JP6296334B2 - Deposition equipment - Google Patents

Description

  The present invention relates to a film forming apparatus for forming a film on the surface of a work material having conductivity such as steel using plasma.

  Conventionally, a technique for forming a film on the surface of a work material having conductivity, such as a steel material, is known from Patent Document 1 or the like. In the technique disclosed in this patent document, plasma is generated in the peripheral region of the inner surface of the quartz window by supplying a microwave toward the material to be processed in the processing container through the quartz window, and the sheath layer is plasma. And the material to be processed. During the supply of the microwave, the plasma generator applies a negative bias voltage to the workpiece material. As a result, a sheath layer is generated along the surface of the workpiece material, and the generated sheath layer is expanded. The supplied microwave propagates along the sheath layer, and the plasma expands. As a result, high-density plasma is generated around the surface of the work material. Therefore, the source gas is decomposed by plasma, and the surface of the material to be processed is subjected to film formation.

JP 2004-47207 A

  In order to propagate microwaves as surface waves along the expanded sheath layer, it is necessary to efficiently propagate microwaves along the surface of the workpiece material from the waveguide supplying the microwaves through the quartz window. There is. For this reason, a coaxial waveguide is used as a waveguide, and a recess into which a work material or a jig for supporting the work material is inserted is formed in a quartz window, and microwaves are supplied to the work material. It is conceivable that the central conductor is disposed at a position facing the recess. In this case, the cross-sectional area of the lower part of the work material or jig facing the bottom surface of the recess is smaller than the cross-sectional area of the recess so that the work material or jig can easily enter the recess of the quartz window. May be. Therefore, the cross-sectional area of the central conductor may be larger than the cross-sectional area of the work material or the lower part of the jig. As a result, the lines of electric force from the center conductor may concentrate on the work material or jig having a cross-sectional area smaller than the cross-sectional area of the center conductor, and may cause abnormal discharge during the film forming process.

  The present invention has been made to solve the above-described problem, and an object thereof is to provide a film forming apparatus capable of reducing the possibility of causing abnormal discharge and stabilizing the plasma film forming process. .

の関係を有することを特徴とするものである。 In order to achieve the above object, the present invention according to claim 1 provides a processing container in which a material to be processed that has a conductive surface and a surface is conductive, and supplies gas to the inside of the processing container. A gas supply unit, a microwave supply unit for supplying a microwave for generating plasma along the processing surface of the workpiece material, and a negative bias for expanding a sheath layer along the processing surface of the workpiece material A negative voltage application unit that applies a voltage to the workpiece material and a microwave that propagates the microwave supplied from the microwave supply unit to the expanded sheath layer are made of a dielectric that transmits microwaves. a microwave supply opening formed of a dielectric, wherein a recess formed in the microwave feed opening, the direction of the area perpendicular to the depth direction of the depth direction of the distal end of said recess, said orthogonal That the direction of smaller than the cross-sectional area of the recess, said a recess surface for supporting the material to be processed is a jig having conductivity is inserted, the said recess opposite the depth direction of the recess A central conductor of a waveguide, which is disposed in the microwave supply port and transmits the microwave supplied from the microwave supply unit, faces each other through the microwave supply port in the depth direction of the recess. The area S1 of the first surface orthogonal to the depth direction at the upper end of the central conductor and the area S2 of the second surface orthogonal to the depth direction at the lower end of the jig are:

It has the relationship of these.

の関係を有するので、中心導体とマイクロ波供給口を挟んで位置する被加工材料、または治具に電気力線が集中しづらくなる。この結果、成膜処理中に異常放電を引き起こす恐れを低減し、プラズマ成膜処理を安定化させることができる。 According to the film forming apparatus of claim 1, the area S1 of the first surface of the central conductor is the area S2 of the second surface of the jig,

Therefore, it is difficult to concentrate the electric lines of force on the work material or jig positioned between the center conductor and the microwave supply port. As a result, the risk of causing abnormal discharge during the film forming process can be reduced, and the plasma film forming process can be stabilized.

の関係を有することを特徴とするものである。 The present invention according to claim 2 is the film forming apparatus according to claim 1, wherein the area S1 and the area S2 are:

It has the relationship of these.

の関係を有するので、中心導体とマイクロ波供給口を挟んで位置する被加工材料、または治具に電気力線がさらに集中しづらくなる。この結果、成膜処理中に異常放電を引き起こす恐れをさらに低減し、プラズマ成膜処理をさらに安定化させることができる。 According to the film forming apparatus of claim 2, the area S1 is the area S2.

Therefore, the lines of electric force are more difficult to concentrate on the work material or jig positioned between the center conductor and the microwave supply port. As a result, the possibility of causing abnormal discharge during the film forming process can be further reduced, and the plasma film forming process can be further stabilized.

  According to a third aspect of the present invention, there is provided the film forming apparatus according to the first or second aspect, wherein the jig is arranged in a first jig on which the material to be processed is mounted, the recess, and the first jig. A second jig that can be electrically contacted with one jig, and the surface of the second jig that faces the first surface in the depth direction of the recess is the second surface. To do.

  According to the film-forming apparatus of Claim 3, since the 2nd jig | tool is arrange | positioned at a recessed part, it becomes difficult to position-shift within a recessed part rather than a 1st jig | tool. As a result, the possibility of causing abnormal discharge during the film forming process can be further reduced, and the plasma film forming process can be further stabilized.

