparatus 10 which is a plasma processing apparatus according to the first embodiment of the present invention. The dry etching apparatus 10 includes a container 1 having a reaction chamber 1a that can be depressurized, a lower electrode 2 that supports a substrate 15 as an object to be processed in the reaction chamber 1a, an opening of the container 1 and an object 15 to be processed. An opposing dielectric member 3 and a coil 4 installed outside the reaction chamber 1a of the dielectric member 3 and generating plasma in the reaction chamber 1a are provided.

  The container 1 has a substantially cylindrical shape with an upper opening, and the upper opening is sealed by a dielectric member 3 that is a lid. The reaction chamber 1a is evacuated by a predetermined exhaust device (not shown) and maintained in a reduced pressure atmosphere. The container 1 is provided with a gate (not shown) for carrying the substrate 15 in and out. A bias voltage is applied to the lower electrode 2. The lower electrode 2 can be provided with a function of holding the substrate 15 by electrostatic adsorption and a circulation path for the refrigerant.

  A first holder 17 that supports the cover 5 is supported on the upper end of the side wall of the container 1, and the cover 5 is supported on the first holder 17 via a second elastic ring 14. The peripheral edge of the cover 5 is fixed by a second holder 18 that supports the dielectric member 3. The dielectric member 3 is supported on the second holder 18 via the first elastic ring 13. The cover 5 serves to protect the surface of the dielectric member 3 on the reaction chamber 1a side from plasma.

  The second holder 18 is provided with a gas inlet 8 for introducing a plasma source gas (process gas) from a predetermined gas supply source into the reaction chamber 1a. The process gas stays in a minute gap 8 a formed between the dielectric member 3 and the cover 5, and then is jetted into the reaction chamber 1 a from a plurality of gas jet ports 9 provided in the cover 5. The plurality of gas ejection ports 9 are preferably distributed concentrically, for example.

As a material constituting the container 1, the first holder 17, the second holder 18, etc., a metal material having sufficient rigidity such as aluminum or stainless steel (SUS), aluminum whose surface is anodized, or the like can be used. . The dielectric member 3, the cover 5 and the like are made of dielectric materials such as yttrium oxide (Y ₂ O ₃ ), aluminum nitride (AlN), alumina (Al ₂ O ₃ ), and quartz (SiO ₂ ). Can be used.

  The dielectric member 3 has a generally circular plate shape along the opening shape of the container 1. On the reaction chamber 1a side of the dielectric member 3, a predetermined electrode pattern and an insulating film covering the predetermined electrode pattern are formed. Hereinafter, a layer including an electrode pattern and an insulating film covering the electrode pattern is referred to as an electrode layer 19.

  The electrode pattern is formed of a conductive material. Since the electrode pattern is formed not on the atmosphere side (coil side) of the dielectric member 3 but on the reaction chamber side, a groove for arranging at least a part of the coil is formed in the dielectric member 3 as will be described later. can do. Therefore, the distance between the coil and the reaction chamber can be made closer, and the plasma density can be easily increased.

  The insulating film may be formed of a dielectric material such as ceramics (for example, white alumina). Since the insulating film covers the electrode pattern, it is possible to suppress the occurrence of metal contamination and particles derived from the metal constituting the electrode pattern in the reaction chamber. Furthermore, the insulating film suppresses damage to the electrode pattern caused by process gas or plasma.

  The electrode pattern may include, for example, an electric heater 6 for heating the dielectric member 3 or a plate electrode 7 for capacitively coupling with plasma in the reaction chamber by applying high frequency power to the dielectric member 3. preferable. When a substance generated from an object to be processed by plasma treatment is a volatile material, only an electrode layer including an electric heater may be disposed. The electrode layer may be a laminate of a plurality of electrode patterns and an insulating film. In this case, the electrode pattern preferably includes the electric heater 6 and the plate electrode 7.

