CN110509179B

CN110509179B - Substrate holding device, substrate polishing device, elastic member, and method for manufacturing substrate holding device

Info

Publication number: CN110509179B
Application number: CN201910420608.2A
Authority: CN
Inventors: 锅谷治
Original assignee: Ebara Corp
Current assignee: Ebara Corp
Priority date: 2018-05-21
Filing date: 2019-05-20
Publication date: 2023-03-10
Anticipated expiration: 2039-05-20
Also published as: CN110509179A; US20190375070A1; TW202004978A; JP2019202361A; JP7075814B2; KR20190132929A

Abstract

The invention provides a substrate holding device, a substrate polishing device, an elastic member, and a method for manufacturing the substrate holding device. The substrate holding device includes: a top ring body; an elastic film having a first surface and a second surface, a plurality of regions being formed between the first surface and the top ring main body, the second surface being located on a side opposite to the first surface and capable of holding the substrate; a first line communicating with a first zone of the plurality of zones and capable of pressurizing the first zone; a second line communicating with the first zone and being capable of exhausting gas from the first zone; a measuring device, the measuring value of which changes based on the flow rate of the first area; a third line that communicates with a second region that is different from the first region among the plurality of regions and is capable of depressurizing the second region; and an elastic member provided between the first line and the second line, the elastic member being separated from the first surface of the elastic film when the second surface of the elastic film does not hold the substrate, and being in contact with the first surface of the elastic film when the second surface of the elastic film holds the substrate.

Description

Substrate holding device, substrate polishing device, elastic member, and method for manufacturing substrate holding device

Cross reference to related applications

The present application claims priority based on japanese laid-open application JP2018-97314 filed on 21/5/2018, the entire contents of which are incorporated by reference in the present specification.

Technical Field

The present invention relates to a substrate holding apparatus, a substrate polishing apparatus, an elastic member, and a method of manufacturing the substrate holding apparatus.

Background

In a substrate polishing apparatus (for example, japanese patent No. 3705670), a substrate is transferred from a substrate transport apparatus to a top ring (substrate holding apparatus), and polishing of the substrate is performed in a state where the substrate is held by the top ring. The top ring has the following structure: a diaphragm is arranged below the top ring main body (base), and the lower surface of the diaphragm adsorbs a substrate.

Japanese patent No. 3705670 discloses a substrate adsorption determination method for determining whether or not a substrate is adsorbed to a membrane. In this method, an upwardly directed projection is provided on the membrane. Further, the following means are used: when the substrate is not adsorbed, a gap is formed between the lower surface of the top ring body and the convex portion of the diaphragm, and when the substrate is adsorbed, the substrate presses the diaphragm upward, so that the convex portion of the diaphragm comes into contact with the lower surface of the top ring body and the gap disappears.

However, the surface of the diaphragm is sometimes wetted by the abrasive slurry, top ring cleaning. In addition, the substrate itself may be wetted by the polishing treatment. In this way, when the diaphragm or the substrate is wet, even if the substrate is attracted, the force with which the substrate presses the diaphragm is dispersed, and the convex portion of the diaphragm may not sufficiently contact the lower surface of the top ring body. Thus, although the substrate is adsorbed, there is a possibility that an erroneous determination that the substrate is not adsorbed occurs.

Therefore, it is also conceivable to narrow the gap between the convex portion of the diaphragm and the top ring in advance. However, when polishing the substrate with the membrane being held thereon, the following problems occur: only the portion of the substrate corresponding to the convex portion has a high polishing rate, and uniform polishing is difficult.

Therefore, a substrate holding apparatus and a method of manufacturing the same, which can more accurately determine that a substrate has been attracted while suppressing unevenness in polishing rate, a substrate polishing apparatus provided with such a substrate holding apparatus, and an elastic member for such a substrate holding apparatus are preferable.

Disclosure of Invention

According to one aspect, there is provided a substrate holding apparatus including: a top ring body; an elastic film having a first surface and a second surface, a plurality of regions being formed between the first surface and the top ring main body, the second surface being located on a side opposite to the first surface and capable of holding a substrate; a first line that communicates with a first region of the plurality of regions and is capable of pressurizing the first region; a second line communicating with the first zone and capable of exhausting gas from the first zone; a measuring device whose measurement value changes based on the flow rate of the first region; a third line that communicates with a second region that is different from the first region among the plurality of regions and is capable of depressurizing the second region; and an elastic member provided between the first line and the second line, the elastic member being separated from the first surface of the elastic film in a case where the second surface of the elastic film does not hold the substrate, and being in contact with the first surface of the elastic film in a case where the second surface of the elastic film holds the substrate.

According to another aspect, there is provided a substrate polishing apparatus including: the above substrate holding device; and a polishing table configured to polish the substrate held by the substrate holding device.

According to another aspect, there is provided an elastic member for a substrate holding apparatus, the substrate holding apparatus including: a top ring body; an elastic film having a first surface and a second surface, a plurality of regions being formed between the first surface and the top ring main body, the second surface being located on a side opposite to the first surface and being capable of holding a substrate; a first line that communicates with a first region of the plurality of regions and is capable of pressurizing the first region; a second line communicating with the first zone and capable of exhausting gas from the first zone; a measuring device whose measurement value changes based on the flow rate of the first region; and a third line communicating with a second region that is a different region from the first region among the plurality of regions, the third line being capable of decompressing the second region, wherein the elastic member is provided between the first line and the second line so as to be separated from the first surface of the elastic film when the second surface of the elastic film does not hold the substrate, and so as to be in contact with the first surface of the elastic film when the second surface of the elastic film holds the substrate.

According to another aspect, there is provided a method of manufacturing a substrate holding apparatus, including a step of attaching a new elastic member to the substrate holding apparatus from which the elastic member is removed.

Drawings

Fig. 1 is a schematic plan view of a substrate processing apparatus including a substrate polishing apparatus.

Fig. 2 is a schematic perspective view of the substrate polishing apparatus 300.

Fig. 3 is a schematic cross-sectional view of the substrate polishing apparatus 300.

Fig. 4A, 4B, and 4C are views for explaining in detail the substrate transfer from the conveyance mechanism 600B to the top ring 1.

