JP6463303B2 - Elastic film, substrate holding device, substrate polishing device, substrate adsorption determination method and pressure control method in substrate holding device - Google Patents

Description

  The present invention relates to an elastic film, a substrate holding device, a substrate polishing device, a substrate adsorption determination method and a pressure control method in a substrate holding device.

  In a substrate polishing apparatus that polishes a substrate such as a semiconductor wafer, the substrate is polished by pressing the substrate held by the top ring against a polishing table. In order to deliver the substrate from the transport mechanism to the top ring, first, the substrate supported by the transport mechanism is brought into contact with a membrane provided on the lower surface of the top ring and concentrically divided into a plurality of areas. And a board | substrate is adsorb | sucked by a membrane by evacuating from the hole formed in the membrane.

  However, a liquid such as water may enter the area where the holes are present, and the pressure applied to the substrate may become unstable. Therefore, in recent years, there is a tendency to make holes formed in the membrane as small as possible. Furthermore, the substrate is adsorbed by eliminating the holes and deforming the surface shape of the membrane by evacuation.

  If the holes are made smaller or eliminated, the adsorption power of the substrate is lowered. If the top ring is moved before the substrate is sufficiently attracted to the top ring, the substrate may be dropped. Therefore, it is necessary to detect that the substrate is attracted to the top ring and the delivery from the transport mechanism is completed. Usually, the vacuum pressure of the evacuated area is measured, and it is determined that the delivery of the substrate is completed when the vacuum pressure reaches a predetermined threshold.

Japanese Patent No. 3705670 JP 2014-61587 A JP 2011-258639 A JP 2014-8570 A JP 2002-521830 A JP-T-2004-516644 JP 2014-17428 A

However, even if the determination is made based on the vacuum pressure of the evacuated area, a sufficient adhesion force is not always generated between the substrate and the membrane. Therefore, for safety, the threshold value must be set strictly, or the top ring must be moved after reaching the threshold value and waiting for a predetermined time. If it does so, the delivery time of a board | substrate will become longer than originally required time, and there exists a problem that a throughput will fall.
Further, even after the substrate is once adsorbed, when the top ring transports the substrate, the adsorbing force is reduced and the substrate may be dropped.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an elastic film capable of appropriately handling a substrate, a substrate holding device, a substrate polishing apparatus having such a substrate holding device, It is to provide a substrate adsorption determination method and a pressure control method in such a substrate holding apparatus.

According to an aspect of the present invention, a top ring body, a first surface that forms a plurality of areas between the top ring body, and a first surface that is opposite to the first surface and can hold a substrate. An elastic membrane having two surfaces, a first line that communicates with a first area of the plurality of areas, and that can pressurize the first area; communicates with the first area; A second line capable of exhausting from one area, a measuring device whose measurement value changes based on a flow rate of the first area, and a second area different from the first area among the plurality of areas There is provided a substrate holding device including a third line that communicates with and can pressurize or depressurize the second area.
By using the flow rate measured by the flow meter, the substrate can be handled appropriately.

  The measuring device may be a flow meter capable of measuring the flow rate of the second line, or may be a pressure meter capable of measuring the pressure of the first line or the second line.

It is desirable that a determination unit that determines whether or not the substrate is adsorbed on the second surface is provided based on the measurement value.
The flow rate measured by the flow meter corresponds to the gap between the top ring body and the first surface of the elastic membrane. When the substrate is attracted, the gap is reduced and the flow rate is reduced. Therefore, it can be accurately determined whether the substrate is attracted.

When the substrate is adsorbed to the second surface, the second area is decompressed via the third line, the first area is pressurized via the first line, and the second line is interposed. A control unit that circulates fluid, and the determination unit determines whether the substrate is adsorbed to the second surface based on the measurement value when the substrate is adsorbed to the second surface. It is desirable to judge.
By measuring the flow rate with the first area open to the atmosphere, it is possible to suppress the elastic film from applying stress to the substrate.

The determination unit determines whether or not the substrate is adsorbed on the second surface based on a measurement value measured by the measuring instrument after a predetermined time has elapsed from the start of decompression of the second area. desirable.
Thereby, it can determine with higher precision.

It is desirable to provide a control unit that controls the pressure in the second area via the third line based on the flow rate measured by the measurement value.
The flow rate measured by the flow meter corresponds to the gap between the top ring body and the first surface of the elastic membrane. This gap corresponds to the swelling of the elastic membrane. Therefore, the swelling of the elastic film can be controlled by monitoring the flow rate.

It is preferable that the control unit controls the pressure in the second area so that the measured value falls within a predetermined range.
Thereby, the swelling of the elastic film can be maintained within a predetermined range.

  When the controller releases the substrate held on the second surface, the controller pressurizes the first area via the first line and distributes the fluid to the first area via the second line. Preferably, the pressure in the second area is controlled via the third line based on the measured value.

The controller may control the pressure in the second area so that fluid is ejected from the release nozzle to a predetermined position.
More preferably, the predetermined position is between the second surface and the held substrate.
Thereby, the ejection of the fluid can be continued between the second surface of the elastic film and the substrate from the release nozzle, and the substrate can be effectively released.

It is desirable that no hole is formed in the elastic membrane.
The second area is preferably not adjacent to the first area.
Thereby, when a board | substrate does not adsorb | suck to a 2nd area, the clearance gap between a 1st area and a 1st surface is maintained.

It is desirable to provide a retainer ring provided on the outer periphery of the elastic membrane.
The retainer ring may include an inner ring and an outer ring provided outside the inner ring.

  According to another aspect of the present invention, there is provided a substrate polishing apparatus comprising the substrate holding device and a polishing table configured to polish a substrate held by the substrate holding device.

  According to another aspect of the present invention, the second area formed between the top ring body and the first surface of the elastic film in the substrate holding device is decompressed, and the top ring body and the elastic film are Pressurizing a first area different from the second area formed between the first surface and circulating fluid through a second line communicating with the first area, the flow rate of the first area Provided is a substrate adsorption determination method in a substrate holding device that determines whether or not a substrate is adsorbed on a second surface of the elastic film opposite to the first surface based on a measured value according to the measured value. .

  According to another aspect of the present invention, the second line that pressurizes the first area formed between the top ring body and the first surface of the elastic film in the substrate holding device and communicates with the first area. Is different from the first area formed between the top ring body and the first surface of the elastic membrane based on a measured value corresponding to the flow rate of the first area. A pressure control method in a substrate holding device for controlling the pressure in a second area is provided.

According to another aspect of the present invention, there is provided an elastic film that is used together with a top ring body provided with a first hole and a second hole on the outer side and the inner side of the first part, respectively, and constitutes a substrate holding device. A second portion engageable with the first portion, and a first surface forming a plurality of areas between the top ring body and a substrate opposite to the first surface to hold the substrate An elastic membrane comprising a possible second surface is provided.
Since the difference between the case where the substrate is held and the case where the substrate is not held is increased by engaging the first portion and the second portion, the substrate suction determination can be performed with high accuracy.

