JP2013098276A - Substrate holder and vacuum processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate holder which can be used in an expanded temperature zone.SOLUTION: A substrate holder 13 comprises: a relay circuit 61 which is connected to a second end of a ground shaft 53 having a first end in conduction with a substrate support surface 45 so as to switch the ground shaft 53 to ground potential; a compression coil spring 59 which urges a cap of the first end of the ground shaft 53 so as to push the cap against the substrate support surface 45; a bellows 57 which includes the second end of the ground shaft 53 arranged at a vacuum side, and expands and contracts in the urging direction of the compression coil spring 59; and an O ring 63 which is held in the urging direction of the compression coil spring 59. In this structure, conduction with the substrate support surface 45 can be ensured even when the ground shaft 53 is thermally expanded.

Description

The present invention relates to a substrate holder including an electrostatic adsorption device and a vacuum processing apparatus including such a substrate holder.

  The electrostatic adsorption device provided in the substrate holder is an apparatus that generates a charge on the electrostatic adsorption plate and the substrate by applying a voltage to the electrostatic adsorption plate, and adsorbs the substrate to the electrostatic adsorption plate. In addition, while a heater is provided in the substrate holder, a gas at a constant pressure is sealed in the gap between the adsorbed substrate and the electrostatic adsorption plate, and the temperature of the substrate can be adjusted via this gas.

  By the way, if the voltage applied to the electrostatic chucking plate is simply turned off, the charges generated on the electrostatic chucking plate and the substrate cannot be sufficiently removed, and a residual charge may be generated. This residual charge also generates an attracting force between the substrate and the electrostatic chucking plate, which may interfere with a mechanism such as a lifter pin when the substrate is detached from the electrostatic chucking plate. In a structure in which the lifter pin is pressed against the substrate and physically peeled off (see, for example, Patent Documents 1-3), the substrate may be damaged or the substrate may be displaced due to interference with the lifter pin.

  In the technology disclosed in Patent Documents 1-3, physical damage to the substrate due to the pressing of the lifter pins, generation of dust due to rubbing between the substrate and the electrostatic chuck, reverse voltage, and electrical damage to the substrate due to plasma are caused. There are concerns that arise.

  In addition to the substrate processing time, the method using a lifter pin requires time to perform a static elimination sequence (lifter pin fine contact operation time, gas filling time, discharge time, reverse voltage application time), which is important in semiconductor manufacturing equipment. There was a risk that the throughput seen would be reduced.

  In order to solve the above problem, a structure is disclosed in which the potential of the surface of the electrostatic chucking plate can be switched to floating or ground by providing a ground switching device in contact with the substrate and the surface of the electrostatic chucking plate (for example, Patent Document 4). reference). According to the technique of Patent Document 4, the ground switching device is set in a floating state during the heating / cooling process, the charge is held on the surface of the substrate and the electrostatic chuck plate, and the suction is maintained. When the switching device is in a ground state, the charges on the surface of the substrate and the electrostatic chucking plate can be instantaneously released to the ground and the substrate can be detached.

  According to the electrostatic adsorption device technique of Patent Document 4, a conductor wiring is provided on the surface of a dielectric plate, and the conductor wiring is a conductor that releases the charges on the surface of the substrate and the electrostatic adsorption plate from the vacuum side to the atmosphere side. The shaft is screwed, and the atmosphere side of the conductor shaft is connected to a ground switching device. The potential from the conductor wiring to the earth switching device is the same. With this mechanism, it is possible to wipe off physical damage and electrical damage that are problematic in the substrate detachment method.

Japanese Patent Laid-Open No. 7-263531 JP 2002-83860 A JP 2006-303138 A JP 2004-022889 A

  However, in the structure disclosed in Patent Document 4, when heat treatment is performed in a high temperature range, heat is transferred to the conductive shaft, and thus thermal expansion of the conductive shaft is inevitable. Thermal expansion of the conductive shaft may place a strong load on the joint with the conductor wiring. When the amount of thermal expansion exceeds the design allowable amount, there is a possibility that the joint portion with the conductor wiring is damaged or the conductor wiring is peeled off from the dielectric plate. Therefore, although the use temperature range was limited by setting the upper limit of the heating temperature or the like, it is desired to expand the usable temperature range.