Fig. 5 is a diagram for explaining in detail the substrate transfer from the conveyance mechanism 600b to the top ring 1.

Fig. 6A is a sectional view schematically showing the configuration of the top ring 1 and the pressure control device 7 in the first embodiment.

Fig. 6B is a modification of fig. 6A.

Fig. 7 is a sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1.

Fig. 8 is an enlarged view of the periphery of the elastic member 91 in fig. 7.

Fig. 9 is a diagram illustrating the operation of each valve in the top ring 1.

Fig. 10 is a flowchart showing the procedure of substrate adsorption determination.

Fig. 11 is a cross-sectional view schematically showing the diaphragm 13 and the top ring body 11 when the adsorption fails.

Fig. 12A is a cross-sectional view schematically showing the substrate W, the diaphragm 13, and the top ring body 11 in a case where the suction is successful.

Fig. 12B is an enlarged view of the periphery of the elastic member 91 in fig. 12A.

Fig. 13 is a diagram schematically showing the flow rate measured by the flow meter FS after the start of adsorption.

Fig. 14A is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 as a first modification.

Fig. 14B is an enlarged view of the periphery of the elastic member 191 in fig. 14A.

Fig. 14C is an enlarged view of the periphery of the elastic member 191 in fig. 14A.

Fig. 14D is an enlarged view of the periphery of the elastic member 191 in fig. 14A.

Fig. 15 is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 as a modification of fig. 14A.

Fig. 16A is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 as a second modification.

Fig. 16B is an enlarged view of the periphery of the elastic member 291 in fig. 16A.

Fig. 17A is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 as a third modification.

Fig. 17B is an enlarged view of the periphery of the elastic member 391 in fig. 17A.

Fig. 17C is an enlarged view of the periphery of the elastic member 391 in fig. 17A.

Fig. 18 is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 as a fourth modification.

Fig. 19 is a sectional view schematically showing the structure of the top ring 1 in the second embodiment.

Fig. 20 is a cross-sectional view schematically showing the diaphragm 13 and the top ring body 11 in the case where the adsorption fails.

Fig. 21 is a cross-sectional view schematically showing the substrate W, the diaphragm 13, and the top ring body 11 in a case where the suction is successful.

Detailed Description

The embodiments are described below in detail with reference to the drawings.

(first embodiment)

Fig. 1 is a schematic plan view of a substrate processing apparatus including a substrate polishing apparatus. The substrate processing apparatus is used for processing various substrates in a manufacturing process of a Semiconductor wafer having a diameter of 300mm or 450mm, a flat panel, an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device), or a magnetic film of an MRAM (Magnetoresistive Random Access Memory).

The substrate processing apparatus includes: a substantially rectangular-shaped housing 100; a load port 200 on which a substrate cassette for storing a plurality of substrates is placed; one or more (four in the mode shown in fig. 1) substrate polishing apparatuses 300; one or more (in the manner shown in fig. 1, two) substrate cleaning apparatuses 400; a substrate drying device 500; conveying mechanisms 600a to 600d; and a control section 700.

The load port 200 is disposed adjacent to the housing 100. The load port 200 can be loaded with an open type wafer cassette, a Standard Mechanical Interface (SMIF) cassette, or a Front Opening Unified Pod (FOUP). SMIF pod, FOUP are the following closed containers: the substrate case is housed inside and covered by the partition wall, so that an environment independent from the external space can be maintained.

The casing 100 accommodates: a substrate polishing apparatus 300 for polishing a substrate; a substrate cleaning device 400 for cleaning the polished substrate; and a substrate drying device 500 that dries the cleaned substrate. The substrate polishing apparatus 300 is arranged along the longitudinal direction of the substrate processing apparatus, and the substrate cleaning apparatus 400 and the substrate drying apparatus 500 are also arranged along the longitudinal direction of the substrate processing apparatus.

The transfer mechanism 600a is disposed in a region surrounded by the load port 200, the substrate polishing apparatus 300 located on the load port 200 side, and the substrate drying apparatus 500. Further, a conveyance mechanism 600b is disposed in parallel with the substrate polishing apparatus 300, the substrate cleaning apparatus 400, and the substrate drying apparatus 500.

The transfer mechanism 600a receives the substrate before polishing from the load port 200 and delivers the substrate to the transfer mechanism 600b, or receives the substrate after drying from the substrate drying apparatus 500.

The conveyance mechanism 600b is, for example, a linear transporter, and delivers the substrate before polishing received from the conveyance mechanism 600a to the substrate polishing apparatus 300. As will be discussed later, a top ring (not shown) in the substrate polishing apparatus 300 receives a substrate from the conveyance mechanism 600b by vacuum suction. The substrate polishing apparatus 300 releases the polished substrate to the transfer mechanism 600b, and the substrate is transferred to the substrate cleaning apparatus 400.

Further, a conveyance mechanism 600c that transfers substrates between the substrate cleaning apparatuses 400 is disposed between the two substrate cleaning apparatuses 400. Further, a transfer mechanism 600d for transferring the substrate between the substrate cleaning apparatus 400 and the substrate drying apparatus 500 is disposed between the substrate cleaning apparatus 400 and the substrate drying apparatus 500.

The control unit 700 controls the operation of each device of the substrate processing apparatus, and may be disposed inside the housing 100, outside the housing 100, or separately provided in the substrate polishing apparatus 300, the substrate cleaning apparatus 400, and the substrate drying apparatus 500.

Fig. 2 and 3 are a schematic perspective view and a schematic cross-sectional view of the substrate polishing apparatus 300, respectively. The substrate polishing apparatus 300 includes: a top ring 1; a top ring shaft 2 having a top ring 1 connected to a lower portion thereof; a polishing table 3 having a polishing pad 3a; a nozzle 4 for supplying the polishing liquid onto the polishing table 3; a top ring head 5; and a support shaft 6.

The top ring 1 is for holding a substrate W, and includes, as shown in fig. 3: a top ring body 11 (also referred to as a carrier or mount); an annular retainer ring 12; a flexible diaphragm 13 (elastic film) provided below the top ring body 11 and inside the retainer ring 12; an air bag 14 provided between the top ring body 11 and the retainer ring 12; and a pressure control device 7.