  The first part may be a concave part, the second part may be a convex part, or the first part may be a convex part, and the second part may be a concave part.

  According to another aspect of the present invention, the top ring main body provided with the first hole and the second hole on the outer side and the inner side of the first part, respectively, and the second part engageable with the first part are provided. An elastic film provided with a first surface that forms a plurality of areas between the top ring body and a second surface that is opposite to the first surface and can hold a substrate; The first hole is located in the first area of the plurality of areas, the first line capable of pressurizing the first area through the first hole, and the second hole is the first area A second line which is located in one area and can be exhausted from the first area through the second hole, a measuring device whose measurement value changes based on the flow rate of the first area, Communicating with a second area different from the first area of the plurality of areas; Substrate holding apparatus comprising: a third line that is capable of a rear elevated or reduced pressure, is provided.

It is desirable that a portion corresponding to the first area of the top ring body is provided with a radially expanding groove.
Thereby, the propagation of pressure in the first area can be accelerated.

It is desirable to have a bypass line that bypasses the first line and the second line, and a valve provided on the bypass line.
By opening the valve on the bypass line, the first area can be pressurized simultaneously from both the first line and the second line. Thereby, even when the second portion is engaged with the first portion when the first area is pressurized, the entire first area can be quickly pressurized with the same pressure.

  By measuring the flow rate in the first area, the substrate can be handled appropriately.

1 is a schematic top view of a substrate processing apparatus including a substrate polishing apparatus. 1 is a schematic perspective view of a substrate polishing apparatus 300. FIG. 1 is a schematic sectional view of a substrate polishing apparatus 300. FIG. The figure explaining in detail the board | substrate delivery to the top ring 1 from the conveyance mechanism 600b. The figure explaining in detail the board | substrate delivery to the top ring 1 from the conveyance mechanism 600b. Sectional drawing which shows the structure of the top ring 1 in 1st Embodiment typically. The modification of FIG. 6A. Sectional drawing which shows the detail of the top ring main body 11 and the membrane 13 in the top ring 1. FIG. FIG. 8 is a cross-sectional view taken along line A-A ′ of FIG. 7. The figure explaining operation | movement of each valve | bulb in the top ring 1. FIG. The flowchart which shows the procedure of board | substrate adsorption | suction determination. The figure which shows typically the cross section of the membrane 13 and the top ring main body 11 at the time of adsorption | suction failure. The figure which shows typically the cross section of the board | substrate W at the time of succeeding in adsorption | suction, the membrane 13, and the top ring main body 11. FIG. The figure which shows typically the flow volume measured with the flowmeter FS after adsorption | suction start. Sectional drawing which shows the structure of the top ring 1 in 2nd Embodiment typically. The figure which shows typically the cross section of the membrane 13 and the top ring main body 11 at the time of adsorption | suction failure. The figure which shows typically the cross section of the board | substrate W at the time of succeeding in adsorption | suction, the membrane 13, and the top ring main body 11. FIG. FIG. 15 is a cross-sectional view schematically showing the structure of a top ring 1 that is a modification of FIG. 14. The figure which shows typically the cross section of the membrane 13 and the top ring main body 11 at the time of adsorption | suction failure. The figure which shows typically the cross section of the board | substrate W at the time of succeeding in adsorption | suction, the membrane 13, and the top ring main body 11. FIG. The figure explaining the board | substrate delivery from the top ring 1 to the conveyance mechanism 600b in detail. The figure explaining the board | substrate delivery from the top ring 1 to the conveyance mechanism 600b in detail. The figure which shows the state before a release start typically. The figure which shows the state after a release start typically. The figure which shows typically the state after the release start following FIG. The figure which shows typically the state after the release start following FIG. The figure which shows typically the structure of the top ring 1 in 3rd Embodiment. The flowchart which shows operation | movement of the top ring 1 at the time of release. The figure which shows typically the flow volume measured with the flowmeter FS at the time of release. The side view which shows typically a mode that the board | substrate W is released from the top ring 1 and delivered to the pusher 160. FIG. Sectional drawing of the top ring main body 11 and the membrane 13 of the area 131 vicinity. The figure which looked at the membrane 13 in the vicinity of the area 131 from upper direction. The figure which looked at the top ring main body 11 in the area 131 vicinity from the downward direction. The figure which shows the structural example of the pressure control apparatus. The figure explaining the pressurization at the time of adsorption | suction determination. The figure explaining pressurization at the time of substrate polish. The figure which shows typically the cross section of the board | substrate W at the time of succeeding in adsorption | suction, the membrane 13, and the top ring main body 11. FIG. FIG. 31 is a cross-sectional view of a top ring 11 and a membrane 13 that are modifications of FIG. 30.

  Embodiments according to the present invention will be specifically described below with reference to the drawings.

(First embodiment)
The first embodiment focuses on accurately determining whether or not a substrate is attracted to the top ring when a substrate such as a semiconductor wafer is transferred to a top ring (substrate holding device) in the substrate polishing apparatus. ing.

FIG. 1 is a schematic top view of a substrate processing apparatus including a substrate polishing apparatus. This substrate processing apparatus is a semiconductor wafer having a diameter of 300 mm or 450 mm, a flat panel, an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device), a magnetic film manufacturing process in an MRAM (Magnetoresistive Random Access Memory), etc. In this method, various substrates are processed.

  The substrate processing apparatus includes a substantially rectangular housing 100, a load port 200 on which a substrate cassette for stocking a large number of substrates is placed, and one or more (four in the embodiment shown in FIG. 1) substrate polishing apparatus 300. One or a plurality of (two in the embodiment shown in FIG. 1) substrate cleaning apparatus 400, a substrate drying apparatus 500, transport mechanisms 600a to 600d, and a control unit 700 are provided.

The load port 200 is disposed adjacent to the housing 100. The load port 200 can be equipped with an open cassette, a SMIF (Standard Mechanical Interface) pod, or a FOUP (Front Opening Unified Pod). SMIF pod,
The FOUP is a sealed container that can maintain an environment independent of the external space by accommodating a substrate cassette inside and covering it with a partition wall.

  A substrate polishing apparatus 300 for polishing the substrate, a substrate cleaning apparatus 400 for cleaning the polished substrate, and a substrate drying apparatus 500 for drying the cleaned substrate are accommodated in the housing 100. 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.

  A transport mechanism 600 a 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 transport mechanism 600 b is disposed in parallel with the substrate polishing apparatus 300, the substrate cleaning apparatus 400, and the substrate drying apparatus 500.