  In view of the above-described problems, the object of the present invention is to charge the surface of the electrostatic chuck plate and the substrate without physical contact by other elements in the operation of removing the substrate from the substrate holder equipped with the electrostatic chuck. It is an object of the present invention to provide a substrate holder and a semiconductor manufacturing apparatus that can widen the usable temperature range while being capable of discharging at the same time.

The substrate holder according to the present invention includes a grounding member having one end connected to the substrate support surface, a switching unit connected to the other end of the grounding member and capable of switching the grounding member to the ground potential, and one end of the grounding member. An urging means for urging the substrate in contact with the substrate support surface, and an elastic partition wall portion in which the other end portion of the grounding member is disposed on the inside and expands and contracts in the urging direction of the urging means. Features.
A substrate holder according to the present invention includes at least a holder main body including an electrostatic adsorption plate to which a voltage for adsorbing a substrate supported on a substrate support surface is applied and a conductor wiring electrically connected to the substrate supported on the substrate support surface. A substrate holder having a holder support portion for supporting the holder main body portion, and a static elimination portion capable of switching the conductor wiring to a grounded state.
A grounding member whose one end is in contact with the conductor wiring, a switching unit which is connected to the other end of the grounding member and switches the conductor wiring between a ground state and a floating state via the grounding member, and a grounding member is in contact with the conductor wiring And an elastic partition wall that is arranged inwardly at the other end of the grounding member and that is hermetically connected between the holder side and the grounding member and expands and contracts in the biasing direction of the biasing means. And comprising

  According to the present invention, in the operation of detaching the substrate from the substrate holder provided with the electrostatic adsorption device, it is possible to simultaneously remove the charge on the surface of the electrostatic adsorption plate and the substrate without physical contact with a lifter pin or the like. In addition, it is possible to provide a substrate holder that improves the reliability of the substrate detachment operation in a wide temperature range, and a vacuum processing apparatus that realizes a high yield rate and a high device operation rate.

1 is a schematic cross-sectional view of a sputter deposition apparatus according to an embodiment of the present invention. It is an enlarged view of the air | atmosphere side edge part of the static elimination part which concerns on one Embodiment of this invention. It is an enlarged view of the vacuum side edge part of the static elimination part which concerns on one Embodiment of this invention.

  The members, arrangements, and the like described below are examples embodying the present invention and do not limit the present invention, and it goes without saying that various modifications can be made within the spirit of the present invention. In order to prevent complication of the drawing, the illustration is omitted except for a part. In the following embodiments, a substrate holder applied to a sputtering film forming apparatus will be described as a vacuum processing apparatus, but it goes without saying that the present invention can be applied to a vacuum processing apparatus including a substrate holder having an electrostatic adsorption device such as a CVD device. It is.

  1 to 3 are views of a vacuum processing apparatus or a substrate holder according to an embodiment of the present invention, FIG. 1 is a schematic cross-sectional view of a sputtering film forming apparatus, and FIG. 2 is an enlarged view of a vacuum side end portion of a static elimination section. FIG. 3 is an enlarged view of the air-side end of the static elimination unit.

FIG. 1 is a schematic sectional view of a sputtering apparatus (vacuum processing apparatus) according to the present invention.
The sputtering apparatus 1 includes a vacuum container 11 that can be evacuated inside, a target electrode 12 that is attached to the top of the vacuum container 11, a target 18 that has a film-forming material, and a substrate holder 13 that can support the substrate W while facing the target electrode 12. have. In FIG. 1, a substrate transfer device, a carry-in / carry-out gate, a lift pin, and the like are omitted.

  The vacuum vessel 11 is configured using a metal member such as stainless steel or aluminum alloy, and is grounded. The vacuum vessel 11 is connected to a gas introduction device 19 and an exhaust device 20. The target electrode 12 is attached to the vacuum vessel 11 via an insulating material 17. The target 18 is formed by bonding a film forming material to a backing plate (not shown), and is attached to the target electrode 12 so that the film forming material faces the plasma forming space. The target electrode 12 is connected to the high frequency power supply 16 through a matching box (not shown).

  The target electrode 12 is provided with a cooling mechanism for preventing the temperature of the target 18 from rising and a magnet unit that forms a magnetic field on the target surface. As the high-frequency power supply 16, a 13.56-MHz one is industrially easy to use, but other frequencies can be used and direct current can be superimposed on the high frequency.

  The substrate holder 13 includes a holder main body portion 21 that supports the substrate W, and a holder support portion 22 that is disposed through the vacuum vessel 11 and is connected to the holder main body portion 21 in the vacuum vessel 11. Yes. The holder main body 21 is configured such that an electrostatic adsorption device 26 that supports the substrate W is disposed on the upper side (target side) of the substrate heating device 24 that heats the substrate W.