The retainer ring 12 is provided on the outer peripheral portion of the top ring body 11. The peripheral edge of the held substrate W is surrounded by the retainer ring 12, and the substrate W does not fly out of the top ring 1 during polishing. The retainer ring 12 may be a single member, or may be a double-layer ring structure including an inner ring and an outer ring provided outside the inner ring. In the latter case, the outer ring may be fixed to the top ring body 11, and the airbag 14 may be provided between the inner ring and the top ring body 11.

The diaphragm 13 is disposed opposite to the top ring body 11. A plurality of concentric circular regions are formed between the upper surface of the diaphragm 13 and the top ring body 11. By depressurizing one or more regions, the lower surface of the membrane 13 can hold the upper surface of the substrate W.

The air bag 14 is provided between the top ring body 11 and the retainer ring 12. The retainer ring 12 is movable relative to the top ring body 11 in the vertical direction by the bladder 14.

The pressure control device 7 individually adjusts the pressure in each region formed between the top ring body 11 and the diaphragm 13 by supplying a fluid between the top ring body 11 and the diaphragm 13, evacuating the space between the top ring body 11 and the diaphragm 13, or opening the atmosphere between the top ring body 11 and the diaphragm 13. In addition, the pressure control device 7 determines whether or not the substrate W is adsorbed to the diaphragm 13. The configuration of the pressure control device 7 will be described in detail later.

In fig. 2, the lower end of the top ring shaft 2 is connected to the center of the upper surface of the top ring 1. The top ring shaft 2 is moved up and down by an unillustrated lift mechanism, and the lower surface of the substrate W held by the top ring 1 is brought into contact with or separated from the polishing pad 3a. Further, the top ring shaft 2 is rotated by a motor not shown, and the top ring 1 is rotated, whereby the held substrate W is also rotated.

A polishing pad 3a is provided on the upper surface of the polishing table 3. The lower surface of the polishing table 3 is connected to the rotating shaft, and the polishing table 3 is rotatable. The polishing liquid is supplied from the nozzle 4, and the substrate W and the polishing table 3 are rotated while the lower surface of the substrate W is in contact with the polishing pad 3a, whereby the substrate W is polished.

The top ring head 5 of fig. 3 has one end connected to the top ring shaft 2 and the other end connected to the support shaft 6. The support shaft 6 is rotated by a motor (not shown), the top ring head 5 swings, and the top ring 1 moves between a substrate delivery position (not shown) and a polishing pad 3a.

Next, an operation when delivering and receiving a substrate from the transport mechanism 600b of fig. 1 to the top ring 1 of fig. 2 and 3 will be described.

Fig. 4A to 4C and fig. 5 are views for explaining in detail the substrate transfer from the transfer mechanism 600b to the top ring 1. Fig. 4A to 4C are diagrams of the conveyance mechanism 600b and the top ring 1 viewed from the side, and fig. 5 is a diagram of the conveyance mechanism 600b and the top ring 1 viewed from above.

As shown in fig. 4A, the substrate W is placed on the hand 601 of the conveyance mechanism 600b. The retainer table 800 is used for transferring the substrate W. The retainer block 800 has an push-up pin 801 that pushes up the retainer ring 12 of the top ring 1. Further, although not shown, the retainer table 800 may have a discharge nozzle.

As shown in fig. 5, the hand 601 supports a part of the outer periphery of the lower surface of the substrate W. The upper push pin 801 and the hand 601 are arranged so as not to contact each other.

In the state shown in fig. 4A, the top ring 1 is lowered, and the conveying mechanism 600b is raised. The push-up pins 801 push up the retainer ring 12 due to the lowering of the top ring 1, and the substrate W approaches the diaphragm 13. When the conveyance mechanism 600B further ascends, the upper surface of the substrate W comes into contact with the lower surface of the film 13 (fig. 4B).

In this state, the region formed between the diaphragm 13 and the top ring body 11 is depressurized, whereby the substrate W is adsorbed to the lower surface of the diaphragm 13 of the top ring 1. However, depending on the case, the substrate W may fall without being adsorbed to the lower surface of the diaphragm 13 or after being temporarily adsorbed. Therefore, in the present embodiment, determination as to whether or not the substrate W is adsorbed to the membrane 13 (substrate adsorption determination) is performed as will be described later.

After that, the conveyance mechanism 600b is lowered (fig. 4C).

Next, the top ring 1 will be explained.

Fig. 6A is a sectional view schematically showing the configuration of the top ring 1 and the pressure control device 7 in the first embodiment. The diaphragm 13 has peripheral walls 13a to 13e extending upward toward the top ring body 11. The peripheral walls 13a to 13e form concentric regions 131 to 135 partitioned by the peripheral walls 13a to 13e between the upper surface of the diaphragm 13 and the lower surface of the top ring body 11. Further, it is preferable that no hole is formed in the lower surface of the diaphragm 13.

Passages 141 to 145 are formed through the top ring body 11 so as to communicate with the regions 131 to 135 at one ends thereof, respectively. Further, an airbag 14 made of an elastic film is provided directly above the retainer ring 12, and a flow path 146 having one end communicating with the airbag 14 is similarly formed. The other ends of the flow paths 141 to 146 are connected to the pressure control device 7. The flow paths 141 to 146 may be provided with pressure sensors and flow sensors.

In order to perform substrate suction determination, a flow path 150 is formed to penetrate the top ring body 11 and have one end communicating with the region 133. The other end of the flow path 150 is opened to the atmosphere.

The pressure control device 7 includes: valves V1 to V6 and pressure regulators R1 to R6 provided to the respective flow paths 141 to 146; a control section 71; and a pressure regulator 72. In order to determine the substrate adsorption, the pressure control device 7 includes a determination unit 73, and a valve V10 and a flow meter FS provided in the flow path 150. Further, since no flow rate is generated when the valve V10 is closed, the valve V10 and the flow meter FS can be set in any order.

The control unit 71 controls the valves V1 to V6, V10, the pressure regulators R1 to R6, and the pressure regulator 72.