  A fourth aspect of the present invention is the film forming apparatus according to the third aspect, wherein the center conductor has the center of the first surface and the center of the second surface coincide with each other in the depth direction. It is characterized by being arranged.

  According to the film forming apparatus of the fourth aspect, since the center of the first surface and the center of the second surface are arranged to coincide with each other, the electric lines of force are more difficult to concentrate on the second jig. As a result, the possibility of causing abnormal discharge during the film forming process can be further reduced, and the plasma film forming process can be further stabilized.

  The present invention according to claim 5 is the film forming apparatus according to claim 3 or 4, wherein the first surface and the second surface are similar.

  According to the film forming apparatus of the fifth aspect, the first surface and the second surface are similar. Therefore, the electric lines of force are more difficult to concentrate on the second jig. As a result, the possibility of causing abnormal discharge during the film forming process can be further reduced, and the plasma film forming process can be further stabilized.

  A sixth aspect of the present invention is the film forming apparatus according to any one of the third to fifth aspects, wherein a surface opposite to the second surface of the second jig in the depth direction is the first film. It has a shape in which the thickness of the second jig increases in the depth direction from the center of the two surfaces toward an orthogonal direction orthogonal to the depth direction.

  According to the film forming apparatus of claim 6, the surface of the second jig opposite to the second surface has a thickness in the depth direction of the second jig from the center of the second surface toward the orthogonal direction. Has an increasing shape. Therefore, the first jig is easily positioned with respect to the second jig, and the first jig and the second jig are more reliably brought into contact with electricity. As a result, the material to be processed is subjected to plasma film formation more stably.

  The present invention according to claim 7 is the film forming apparatus according to claim 6, wherein the second surface has a shape in which the entire surface from the center of the second surface to the outer periphery of the second surface is in contact with the recess. It is characterized by being.

  According to the film forming apparatus of the seventh aspect, since the entire surface of the second surface is in contact with the concave portion, the electric lines of force from the center conductor are difficult to concentrate on the second jig. As a result, the possibility of causing abnormal discharge during the film forming process can be further reduced, and the plasma film forming process can be further stabilized.

  The present invention according to claim 8 is the film forming apparatus according to any one of claims 3 to 7, wherein a surface opposite to the second surface of the second jig in the depth direction is a surface roughening. Is 0.1 μm or more and 1 mm or less.

  According to the film-forming apparatus of Claim 8, since the surface roughness on the opposite side to the 2nd surface of a 2nd jig | tool is 0.1 micrometer or more, removal of a 1st jig | tool and a 2nd jig | tool is possible. It becomes easy. As a result, it is possible to shorten the time for continuously forming a plurality of materials to be processed into a plasma film. Further, since the surface roughness is 1 mm or less, the possibility of causing abnormal discharge can be reduced.

の関係を有することを特徴とするものである。 In order to achieve the above object, the present invention according to claim 9 provides a processing container in which a material to be processed which has a conductive surface and a surface to be formed can be disposed, and a gas is supplied to the inside of the processing container. A gas supply unit, a microwave supply unit for supplying a microwave for generating plasma along the processing surface of the workpiece material, and a negative bias for expanding a sheath layer along the processing surface of the workpiece material A negative voltage application unit that applies a voltage to the workpiece, and a microwave supply port that is made of a dielectric that transmits microwaves that propagate microwaves supplied from the microwave supply unit to the expanded sheath layer; A recess formed in the microwave supply port and having a conductive surface for supporting the material to be processed inserted therein, and a front side opposite to the recess in the depth direction of the recess. A central conductor of a waveguide that transmits a microwave supplied from the microwave supply unit, disposed at a microwave supply port, and a conductive film that is disposed in the recess and is thinner than the depth in the depth direction of the recess. And an area S1 of the first surface orthogonal to the depth direction at the upper end of the central conductor facing each other through the microwave supply port in the depth direction, and a bottom of the conductive member The area S2 of the second surface perpendicular to the depth direction at the tip on the side is:

It has the relationship of these.

の関係を有するので、中心導体とマイクロ波供給口を挟んで位置する金属板に電気力線が集中しづらくなる。この結果、成膜処理中に異常放電を引き起こす恐れを低減し、プラズマ成膜処理を安定化させることができる。 According to the film forming apparatus of claim 9, the area S1 of the first surface is the area S2 of the second surface of the metal plate,

Therefore, it is difficult for electric lines of force to concentrate on the metal plate located between the central conductor and the microwave supply port. As a result, the risk of causing abnormal discharge during the film forming process can be reduced, and the plasma film forming process can be stabilized.

It is explanatory drawing which shows schematic structure of the film-forming apparatus which concerns on this embodiment. It is explanatory drawing which shows the state by which the holding jig which supports a workpiece material has been arrange | positioned at the recessed part. It is explanatory drawing which shows the state before the holding jig which supports a workpiece material is arrange | positioned at a recessed part. It is a graph which shows the relationship between the value T which remove | divided the area of the bottom face of the metal plate by the area of the upper surface of a center conductor, and VSWR. It is explanatory drawing which shows the shape of a metal plate, and the shape of a center conductor. It is explanatory drawing which shows the state by which the holding jig which supports the workpiece material in a modification is arrange | positioned in the recessed part.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a film forming apparatus according to the present invention will be described in detail with reference to the drawings based on an embodiment that is embodied.