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

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

  Further, a transport mechanism 600 c that transfers substrates between the two substrate cleaning apparatuses 400 is disposed between the two substrate cleaning apparatuses 400. Further, a transfer mechanism 600 d that transfers a 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 movement of each device of the substrate processing apparatus, and may be disposed inside the housing 100, may be disposed outside the housing 100, the substrate polishing apparatus 300, and the substrate cleaning. Each of the apparatus 400 and the substrate drying apparatus 500 may be provided.

  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 to which the top ring 1 is connected at the bottom, a polishing table 3 having a polishing pad 3a, a nozzle 4 for supplying a polishing liquid onto the polishing table 3, A top ring head 5 and a support shaft 6 are provided.

  The top ring 1 holds the substrate W and is provided below the top ring body 11 (carrier), the annular retainer ring 12, the top ring body 11 and inside the retainer ring 12, as shown in FIG. The flexible membrane 13 (elastic film), the airbag 14 provided between the top ring main body 11 and the retainer ring 12, the pressure control device 7, and the like.

  The retainer ring 12 is provided on the outer periphery of the top ring body 11. The peripheral edge of the held substrate W is surrounded by the retainer ring 12 so that the substrate W does not jump out of the top ring 1 during polishing. The retainer ring 12 may be a single member, or may have a double ring configuration 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 membrane 13 is provided to face the top ring body 11. A plurality of concentric areas are formed between the top surface of the membrane 13 and the top ring body 11. By reducing the pressure in one or more areas, the lower surface of the membrane 13 can hold the upper surface of the substrate W.

  The airbag 14 is provided between the top ring body 11 and the retainer ring 12. With the airbag 14, the retainer ring 12 can be moved relative to the top ring body 11 in the vertical direction.

  The pressure control device 7 supplies each fluid between the top ring body 11 and the membrane 13, evacuates it, or releases it to the atmosphere, thereby forming each of the pressure control devices 7 between the top ring body 11 and the membrane 13. Adjust the area pressure individually. Further, the pressure control device 7 determines whether or not the substrate W is adsorbed on the membrane 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. A lifting mechanism (not shown) raises and lowers the top ring shaft 2 so that the lower surface of the substrate W held on the top ring 1 comes into contact with or separates from the polishing pad 3a. Further, the top ring 1 is rotated by rotating the top ring shaft 2 by a motor (not shown), and the substrate W held thereby is also rotated.

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

  The top ring head 5 of FIG. 3 has a top ring shaft 2 connected to one end and a support shaft 6 connected to the other end. When the motor (not shown) rotates the support shaft 6, the top ring head 5 swings, and the top ring 1 moves back and forth between the polishing pad 3a and the substrate transfer position (not shown).

Next, an operation when the substrate is transferred from the transport mechanism 600b in FIG. 1 to the top ring 1 in FIGS. 2 and 3 will be described.
4 and 5 are diagrams for explaining in detail the substrate delivery from the transport mechanism 600b to the top ring 1. FIG. 4 is a view of the transport mechanism 600b and the top ring 1 as seen from the side, and FIG. 5 is a view of these as seen from above.

  As shown in FIG. 4A, the substrate W is placed on the hand 601 of the transport mechanism 600b. A retainer ring station 800 is used for delivery of the substrate W. The retainer ring station 800 includes a push-up pin 801 that pushes up the retainer ring 12 of the top ring 1. In addition, although the retainer ring station 800 may have a release nozzle, it is not illustrated.

  As shown in FIG. 5, the hand 601 supports a part of the outer peripheral side of the lower surface of the substrate W. The push-up 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 transport mechanism 600b is raised. When the top ring 1 is lowered, the push-up pin 801 pushes up the retainer ring 12 and the substrate W approaches the membrane 13. When the transport mechanism 600b is further raised, the upper surface of the substrate W comes into contact with the lower surface of the membrane 13 (FIG. 4B).

In this state, the area formed between the membrane 13 and the top ring main body 11 is depressurized, whereby the substrate W is adsorbed to the lower surface of the membrane 13 of the top ring 1. However, depending on the case, the substrate W may not be adsorbed on the lower surface of the membrane 13, or may be dropped after being adsorbed once. Therefore, in this embodiment, as described later, it is determined whether or not the substrate W is attracted to the membrane 13 (substrate adsorption determination).
Thereafter, the transport mechanism 600b is lowered (FIG. 4C).

Next, the top ring 1 will be described.
FIG. 6A is a cross-sectional view schematically showing the structure of the top ring 1 in the first embodiment. The membrane 13 is formed with peripheral walls 13 a to 13 h extending upward toward the top ring main body 11. These peripheral walls 13 a to 13 h form concentric areas 131 to 138 separated by the peripheral walls 13 a to 13 h between the upper surface of the membrane 13 and the lower surface of the top ring body 11. It is desirable that no hole is formed on the lower surface of the membrane 13.

Flow paths 141 to 148 that pass through the top ring body 11 and have one end communicating with the areas 131 to 138 are formed. An airbag 14 made of an elastic film is provided immediately above the retainer ring 12, and a flow path 149 whose one end communicates with the airbag 14 is similarly formed. The other ends of the flow paths 141 to 149 are connected to the pressure control device 7. A pressure sensor or a flow rate sensor may be provided on the flow paths 141 to 149.
Further, a flow path 150 that penetrates the top ring main body 11 and has one end communicating with the area 131 is formed for the substrate suction determination. The other end of the flow path 150 is open to the atmosphere.

  The pressure control device 7 includes valves V1 to V9 and pressure regulators R1 to R9 provided in the flow paths 141 to 149, a control unit 71, and a pressure regulator 72, respectively. For substrate adsorption determination, the pressure control device 7 includes a valve V10 and a flow meter FS provided in the flow path 150, and a determination unit 73. Since the flow rate does not occur when the valve V10 is closed, the installation order of the valve V10 and the flow meter FS does not matter.

  The control unit 71 controls the valves V1 to V10, the pressure regulators R1 to R9, and the pressure regulator 72.

  The pressure adjuster 72 is connected to one end of the flow paths 141 to 149, and adjusts the pressure of the areas 131 to 138 and the airbag 14 according to the control of the control unit 71. Specifically, the pressure regulator 72 supplies fluids such as air through the flow paths 141 to 149 to pressurize the areas 131 to 138 and the airbag 14 or evacuate the areas 131 to 138 and The air bag 14 is depressurized, and the areas 131 to 138 and the air bag 14 are opened to the atmosphere.

  In the case of FIG. 6A, an example in which one valve V1 to V9 is connected to each of the flow paths 141 to 149 is shown. FIG. 6B is a modification of FIG. 6A, and a plurality of valves may be connected to each of the flow paths 141 to 149. FIG. 6B shows a case where three valves V3-1, V3-2, and V3-3 are connected to the flow path 143 as an example. The valve V3-1 is connected to the pressure regulator R3, the valve V3-2 is connected to the atmosphere release source, and the valve V3-3 is connected to the vacuum source. When pressurizing the area 133, the valves V3-2 and V3-3 are closed, the valve V3-1 is opened, and the pressure regulator R3 is operated. When the area 133 is opened to the atmosphere, the valves V3-1 and V3-3 are closed and the valve V3-2 is opened. When the area 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 area 135, the control unit 71 opens the valve V5 and controls the pressure regulator 72 so that air is supplied to the area 135. This is simply expressed as the control unit 71 pressurizing the area 135.

