Patent Application
20140261161
The present invention relates to a substrate holder apparatus and a vacuum processing apparatus.
Conventionally, there is known an arrangement configured to supply power to the electrostatic chuck of a substrate holder by using a power supply mechanism (for example, PTL 1). A support column supports the substrate holder in PTL 1. A driving unit can rotate the support column. Since a rotating seal, a bearing, a motor, a power supply rotating mechanism, and the like are sequentially arranged as the components of the driving unit along the rotation axis direction of the support column, the support column is long in the axis direction. Increasing the length of the support column may decrease the rotational position accuracy of the support column because of the influence of tolerances at the time of assembly and processing and increase load on the bearing because of the wobbling rotation of the support column and lead to a reduction in the service life of the bearing.
For this reason, a support column which supports a substrate holder is supported by bearings at two positions in the axial direction of the support column to improve rotational position accuracy and increase the service life of the bearings.
PTL 1: Japanese Patent Laid-Open No. 2008-156746
In a structure configured to support a support column by bearings at two positions, one bearing positions the support column, and a gap is provided between the outer circumferential portion of the support column and the inner circumferential portion of the other bearing to prevent any excessive load from being imposed on the other bearing. For this reason, a change in rotational angle caused by tolerances at the time of assembly and processing may lead to fluctuations in the contact state between the support column and the bearing placed in the gap provided with respect to the support column.
On the other hand, there is known an arrangement configured to apply bias power to a substrate upon superimposing the power on the power applied to an ESC electrode via a substrate holder. In the substrate holder designed to apply such bias power, fluctuations in the contact state with a bearing may influence the bias power applied to a substrate. More specifically, as the resistance value of the route on the feedback side of the bias power applied to a substrate changes depending on the contact state with the bearing, reflected waves may be generated by waves striking a plasma, resulting in influencing the discharge state of the plasma. Therefore, demands have arisen for a substrate holder apparatus which can further stabilize applied bias power without being influenced by a change in contact state with a bearing.
The present invention has been made in consideration of the above problem, and has as its object to provide a technique capable of further stabilizing bias power to be applied without being influenced by a change in contact state with a bearing.
In order to achieve the above object, a substrate holder apparatus according to one aspect of the present invention is comprising: a substrate holder configured to hold a substrate in a vacuum processing space in a chamber; a support column coupled to the substrate holder; a first rotating support unit configured to rotatably support the support column; a second rotating support unit configured to rotatably support the support column at a position spaced apart from a position where the first rotating support unit supports the support column; a housing configured to support the first rotating support unit and the rotating support unit; and a conductive member configured to electrically connect the support column to the housing.
Alternatively, a vacuum processing apparatus according to another aspect of the present invention is comprising: a vacuum processing chamber configured to process a substrate; a substrate holder apparatus provided inside the vacuum processing chamber; and a processing unit configured to process a substrate configured to be held by the substrate holder apparatus.
According to the present invention, it is possible to further stabilize bias power to be applied without being influenced by a change in the contact state of a bearing.
It is possible to stabilize the discharge state of a plasma by stabilizing bias power.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings. Note that the same reference numerals denote the same or like components throughout the accompanying drawings.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the present invention.
Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the constituent elements described in the embodiments are merely examples. The scope of the present invention is not limited to only them.
(Arrangement of Substrate Processing Apparatus)
The arrangement of a substrate processing apparatus 100 (vacuum processing apparatus) according to an embodiment of the present invention will be described with reference to
The substrate processing apparatus 100 includes a chamber 1, a stage 13, a power supply 14, a sputtering electrode 15, a sputtering power supply 17, a gas supply device 18, an exhaust device 19, an exhaust valve 20, a support column 30, a power supply unit 61, a driving unit 79, and a housing 50.
The interior (vacuum processing chamber S) of the chamber 1 is connected to the exhaust device 19 via the exhaust valve 20. The exhaust valve 20 can control the internal pressure of the chamber 1. The exhaust device 19 sets the interior of the chamber 1 to a required vacuum state suitable for a substrate process. In addition, the interior (vacuum processing chamber S) of the chamber 1 is connected to the gas supply device 18. The gas supply device 18 supplies a gas used for plasma generation into the vacuum processing chamber S of the chamber 1.
The sputtering power supply 17 functioning as an arrangement for processing a substrate supplies power to a target 16 through the sputtering electrode 15. When the sputtering power supply 17 supplies power to the target 16, the target 16 is sputtered by a sputtering discharge. A material sputtered from the target 16 is deposited on a substrate 10. A material used for the target 16 corresponds to the substance to be deposited on the substrate 10.
The exhaust device 19 evacuates the chamber 1. The gas supply device 18 then supplies a sputtering gas into the chamber 1. After pressure control by the exhaust valve 20, the sputtering power supply 17 supplies power to the sputtering electrode 15 to sputter the target 16 to form a film on the substrate 10 held on the stage 13.
The stage 13 (substrate holder) includes a substrate mounting surface on which the substrate 10 can be held in the processing space S evacuated in the chamber 1 and an electrostatic chuck for fixing the mounted substrate 10 by electrostatic adsorption. The electrostatic chuck is internally provided with an electrode 53. The electrode 53 receives required power via a power supply line 54 provided in the stage 13 and the support column 30 having a hollow structure. The power supply line 54 is covered by an insulating member 55 inside the support column 30.