The pressure regulator 72 is connected to one end of the flow paths 141 to 146, and regulates the pressures of the regions 131 to 135 and the airbag 14 under the control of the control unit 71. Specifically, the pressure regulator 72 supplies a fluid such as air through the flow paths 141 to 146 to pressurize the regions 131 to 135 and the airbag 14, or evacuates the regions 131 to 135 and the airbag 14 to reduce the pressure, or opens the regions 131 to 135 and the airbag 14 to the atmosphere.

In the case of fig. 6A, one valve V1 to V6 is connected to each of the flow paths 141 to 146. Fig. 6B is a modification of fig. 6A, and a plurality of valves may be connected to the flow paths 141 to 146. FIG. 6B shows an example in which three valves V3-1, V3-2, and V3-3 are connected to the flow path 143. The valve V3-1 is connected to a pressure regulator R3, the valve V3-2 is connected to an atmosphere open source, and the valve V3-3 is connected to a vacuum source. When the region 133 is pressurized, the valves V3-2 and V3-3 are closed, the valve V3-1 is opened, and the pressure regulator R3 is operated. When the region 133 is set to the atmosphere-open state, the valves V3-1 and V3-3 are closed and the valve V3-2 is opened. When the region 133 is in a vacuum state, the valves V3-1 and V3-2 are closed and the valve V3-3 is opened.

In fig. 6A, for example, in order to pressurize the region 135, the control unit 71 controls the pressure regulator 72 to open the valve V5 and supply air to the region 135. This is simply expressed as the control section 71 pressurizing the area 135 or the like.

The flow meter FS measures the flow rate of the fluid flowing through the flow path 150, in other words, the flow rate of the fluid flowing through the region 133, and notifies the determination unit 73 of the measurement result. In addition, unless otherwise specified, the flow rate refers to the volume of fluid (particularly air) flowing per unit time. The position of the flow meter FS is not particularly limited as long as the flow meter FS can measure the flow rate of the flow path 150, and the flow path 143 is connected to the flow path 150, and therefore, the flow meter FS may be disposed in the flow path 143, for example.

The determination unit 73 performs substrate adsorption determination based on the flow rate measured by the flow meter FS.

The top ring 1 includes an elastic member 91 made of NBR, silicone rubber, EPDM, fluororubber, chloroprene rubber, urethane rubber, or the like, which will be described later.

Fig. 7 is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 (only the left half is shown in fig. 7, and the same applies to the following drawings). As shown in the drawing, the diaphragm 13 includes: a circular abutting portion 130 that contacts the substrate W; and five peripheral walls 13a to 13e that are directly or indirectly connected to the abutting portion 130. The contact portion 130 is held in contact with the back surface of the substrate W, i.e., the surface opposite to the surface to be polished. The contact portion 130 presses the substrate W against the polishing pad 3a during polishing. The peripheral walls 13a to 13e are annular peripheral walls arranged concentrically.

The upper ends of the peripheral walls 13a to 13d are held between the retaining rings 21 and 22 and the lower surface of the top ring body 11, and are attached to the top ring body 11. These holding rings 21 and 22 are detachably fixed to the top ring body 11 by a holding member (not shown). Thus, when the holding member is contacted, the holding rings 21, 22 are separated from the top ring body 11, whereby the diaphragm 13 can be detached from the top ring body 11. As the holding member, a screw or the like can be used.

Retaining rings 21, 22 are located in

regions

132, 134, respectively. The

flow passages

142 and 144 penetrate the top ring body 11 and the retaining rings 21 and 22, respectively, and communicate with the

regions

132 and 134, respectively. The

flow paths

141, 143, and 145 penetrate the top ring body 11 and communicate with the

regions

131, 133, and 135, respectively. The flow path 150 penetrates the top ring body 11 and communicates with the region 133.

In the region 133, a gap g (described later in fig. 11 and the like) through which a fluid (air) can flow from the flow path 143 to the flow path 150 exists between the lower surface of the top ring body 11 and the diaphragm 13 in a state where the substrate W is not adsorbed. When the substrate W is adsorbed on the lower surface of the diaphragm 13, the diaphragm 13 is lifted toward the top ring main body 11 side, and thus the gap g is almost eliminated. It is preferable that the gap g be as narrow as possible.

As one feature of the present embodiment, the top ring 1 includes an elastic member 91 (fig. 8 shows an enlarged view of the periphery of the elastic member 91 (within the one-dot chain line in fig. 7)). The elastic member 91 is fitted in the region 133 into the recessed portion 90 provided between the flow path 143 and the flow path 150 of the top ring body 11. The elastic member 91 is annular and has a wide portion 91a at the upper portion. Since the wide portion 91a is hooked on the shoulder portion 90a of the recess 90, the elastic member 91 is less likely to fall off the top ring body 11. However, the elastic member 91 can be detached from the recess 90 by applying a certain degree of force. In the case where the elastic member 91 is consumed, the consumed elastic member 91 is detached from the recess 90, and a new elastic member 91 is fitted into the recess 90, whereby a new top ring 1 is produced.

In a state where the top ring 1 does not hold the substrate W, the lower surface of the elastic member 91 is separated from the upper surface of the diaphragm 13, and a gap g exists. In addition, it is preferable that a convex portion 92 is provided on the upper surface of the diaphragm 13 at a position opposing the elastic member 91. The function of the elastic member 91 is discussed later. Further, the elastic member 91 may be hollow and have a cavity inside or may not have a cavity.

Fig. 9 is a diagram illustrating the operation of each valve in the top ring 1. When the substrate W is sucked or polished, the pressure in one or more of the

regions

131, 132, 134, and 135 may be adjusted, and hereinafter, the pressure in the region 135 is adjusted, and the

other regions

131, 132, and 134 may be adjusted as desired.

When the diaphragm 13 is opened during idling or the like, the control unit 71 opens the valves V3, V5, and V10 to open the

areas

133 and 135 to the atmosphere.

When polishing the substrate W, the control unit 71 opens the valves V3 and V5 to pressurize the

regions

133 and 135 and closes the valve V10 in order to press the substrate W against the polishing pad 3a to pressurize the membrane 13.