  FIG. 2A is a longitudinal sectional view schematically showing the configuration of the dielectric member 3 and the electrode layer 19 according to the present embodiment. In FIG. 2B, for easy understanding, the dimension in the vertical direction (thickness direction) of the dielectric member 3 and the electrode layer 19 is shown enlarged. These are sectional views taken along line BB in FIG.

  The illustrated electrode layer 19 includes a first electrode layer 6 formed on the surface of the dielectric member 3 on the reaction chamber 1a side, and a second electrode layer formed on the surface of the first electrode layer 6 on the reaction chamber 1a side. 7 is a laminated structure. The first electrode layer 6 includes a first electrode pattern 6b formed on the surface of the dielectric member 3, and a first insulating film 6c covering the first electrode pattern 6b. Similarly, the second electrode layer 7 includes a second electrode pattern 7b and a second insulating film 7c covering the second electrode pattern 7b.

  Hereinafter, a case where the first electrode pattern 6b is an electric heater and the second electrode pattern 7b is a flat plate electrode will be described.

  Since the electric heater 6b is disposed on the surface of the dielectric member 3 on the reaction chamber 1a side, the surface of the dielectric member 3 on the reaction chamber side can be efficiently heated with a small amount of power. Therefore, it is possible to effectively suppress non-volatile substances from adhering to the dielectric member 3 and the cover 5 with less power.

  Here, as described above, by forming a Faraday shield (FS) in the vicinity of the dielectric member 3, it is possible to suppress adhesion of a nonvolatile substance to the dielectric member 3 and the cover 5. By applying high frequency power to the plate electrode 7b, a bias voltage is generated between the dielectric member 3 and the cover 5 and the plasma, and the plate electrode 7b functions as an FS electrode. Since the flat plate electrode 7b is also disposed on the surface of the dielectric member 3 on the reaction chamber 1a side, a bias effect by the flat plate electrode 7b is obtained closer to the reaction chamber 1a. That is, the nonvolatile material attached to the dielectric member 3 and the cover 5 can be easily removed while keeping the power supplied to the flat plate electrode 7b low.

  The above configuration is merely an example, and only the electrode layer including the electric heater may be disposed on the surface of the dielectric member 3 on the reaction chamber 1a side, or only the electrode layer including the flat plate electrode may be disposed. Or contrary to the said structure, a flat electrode may be provided as a 1st electrode pattern and an electric heater may be provided as a 2nd electrode pattern. Especially, it is preferable that the 1st electrode pattern near the dielectric material member 3 is an electric heater, and a 2nd electrode pattern is a flat electrode. This is because the dielectric member 3 is efficiently heated.

  FIG. 3 is a plan view showing an example of the electric heater 6b. The electric heater 6b includes a line pattern made of a high-resistance metal. The line pattern is drawn in a serpentine shape, for example. The electric heater 6 b is connected to a heater terminal 6 a that penetrates the dielectric member 3, and the heater terminal 6 a is electrically connected to an AC power source 16. By supplying power from the AC power supply 16 to the heater terminal 6a, the first electrode pattern 6b generates heat. For example, tungsten (W) is preferably used as the high resistance metal.

  FIG. 4 is a plan view showing an example of the plate electrode 7b. The plate electrode 7b includes a planar pattern made of a wide metal thin film. Tungsten (W) can also be used for the plate electrode 7b. The plate electrode 7b is preferably formed so as to cover, for example, the electrode pattern of the electric heater and cover, for example, 50% or more of the surface of the dielectric member 3 on the reaction chamber 1a side. Thereby, most of the dielectric member 3 and the cover 5 can be shielded. The plate electrode 7b is provided with a plurality of radial slits 3s for transmitting high-frequency power output from the first high-frequency power source 11 and the coil 4.

  The plate electrode 7 b is connected to an FS terminal 7 a that penetrates the dielectric member 3 in the vicinity of the center of the dielectric member 3, and the FS terminal 7 a is electrically connected to the second high-frequency power source 12. By supplying electric power from the second high frequency power supply 12 to the FS terminal 7a, a bias voltage is generated in the vicinity of the second electrode pattern 7b, and adhesion of the non-volatile substance to the dielectric member 3 and the cover 5 is suppressed.