  First, the substrate heating device 24 will be described. The substrate heating device 24 includes a lower casing 31 that supports the electrostatic chuck 26 and a heater electrode 33 (heating unit) provided in the lower casing 31 as main components. The heater electrode 33 has an electrode pattern such as a spiral shape or a meandering shape. By connecting a power source (not shown) to this electrode pattern and applying DC or AC power, a current flows through the heater electrode 33, and the substrate temperature can be controlled by the generated Joule heat. In the present embodiment, graphite is used as the heater electrode 33, but tungsten, PG / PBN heater, or the like may be used.

  Further, a substrate cooling device may be provided instead of the substrate heating device. In this case, a structure in which a cooling pipe through which a refrigerant such as liquid nitrogen or liquid helium flows is incorporated in the lower housing 31 instead of the heater electrode 33 is desirable. Of course, the lower housing 31 may be provided with both the heater electrode 33 and the cooling pipe.

  The electrostatic adsorption device 26 will be described. The electrostatic adsorption device 26 includes a dielectric layer 35, an electrostatic adsorption plate 37, a static elimination unit 40, and a gas introduction unit (not shown). The dielectric layer 35 is a member constituting the housing of the electrostatic adsorption device 26, and is made of a dielectric material. An embossed substrate support surface 45 is formed on the surface of the dielectric layer 35. The embossing of the substrate support surface 45 has a shape in which the back surface of the substrate is supported by a plurality of convex portions 46, and a gap with a predetermined height is formed between the portion other than the convex portions 46 and the back surface of the substrate W.

  Furthermore, a metal coat 43 (conductor wiring) made of a conductive film-like material is formed on the substrate support surface 45. The metal coat 43 has a pattern formed so as to pass through the surface of the convex portion 46. That is, the substrate W is supported by the substrate holder 13 while being in contact with the metal coat 43 on the surface of the convex portion 46.

  The electrostatic attraction plate 37 is an electrode disposed inside the dielectric layer 35 in parallel with the substrate support surface 45, and is configured in a spiral shape, a meandering shape, a radial shape, or the like. The electrostatic chucking plate 37 is connected to a DC power supply circuit, and the substrate W is electrostatically chucked to the substrate support surface 45 of the electrostatic chucking device 26 by applying a predetermined voltage from the DC power supply circuit (Ea, Eb). can do. The electrostatic attraction plate 37 of the present embodiment has a bipolar electrode structure composed of a pair of electrodes for applying positive and negative voltages inside the dielectric layer 35. Of course, the present invention can also be applied to an electrostatic attraction plate having a monopolar electrode structure.

  The gas introduction unit is a mechanism that introduces gas into the gap between the substrate W and the substrate support surface 45 in order to efficiently transfer the heat from the heater electrode 33 to the substrate, and Ar is introduced from the gas introduction hole formed in the substrate support surface 45. Or a gas such as He is introduced. The substrate W is supported in a state where a gap is formed between the substrate W and the substrate support surface 45 by the embossed convex portions 46 formed on the substrate support surface 45.

  2 and 3 are partial cross-sectional views of the charge removal unit 40, FIG. 2 is an enlarged view of the vacuum side end of the charge removal unit 40, and FIG. 3 is an enlarged view of the atmosphere side end of the charge removal unit 40. The static elimination unit 40 includes a conductive terminal (cap) 51 electrically connected to the metal coat 43 on the substrate support surface 45, a ground shaft 53 (ground member or shaft portion) provided integrally with the conductive terminal, and a termination ring 55. And a bellows 57 and a compression coil spring 59. The ground shaft 53 is connected to a relay circuit 61 (switching unit) that can switch the potential state of the ground shaft 53 between a floating state and a ground state. In addition, a disk-like member (flange portion 56) similar to the termination ring 55 is integrally provided at the atmosphere-side end (vacuum-side end) of the ground shaft 53.

  Based on FIG. 2, the end portion on the vacuum side of the static elimination unit 40 will be described. The substrate holder 13 is formed with a through hole 52 that penetrates the holder main body 21 and the holder support 22 in the direction of gravity. The ground shaft 53 is a stainless steel shaft-like member disposed through the through hole 52. A portion (one end side) of the ground shaft 53 disposed in the vacuum vessel is located in a vacuum atmosphere. An end (one end) on the vacuum side of the ground shaft 53 is screwed into a conductive terminal 51 (cap), and is electrically connected to the metal coat 43 on the substrate support surface 45 via the conductive terminal 51.