When the substrate W is transferred from the transfer mechanism 600b to the top ring 1 and adsorbed on the membrane 13, the control unit 71 opens the valve V3 to reduce the pressure in the region 135. To further perform the substrate adsorption determination, the control unit 71 opens the valve V5 to slightly pressurize the region 133, and opens the valve V10 to open the region 133 to the atmosphere. The determination unit 73 determines whether or not the substrate is adsorbed to the diaphragm 13 as follows based on the measurement value of the flow meter FS.

Fig. 10 is a flowchart showing a procedure of substrate adsorption determination. Hereinafter, the region 133 where the flow meter FS is provided is referred to as a "determination region", and the region 135 where pressure is reduced for adsorption is referred to as an "adsorption region".

First, the control unit 71 depressurizes the adsorption region 135 (step S1). Then, the control unit 71 opens the valve V3 to pressurize the determination region 133, and opens the valve V10 to open the determination region 133 to the atmosphere (step S2). That is, the control unit 71 pressurizes the determination region 133 through the flow path 143 and opens the determination region 133 to the atmosphere through the flow path 150.

In step S1, the control unit 71 decompresses the suction region 135 to about-500 hPa, and in step S2, the control unit 71 pressurizes the determination region 133 to about 200hPa or less, preferably about 50 hPa. This is because, when the determination region 133 is excessively pressurized, a force acting downward on the substrate W increases, which hinders substrate suction.

Next, the determination unit 73 waits until a predetermined determination start time T0 elapses (step S3). When the determination start time T0 has elapsed, the determination unit 73 compares the flow rate measured by the flow meter FS with a predetermined threshold value to determine whether or not the substrate W is adsorbed to the diaphragm 13 (step S4).

Fig. 11 is a cross-sectional view schematically showing the diaphragm 13 and the top ring body 11 when the adsorption fails. When the substrate W is not sucked, the diaphragm 13 has flexibility, and therefore, the portion of the diaphragm 13 corresponding to the suction region 135 is lifted up toward the top ring body 11, but the portion corresponding to the determination region 133 is not lifted up, and a gap g remains between the portion and the top ring body 11. Therefore, the flow rate measured by the flow meter FS becomes large.

Fig. 12A is a cross-sectional view schematically showing the substrate W, the diaphragm 13, and the top ring body 11 in a case where the suction is successful. When the substrate W is sucked, the entire diaphragm 13 including the portion corresponding to the determination region 133 is lifted and brought into close contact with the top ring body 11. Therefore, the gap g is almost eliminated and the flow rate measured by the flow meter FS becomes small.

As can be seen from the above, the flow rate flowing into the determination region 133 corresponds to the size of the gap g, and the larger the gap g, the larger the flow rate.

Fig. 12B is an enlarged view of the periphery of the elastic member 91 in fig. 12A. When the substrate W is adsorbed, (the convex portion 92 of) the upper surface of the diaphragm 13 comes into contact with the lower surface of the elastic member 91. This reliably closes the gap g, and reduces the flow rate measured by the flow meter FS.

Therefore, when the flow rate is equal to or less than the threshold value (that is, when the gap g is small), the determination unit 73 determines that the adsorption of the substrate W is successful (or that the substrate W is adsorbed) (yes in step S4 of fig. 10, fig. 5 and 12). Then, the substrate processing apparatus continues the operation of transporting the substrate W by the top ring 1 (step S6). Thereafter, the determination of step S4 is repeated as long as the suction of the substrate W should be continued (yes in step S7).

The substrate W is polished in a state where the top ring 1 holds the substrate W, that is, in a state where the upper surface of the diaphragm 13 is in contact with the lower surface of the elastic member 91. As shown in fig. 9, the

regions

133, 135 are pressurized during polishing.

If a rigid member is used instead of the elastic member 91, the height of the top ring 1 is set low, and when the rigid member comes into contact with the convex portions 92 of the elastic film even when the region 133 is pressurized, the convex portions 92 pressed against the rigid member press the substrate W, and the polishing rate increases.

In contrast, in the present embodiment, the elastic member 91 has elasticity, and therefore, even when the height of the top ring 1 is set to be low, the substrate W is not strongly pressed against the polishing pad 3a. Therefore, the polishing rate of the entire surface of the substrate W can be made uniform.

Returning to fig. 10, when the flow rate is larger than the threshold value even when the predetermined error check time elapses (that is, when the gap g is large), the determination unit 73 determines that the suction of the substrate W has failed (or the substrate W has not been sucked) (no in S4, yes in S8, S9, and fig. 11). Then, the substrate processing apparatus stops the operation and issues an error alarm if necessary (step S10).

In the present embodiment, even after the substrate W is once adsorbed to the membrane 13, the determination is continued (yes in step S7, S4). Therefore, when the substrate W drops during conveyance of the substrate W or the like, it is possible to detect that the flow rate is greater than the threshold value and the substrate W does not exist (step S9).

Fig. 13 is a diagram schematically showing the flow rate measured by the flow meter FS after the start of adsorption, the solid line shows the flow rate measured by the flow meter FS when adsorption has succeeded, the broken line shows the flow rate measured by the flow meter FS when adsorption has failed, the single-dot chain line shows the flow rate measured by the flow meter FS when adsorption has once succeeded but then dropped, and the horizontal axis shows time.

As shown in the figure, when the adsorption is started at time t1 (step S1 in fig. 10), the flow rate is increased. This is because, at the time of start of adsorption, a gap g exists between the upper surface of the diaphragm 13 and the lower surface of the top ring body 11, and air flows regardless of success or failure of adsorption.

In the case where the adsorption is successful (solid line in fig. 13), the substrate W is adsorbed to the diaphragm 13, and thus the gap g between the diaphragm 13 and the top ring body 11 is reduced. Thus, after a certain time t2, the flow rate starts to decrease. At time t3 when the flow rate becomes equal to or less than the threshold value, it is determined that the adsorption has succeeded (step S5 in fig. 10). Thereafter, when the substrate W is completely adsorbed on the diaphragm 13 at time t4 in fig. 13, the gap g between the diaphragm 13 and the top ring body 11 is almost eliminated and the flow rate becomes substantially constant.