  In FIG. 1, the first high frequency power source 11 is connected to the coil 4 and the second high frequency power source 12 is connected to the second electrode layer 7 (plate electrode 7b). May be connected in parallel to the same high-frequency power source via a variable choke or a variable capacitor. A first high frequency power source 11 is connected to the coil 4, a variable choke or a variable capacitor is connected to the plate electrode 7b, and the electric power oscillated from the first high frequency power source 11 is supplied from the coil 4 to the plate electrode 7b via air. The power ratio applied to the coil 4 and the plate electrode 7b may be adjusted with a variable choke or a variable capacitor.

  When the dielectric member 3 is viewed from a direction perpendicular thereto, the electric heater 6b is preferably arranged so as not to protrude from the plate electrode 7b, as indicated by a broken line in FIG. Thereby, the loss of the high frequency power which permeate | transmits slit 3s can be suppressed.

Next, an example of a method for manufacturing the electrode layer 19 will be described.
First, a disk-shaped dielectric member 3 having a groove 3a formed on one surface (first surface) is prepared. In the dielectric member 3, the thickness of the portion without the groove 3a is, for example, 10 to 40 mm.

  The dielectric member 3 preferably has a flat portion on the surface on the reaction chamber side, and the electrode layer 19 is preferably formed on the flat portion. When the electrode layer 19 is formed on the flat portion of the dielectric member 3, it can be formed by a relatively simple process, and a plurality of electrode layers 19 can be laminated. Further, by forming the electrode on the flat portion, problems such as disconnection of the electrode pattern and short-circuiting of the electrode pattern due to poor coating of the insulating film covering the electrode pattern are less likely to occur. Moreover, the surface of the dielectric member 3 on the reaction chamber side can be made flat, and the cover 5 covering the surface of the dielectric member 3 on the reaction chamber side can also be made flat. Thereby, the plasma distribution is likely to be uniform, and the etching uniformity is further improved. Furthermore, maintenance is easy.

  The electrode layer 19 is formed on the other surface (second surface) of the dielectric member 3 in the following manner.

  A predetermined number of through holes are formed in the dielectric member 3. The heater terminal 6a and the FS terminal 7a are formed by filling the through hole with a conductor or passing the conductor therethrough.

  Next, the electric heater 6b is formed on the second surface. The electric heater 6b can be formed by spraying a high resistance metal such as tungsten on the second surface with a mask corresponding to the first electrode pattern interposed. The thickness of the spray pattern is, for example, 10 to 300 μm. Alternatively, the tungsten wire may be bent into the shape of the first electrode pattern, and then the tungsten wire may be fixed to the second surface. At this time, the electrode pattern formed using the spray pattern or other methods is electrically connected to the heater terminal 6a.

  Next, a first insulating film 6c is formed so as to completely cover the electric heater 6b. As a material of the first insulating film 6c, white alumina is suitable. The first insulating film 6c is formed by spraying white alumina on the second surface by thermal spraying. Before the white alumina is sprayed, an adhesion layer such as yttria may be sprayed on the second surface in order to improve the adhesion between the dielectric member 3 and the first insulating film 6c. The thickness of the first electrode layer 6 is, for example, 10 to 300 μm.

  Subsequently, the plate electrode 7 b is formed on the surface of the first electrode layer 6. The flat plate electrode 7b can be formed by spraying metal on the surface of the first electrode layer 6 with a mask corresponding to the second electrode pattern interposed. At this time, the plate electrode 7b is formed in a shape having a plurality of slits 3s arranged radially. The thickness of the plate electrode 7b is, for example, 10 to 300 μm. Alternatively, the plate electrode 7 b having the shape of the second electrode pattern may be formed from a metal foil or a metal plate, and then the plate electrode 7 may be fixed to the surface of the first electrode layer 6. The plate electrode 7b is disposed so as to completely cover the electric heater 6b via the first insulating film 6c, and is electrically connected to the FS terminal 7a.