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 area 131, and notifies the determination unit 73 of the measurement result. The flow rate means the volume of fluid (particularly air) flowing per unit time unless otherwise specified. In addition, if the flowmeter FS can measure the flow volume of the flow path 150, there will be no restriction | limiting in particular in the arrangement position, and since the flow path 141 and the flow path 150 are connected, you may arrange | position in the flow path 141, for example.
The determination unit 73 performs substrate adsorption determination based on the flow rate measured by the flow meter FS.

  FIG. 7 is a cross-sectional view showing details of the top ring body 11 and the membrane 13 in the top ring 1. As illustrated, the membrane 13 includes a circular contact portion 130 that contacts the substrate W, and eight peripheral walls 13 a to 13 h that are directly or indirectly connected to the contact portion 130. The abutting portion 130 contacts and holds the back surface of the substrate W, that is, the surface opposite to the surface to be polished. The abutting portion 130 presses the substrate W against the polishing pad 3a during polishing. The peripheral walls 13a to 13h are annular peripheral walls arranged concentrically.

  The upper ends of the peripheral walls 13 a to 13 h are sandwiched between the holding rings 22, 24, 26, and 28 and the lower surface of the top ring body 11 and are attached to the top ring body 11. These holding rings 22, 24, 26, and 28 are detachably fixed to the top ring body 11 by holding means (not shown). Accordingly, when the holding means is released, the holding rings 22, 24, 26, and 28 are separated from the top ring body 11, whereby the membrane 13 can be detached from the top ring body 11. A screw or the like can be used as the holding means.

  Retaining rings 22, 24, 26, and 28 are in areas 132, 134, 136, and 138, respectively. The flow paths 142, 144, 146, and 148 pass through the top ring main body 11 and the holding rings 22, 24, 26, and 28, respectively. Further, the top ring main body 11 has projecting portions 21, 23, 25, 27 projecting downward toward the areas 131, 133, 135, 137, respectively. And the flow path 141,143,145,147 penetrates the protrusion parts 21,23,25,27, respectively. Although not shown, the flow path 150 penetrates the protruding portion 21.

  The lower surfaces of the retaining rings 22, 24, 26, 28 and the projecting portions 21, 23, 25, 27 are preferably on the same plane. This is because these lower surfaces form a reference surface when the substrate W is sucked and held.

Further, there is a gap g (described later in FIG. 11 and the like) through which air can flow from the channel 141 to the channel 150 between the lower surface and the membrane 13. When the substrate W is attracted to the lower surface of the membrane 13, the membrane 13 is pulled up toward the top ring body 11, so this gap g is almost eliminated. If the gap g is too small, the difference in the change in the gap g is small between when the substrate W is sucked and when the substrate W is not sucked, and the determination margin described later becomes small. On the other hand, if the gap g is too large, the peripheral walls 13a to 13h of the membrane 13 need to be greatly contracted when the substrate is adsorbed, and the downward repulsive force from the peripheral walls 13a to 13h to the substrate W increases and the adsorbing force decreases. The board will be damaged.
In consideration of the above, it is necessary to appropriately set the width of the gap g. Specifically, it is preferably about 0.1 to 2 mm, and more preferably about 0.5 mm.

  FIG. 8 is a cross-sectional view taken along line A-A ′ of FIG. 7. As shown in the figure, the protrusion 21 is formed with a hole 21 a communicating with the flow channel 141 (FIG. 7) and a hole 21 b communicating with the flow channel 150. Further, holes 23a, 25a, and 27a communicating with the flow paths 143, 145, and 147 are formed in the protrusions 23, 25, and 27, respectively. Furthermore, holes 22a, 24a, and 26a communicating with the flow paths 142, 144, and 146 are formed in the holding rings 22, 24, and 26, respectively. In addition, there is no restriction | limiting in particular in the number and arrangement | positioning of a hole.

  FIG. 9 is a diagram for explaining the operation of each valve in the top ring 1. When adsorbing or polishing the substrate W, the pressure in any one or more of the areas 132 to 137 may be adjusted. In the following, the case where the pressure in the area 133 is adjusted is shown. In these areas 132 and 134 to 137, arbitrary pressure adjustment is possible.

  When opening the membrane 13 during idling or the like, the control unit 71 opens the valves V1, V3, and V10 and opens the areas 131 and 133 to the atmosphere.

  When polishing the substrate W, in order to pressurize the membrane 13 and press the substrate W against the polishing pad 3a, the controller 71 opens the valves V1 and V3 to pressurize the areas 131 and 133, and closes the valve V10.

  When the substrate W is transferred from the transport mechanism 600b to the top ring 1 and is adsorbed to the membrane 13, the control unit 71 opens the valve V3 to decompress the area 133. Further, in order to perform the substrate adsorption determination, the control unit 71 opens the valve V10 to slightly pressurize the area 131, and opens the valve V10 to release the area 131 to the atmosphere. And based on the measurement value by the flowmeter FS, the determination part 73 determines whether the board | substrate adsorb | sucked to the membrane 13 as follows.

  FIG. 10 is a flowchart showing the procedure for determining the substrate suction. Hereinafter, the area 131 in which the flow meter FS is provided is referred to as a “determination area”, and the area 133 where the pressure is reduced for suction is referred to as a “suction area”.

  First, the controller 71 depressurizes the suction area 133 (step S1). Then, the control unit 71 opens the valve V1 to pressurize the determination area 131, and opens the valve V10 to release the determination area 131 to the atmosphere (step S2). That is, the control unit 71 pressurizes the determination area 131 via the flow path 141 and opens the determination area 131 to the atmosphere via the flow path 150.

  In step S1, the control unit 71 depressurizes the suction area 133 to about -500 hPa, whereas in step S2, the control unit 71 pressurizes the determination area 131 to 200 hPa or less, preferably about 50 hPa. This is because if the determination area 131 is pressurized too much, a force acting downward on the substrate W becomes large, which hinders substrate adsorption.

  Next, the determination unit 73 waits until a predetermined determination start time T0 has elapsed (step S3). When the determination start time T0 elapses, 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 has been attracted to the membrane 13 (step S4).

  FIG. 11 is a diagram schematically showing a cross section of the membrane 13 and the top ring body 11 when the adsorption has failed. When the substrate W is not adsorbed, the membrane 13 has flexibility, so that the portion corresponding to the adsorption area 133 in the membrane 13 is pulled up to the top ring body 11, but the portion corresponding to the determination area 131 is not pulled up, and the top A gap g remains between the ring body 11 and the ring body 11. Therefore, the flow rate measured by the flow meter FS increases.