  As shown in FIG. 1, the film forming apparatus 1 includes a processing container 2, a vacuum pump 3, a gas supply unit 5, a control unit 6, and the like. The processing container 2 is made of metal such as stainless steel and has a hermetic structure. The vacuum pump 3 is a pump capable of evacuating the inside of the processing container 2 via the pressure adjustment valve 7. Inside the processing container 1, a conductive work material 8 that is a film formation target is held by a holding jig 9. The holding jig 9 is an example of the first jig of the present invention.

  The material of the work material 8 is not particularly limited as long as the surface has conductivity, but in the present embodiment, it is a low-temperature tempered steel. Here, the low temperature tempered steel is a material such as JIS G4051 (carbon steel material for mechanical structure), G4401 (carbon tool steel material), G44-4 (steel material for alloy tool), or maraging steel material. In addition to the low-temperature tempered steel, the workpiece material may be a ceramic or a resin coated with a conductive material.

  The gas supply unit 5 supplies a film forming source gas and an inert gas into the processing container 2. Specifically, an inert gas such as He, Ne, Ar, Kr, or Xe and a source gas such as CH4, CH2, C2H2, or TMS (tetramethylsilane) are supplied. In the present embodiment, description will be made assuming that the material to be processed 8 is subjected to a DLC film formation process using CH4, C2H2, and TMS source gases. Source gas and inert gas are examples of the gas of the present invention.

  The flow rate and pressure of the source gas and the inert gas supplied from the gas supply unit 5 may be controlled via the control unit 6 or may be controlled by an operator. The source gas may be a gas containing a compound having a CH bond such as alkyne, alkene, alkane, aromatic compound, or a compound containing carbon. H2 may be included in the source gas.

  Plasma for performing the DLC film forming process on the material 8 to be processed held inside the processing container 2 is generated. This plasma is generated by the microwave pulse controller 11, the microwave oscillator 12, the microwave power source 13, the negative voltage power source 15, and the negative voltage pulse generator 16. In the present embodiment, description will be made on the assumption that surface wave excitation plasma is generated by a method disclosed in Japanese Patent Application Laid-Open No. 2004-47207 (hereinafter referred to as “MVP method (Microwave shear-Voltage combination Plasma method)”). In the following description, the MVP method will be described.

  The microwave pulse control unit 11 oscillates a pulse signal in accordance with an instruction from the control unit 6 and supplies the oscillated pulse signal to the microwave oscillator 12. The microwave oscillator 12 generates a microwave pulse according to the pulse signal from the microwave pulse controller 11. The microwave power source 13 supplies power to the microwave oscillator 12 that oscillates a microwave of 2.45 GHz with the instructed output in accordance with an instruction of the control unit 6. That is, the microwave oscillator 12 supplies a 2.45 GHz microwave to the isolator 17 described later as a pulsed microwave pulse according to the pulse signal from the microwave pulse control unit 11.

  The microwave pulse is transmitted from the microwave oscillator 12 to the isolator 17, the tuner 18, the waveguide 19, the coaxial waveguide 21 protruding from the waveguide 19 through a coaxial waveguide converter (not shown), quartz, and the like. Is supplied to the holding jig 9 and the processing surface of the work material 8 through a microwave supply port 22 made of a dielectric material or the like that transmits the microwave. The isolator 17 prevents the reflected wave of the microwave from returning to the microwave oscillator 12. The tuner 18 matches the impedances before and after the tuner 18 so that the reflected wave of the microwave is minimized. The coaxial waveguide 21 is an example of the waveguide of the present invention.

  As shown in FIG. 2, the outer peripheral surface of the microwave supply port 22 excluding the upper end surface 22A is covered with a side conductor 23 formed of a metal such as stainless steel. The side conductor 23 is fixed to the inner side surface of the processing container 2 by screwing or the like, and is electrically connected to the processing container 2 shown in FIG. A central conductor 21 </ b> C of the coaxial waveguide 21 is extended at the center of the microwave supply port 22. In order to efficiently propagate the surface wave to the work material 8, it is necessary to dispose the work material 8 as an extension of the central conductor of the coaxial waveguide 21. For this reason, the holding jig 9 is also disposed on the extension of the central conductor 21 </ b> C of the coaxial waveguide 21, and the holding jig 9 becomes a central conductor in the microwave supply port 22. Therefore, the central conductor 21C, the holding jig 9 and the side conductor 23 of the microwave supply port 22 function as a coaxial waveguide.

  Due to the microwave pulse supplied to the microwave supply port 22, the microwave propagates near the upper end surface 22 </ b> A where the holding jig 9 is disposed, thereby generating plasma. That is, the microwave is supplied in the Z-axis direction, which is the direction in which the central conductor extends. A dielectric such as quartz is disposed as the microwave supply port 22 between the central conductor 21C of the coaxial waveguide 21 and the holding jig 9 in order to maintain a vacuum. In the following description, the Z-axis direction that is the microwave supply direction may be described as the upper side, and the direction opposite to the Z-axis direction may be described as the lower side.