  Finally, the second insulating film 7c is formed so as to completely cover the plate electrode 7b. White alumina is also suitable as a material for the second insulating film 7c. The second insulating film 7c is formed by spraying white alumina onto the surface of the first electrode layer 6 by thermal spraying. The thickness of the second electrode layer 7 is, for example, 10 to 300 μm. The method for forming the first and second insulating films is not particularly limited, and examples thereof include sputtering, chemical vapor deposition (CVD), vapor deposition, and coating.

  According to the present embodiment, the dielectric member having the electrode layer 19 can be formed by such a simple method. Further, since the dielectric member 3 and the electrode layer 19 have an integral structure, the cover 5 can be formed into a single flat plate structure, and the replacement work is facilitated.

  A groove 3a is preferably formed on the outer surface of the dielectric member 3 with respect to the reaction chamber 1a in order to partially thin the dielectric member 3. At least a part of the coil 4 can be arranged in the groove 3a. Thereby, the part arrange | positioned in the groove | channel 3a of the coil 4 becomes short with the reaction chamber. Therefore, loss of high frequency power can be suppressed. On the other hand, since the groove 3a can be partially formed on one surface of the plate-like dielectric member 3, a decrease in mechanical strength of the dielectric member 3 is suppressed.

  According to this embodiment, since the electrode layer is formed on the surface of the dielectric member on the reaction chamber side, the groove 3a for disposing at least a part of the coil is formed on the outer surface of the dielectric member with respect to the reaction chamber. can do. Therefore, it is possible to arrange the coil so as to suppress the loss of high-frequency power while effectively suppressing the attachment of the nonvolatile substance.

  FIG. 5A schematically shows the arrangement of the dielectric member 3 and the coil 4 according to this embodiment. When the coil 4 is viewed from a direction perpendicular to the dielectric member 3 (the surface direction thereof), the coil 4 is formed by a conductor 4a extending in a spiral shape from the center toward the outer peripheral side. The conductor 4a may be, for example, a ribbon-like metal plate or a metal wire. The number of conductors 4a forming the coil 4 is not particularly limited, and the shape of the coil 4 is not particularly limited. For example, it may be a single spiral type coil composed of one conductor 4a, or a multi spiral type coil in which coils composed of a plurality of conductors 4a are connected in parallel. Further, it may be a planar coil formed by spirally extending the conductor 4a in the same plane parallel to the surface of the dielectric member 3, or the surface of the dielectric member 3 while extending the conductor 4a spirally. Alternatively, a three-dimensional coil with a change in the vertical direction may also be used. The coil 4 is electrically connected to the first high frequency power supply 11 via a matching circuit (not shown). In FIGS. 1 and 5, the distance from the dielectric member 3 near the center of the coil 4 is formed to be larger than the outer peripheral side, but the positional relationship between the coil 4 and the dielectric member 3 is limited to this. Not.

  As shown in FIG. 5B, the groove 3 a is preferably an annular shape having the same center as the center of the coil 4. Thereby, it becomes easy to arrange | position the coil 4 in the groove | channel 3a. Note that the fact that the centers of the coil 4 and the annular groove 3a are the same does not necessarily mean that the respective centers coincide. Here, when the center of the coil 4 and the annular groove 3a is the same, when the dielectric member 3 and the coil 4 are viewed from a direction perpendicular to the dielectric member 3, each center has a radius of 100 mm. Means it is in the circle. In FIG. 5B, the conductor 4a is omitted for convenience.

  The depth of the groove 3a is not particularly limited. Even if the depth of the groove 3a is small, a corresponding effect of suppressing the loss of high frequency power can be obtained. However, when the thickness of the plate-shaped dielectric member 3 having a uniform thickness before forming the groove 3a is T, the maximum depth D of the groove 3a is D = 0.25T to 0.45T. It is preferable to form as follows. At this time, from the viewpoint of securing the strength, the ratio (100 s / S (%)) of the area s where the groove 3a is dug out of the surface area S where the groove 3a of the dielectric member 3 is formed is 2 to 50%. It is preferable that

  The groove 3a can be formed by machining one surface of a plate-like dielectric member having a flat and uniform thickness on both sides, such as cutting.