  The conductive terminal 51 is formed in a size lower than the height of the recess 45 a formed in the substrate support surface 45 and has a diameter larger than the inner diameter of the through hole 52. Therefore, when the grounding shaft 53 is urged downward, the conductive terminal 51 can be prevented from coming into contact with the substrate W placed on the substrate holder 13. In addition, when the conductive terminal 51 and the metal coat 43 are brought into contact with each other, conduction between the ground shaft 53 and the metal coat 43 can be ensured via the conductive terminal 51.

  Based on FIG. 3, an end portion on the atmosphere side of the static elimination unit 40 will be described. The end (other end) on the atmosphere side of the ground shaft 53 has a seal structure and is electrically connected to the relay circuit 61. Specifically, a disk-shaped flange portion 56 is integrally provided at an end of the ground shaft 53 on the atmosphere side, and a bellows 57 (elastic partition wall portion or second urging means) is provided on the flange portion 56. Airtight connection. Since the bellows 57 is attached to the vacuum side end side (the other end side) of the flange portion 56, the ground shaft 53 is disposed on the vacuum side inside the bellows 57.

  The compression coil spring 59 can be arranged on either the outside or the inside of the bellows 57. However, by disposing the compression coil spring 59 outside the bellows 57, an increase in the surface area of the member disposed on the vacuum side can be suppressed. Therefore, the time required for evacuation can be shortened. A ring-shaped end ring 55 is airtightly connected to the opposite side of the bellows 57 from the flange portion 56.

  By supporting (holding) the O-ring 63 serving as a sealing member between the terminal ring 55 and the holder support portion 22, the inside of the flange portion 56 and the bellows 57 can be held in a vacuum. The space inside the bellows 57 communicates with the space in the vacuum vessel 11 through the through hole 52. As the sealing member, an O-ring 63 made of fluororubber is preferably used, but other resins and metallic sealing members can be used.

  The bellows 57 (elastic partition wall or second urging means) has elasticity that expands and contracts in the axial direction, and is located between the flange portion 56 and the terminal ring 55. Therefore, by adjusting the length of the bellows 57 or the length of the grounding shaft 53, an elastic force (biasing force) that biases the grounding shaft 53 downward can be applied to the flange portion 56.

By urging the ground shaft 53 downward, the conductive terminal 51 can be pressed against the metal coat 43, and reliable conduction between these members can be ensured.
That is, even if the members constituting the substrate holder 13 such as the ground shaft 53 and the dielectric layer 35 expand / shrink due to heat, the conductive terminal 51 can be pressed against the metal coat 43 with a predetermined pressure. Sufficient conduction between 51 and the metal coat 43 can be ensured.

  Note that the configuration of the present invention can also be applied to a structure in which the grounding shaft 53 is urged upward to press the conductive terminal 51 against the metal coat 43. For example, the conductive terminal 51 may be pressed against the metal coat 43 extending to the back side of the substrate holder (the opposite side of the target). That is, the direction in which the urging means urges the conductive terminal 51 is a direction in which the conductive terminal 51 is pressed against the metal coat 43.

  The compression coil spring 59 is a member for increasing the biasing force that biases the ground shaft 53 downward. An urging force stronger than that of the bellows 57 can be obtained by the compression coil spring 59, and conduction between the conductive terminal 51 and the metal coat 43 can be further ensured. In the present embodiment, the compression coil spring 59 is mainly used as the urging means, but the bellows 57 also has an urging force, so that it can function as the urging means. That is, the bellows 57 has a function as an urging means in addition to the function of the vacuum partition. If the urging force of the bellows 57 is sufficiently strong, the urging means can be configured without using the compression coil spring 59.

  The conduction between the conductive terminal 51 and the metal coat 43 can be ensured by the biasing means. Therefore, after the vacuum process such as the sputter film forming process is completed, the relay circuit 61 is switched, and the metal coat 43 in contact with the back surface of the substrate W is set to the ground potential, so that the electrostatic adsorption of the substrate W is promptly performed. It can be canceled. That is, the substrate W can be replaced more quickly and reliably than in the past.