  As shown in FIG. 3, the holding jig 9 includes a substrate 9B, support pins 9U, and insertion pins 9L. The support pins 9L extend upward from the substrate 9B, and the work material 8 is mounted thereon. The insertion pin 9U extends downward from the substrate 9B and is inserted into a recess 22R described later. The substrate 9B, the support pins 9U, and the insertion pins 9L are only required to have conductive surfaces, and may be integrally formed or separate members may be assembled.

  A concave portion 22R is formed in the upper end surface 22A so that the holding jig 9 is stably disposed in the microwave supply port 22. That is, the length L1 of the insertion pin 9L in the R-axis direction is shorter than the length L2 of the recess 22R in the R-axis direction. The R-axis direction is the radial direction of the recess 22R and is orthogonal to the Z-axis. Also, the lower shape of the insertion pin 9L is preferably a shape that can be easily inserted into the recess 22R, and is, for example, a curved shape. That is, the lower side of the insertion pin 9L has a tapered shape in the downward direction. Therefore, the cross-sectional area S3 in the R direction of the lower end 9LB on the lower side of the insertion pin 9L is smaller than the cross-sectional area R4 in the R direction of the recess 22R. The depth direction of the recess 22R is parallel to the Z axis.

  As shown in FIG. 2, a metal plate 9S is inserted and arranged on the bottom surface of the recess 22R. In a state where the insertion pin 9L is inserted into the recess 22R, the insertion pin 9L contacts the metal plate 9S disposed on the bottom surface of the recess 22R. That is, the metal plate 9 </ b> S supports the workpiece material 8. The metal plate 9S is an example of the jig, the second jig, and the conductive member of the present invention. The surface of the metal plate 9S only needs to have conductivity. Therefore, the holding jig 9 and the metal plate 9S can be electrically contacted. In a state where the metal plate 9S is disposed on the bottom surface of the recess 22R, the bottom surface 9SL of the metal plate 9S and the upper surface 21CU of the central conductor 21C of the coaxial waveguide 21 face each other in the Z-axis direction via the microwave supply port 22. To do. The area S2 in the R-axis direction of the metal plate 9S has a relationship described later with the area S1 in the R-axis direction of the central conductor 21C of the coaxial waveguide 21. The center conductor 21 </ b> C is disposed in the microwave supply port 22 on the side opposite to the recess 22. Moreover, the metal plate 9S is thinner than the depth which is the length of the recess 22R in the Z direction.

  When the metal plate 9S is not disposed on the bottom surface of the recess 22R, the coaxial waveguide disposed via the recess 22R when the lower surface of the insertion pin 9L has a small shape such as a curved surface and the area contacting the bottom surface of the recess 22R is small. The electric lines of force from the center conductor 21C of 21 are concentrated below the insertion pin 9L having a small area. As a result, abnormal discharge occurs during plasma film formation, and film formation processing becomes unstable such as deterioration of film quality and prolonged film formation time.

の関係を有する。この結果、同軸導波管２１の中心導体２１Ｃとマイクロ波供給口２２を挟んで位置する保持治具９に電気力線が集中しづらくなる。この結果、成膜処理中に異常放電が発生しづらくなり、プラズマ成膜処理を安定化させることができる。なお、同軸導波管２１の中心導体２１Ｃの上面２１ＣＵの面積Ｓ１は、５ｍｍよりも大きく。金属板９Ｓの底面９ＳＬの面積Ｓ２は、凹部２２Ｒの底面の面積よりも小さい。上面２１ＣＵが本発明の第１面の一例であり、底面９ＳＬが本発明の第２面の一例である。 In the present embodiment, the area S1 of the upper surface 21CU of the central conductor 21C of the coaxial waveguide 21 is equal to the area S2 of the bottom surface 9SL of the metal plate 9S,

Have the relationship. As a result, it is difficult for electric lines of force to concentrate on the holding jig 9 located between the central conductor 21 </ b> C of the coaxial waveguide 21 and the microwave supply port 22. As a result, abnormal discharge is less likely to occur during the film forming process, and the plasma film forming process can be stabilized. The area S1 of the upper surface 21CU of the central conductor 21C of the coaxial waveguide 21 is greater than 5 mm. The area S2 of the bottom surface 9SL of the metal plate 9S is smaller than the area of the bottom surface of the recess 22R. The upper surface 21CU is an example of the first surface of the present invention, and the bottom surface 9SL is an example of the second surface of the present invention.

  In the graph shown in FIG. 4, the vertical axis represents VSWR (Voltage Standing Wave Ratio), and the horizontal axis represents the value T obtained by dividing the area S2 of the bottom surface 9SL of the metal plate 9S by the area S1 of the upper surface 21CU of the central conductor 21C. The VSWR is a value indicating the standing wave ratio, and is determined by the shape of the holding jig 9, the workpiece material 8, or the plasma state. When VSWR is “1”, there is an impedance, and the material 8 to be processed is stably formed into a plasma. When the value of VSWR is large, there is no impedance, and reflection on a member in the direction of supplying microwaves is greater than that of the tuner 18. The tuner 18 is adjusted so that this reflection is reduced, but the allowable range of adjustment is narrowed, and the plasma film forming process becomes unstable. If the VSWR is “12” or more, the tuner 18 cannot adjust the reflected wave to be small, the reflection becomes large, and the plasma state becomes unstable. As a result, the plasma film forming process becomes unstable, and the plasma film forming on the work material 8 cannot be sufficiently stabilized.