  In order to obtain plasma with good in-plane uniformity on the surface of the substrate 15, plasma having a distribution (doughnut-shaped distribution) in which the plasma density in the outer periphery is higher than the plasma density near the center is generated in the upper part of the reaction chamber. This is preferably diffused on the substrate. Since plasma having a donut-shaped distribution is formed in the upper part of the reaction chamber, the degree of coupling with the plasma can be reduced by increasing the distance between the coil 4 and the reaction chamber 1a near the center. Therefore, the center side of the coil 4 may not be disposed in the groove 3a. Therefore, as shown in FIGS. 1 and 5, at least a portion corresponding to the center of the coil 4 may be disposed completely outside the groove 3a.

  On the other hand, in the outer peripheral portion, by disposing the coil 4 in the groove 3a, the distance between the coil 4 and the reaction chamber 1a can be relatively reduced, and the degree of coupling between the coil 4 and the plasma can be increased. Therefore, when the conductor 4a of length L forming the coil 4 is divided into a center side portion from the center to 0.5L and the remaining outer peripheral side portion, the center side portion is disposed in the groove 3a. It is preferable to increase the ratio at which the outer peripheral portion is disposed in the groove 3a rather than the ratio. Moreover, it is preferable that at least a part corresponding to the outermost periphery of the coil 4 is disposed in the groove 3a. Furthermore, it is preferable that at least a part of the outer peripheral side portion from at least the outermost end (winding end) to 0.3 L is disposed in the groove 3a.

  Hereinafter, an example of the operation of the dry etching apparatus 10 of the present embodiment will be described.

  First, the reaction chamber 1a is evacuated. The inside of the reaction chamber 1a is a reduced-pressure atmosphere, and the dielectric member 3 is given a pressure almost the same as the atmospheric pressure. The dielectric member 3 has a groove 3a, and a portion corresponding to the groove 3a is thin. However, since the groove 3a is formed in an annular shape so that the mechanical strength is sufficiently maintained, the dielectric member 3 is not damaged.

Thereafter, a process gas is introduced into the reaction chamber 1a from a predetermined gas supply source through the gas introduction port 8. The substrate 15 to be etched has a resist mask corresponding to the etching pattern. When the substrate 15 is, for example, Si, for example, a fluorine-based gas (SF ₆ or the like) is used as the process gas. When the substrate 15 is aluminum, for example, a chlorine-based gas (such as HCl) is used as the process gas.

  Next, high frequency power is supplied from the first high frequency power supply 11 to the coil 4, and plasma is generated in the reaction chamber 1a. At this time, a bias voltage is also applied to the lower electrode 2 holding the substrate 15 from a predetermined high-frequency power source. Thereby, radicals and ions in the plasma are transported to the surface of the substrate 15, accelerated by the bias voltage, and collide with the substrate 15. As a result, the substrate 15 is etched.

  Here, of the conductor 4 a forming the coil 4, the outer peripheral side portion having a high coil density is disposed in the annular groove 3 a formed in the dielectric member 3. Therefore, by applying relatively small electric power, a donut-shaped high-density plasma is generated in the vicinity of the dielectric member 3 on the reaction chamber 1a side, and this reaches the substrate 15 as diffusion plasma.

  On the other hand, power is supplied from the second high-frequency power source 12 to the plate electrode 7b disposed on the surface of the dielectric member 3 on the reaction chamber 1a side, and a bias voltage is generated in the vicinity of the plate electrode in the reaction chamber. As a result, some of the ions in the plasma are accelerated by the bias voltage and enter the dielectric member 3 (or electrode layer 19) and the cover 5. As a result, the adhesion of the nonvolatile material to the dielectric member 3 (or the electrode layer 19) and the cover 5 is suppressed.