  FIG. 12 is a diagram schematically showing a cross section of the substrate W, the membrane 13 and the top ring body 11 when the adsorption is successful. When the substrate W is attracted, the entire membrane 13 including the portion corresponding to the determination area 131 is pulled up and is in 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 in the determination area 131 corresponds to the size of the gap g, and the larger the gap g, the larger the flow rate.

  Therefore, when the flow rate is equal to or smaller than the threshold (that is, when the gap g is small), the determination unit 73 determines that the substrate W has been successfully sucked (or the substrate W is sucked) (YES in step S4 in FIG. 10). , S5, FIG. 12). Then, the substrate processing apparatus continues operations such as transport of the substrate W by the top ring 1 (step S6). Thereafter, if the adsorption of the substrate W should be continued (YES in step S7), the determination in step S4 is repeated.

  On the other hand, when the flow rate is greater than the threshold value (that is, when the gap g is large) even after the predetermined error confirmation time has elapsed, the determination unit 73 determines that the adsorption of the substrate W has failed (or the substrate W has not been adsorbed). (NO in S4, YES in S8, S9, FIG. 11). Then, the substrate processing apparatus stops its operation and issues an error as necessary (step S10).

  In the present embodiment, the determination is continued even after it has been confirmed that the substrate W has been adsorbed to the membrane 13 (YES in step S7, S4). Therefore, when the substrate W is dropped during the transfer of the substrate W or the like, it can be detected that the flow rate is larger than the threshold value and the substrate W no longer exists (step S9).

  FIG. 13 is a diagram schematically showing the flow rate measured by the flow meter FS after the start of adsorption, where the solid line indicates successful adsorption, the broken line indicates failure in adsorption, and the alternate long and short dash line once succeeds in adsorption. Each flow rate measured by the flow meter FS when falling is shown, and the horizontal axis shows time.

  As shown in the figure, when the adsorption starts at time t1 (step S1 in FIG. 10), the flow rate increases. This is because there is a gap g between the upper surface of the membrane 13 and the lower surface of the top ring body 11 at the start of the adsorption, regardless of whether the adsorption succeeds or fails.

  In the case of successful adsorption (solid line in the figure), since the substrate W is adsorbed to the membrane 13, the gap g between the membrane 13 and the top ring body 11 is reduced. Therefore, after a certain time t2, the flow rate starts to decrease. Then, 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 to the membrane 13 at time t4 in FIG. 13, the gap g between the membrane 13 and the top ring body 11 is almost eliminated, and the flow rate becomes substantially constant.

  Assuming that the substrate W has dropped from the top ring 1 at time t11, the flow rate increases again (the dashed line in the figure). This is because the gap g is generated again between the membrane 13 and the top ring body 11 when the substrate W is separated from the membrane 13. In this case, it is determined that the adsorption has failed (step S9 in FIG. 10) after a predetermined error confirmation time has elapsed from time t12 when the flow rate becomes greater than the threshold value (step 8).

  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 eventually becomes constant. Therefore, even if the error confirmation time has elapsed, the flow rate remains larger than the threshold value, and it is determined that the adsorption has failed (step S9 in FIG. 10).

  The reason for setting the determination start time T0 is to prevent it from being determined that the substrate has been adsorbed before it is sufficiently adsorbed to the membrane (before time t5 in FIG. 13). Error confirmation time is also required in the following cases. After the polishing, when the substrate W adsorbed on the top ring 1 is pulled up from the polishing pad 3a, the flow rate temporarily increases due to the adsorbing force between the polishing pad 3a and the substrate W, and may exceed the threshold value. Because.

  Thus, in the first embodiment, the determination area 131 is pressurized and opened to the atmosphere, and the flow rate in the area 131 is measured. This flow rate corresponds to the size of the gap g between the membrane 13 and the top ring body 11. Therefore, by monitoring the flow rate, it can be accurately determined whether or not the adsorption of the substrate W has succeeded, and the substrate W can be handled appropriately. Further, the determination can be continued even after the adsorption, and even when the substrate W falls after the successful adsorption, this can be detected.

  In the present embodiment, the flow path 150 is opened to the atmosphere. For example, the flow rate adjustment valve is used to adjust the flow rate to a flow range suitable for substrate adsorption detection, or a pressure regulator is connected instead of opening to the atmosphere to adjust the flow rate. You may exhaust. When a pressure regulator is connected to the flow path 150, for example, R1 is set to 100 hPa pressurization, and the added pressure regulator is set to 50 hPa pressurization so that air flows through the flow path 150.

  The substrate adsorption determination according to the present embodiment is also applicable to the membrane 13 in which no hole is formed. Further, since the valve V10 is opened at the time of substrate adsorption determination, the determination area 131 is not closed, and the pressure in the determination area 131 does not increase so much. Therefore, the determination area 131 in the membrane 13 hardly applies stress to the substrate W.

  In the present embodiment, the central area 131 is the determination area and the area 133 is the suction area, but other areas may be the determination area and the suction area. That is, a configuration corresponding to the valve V10, the flow path 150, and the flow meter FS can be provided in at least one area as the determination area, and one or more other areas can be used as the adsorption area.

  Note that it is desirable that the determination area is not adjacent to the suction area and is separated from one or more areas. If the determination area and the adsorption area are adjacent to each other, even if the adsorption of the substrate W has failed, the portion corresponding to the determination area in accordance with the lifting of the portion corresponding to the adsorption area in the membrane 13 Can also be raised. This is because there is a possibility that an erroneous determination may occur due to a decrease in the flow rate flowing in the determination area.

(Second Embodiment)
In the first embodiment, the flow rate of the fluid flowing through the determination area 131 is directly measured by the flow meter FS. However, even if another physical quantity is measured using a measuring device whose measurement value changes according to the flow rate. Good. Therefore, in a second embodiment described below, an example in which a pressure gauge is used instead of the flow meter FS is shown.

  FIG. 14 is a cross-sectional view schematically showing the structure of the top ring 1 in the second embodiment. As a difference from FIG. 6A, a pressure gauge PS is provided in the flow path 141 communicating with the determination area 131. The pressure gauge PS measures the pressure in the flow path 141 and notifies the determination unit 73 of the measurement result. The pressure measured by the pressure gauge PS corresponds to the flow rate of the fluid flowing through the determination area 131.

  FIG. 15 is a diagram schematically showing a cross section of the membrane 13 and the top ring body 11 when the adsorption has failed, and corresponds to FIG. 11. As illustrated, there is a gap g between the determination area 131 and the membrane 13, and the flow rate of the determination area 131 is large. In this case, since the gas easily flows from the flow path 141 to the determination area 131, the pressure of the flow path 141 becomes low. As a result, the measurement result by the pressure gauge PS becomes low.