であれば、ＶＳＷＲが「１２」以下となり、プラズマ成膜処理が安定する。尚、数８の逆数が数７である。また、本実施形態では、凹部２２ＲのＲ軸方向の断面積は、面積Ｓ１以下である、従って、凹部２２Ｒに配置される金属板９Ｓの底面９ＳＬの面積Ｓ２は、面積Ｓ１以下である。この結果、

が成り立つ。 As shown in FIG. 4, the value T1 corresponding to VSWR “12” is 0.09. That is,

If so, the VSWR becomes “12” or less, and the plasma film forming process is stabilized. Note that the reciprocal of Equation 8 is Equation 7. In the present embodiment, the cross-sectional area in the R-axis direction of the recess 22R is not more than the area S1, and therefore the area S2 of the bottom surface 9SL of the metal plate 9S disposed in the recess 22R is not more than the area S1. As a result,

Holds.

の関係を満たせばよい。
数１０の逆数が、

である。 As shown in FIG. 4, when the value T is 0.35 or more, the VSWR becomes 2 or less, and the plasma film forming process is further stabilized. That is, the area S1 and the area S2 are

Satisfy this relationship.
The reciprocal of Equation 10 is

It is.

Figure 5 (A1), (B1) , (C1) is a bottom view of the three metal plates 9S having different shapes, the bottom 9SL are shown. 5A2, 5 </ b> B <b> 2, and 2 </ b> C <b> 2 are cross-sectional views in the front direction when the metal plate 9 </ b> S is cut in a direction parallel to the center line CL illustrated in FIG. 3. In FIG. 3, the center line CL passes through the center of the bottom surface of the recess 22R. FIGS. 5A3, 5B3, and 5C3 are top views of the center conductor 21C of the coaxial waveguide 21, showing the top surface 21CU of the center conductor 21C. Hereinafter, the metal plate 9SA and the central conductor 21CA are referred to with reference to FIGS. 5A1, (A2), and (A3), and the metal plate 9SB is referred to with reference to FIGS. 5B1, (B2), and (B3). The metal plate 9SC and the center conductor 21CC will be described with reference to FIGS. 5C1, 5C2 and 5C3.

  As shown in FIGS. 5A1, (A2), and (A3), the metal plate 9SA has a disk shape, and the shape of the bottom surface 9SAL of the metal 9SA is similar to the shape of the upper surface 21CAU of the center conductor 21CA. It is a shape. The center Cp1 of the bottom surface 9SAL of the metal plate 9SA coincides with the center Cp2 of the upper surface 21CAU of the center conductor 21CA in the Z direction and passes through the center line CL.

As shown in FIGS. 5 (B1), (B2), and (B3), the metal plate 9SB has a disk shape, and the thickness in the Z direction outside the R direction on the upper surface 9SBU is in the Z direction inside the R direction. Thicker than thickness. In other words, the upper surface 9SBU has a concave shape. That is, the metal plate 9SB has a shape in which the thickness in the Z direction increases with increasing distance from the center line CL in the R direction. The shape of the bottom surface 9SBL of the metal plate 9SB is similar to the shape of the upper surface 21CBU of the center conductor 21CB. The center Cp1 of the bottom surface 9SBL of the metal plate 9SB coincides with the center Cp2 of the upper surface 21CBU of the center conductor 21CB in the Z direction and passes through the center line CL. Bottom surface 9SBL the entire surface from the center Cp1 to the outer periphery 9SBP is in contact with the bottom surface of the recess 22R.

  As shown in FIGS. 5 (C1), (C2), and (C3), the metal plate 9SC has a hollow disk shape, and the thickness in the Z direction outside the R direction on the upper surface 9SCU is Z in the R direction inside. Thicker than the thickness in the direction. That is, the metal plate 9SC has a shape in which the thickness in the Z direction increases with increasing distance from the center line CL in the R direction. The shape of the bottom surface 9SCL of the metal 9SC is similar to the shape of the upper surface 21CCU of the center conductor 21CC. That is, the upper surface 21CCU of the center conductor 21CC is also hollow. The center Cp1 of the bottom surface 9SCL of the metal plate 9SC coincides with the center Cp2 of the upper surface 21CCU of the center conductor 21CC in the Z direction and passes through the center line CL.

  The areas of the top surfaces 21CAU, 21CBU, and 21CCU shown in FIG. 5 are the area S1, and the areas of the bottom surfaces 9SAL, 9SBL, and 9SCL are the area S2. It suffices that these areas S1 and S2 satisfy the above formula 7.

  The surface roughness of the upper surfaces 9SAU, 9SBU, and 9SCU shown in FIG. 5 is 0.1 μm or more and 1 mm or less. When the surface roughness is less than 0.1 μm, it is difficult to remove the holding jig 9 and the metal plate 9S. On the other hand, if the surface roughness is larger than 1 mm, the voltage distribution in the R direction of the upper surfaces 9SAU, 9SBU, and 9SCU increases, which may cause abnormal discharge. On the other hand, since the surface roughness of the upper surfaces 9SAU, 9SBU, and 9SCU is 0.1 μm or more, it is possible to shorten the time for continuously forming a plurality of workpieces 8 on the plasma. Further, since the surface roughness is 1 mm or less, the possibility of causing abnormal discharge can be reduced.