  The etching process is continuously performed on the plurality of substrates 15. Therefore, in order to ensure process stability, electric power is supplied from the third high-frequency power supply 16 to the electric heater 6b provided on the surface of the dielectric member 3 on the reaction chamber 1a side, and temperature management is performed by heating the dielectric member 3. Is done.

(Second Embodiment)
In the plasma processing apparatus according to this embodiment, the dielectric member has a concave portion having a flat bottom surface on the reaction chamber side surface (second surface), and the electrode layer 19 is formed in the concave portion. Except for this, it is the same as the first embodiment. FIG. 6 is a vertical cross-sectional view schematically showing the configuration of the dielectric member and the electrode layer according to the present embodiment, and the recess is a portion other than the contact portion between the second holder 18 and the dielectric member 3 not shown. It is formed in the part. Each element of this embodiment corresponding to each element of the first embodiment is denoted by the same reference numeral.

  The recess can be formed by cutting the second surface of the dielectric member 3 or the like. The depth of the recess is not particularly limited, and may be such that all of the electrode layer 19 can be formed in the recess or only a part of the electrode layer 19 can be formed. For example, it is 0.2 to 3.0 mm. In addition, the dielectric member 3 may have a convex portion having a flat top portion at a portion other than the contact portion with the second holder 18. In this case, the electrode layer 19 is formed on this convex portion.

  In any case, the electrode layer 19 can be formed relatively easily by forming the electrode layer 19 on the flat portion of the surface of the dielectric member 3 on the reaction chamber side. Furthermore, problems such as disconnection or short circuit of the electrode pattern are unlikely to occur. Moreover, the cover 5 can be made into a flat structure. Thereby, the plasma distribution is likely to be uniform, and the etching uniformity is further improved.

(Third embodiment)
The plasma processing apparatus according to this embodiment is the same as that of the first embodiment except that the shape of the groove of the dielectric member and the positional relationship between the dielectric member and the coil are different. FIG. 7A is a longitudinal sectional view schematically showing the arrangement of the dielectric member and the coil according to the present embodiment. FIG. 7B is a plan view of the dielectric member according to the present embodiment. Each element of this embodiment corresponding to each element of the first embodiment is denoted by the same reference numeral. In FIG. 7B, the conductor 4a is omitted for convenience.

  The dielectric member 3 has a circular plate shape, and an annular groove 3 a having the same center as the center of the coil 4 is formed on the surface of the dielectric member 3 facing the coil 4. However, the groove 3a includes a deeper first groove 3x on the outside and a shallower second groove 3y on the inner side, and is deepened in two steps from the center toward the outside. A part of the coil 4 is disposed in each of the first groove 3x and the second groove 3y. In this case, if the width of the groove 3a is the same as that of the first embodiment, the average thickness of the dielectric member 3 is larger than that of the first embodiment. As a result, the strength of the dielectric member 3 can be maintained even higher.

  Further, by arranging the relatively deep first groove 3x on the outer side of the dielectric member and the shallow second groove 3y on the inner side, the degree of inductive coupling between the coil and the plasma becomes stronger toward the outer peripheral side of the dielectric member 3a. Therefore, a denser donut-shaped plasma can be generated in the vicinity of the dielectric member. Thereby, it is possible to reach the substrate 15 with higher density and uniform diffusion plasma. When the depth of the groove 3a is increased stepwise from the center toward the outside, the depth may be changed in three steps or more. Moreover, you may change the depth of the groove | channel 3a so that it may become deep continuously continuously toward an outer side from the center.

  In FIG. 7, the average distance between the dielectric member 3 and the conductor 4 forming the coil 4 gradually increases from the outermost periphery toward the center. In such a case, it is preferable to increase the depth of the groove 3a stepwise or continuously from the center toward the outside.

(Fourth embodiment)
The plasma processing apparatus according to this embodiment is the same as that of the first embodiment except that the shape of the coil, the shape of the groove of the dielectric member, and the positional relationship between the dielectric member and the coil are different. FIG. 8A is a longitudinal sectional view schematically showing the arrangement of dielectric members and coils according to the present embodiment. FIG. 8B is a plan view of the dielectric member according to the present embodiment, and the position of the coil 4 is indicated by a broken line. Each element of this embodiment corresponding to each element of the first embodiment is denoted by the same reference numeral. In FIG. 8B, the conductor 4a is omitted for convenience.