When the substrate W falls from the top ring 1 at time t11, the flow rate increases again (the one-dot chain line in fig. 13). The reason for this is that the substrate W is separated from the diaphragm 13, and a gap g is again generated between the diaphragm 13 and the top ring body 11. In this case, after a predetermined error check time has elapsed from time t12 when the flow rate becomes larger than the threshold value (step 8), it is determined that the adsorption has failed (step S9 in fig. 10).

On the other hand, in the case of adsorption failure (broken line in fig. 13), the flow rate continues to increase after time t2, and becomes constant in the near future. Therefore, even if the error check time elapses, the flow rate is kept larger than the threshold value, and it is determined that the adsorption has failed (step S9 in fig. 10).

The reason why the determination start time T0 is set is to prevent the substrate from being determined to have been adsorbed before the substrate is sufficiently adsorbed on the membrane 13 (before time T5 in fig. 13). An error confirmation time is also required in the following cases. This is because, when the substrate W sucked to the top ring 1 is lifted from the polishing pad 3a after polishing, the flow rate may temporarily increase and exceed the threshold value for the suction force between the polishing pad 3a and the substrate W.

In this manner, in the first embodiment, the judgment region 133 is pressurized and the atmosphere is opened, and the flow rate of the region 131 is measured. This flow rate corresponds to the size of the gap g between the diaphragm 13 and the top ring body 11. Therefore, by monitoring the flow rate, it is possible to accurately determine whether or not the suction of the substrate W has succeeded, and it is possible to appropriately process the substrate W. Further, the determination can be continued even after the suction, and even when the substrate W falls after the temporary suction is successful, the determination can be detected.

In the present embodiment, the elastic member 91 is provided in the top ring 1, and the elastic member 91 is in contact with the diaphragm 13. Therefore, the gap g in the case where the substrate W is not adsorbed can be reduced. This is because, as long as the elastic member 91 is used, the substrate W is not strongly pressed by the elastic member 91 when polishing the substrate W in a state where the substrate W is adsorbed, and the polishing rate can be made uniform over the entire substrate W. By reducing the gap g, the gap g is reliably closed when the substrate W is adsorbed, and therefore, the accuracy of determination is improved.

That is, by providing the elastic member 91, the accuracy of determining the substrate suction can be improved while suppressing the local unevenness in the polishing rate of the substrate W.

In the present embodiment, the flow path 150 is opened to the atmosphere, but for example, the valve V10 may be adjusted to a flow rate range suitable for adsorption detection of the substrate by using a flow rate adjustment valve, or may be connected to a pressure regulator to adjust the flow rate or to exhaust the gas, instead of being opened to the atmosphere. When the pressure regulator is connected to the flow path 150, for example, R1 is set to 100hPa to pressurize, and the additional pressure regulator is set to 50hPa to pressurize, thereby allowing air to flow through the flow path 150.

The substrate suction determination of the present embodiment can also be applied to the membrane sheet 13 in which no hole is formed. In addition, since the valve V10 is opened at the time of substrate adsorption determination, the determination region 133 is not closed, and the pressure in the determination region 133 does not increase so much. Therefore, the determination region 133 in the diaphragm 13 also exerts little stress on the substrate W.

In the present embodiment, the region 133 is set as a determination region and the region 135 is set as an adsorption region, but other regions may be set as a determination region and an adsorption region. That is, at least one region can be set to have a structure corresponding to the valve V10, the flow path 150, and the flow meter FS to be a determination region, and the other one or more regions can be set to be an adsorption region.

Preferably, the determination region is not adjacent to the adsorption region and is separated by one or more regions. If the determination region and the suction region are adjacent to each other, even if the suction of the substrate W fails, the portion corresponding to the determination region can be lifted as the portion corresponding to the suction region in the film 13 is lifted. This is because the flow rate flowing into the determination region is reduced, and thus, there is a possibility that erroneous determination may occur.

Several modifications of the elastic member 91 of the top ring 1 will be described below. Note that description of points common to the top ring 1 shown in fig. 7 and 8 is omitted.

Fig. 14A is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 as a first modification. The top ring 1 includes an elastic member 191 (fig. 14B shows an enlarged view of the periphery of the elastic member 191). The elastic member 191 has

horizontal surfaces

191a, 191b and a vertical surface 191c.

The horizontal plane 191a (third surface) is substantially parallel to the diaphragm 13. In a state where the top ring 1 does not hold the substrate W, the lower surface of the horizontal surface 191a is separated from the upper surface of the diaphragm 13. When the top ring 1 holds the substrate W, the upper surface of (the convex portion 92 of) the diaphragm 13 comes into contact with the lower surface of the horizontal surface 191 a.

The horizontal surface 191b (fourth surface) is substantially parallel to the diaphragm 13, is located above the horizontal surface 191a (on the opposite side of the diaphragm 13), and is separated from the horizontal surface 191 a. The vertical surface 191c (fifth surface) connects the horizontal surface 191a and the horizontal surface 191b, and preferably connects the flow channel 150 sides of the

horizontal surfaces

191a and 191 b. Thus, the elastic member 191 is formed with a slit 191d opening on the side of the flow path 143.

According to the elastic member 191, when the substrate W is held by the top ring 1, the diaphragm 13 is more reliably brought into contact with the elastic member 191, and the gap between the flow path 143 and the flow path 150 can be blocked. The reason for this is as follows.

As shown in fig. 14C, when the substrate W is held, a slight gap is formed between the convex portion 92 of the diaphragm 13 and the horizontal surface 191 a. In this case, when the pressure is applied from the flow path 143, the flow velocity of the fluid in the gap becomes high, and a negative pressure is generated in the gap according to the bernoulli theorem. Then, the horizontal surface 191a is deformed downward by the elasticity of the horizontal surface 191a, and comes into contact with the convex portion 92 (fig. 14D). When the contact is made, the fluid from the flow path 143 enters the slit 191d, so that the pressure inside the slit 191d becomes high, and a force pressing the horizontal surface 191a downward is generated. Thereby, the contact state between the horizontal surface 191a of the elastic member 191 and the convex portion 92 of the diaphragm 13 is stabilized.

Further, the flow path 143 for pressurizing the top ring 1 shown in fig. 14A is located on the center side of the top ring 1, and the flow path 150 in which the atmosphere is open is located outside the top ring 1. Therefore, the center side (the flow path 143 side) of the top ring 1 of the slit 191d is opened.