  As shown in FIG. 5, since the entire bottom surfaces 9SAL and 9SBL are in contact with the bottom surface of the recess 22R, the possibility of abnormal discharge due to gas entering the space between the bottom surface of the recess 22R and the metal plates 9SA and 9SB is reduced. it can.

  As shown in FIGS. 1 and 2, the work material 8 is disposed so as to protrude toward the inside of the processing container 2 from the holding jig 9 that holds the work material 8 with respect to the microwave supply port 22. Has been.

  A negative voltage electrode 25 for applying a negative bias voltage pulse is electrically connected to the upper end portion of the work material 8 at the upper end portion of the work material 8.

  The negative voltage power supply 15 supplies a negative bias voltage to the negative voltage pulse generator 16 in accordance with an instruction from the controller 6. The negative voltage pulse generator 16 pulses the negative bias voltage supplied from the negative voltage power supply 15. This pulsing process is a process in which the negative voltage pulse generator 16 controls the magnitude, cycle, and duty ratio of the negative bias voltage pulse in accordance with an instruction from the controller 6. A negative bias voltage pulse, which is a pulsed negative bias voltage, is applied to the workpiece 8 held inside the processing vessel 2 via the negative voltage electrode 25.

  Even when the work material 8 is a metal substrate, or when a conductive material is coated on ceramic or resin, a negative bias voltage pulse is applied to at least the entire processing surface of the work material 8. The A negative bias voltage pulse is also applied to the entire surface of the holding jig 9 via the workpiece 8.

  The surface wave excitation plasma 28 is generated by controlling the generated microwave pulse and the negative bias voltage pulse to be applied at the same time. The microwave is not limited to 2.45 GHz, but may have a frequency of 0.3 GHz to 50 GHz. The negative voltage power supply 15, the negative voltage pulse generator 16, and the negative voltage electrode 25 are examples of the negative voltage application unit of the present invention.

  The microwave control unit 11, the microwave oscillator 12, the microwave power source 13, the isolator 17, the tuner 18, the waveguide 19, and the coaxial waveguide 21 are examples of the microwave supply unit of the present invention. The film forming apparatus 1 includes the negative voltage power supply 15 and the negative voltage pulse generator 16, but may further include a positive voltage power supply and a positive voltage pulse generator, or instead of the negative voltage pulse generator 16. In addition, a negative voltage generator for applying a continuous negative bias voltage instead of a pulsed negative bias voltage may be provided.

  A radiation thermometer 29 is arranged at a position near the outside of the quartz window 27 provided on the side wall of the processing container 2. The radiation thermometer 29 is electrically connected to the control unit 6. The radiation thermometer 29 receives infrared rays and calculates the intensity of the received infrared rays. The surface temperature of the workpiece 8 is calculated from the calculated infrared intensity. The radiation thermometer 29 outputs the calculated temperature information of the work material 8 to the control unit 6.

  The control unit 6 outputs control signals to the negative voltage power supply 15 and the microwave power supply 13 to control the applied power of the microwave pulse and the applied voltage of the negative voltage pulse. The control unit 6 outputs a control signal to the negative voltage pulse generation unit 16 and the microwave pulse control unit 11, thereby generating a pulsed negative bias voltage pulse application timing, a supply voltage, and a microwave oscillator 12. Control the supply timing and power supply of the microwave pulse.

  The control unit 6 outputs a flow rate control signal to the gas supply unit 5 to control the supply of the source gas and the inert gas. The control unit 6 outputs a control signal to the pressure adjustment valve 7 based on a pressure signal representing the pressure in the processing container 2 input from the vacuum gauge 26 attached to the processing container 2, and Control the pressure.

[Description of surface wave excitation plasma]
Usually, when generating surface wave excitation plasma, a microwave is supplied along the interface between a plasma having a certain level of electron (ion) density and a dielectric in contact with the plasma. The supplied microwave is propagated as a surface wave with the energy of electromagnetic waves concentrated on this interface. As a result, the plasma in contact with the interface is excited by a high energy density surface wave and further amplified. Thereby, a high density plasma is generated and maintained. However, when this dielectric is replaced with a conductive material, the conductive material does not function as a surface wave waveguide, and preferable surface wave propagation and plasma excitation cannot occur.

  On the other hand, an essentially unipolar charged particle layer, a so-called sheath layer, is formed near the surface of an object in contact with plasma. In the case where the object is a work material 8 having conductivity to which a negative bias voltage is applied, the sheath layer is a layer having a low electron density, that is, positive polarity, and substantially has a relative dielectric constant in the microwave frequency band. It is a layer of ε≈1. For this reason, the sheath thickness of the sheath layer can be increased by making the absolute value of the negative bias voltage to be applied larger than the absolute value of, for example, −100V. That is, the sheath layer expands. This sheath layer acts as a dielectric that propagates surface waves to the interface between the plasma and the object in contact with the plasma.

  Therefore, a microwave is supplied from the microwave supply port 22 disposed in the vicinity of one end of the holding jig 9 that holds the workpiece 8, and a negative bias voltage is applied to the workpiece 8 and the holding jig 9. When applied, the microwave propagates as a surface wave along the interface between the sheath layer and the plasma. As a result, high-density excitation plasma based on surface waves is generated along the surfaces of the work material 8 and the holding jig 9. This high-density excitation plasma is the surface wave excitation plasma 28 described above.