  The dielectric member 3 has a circular plate shape, and a spiral groove 3 a is formed on the surface of the dielectric member 3 facing the coil 4. The conductor 4a forming the coil 4 extends planarly and spirally along the groove 3a, and almost the entire coil 4 is disposed in the groove 3a. Thus, when the shape of the coil 4 is planar, the shape of the groove 3a may correspond to the spiral shape of the conductor 4a. Thereby, the width | variety of the groove | channel 3a can be made small and it becomes still easier to ensure the intensity | strength of the dielectric member 3. FIG.

  The plasma processing apparatus of the present invention is useful in processes requiring simple maintenance and high-density plasma, and can be applied to various plasma processing apparatuses including a dry etching processing apparatus and a plasma CVD apparatus.

  1: container, 1a: reaction chamber, 2: lower electrode, 3: dielectric member, 3a: groove, 3x: first groove, 3y: second groove, 3s: slit, 4: coil, 4a: conductor, 5: Cover, 6: first electrode layer, 6a: heater terminal, 6b: first wiring pattern (electric heater), 6c: first insulating film, 7: second electrode layer, 7a: FS terminal, 7b: second wiring pattern (Flat plate electrode), 7c: second insulating film, 8: gas introduction port, 8a: gap, 9: gas ejection port, 10: dry etching apparatus, 11: first high frequency power source, 12: second high frequency power source, 13th 1 elastic ring, 14: second elastic ring, 15: substrate, 16: AC power supply, 17: first holder, 18: second holder, 19: electrode layer

Claims (9)

A container having a reaction chamber capable of depressurization;
A lower electrode for supporting an object to be processed in the reaction chamber;
A dielectric member that closes the opening of the container and faces the object to be processed;
A coil which is installed outside the reaction chamber of the dielectric member and generates plasma in the reaction chamber;
A cover disposed apart from the dielectric member between the lower electrode and the dielectric member ;
Wherein the surface of the reaction chamber side of the dielectric member, and the first electrode pattern, a first insulating film covering the first electrode pattern, is formed,
A second electrode pattern and a second insulating film covering the second electrode pattern are formed on the surface of the first insulating film,
The first electrode pattern is an electric heater for heating the dielectric member, and the second electrode pattern is capacitively coupled to the plasma in the reaction chamber by applying high frequency power to the dielectric member. A plasma processing apparatus which is a flat plate electrode . The plasma processing apparatus according to claim 1 , wherein at least one of the first electrode pattern and the second electrode pattern is formed by thermal spraying. Said dielectric member, when viewed from a direction perpendicular to the dielectric member, the electric heater is arranged so as not to protrude from the flat electrode, the plasma processing apparatus according to claim 1 or 2 . The reaction chamber side surface of the dielectric member has a flat portion,
It said electrode pattern, wherein formed on the flat portion, the plasma processing apparatus according to any one of claims 1-3. A groove is formed on the outer surface of the dielectric member with respect to the reaction chamber;
At least in part, the are arranged in the groove, the plasma processing apparatus according to any one of claims 1 to 4 in the coil. The plasma processing apparatus according to claim 5 , wherein the groove has an annular shape having the same center as the center of the coil. The plasma processing apparatus according to claim 6 , wherein the groove deepens continuously or stepwise from the center toward the outside. When the conductor of length L that forms the coil is divided into a center side portion from the center to 0.5 L and the remaining outer peripheral side portion, the ratio of the center side portion being arranged in the groove is more than , a large proportion of the outer peripheral portion is disposed in said groove, the plasma processing apparatus according to any one of claims 5-7. The plasma processing apparatus according to claim 8 , wherein a coil density of the outer peripheral side portion is larger than a coil density of the center side portion.

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