  FIG. 16 is a diagram schematically showing a cross section of the substrate W, the membrane 13, and the top ring body 11 when the adsorption is successful, and corresponds to FIG. As shown in the figure, there is almost no gap g between the determination area 131 and the membrane 13, and the flow rate of the determination area 131 is small. In this case, it is difficult for gas to flow from the flow path 141 to the determination area 131, so the pressure in the flow path 141 increases. As a result, the measurement result by the pressure gauge PS becomes high.

  Thus, the pressure gauge PS corresponds to the flow rate. Therefore, instead of step S4 in FIG. 10 (whether the flow rate is equal to or lower than the threshold value), it may be determined whether the pressure exceeds the threshold value.

  FIG. 17 is a cross-sectional view schematically showing the structure of a top ring 1 which is a modification of FIG. As a difference from FIG. 17, a pressure gauge PS is provided in the flow path 150 communicating with the determination area 131. The pressure gauge PS measures the pressure in the flow path 150 and notifies the determination unit 73 of the measurement result. The pressure measured by the pressure gauge PS corresponds to the flow rate of the fluid flowing through the determination area 131.

  FIG. 18 is a diagram schematically illustrating a cross section of the membrane 13 and the top ring body 11 when the adsorption has failed, and corresponds to FIG. 11. As illustrated, there is a gap g between the determination area 131 and the membrane 13, and the flow rate of the determination area 131 is large. In this case, since the gas easily flows from the determination area 131 into the flow path 150, the pressure in the flow path 150 increases. As a result, the measurement result by the pressure gauge PS becomes high.

  FIG. 19 is a diagram schematically showing a cross section of the substrate W, the membrane 13, and the top ring body 11 when the adsorption is successful, and corresponds to FIG. As shown in the figure, there is almost no gap g between the determination area 131 and the membrane 13, and the flow rate of the determination area 131 is small. In this case, since it is difficult for gas to flow from the determination area 131 to the flow path 150, the pressure of the flow path 150 becomes low. As a result, the measurement result by the pressure gauge PS becomes low.

  Thus, the pressure gauge PS corresponds to the flow rate. Therefore, instead of step S4 in FIG. 10 (whether the flow rate is equal to or lower than the threshold value), it may be determined whether the pressure is equal to or higher than the threshold value.

  As described above, in the second embodiment, it is possible to accurately determine whether or not the adsorption of the substrate W has succeeded by measuring the pressure that changes according to the flow rate.

(Third embodiment)
The third embodiment focuses on reliably releasing the substrate adsorbed on the top ring. Hereinafter, a description will be given focusing on differences from the first embodiment.

  20 and 21 are diagrams for explaining in detail the substrate delivery from the top ring 1 to the transport mechanism 600b. 20 is a side view of the transport mechanism 600b and the top ring 1, and FIG. 21 is a top view of the top ring 1 and the retainer ring station 800 (however, the transport mechanism 600b in FIG. 20 is omitted). is there. As shown in these drawings, the retainer ring station 800 has, for example, three release nozzles 802 facing inward (substrate W side).

  FIG. 20A shows a state where the substrate W is adsorbed to the membrane 13. At this time, no fluid (release shower) is ejected from the release nozzle 802.

  As shown in FIG. 20B, the top ring 1 is lowered and the transport mechanism 600b is raised. As a result, the hand 601 of the transport mechanism 600b approaches the lower surface of the substrate W, but they are not in contact with each other. Further, the push-up pin 801 pushes up the retainer ring 12.

  In this state, an area between the membrane 13 and the top ring main body 11 (hereinafter referred to as area 133) is pressurized. Further, a fluid such as air is ejected from the release nozzle 802. As a result, the substrate W is released from the membrane 13 and placed on the hand 601. Details of this point will be described later.

  Thereafter, as shown in FIG. 20C, the hand 601 on which the substrate W is placed is lowered, and the top ring 1 is raised.

The release in FIG. 20B will be described in detail.
FIG. 22 is a diagram schematically showing a state before the start of release. Before the pressurization of the area 133 is started, the substrate W is adsorbed to the membrane 13, and therefore there is almost no gap g between the upper surface of the membrane 13 and the lower surface of the top ring body 11. Prior to the start of pressurization, no fluid is ejected from the release nozzle 802.

  FIG. 23 is a diagram schematically illustrating a state after the start of release. When pressurization of the area 133 is started, the membrane 13 swells, and the upper surface of the membrane 13, the top ring body 11, and the gap g gradually increase. That is, the membrane 13 moves downward. In this state, the fluid is ejected from the release nozzle 802, but the fluid hits the lower side of the substrate W and hardly hits the membrane 13. That is, FIG. 23 shows a state where the membrane 13 is not sufficiently bulged, in other words, a state where the gap g between the membrane 13 and the top ring body 11 is too small.

  FIG. 24 is a diagram schematically showing a state after the release start following FIG. When the area 133 is further pressurized, the membrane 13 further expands, and the gap g between the upper surface of the membrane 13 and the top ring body 11 becomes larger. That is, the membrane 13 moves downward. In this state, the fluid ejected from the release nozzle 802 hits the vicinity of the boundary between the substrate W and the membrane 13. Therefore, the fluid flows between the substrate W and the membrane 13.

Thus, the state in which the fluid is ejected from the side between the membrane 13 swelled to a certain extent and the substrate W continues, whereby the substrate W can be effectively released from the membrane 13. That is, FIG. 24 shows a state where the swelling of the membrane 13 is appropriate, in other words, a state where the gap g between the membrane 13 and the top ring body 11 is appropriate.
However, the state of FIG. 24 cannot always be continued.

  FIG. 25 is a diagram schematically showing a state after the start of release following FIG. When the area 133 is further pressurized, the membrane 13 is further expanded, and the gap g between the upper surface of the membrane 13 and the top ring body 11 is further increased. That is, the membrane 13 moves further downward. In this state, the fluid ejected from the release nozzle 802 hits the membrane 13 but hardly hits the substrate W. That is, FIG. 25 shows a state where the swelling of the membrane 13 is too large, in other words, a state where the gap g between the membrane 13 and the top ring body 11 is too large.

  Thus, in order to reliably release the substrate W, it is necessary to control the swelling of the membrane 13 (in other words, the gap g between the membrane 13 and the top ring body 11). Therefore, in the present embodiment, the pressure control of the area 133 is performed as follows so that the swelling of the membrane 13 as shown in FIG. 24 can be maintained in an appropriate state.

  FIG. 26 is a diagram schematically showing the structure of the top ring 1 in the third embodiment. As a difference from FIG. 6A, the measurement value of the flow meter FS is input to the control unit 71. And the control part 71 controls the pressure regulator 72, valve | bulb V1-V9, and pressure regulator R1-R9 based on the measured value of the flowmeter FS.