On the other hand, when the channel 14 for pressurizing is located outside the top ring 1 and the channel 150 in which the atmosphere is open is located on the center side of the top ring 1, the slit 191d may be open on the outside of the top ring 1 (or on the channel 143 side) as shown in fig. 15.

Fig. 16A is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 as a second modification. The top ring 1 includes an elastic member 291 (fig. 16B shows an enlarged view of the periphery of the elastic member 291). The elastic member 291 has

horizontal surfaces

291a, 291b and an inclined surface 291c.

The horizontal plane 291a (third surface) is substantially parallel to the diaphragm 13. In a state where the top ring 1 does not hold the substrate W, the lower surface of the horizontal surface 291a is separated from the upper surface of the diaphragm 13. When the top ring 1 holds the substrate W, the upper surface of the diaphragm 13 is in contact with the lower surface of the horizontal surface 291 a.

The horizontal surface 291b (fourth surface) is substantially parallel to the diaphragm 13, is located above the horizontal surface 291a (on the side opposite to the diaphragm 13), and is separated from the horizontal surface 291 a. The inclined surface 291c connects the horizontal surface 291a and the horizontal surface 291b obliquely (in a direction not orthogonal to the diaphragm 13), and preferably connects one end side (for example, the flow path 150 side) of the horizontal surface 291a and the other end side (for example, the flow path 143 side) of the horizontal surface 191 b.

Such an elastic member 291 is easily expanded and contracted in the vertical direction (the direction orthogonal to the diaphragm 13). Therefore, even when the substrate W is polished while the height of the top ring 1 is set low, the influence of the portion located below the horizontal surface 291a pressing the substrate W can be reduced, and thus the polishing rate of the entire surface of the substrate W becomes uniform.

Fig. 17A is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 as a third modification. The top ring 1 includes an elastic member 391 and a flow channel 392 (fig. 17B shows an enlarged view of the periphery of the elastic member 391). The elastic member 391 forms a fluid housing portion 391a (air bag) having an upper opening, and a flow channel 392 is connected to the opening. The flow channel 392 is connected to the pressure controller 72 shown in fig. 6, for example, and can pressurize (supply) the fluid housing portion 391 a.

When the adsorption determination is made, the fluid is supplied from the channel 392 to the fluid storage portion 391 a. Thereby, the elastic member 391 expands downward (toward the diaphragm 13) to approach the diaphragm 13 (fig. 17C). Therefore, when the top ring 1 holds the substrate W, the lower surface of the elastic member 391 stably contacts the upper surface of the diaphragm 13. In addition, the fluid housing 392a may be depressurized (normal state) during substrate polishing.

Fig. 18 is a cross-sectional view showing details of the top ring body 11 and the diaphragm 13 in the top ring 1 as a fourth modification. The top ring 1 includes an elastic member 491. A downward projection 491a is provided on the lower surface of the elastic member 491, not on the diaphragm 13. In this manner, the convex 491a may be provided on the elastic member 491 side. Further, a convex portion may be provided on the lower surface of the elastic member in each modification.

(second embodiment)

In the first embodiment, the flow rate of the fluid flowing through the determination region 133 is directly measured by the flow meter FS, but other physical quantities may be measured by using a measuring device in which the measured value changes according to the flow rate. Therefore, in the second embodiment described below, an example is shown in which a pressure gauge is used instead of the flow meter FS.

Fig. 19 is a sectional view schematically showing the structure of the top ring 1 in the second embodiment. As a point different from fig. 6A, a pressure gauge PS is provided in the flow path 143 communicating with the determination region 133. The pressure gauge PS measures the pressure in the flow path 143 and notifies the measurement result to the determination unit 73. The pressure measured by the pressure gauge PS corresponds to the flow rate of the fluid flowing through the determination region 133. In the present embodiment, the elastic member described in the first embodiment is also provided in the top ring 1, but the description thereof is omitted.

Fig. 20 is a cross-sectional view schematically showing the diaphragm 13 and the top ring body 11 in the case of failure in suction, and corresponds to fig. 11. As shown in the drawing, a gap g exists between the determination region 133 and the diaphragm 13, and the flow rate of the determination region 133 is large. In this case, the fluid easily flows from the flow path 141 to the determination region 133, and therefore the pressure of the flow path 143 becomes low. As a result, the measurement result of the pressure gauge PS becomes low.

Fig. 21 is a cross-sectional view schematically showing the substrate W, the diaphragm 13, and the top ring body 11 in a case where the suction is successful, and corresponds to fig. 12A. As shown in the drawing, there is almost no gap g between the determination region 133 and the diaphragm 13, and the flow rate of the determination region 133 is small. In this case, since the fluid hardly flows from the flow path 143 to the determination region 133, the pressure of the flow path 143 becomes high. As a result, the measurement result of the pressure gauge PS becomes higher.

Thus, the pressure gauge PS corresponds to the flow rate. Therefore, instead of step S4 in fig. 10 (whether or not the flow rate is equal to or less than the threshold), it is sufficient to determine whether or not the pressure exceeds the threshold.

Further, a pressure gauge PS may be provided in the flow path 150 communicating with the determination region 133.

Thus, the pressure gauge PS corresponds to the flow rate. Therefore, instead of step S4 in fig. 10 (whether or not the flow rate is equal to or less than the threshold), it is sufficient to determine whether or not the pressure is equal to or more than the threshold.

As described above, in the second embodiment, the pressure that changes according to the flow rate is measured, and whether or not the adsorption of the substrate W has succeeded can be accurately determined.

The above-described embodiments are described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention pertains to practice the present invention. It is needless to say that various modifications of the above-described embodiment can be made by those skilled in the art, and the technical idea of the present invention can be applied to another embodiment. Therefore, the present invention is not limited to the embodiments described above, and should be set to the widest scope according to the technical idea defined by the claims.

From the above, for example, the following embodiments are conceivable.