The electron density of the high-density plasma due to surface wave excitation in the vicinity of the surface of the workpiece 8 reaches 1011 to 1012 cm-3. DLC by plasma CVD using this MVP method
When film formation is performed, film formation speeds of 3 to 30 (nanometers / second), which are one to two orders of magnitude higher than those when DLC film formation is performed by normal plasma CVD, can be achieved. is there.

  In this MVP method, high-density excitation plasma is generated in the vicinity of the surfaces of the work material 8 and the holding jig 9 that are metal substrates, and therefore the surface temperature of the work material 8 and the holding jig 9 is likely to rise (for example, About 250 ° C. to about 320 ° C.). However, since high-speed film formation is possible, the film formation time is 1/10 to 1/100 of the normal plasma CVD film formation time. That is, since the film formation time can be shortened to several tens of seconds to several minutes, the softening of the work material 8 can be suppressed even if the surface temperature of the work material 8 exceeds the tempering temperature.

  In the present embodiment, a negative bias voltage is applied to the work material 8 and the holding jig 9, and microwaves are supplied to generate high-density plasma. That is, the center conductor 21C of the coaxial waveguide 21 faces the metal plate 9S that contacts the holding jig 9 to which a negative bias voltage is applied, with the microwave supply port 22 interposed therebetween. Therefore, the electric lines of force from the central conductor 21C are directed to the metal plate 9S, not the lower side of the insertion pin 9L of the holding jig 9, inside the recess 22R, which is a region where high-density plasma is generated. As a result, it is difficult for electric lines of force to concentrate and the possibility of abnormal discharge is reduced.

  Specific microwave pulse and negative bias voltage pulse application methods in the present embodiment are described in JP-A-2004-47207, JP-A-2013-155409, and the like, and will not be described.

  As shown in FIG. 2, since the metal plate 9S is disposed in the recess 22R, the metal plate 9S is less likely to be displaced in the recess 22R than the holding jig 9 attached and detached together with the work material 8. As a result, the possibility of causing abnormal discharge during the film forming process can be further reduced, and the plasma film forming process can be further stabilized.

  As shown in FIG. 5, since the center Cp2 of the upper surface 21CU of the center conductor 21C having the area S1 and the center Cp1 of the bottom surface 9SL of the metal plate 9S having the area S2 are arranged to coincide with each other, the electric power is supplied to the metal plate 9S. It makes it harder to concentrate the lines of force. As a result, the possibility of causing abnormal discharge during the film forming process can be further reduced, and the plasma film forming process can be further stabilized.

  As shown in FIG. 5, the upper surface 21CU of the central conductor 21C having the area S1 and the bottom surface 9SL of the metal plate 9S having the area S2 are similar. Therefore, the electric lines of force are more difficult to concentrate on the metal plate 9S. As a result, the possibility of causing abnormal discharge during the film forming process can be further reduced, and the plasma film forming process can be further stabilized.

  As shown in FIG. 5 (B1), (B2), (B3), (C1), (C2), (C3), the upper surfaces 9SBU, 9SCU of the metal plates 9SB, 9SC are directed from the center toward the R direction. The metal plate 9S has a shape in which the thickness in the Z direction increases. Therefore, the holding jig 9 can be easily positioned with respect to the metal plate 9S, and the holding jig 9 and the metal plate 9S are electrically contacted more reliably. As a result, the material 8 to be processed is subjected to plasma film formation more stably.

Figure 5 (B1), (B2) , as shown in (B3), the bottom surface 9SBL metal plate 9S, since the recess 22R and the entire surface is in contact, the electric lines of force from the center conductor 21C is concentrated to the metal plate 9S It becomes difficult. As a result, the possibility of causing abnormal discharge during the film forming process can be further reduced, and the plasma film forming process can be further stabilized.

  In the embodiment described above, the holding jig 9 on which the work material 8 is mounted contacts the metal plate 9S. However, the work material 8 may contact the metal plate 9S. Also in this case, the area of the bottom surface 9SL of the metal plate 9S is the cross-sectional area S2 of the present invention.

  In the above embodiment, the metal plate 9S is disposed in the recess 22R, but the present invention is not limited to this. As shown in FIG. 6, the holding jig 9a includes an insertion pin 9La. The holding jig 9a is an example of the jig of the present invention. The lower side of the insertion pin 9La has a tapered shape, not a spherical shape. Similar to the above embodiment, the lower side of the insertion pin 9La has a tapered shape in the downward direction. Therefore, the cross-sectional area of the lower surface, which is the lower end of the insertion pin 9La, is smaller than the cross-sectional area R4 in the R direction of the recess 22R. The lower surface of the insertion pin 9La is in surface contact with the bottom surface of the recess 22R. The area of the lower surface of the insertion pin 9La that contacts the bottom surface of the recess 22R is an example of the area S2 of the present invention. It is only necessary that the area S2 of the lower surface of the insertion pin 9La has the relationship of the expression S7 with the area S1 of the upper surface 21CU of the central conductor 21C.

  In the above embodiment, the shapes of the bottom surfaces 9SAL, 9SBL, and 9SCL of the metals 9SA, 9SB, and 9SC are similar to the shapes of the top surfaces 21CAU, 21CBU, and 21CCU of the center conductor 21CA. For example, it may not be similar. Further, the center Cp1 of the bottom surface 9SL of the metal plate 9S coincides with the center Cp2 of the upper surface 21CU of the center conductor 21C in the Z direction and passes through the center line CL, but the center Cp1 and the center Cp2 do not have to coincide with each other. It does not have to pass through the center line CL.