  When performing the release, the control unit 71 opens the valve V1 to slightly pressurize the area 131, and opens the valve V10 to release the area 131 to the atmosphere. As described in the first embodiment, the flow rate measured by the flow meter FS corresponds to the size of the gap g between the membrane 13 and the top ring body 11. The size of the gap g corresponds to the swelling of the membrane 13. Therefore, the control unit 71 appropriately controls the pressure in the area 133 by monitoring the flow rate.

  FIG. 27 is a flowchart showing the operation of the top ring 1 at the time of release. FIG. 28 is a diagram schematically showing the flow rate measured by the flow meter FS at the time of release. As described below, the control unit 71 controls the pressure in the area 133 so that the flow rate falls within a predetermined range from the upper limit threshold to the lower limit threshold. The fact that the flow rate falls within the predetermined range corresponds to the appropriate swelling of the membrane 13, as shown in FIG. In other words, the range of the flow rate at which the swelling of the membrane 13 is appropriate is set as the predetermined range.

  First, the controller 71 starts pressurization of the suction area 133 (step S21 in FIG. 27, time t20 in FIG. 28). Accordingly, the flow rate increases, but the control unit 71 continues to pressurize the suction area 133 until the flow rate reaches the upper limit threshold (NO in step S22, S21). This pressurization is performed by supplying air to the area 133 continuously or intermittently. During this time, the membrane 13 gradually expands, and the flow rate increases accordingly (see FIG. 28). After time t21 when the flow rate reaches the lower limit threshold (that is, when the swelling of the membrane 13 becomes appropriate), the fluid can be ejected from the release nozzle 802 between the substrate W and the membrane 13.

  When the flow rate reaches the upper limit threshold (time t22, YES in step S22 in FIG. 27), the control unit 71 determines that the swelling of the membrane 13 is sufficient and stops pressurization of the adsorption area 133 (step S23). Specifically, the control unit 71 may stop air supply to the adsorption area 133, close the valve V3, or open the area 133 to the atmosphere. Alternatively, the controller 71 may depressurize the suction area 133.

  When the pressurization of the adsorption area 133 is stopped, the swelling of the membrane 13 decreases, and the flow rate may decrease accordingly. Therefore, the controller 71 stops pressurization of the adsorption area 133 until the flow rate reaches the lower limit threshold (NO in step S24, S23), but when the flow rate reaches the lower limit threshold (YES in step S24, FIG. 28). At time t23), it is determined that the swelling of the membrane 13 is insufficient, and pressurization of the suction area 133 is resumed (step S25).

  By repeating the above, the flow rate falls within a predetermined range, the swelling of the membrane 13 becomes appropriate, and the ejection of fluid between the substrate W and the membrane 13 can be continued as shown in FIG.

  The release operation shown in FIG. 27 may be continued for a predetermined time, or the release operation may be terminated when the release detection sensor (not shown) detects that the substrate W has been released. The release detection sensor can be composed of a light emitting unit and a light receiving unit fixed to the retainer ring station 800, for example.

  As another method for estimating the swelling of the membrane 13, it is also conceivable to estimate the swelling of the membrane 13 from the integrated amount of air supplied to the suction area 133. However, the air not only flows into the adsorption area 133 but also flows into the flow path 143 on the way, piping of a rotary joint (not shown), and the like. For this reason, it is difficult to accurately estimate the swelling of the membrane 13 from the integrated amount of air.

  On the other hand, in this embodiment, the flow rate of the determination area 131, that is, the volume of air flowing per unit time is used. The flow rate corresponds to the size of the gap g between the membrane 13 and the top ring body 11, and this gap g corresponds to the swelling of the membrane 13. Therefore, the swelling of the membrane 13 can be accurately detected, and the pressure in the adsorption area 133 can be adjusted with high accuracy so that the appropriate swelling can be maintained.

  20 to 25 show examples in which the release nozzle 802 is attached to the retainer ring station 800. Since the retaining ring station 800 does not move, the release nozzle 802 is also fixed. As another example, when the substrate W is transferred using a so-called pusher instead of the retainer ring station 800, a release nozzle may be attached to the pusher.

  FIG. 29 is a side view schematically showing how the substrate W is released from the top ring 1 and delivered to the pusher 160. The pusher 160 includes a top ring guide 161, a pusher stage 162, and a release nozzle 802 'formed in the top ring guide 161. When releasing the substrate W, the pusher 160 rises and approaches the top ring 1. Other operations are the same as when the retainer ring station 800 is used. When the pusher 160 is used, the release nozzle 802 ′ moves together with the pusher 160.

  In the third embodiment, a pressure gauge may be installed in the flow channel 141 or the flow channel 150 to measure the pressure corresponding to the flow rate in the determination area 131. In this case, “flow rate” in FIG. 28 may be appropriately read as “pressure”.

(Fourth embodiment)
The fourth embodiment to be described next relates to a desirable shape of the membrane 13.
FIG. 30 is a cross-sectional view of the top ring body 11 and the membrane 13 in the vicinity of the area 131, and the alternate long and short dash line in FIG. 30 indicates the centers of the top ring body 11 and the membrane 13. FIG. 31 is a view of the membrane 13 in the vicinity of the area 131 as viewed from above (top ring body 11 side). FIG. 32 is a view of the top ring body 11 in the vicinity of the area 131 as viewed from below (the membrane 13 side).

  As shown in FIGS. 30 and 31, an annular convex portion 131 a toward the top ring body 11 is formed in a portion corresponding to the area 131 on the upper surface of the membrane 13.

  Further, as shown in FIGS. 30 and 32, an annular recess 11 a is formed in a portion corresponding to the area 131 of the top ring body 11. The hole 21a (first hole) of the top ring main body 11 that communicates with the flow path 141 is outside the recess 11a, and the hole 21b (second hole) of the top ring main body 11 that communicates with the flow path 150 corresponds to the recess 11a. On the inside.

  The convex portions 131a in the membrane 13 are at positions facing the concave portions 11a in the top ring body 11, and can be engaged with each other.

  When the top ring 1 does not hold the substrate, there is a gap between the convex portion 131 a in the membrane 13 and the concave portion 11 a in the top ring body 11. On the other hand, when the top ring 1 holds the substrate by suction, this gap is eliminated or at least narrowed. That is, the convex portion 131 a and the concave portion 11 a can be said to be seal portions that seal the area 131.

As shown in FIG. 32, the top ring body 11 is provided with a plurality of grooves 11b extending radially. Thereby, the pressure easily propagates in the area 131, and the pressure can be made uniform. In FIG. 32, the groove 11b is provided on the inner side of the recess 11a, but may be provided on the outer side or may be provided on other areas such as the area 132 so that the pressure can easily propagate through the entire top ring.
The depth of the concave portion 11a is the same as or deeper than that of the groove 11b, and the height of the convex portion 131a is set so that the concave portion 11a can come into contact with the concave portion 11a. It becomes possible to seal with 11a and the convex part 131a.