The stage 13 (substrate holder) is coupled to the upper end portion of the support column. The lower end portion of the support column 30 is provided with the power supply unit 61 for supplying power to the electrode 53 of the electrostatic chuck. The power supply 14 is connected to the power supply unit 61. The power supply unit 61 supplies, via the power supply line 54, power for actuating the electrostatic chuck and bias power for controlling the properties of a film or a sputtering coverage.
In order to improve the uniformity of a film formation distribution on a substrate surface, the driving unit 79 rotates the substrate 10 held on the stage 13 through the support column 30.
The driving unit 79 includes a movable element portion 77 placed on the outer circumferential portion of the support column 30 and a stator portion 58 fixed to the inner circumferential surface of the housing 50. The driving unit 79 functions as a motor for rotating the support column 30 owing to the interaction between the movable element portion 77 and the stator portion 58 placed around the movable element portion 77. Assume that in this case, the housing 50 is connected to the chamber 1 and grounded through the chamber 1.
A bearing 57 (main bearing) and a bearing 59 (sub-bearing) support the rotation of the support column 30 by the driving unit 79.
The outer circumferential portions of the bearings 57 and 59 are fixed to the inner circumferential surface of the housing 50. A vacuum rotating seal 56 is provided between the support column 30 and the housing 50 to maintain a vacuum atmosphere in the chamber 1.
Of the components of the substrate processing apparatus 100 (vacuum processing apparatus), the stage 13, the support column 30, the bearing 57, the bearing 59, and the housing 50 constitute a substrate holder apparatus capable of holding a substrate. The arrangement of the substrate holder apparatus according to an embodiment of the present invention will be described in detail below.
A main bearing 157 (first rotating support member) positions a support column 130 and rotatably supports the support column 130. A sub-bearing 159 (second rotating support member) rotatably supports the support column 130. A housing 150 holds the outer circumferential portions of the main bearing 157 and sub-bearing 159. Although the main bearing 157 is constituted by a plurality of bearings, the main bearing 157 may be formed from one bearing.
A slight gap is provided between the inner circumferential portion of the sub-bearing 159 and the outer circumferential portion of the support column 130. This gap can prevent a deterioration in the rotational position accuracy of the support column caused by tolerances at the time of assembly of the substrate holder apparatus 200 and processing on the support column 130 and reduce the load on the sub-bearing 159 which is imposed by the wobbling rotation of the support column.
A conductive member 182 which electrically connects the support column 130 to the housing 150 is provided between the support column 130 and the housing 150. The conductive member 182 includes, as constituent elements, a conductive elastic member 181 provided on the housing 150 and a conductive energization member 180 which comes into contact with the outer circumference of the support column 130 with the elastic force of the elastic member 181. The energization member 180 is pressed against the outer circumference of the support column 130 and comes into contact with the outer circumference of the support column 130 with the elastic force of the elastic member 181. Electrically connecting the support column 130 to the housing 150 via the energization member 180 sets the support column 130 and the housing 150 at the same potential.
Even when the contact state between the sub-bearing 159 and the support column 130 changes, the elastic force of the elastic member 181 maintains the contact state between the outer circumference of the support column 130 and the energization member 180. For this reason, even when the contact state between the sub-bearing 159 and the support column 130 changes as the support column 130 rotates, the support column 130 is stably electrically connected to the housing 150 via the conductive member 182. This prevents any change in the conductive state of the substrate holder apparatus 200.
According to this embodiment, it is possible to further stabilize bias power to be applied without being influenced by a change in the contact state of the sub-bearing 159. Stabilizing the bias power can stabilize the discharge state of a plasma.
Note that
A slight gap is provided between the inner circumferential portion of the sub-bearing 259 and the outer circumferential portion of the support column 230. This gap can prevent a deterioration in the rotational position accuracy of the support column caused by tolerances at the time of assembly of the substrate holder apparatus 300 and processing on the support column 230 and reduce the load on the sub-bearing 259 which is imposed by the wobbling rotation of the support column.
Even when the contact state between the support column 230 and the sub-bearing 259 changes, providing the elastic member 285 (conductive member) connected to the conductive sub-bearing 259 stably electrically connects the support column 230 to the housing 250. This prevents a change in the conductive state of the substrate holder apparatus 300 even with a change in the contact state between the support column 230 and the sub-bearing 259.
According to this embodiment, it is possible to further stabilize bias power to be applied without being influenced by a change in the contact state of the sub-bearing 259. Stabilizing bias power can stabilize the discharge state of a plasma.
The present invention is not limited to the above embodiments and various changes and modifications can be made within the spirit and scope of the present invention. Therefore, to apprise the public of the scope of the present invention, the following claims are made.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-275075 | Dec 2011 | JP | national |
This application is a continuation of International Patent Application No. PCT/JP2012/005407 filed on Aug. 28, 2012, and claims priority to Japanese Patent Application No. 2011-275075 filed on Dec. 15, 2011, the entire content of both of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2012/005407 | Aug 2012 | US |
| Child | 14293549 | US |