  As described above, the O-ring 63 is disposed so as to be sandwiched between two members (the terminal ring 55 and the flange portion 56) in the biasing direction of the ground shaft 53. Since the O-ring 63 has a structure that does not come into contact with the ground shaft 53, the O-ring 63 will not be twisted even if the ground shaft 53 is replaced for maintenance or the like. Therefore, the seal can be maintained more reliably. Further, since the replacement life of the O-ring 63 can be extended, the maintenance interval can be extended.

  According to the present invention, in the operation of detaching the substrate from the substrate holder provided with the electrostatic adsorption device, it is possible to simultaneously remove the charge on the surface of the electrostatic adsorption plate and the substrate without physical contact by other elements. In addition, it is possible to provide a substrate holder that improves the reliability of the substrate detachment operation in a wide temperature range, and a vacuum processing apparatus that realizes a high yield rate and a high device operation rate.

  Specifically, by using the substrate holder according to the present invention, it has become possible to greatly improve the reliability of static elimination in a wide range from 0 ° C. or lower to 500 ° C. or higher. Therefore, it is possible to realize a semiconductor manufacturing apparatus capable of reducing the throughput for 30 to 60 seconds per substrate. Thereby, the vacuum processing apparatus which implement | achieves a high non-defective rate and an apparatus operation rate can be provided.

DESCRIPTION OF SYMBOLS 1 Sputtering apparatus 11 Vacuum vessel 12 Target electrode 13 Substrate holder 16 High frequency power supply 17 Insulating material 18 Target 19 Gas introduction apparatus 20 Exhaust apparatus 21 Holder body part 22 Holder support part 24 Substrate heating apparatus 26 Electrostatic adsorption apparatus 31 Lower housing 33 Heater Electrode 35 Dielectric layer 37 Electrostatic adsorption plate 40 Static elimination part 43 Metal coat 45 Substrate support surface 46 Convex part 51 Conductive terminal 52 Through hole 53 Ground shaft 55 Termination ring 56 Flange part 57 Bellows (second urging means or elastic partition wall) Part)
59 Compression coil spring (biasing means)
61 Relay circuit 63 O-ring (sealing member)

Claims (8)

A grounding member having one end connected to the substrate support surface;
A switching unit connected to the other end of the grounding member and capable of switching the grounding member to a ground potential;
An urging means for urging the one end side of the grounding member in a direction in contact with the substrate support surface;
A substrate holder, comprising: the other end portion of the grounding member disposed inside, and an elastic partition wall portion extending and contracting in a biasing direction of the biasing means. An electrostatic chucking plate to which a voltage for adsorbing the substrate supported by the substrate support surface is applied, and a holder main body portion including at least a conductor wiring electrically connected to the substrate supported by the substrate support surface;
A holder support part for supporting the holder body part;
A neutralization unit capable of switching the conductor wiring to a grounded state, and a substrate holder,
The static eliminator is
A grounding member whose one end is in contact with the conductor wiring;
A switching unit that is connected to the other end of the ground member and switches the conductor wiring between a ground state and a floating state via the ground member;
Urging means for urging the grounding member in a direction in contact with the conductor wiring;
The other end portion of the grounding member is disposed inside, and includes an elastic partition wall that hermetically connects the holder side and the grounding member side and expands and contracts in the biasing direction of the biasing means. A featured substrate holder. The grounding member is disposed through the holder support portion and has a flange portion on the other end side,
3. The substrate according to claim 2, wherein one end portion of the elastic partition wall portion is airtightly connected to the flange portion, and the other end portion is airtightly connected to the holder support portion via a sealing member. holder. The substrate holder according to claim 3, wherein the sealing member is sandwiched between the holder support portion and the elastic partition wall portion in a biasing direction of the biasing means. 5. The substrate holder according to claim 2, wherein a cap that comes into contact with the conductor wiring from the substrate support surface side is provided at one end of the grounding member. The elastic partition wall is a bellows,
6. The substrate holder according to claim 1, wherein the bellows also serves as the urging means. The biasing means has at least a compression coil spring,
The substrate holder according to any one of claims 1 to 6, wherein the elastic partition wall is disposed inside the compression coil spring. A vacuum processing apparatus comprising at least the substrate holder according to claim 1 and a vacuum container,
The holder body is disposed in the vacuum container, and the holder support is disposed through the vacuum partition of the vacuum container,
The inside of the said elastic partition part is connected with the inside of the said vacuum vessel, The vacuum processing apparatus characterized by the above-mentioned.