According to one aspect, there is provided a substrate holding apparatus including: a top ring body; an elastic film having a first surface and a second surface, a plurality of regions being formed between the first surface and the top ring main body, the second surface being located on a side opposite to the first surface and capable of holding a substrate; a first line that communicates with a first region among the plurality of regions and is capable of pressurizing the first region; a second line communicating with the first zone and capable of exhausting gas from the first zone; a measuring device whose measurement value changes based on the flow rate of the first region; a third line that communicates with a second region that is different from the first region among the plurality of regions and is capable of depressurizing the second region; an elastic member provided between the first line and the second line, the elastic member being separated from the first surface of the elastic film when the second surface of the elastic film does not hold the substrate, and the elastic member being in contact with the first surface of the elastic film when the second surface of the elastic film holds the substrate.

Preferably, a convex portion is provided on the first surface of the elastic film at a position facing the elastic member.

Preferably, the elastic member is formed with a slit that opens toward the first line side.

Preferably, the elastic member has: a third surface that is substantially parallel to the elastic film, and that contacts the first surface of the elastic film when the substrate is held by the second surface of the elastic film; a fourth surface substantially parallel to the elastic film, separated from the first surface and located on the opposite side of the elastic film; and a fifth surface that connects the second line side of the third surface and the second line side of the fourth surface.

Preferably, the resilient member is hollow.

Preferably, the elastic member has: a third surface that is substantially parallel to the elastic film, and that contacts the convex portion of the first surface of the elastic film when the substrate is held by the second surface of the elastic film; a fourth surface substantially parallel to the elastic film, separated from the first surface and located on the opposite side of the elastic film; and an inclined surface that connects the third surface and the fourth surface in a direction that is not orthogonal to the third surface.

Preferably, the elastic member forms a fluid storage portion, and at least a part of the elastic member is brought close to the elastic membrane by supplying a fluid to the fluid storage portion.

Preferably, the elastic member is provided with a convex portion at a position facing the first surface of the elastic film.

Preferably, the material of the elastic member is any one of NBR, silicone rubber, EPDM, fluororubber, chloroprene rubber, and urethane rubber.

According to another aspect, there is provided a substrate polishing apparatus including: the substrate holding device described above; and a polishing table configured to polish the substrate held by the substrate holding device.

According to another aspect, there is provided an elastic member for a substrate holding apparatus, the substrate holding apparatus including: a top ring body; an elastic film having a first surface and a second surface, a plurality of regions being formed between the first surface and the top ring main body, the second surface being located on a side opposite to the first surface and capable of holding a substrate; a first line that communicates with a first region of the plurality of regions and is capable of pressurizing the first region; a second line communicating with the first zone and capable of exhausting gas from the first zone; a measuring device whose measurement value changes based on the flow rate of the first region; and a third line that communicates with a second region that is different from the first region among the plurality of regions and is capable of depressurizing the second region, wherein the elastic member is provided between the first line and the second line so as to be separated from the first surface of the elastic film when the second surface of the elastic film does not hold the substrate, and so as to be in contact with the first surface of the elastic film when the second surface of the elastic film holds the substrate.

According to another aspect, there is provided a method of manufacturing a substrate holding apparatus, including: the substrate holding apparatus described in the above aspect, after the elastic member is removed therefrom, is mounted with a new elastic member.

Claims

1. A substrate holding device is characterized by comprising:

a top ring body;

an elastic film having a first surface and a second surface, a plurality of regions being formed between the first surface and the top ring main body, the second surface being located on a side opposite to the first surface and capable of holding a substrate;

a first line that communicates with a first region among the plurality of regions and is capable of pressurizing the first region;

a second line communicating with the first zone and capable of exhausting gas from the first zone;

a measuring device whose measurement value changes based on the flow rate of the first region;

a third line that communicates with a second region that is a different region from the first region among the plurality of regions and is capable of depressurizing the second region; and

an elastic member provided between the first line and the second line, the elastic member being separated from the first surface of the elastic film in a case where the second surface of the elastic film does not hold the substrate, the elastic member being in contact with the first surface of the elastic film in a case where the second surface of the elastic film holds the substrate,

the elastic member has:

a third surface substantially parallel to the elastic film, the third surface being in contact with the first surface of the elastic film when the substrate is held on the second surface of the elastic film;

a fourth surface substantially parallel to the elastic film, separated from the first surface and located on the opposite side of the elastic film; and

a fifth surface connecting the second line side of the third surface and the second line side of the fourth surface,

the slit of the first line side opening is formed by the third surface, the fourth surface, and the fifth surface.

2. The substrate holding apparatus according to claim 1,

a convex portion is provided on the first surface of the elastic film at a position facing the elastic member.

3. The substrate holding apparatus according to claim 1,

the elastic member is hollow.

4. The substrate holding apparatus according to claim 2,

when a fluid is supplied from the first line to pressurize the first region, the third surface of the elastic member is deformed downward according to bernoulli's theorem, and the fluid enters the slit, whereby the contact state between the third surface and the first surface is stabilized.

5. The substrate holding apparatus according to claim 1,

the elastic member is provided with a convex portion at a position facing the first surface of the elastic film.

6. The substrate holding apparatus according to claim 1,

the elastic member is made of any one of NBR, silicone rubber, EPDM, fluororubber, chloroprene rubber, and urethane rubber.

7. A substrate polishing apparatus is characterized by comprising:

the substrate holding apparatus of claim 1; and

and a polishing table configured to polish the substrate held by the substrate holding device.

8. An elastic member for a substrate holding apparatus,

the substrate holding device includes:

a top ring body;

a first line that communicates with a first region of the plurality of regions and is capable of pressurizing the first region;

a measuring device whose measurement value changes based on the flow rate of the first region; and

a third line that communicates with a second region that is a different region from the first region among the plurality of regions and is capable of depressurizing the second region,

the elastic member is characterized in that the elastic member is,

the elastic member is provided between the first line and the second line so as to be separated from the first surface of the elastic film when the second surface of the elastic film does not hold the substrate, so as to be in contact with the first surface of the elastic film when the second surface of the elastic film holds the substrate,

the elastic member has:

a third surface that is substantially parallel to the elastic film, and that contacts the first surface of the elastic film when the substrate is held by the second surface of the elastic film;

9. A method for manufacturing a substrate holding device, comprising the steps of:

for the substrate holding apparatus in which the elastic member is detached from the substrate holding apparatus of claim 1, a new elastic member is attached.