  In the above embodiment, the source gas and the inert gas are used as examples of the gas. However, a gas such as an etching gas or an ashing gas may be used.

  In the above-described embodiment, the area S1 is the area of the upper surface 21CU of the central conductor 21C facing the microwave supply port 22. However, when the upper surface 21C has irregularities or is curved, the microwave supply port 22 is used. An area S1 is a cross-sectional area in the R direction at the tip of the center conductor 21C that faces the center. The area S2 is the area of the bottom surface 9SL of the metal plate 9 facing the bottom surface of the recess 22R, that is, the area of the bottom surface 9SL of the metal plate 9 contacting the bottom surface extending in the R direction of the recess 22R. In the state where the metal plate 9S is arranged, when the bottom surface 9SL of the metal plate 9 has a region extending in the direction intersecting the R direction, the bottom surface 9SL of the metal plate 9 farthest from the center line CL in each R direction The area surrounded by the plurality of contacts with the recess 22R is the area S2. That is, in a state where the metal plate 9S is disposed in the recess 22R, if the VSWR is 12 or less, it can be said that the area S1 and the area S2 satisfy the relationship of Equation 7.

DESCRIPTION OF SYMBOLS 1 Film-forming apparatus 2 Processing container 6 Control part 8 Work material 9 Holding jig 9L Insertion pin 9S Metal plate 11 Microwave pulse control part 12 Microwave oscillator 13 Microwave power supply 15 Negative voltage power supply 16 Negative voltage pulse generation part 17 Isolator 18 Tuner 21 Coaxial Waveguide 21C Center Conductor 22 Microwave Supply Port 25 Negative Voltage Electrode CL Center Line Cp1 Center Cp2 Center

Claims (9)

A processing container capable of arranging a work material which is a film formation target and has a conductive surface inside;
A gas supply unit for supplying gas into the processing container;
A microwave supply unit for supplying microwaves for generating plasma along the processing surface of the workpiece material;
A negative voltage application unit that applies a negative bias voltage to the workpiece material to expand a sheath layer along the processing surface of the workpiece material;
A microwave supply port made of a dielectric material that transmits microwaves that propagate microwaves supplied from the microwave supply unit to the expanded sheath layer;
Wherein a recess formed in the microwave feed opening, the direction of the area perpendicular to the depth direction of the depth direction of the distal end of the concave portion, rather smaller than the cross-sectional area of the recess in the direction the perpendicular, A recess into which a jig having conductivity on the surface for supporting the work material is inserted;
A central conductor of a waveguide that transmits the microwave supplied from the microwave supply unit, disposed in the microwave supply port on the opposite side of the recess in the depth direction of the recess;
In the depth direction of the concave portion, the area S1 of the first surface perpendicular to the depth direction at the upper end of the central conductor facing each other through the microwave supply port, and the lower end of the jig And the area S2 of the second surface perpendicular to the depth direction is

A film forming apparatus having the following relationship: The area S1 and the area S2 are:

The film forming apparatus according to claim 1, wherein: The jig includes a first jig on which the material to be processed is mounted, and a second jig that is disposed in the recess and can be electrically contacted with the first jig,
3. The film forming apparatus according to claim 1, wherein a surface of the second jig facing the first surface in the depth direction of the recess is the second surface. The film forming apparatus according to claim 3, wherein the center conductor is arranged such that a center of the first surface and a center of the second surface are aligned in the depth direction. 5. The film forming apparatus according to claim 3, wherein the first surface and the second surface are similar. The surface of the second jig opposite to the second surface in the depth direction is directed from the center of the second surface to an orthogonal direction orthogonal to the depth direction, and the depth of the second jig. The film forming apparatus according to claim 3, wherein the film forming apparatus has a shape in which the thickness in the vertical direction increases. The film forming apparatus according to claim 6, wherein the second surface has a shape in which the entire surface from the center of the second surface to the outer periphery of the second surface is in contact with the recess. 8. The surface roughness of the surface opposite to the second surface of the second jig in the depth direction is 0.1 μm or more and 1 mm or less. Film forming equipment. A processing container capable of arranging a work material which is a film formation target and has a conductive surface inside;
A gas supply unit for supplying gas into the processing container;
A microwave supply unit for supplying microwaves for generating plasma along the processing surface of the workpiece material;
A negative voltage application unit that applies a negative bias voltage to the workpiece material to expand a sheath layer along the processing surface of the workpiece material;
A microwave supply port made of a dielectric material that transmits microwaves that propagate microwaves supplied from the microwave supply unit to the expanded sheath layer;
A recess formed in the microwave supply port and into which a jig having a conductive surface for supporting the work material is inserted;
A central conductor of a waveguide that transmits the microwave supplied from the microwave supply unit, disposed in the microwave supply port on the opposite side of the recess in the depth direction of the recess;
A conductive member disposed in the recess and thinner than the depth of the recess in the depth direction;
In the depth direction, the area S1 of the first surface perpendicular to the depth direction at the upper end of the central conductors facing each other through the microwave supply port, and the lower end of the conductive member The area S2 of the second surface orthogonal to the depth direction is

A film forming apparatus having the following relationship:

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