  FIG. 33 is a diagram illustrating a configuration example of the pressure control device 7 in the case where the substrate suction determination using the flow meter FS is performed as described in the first embodiment. In addition, although it is the same as that of FIG. 6A, the flow paths 141 and 150 are connected to the top ring main body 11 via a rotary joint (not shown), for example. As a difference from FIG. 6A, the pressure control device 7 includes a bypass channel 151 that bypasses the channel 141 and the channel 150, and a valve V <b> 20 provided on the bypass line 151. By opening the valve V20, the pressure control device 7 can also control (for example, pressurize) the pressure in the area 131 from the flow path 150 through the hole 21b.

  In the adsorption determination in the first embodiment described above, the determination area 131 is pressurized via the flow path 141 and released to the atmosphere via the flow path 150. In addition, the determination area 131 is pressurized during polishing. These pressurizations will be described.

  FIG. 34 is a diagram illustrating pressurization at the time of adsorption determination. As shown, valves V1 and V10 are opened and valve V20 is closed. As a result, the determination area 131 can be pressurized via the flow path 141 and released to the atmosphere via the flow path 150 as in the first embodiment.

  FIG. 35 is a diagram illustrating pressurization during substrate polishing. As illustrated, valves V1 and V20 are opened and valve V10 is closed. Thereby, the area 131 is pressurized simultaneously from both the flow paths 141 and 150. That is, the outside of the annular portion sealed by the concave portion 11a and the convex portion 131a can be pressurized from the channel 141. Moreover, the inside of the annular part sealed by the recessed part 11a and the convex part 131a can be pressurized from the flow path 150. FIG. In particular, by providing the groove 11b as shown in FIG. 32, the pressure is transmitted to the entire inside of the sealed annular portion.

  Furthermore, since the pressure applied during the adsorption determination acts from the outside of the sealed annular portion and the inside of the sealed annular portion is opened to the atmosphere, the central portion of the substrate W is not pressurized, The deformation of the substrate W is suppressed and the stress is reduced.

  By using such a top ring main body 11 and the membrane 13, the adsorption determination described in the first embodiment can be performed with higher accuracy.

  FIG. 36 is a diagram schematically showing cross sections of the substrate W, the membrane 13 and the top ring body 11 when the adsorption is successful, and corresponds to FIG. As can be seen from FIG. 36, when the substrate adsorption is successful, the convex portion 131a of the membrane 13 engages with the concave portion 11a of the top ring body 11, and the gap between the two is almost eliminated. As a result, the flow rate measured by the flow meter FS becomes extremely small, and the determination accuracy is improved.

Thus, in 4th Embodiment, the convex part 131a is provided in the membrane 13, and the recessed part 11a is provided in the top ring main body 11. FIG. Therefore, the convex portion 131a and the concave portion 11a serve as a seal portion, and the membrane 13 adheres to the top ring main body 11 when the substrate is attracted. Therefore, the difference between the flow rate when the substrate suction is successful and the flow rate when the substrate suction is unsuccessful is increased, and the accuracy of the substrate suction determination is improved.
Although it is desirable that a state where the convex portion 131a and the concave portion 11a are completely sealed can be realized, it is sufficient that a certain portion of the membrane 13 and a certain portion of the top ring body are substantially sealed.

  In the present embodiment, the convex portion 131a is provided on the membrane 13 and the concave portion 11a is provided on the top ring body 11. However, as the sealing portion, the concave portion 131b is provided on the membrane 13, and the convex portion 11c is provided on the top ring main body 11. (See FIG. 37). Further, when the area other than the area 131 is set as the determination area, a concave portion or a convex portion as a seal portion may be provided in the determination area.

  Further, as described in the second embodiment, when the substrate adsorption determination using the pressure gauge PS is performed, the pressure gauge PS may be provided in the flow channel 141 as in FIG.

  The embodiment described above is described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention should not be limited to the described embodiments, but should be the widest scope according to the technical idea defined by the claims.

DESCRIPTION OF SYMBOLS 1 Top ring 7 Pressure control apparatus 71 Control part 72 Pressure regulator 73 Determination part 11 Top ring main body 11a Concave part 11b Groove 11c Convex part 12 Retainer ring 13 Membrane 131-138 Area 13a Convex part 13b Concave part 141-148, 150 Flow path 151 Bypass channel FS Flow meter PS Pressure gauge

Claims (22)

The top ring body,
An elastic film having a first surface that forms a plurality of areas between the top ring body and a second surface that is opposite to the first surface and can hold a substrate;
A first line communicating with a first area of the plurality of areas and capable of pressurizing the first area;
A second line communicating with the first area and capable of exhausting from the first area;
A measuring device whose measurement value changes based on the flow rate of the first area;
A third line communicating with a second area different from the first area of the plurality of areas and capable of pressurizing or depressurizing the second area;
When the substrate is adsorbed to the second surface, the second area is decompressed via the third line, the first area is pressurized via the first line, and the second line is interposed. A control unit for circulating the fluid,
And a determination unit that determines whether the substrate is adsorbed to the second surface based on the measurement value when the substrate is adsorbed to the second surface. The top ring body,
An elastic film having a first surface that forms a plurality of areas between the top ring body and a second surface that is opposite to the first surface and can hold a substrate;
A first line communicating with a first area of the plurality of areas and capable of pressurizing the first area;
A second line communicating with the first area and capable of exhausting from the first area;
A measuring device whose measurement value changes based on the flow rate of the first area;
A third line communicating with a second area different from the first area of the plurality of areas and capable of pressurizing or depressurizing the second area;
A determination unit that determines whether the substrate is adsorbed on the second surface based on the measurement value when the substrate is adsorbed on the second surface ;
The substrate holding device, wherein no hole is formed in the second surface of the elastic film. The top ring body,
An elastic film having a first surface that forms a plurality of areas between the top ring body and a second surface that is opposite to the first surface and can hold a substrate;
A first line communicating with a first area of the plurality of areas and capable of pressurizing the first area;
A second line communicating with the first area and capable of exhausting from the first area;
A measuring device whose measurement value changes based on the flow rate of the first area;
A third line communicating with a second area different from the first area of the plurality of areas and capable of pressurizing or depressurizing the second area;
A determination unit that determines whether the substrate is adsorbed on the second surface based on the measurement value when the substrate is adsorbed on the second surface ;
The first surface is provided with a convex portion toward the top ring body,
The convex portion is formed in an annular shape, is located at a position corresponding to the outside of the hole communicating with the first line of the top ring body, and corresponds to the inside of a hole communicating with the second line of the top ring body. A substrate holding device in a position to perform. The top ring body,
An elastic film having a first surface that forms a plurality of areas between the top ring body and a second surface that is opposite to the first surface and can hold a substrate;
A first line communicating with a first area of the plurality of areas and capable of pressurizing the first area;
A second line communicating with the first area and capable of exhausting from the first area;
A measuring device whose measurement value changes based on the flow rate of the first area;
A third line communicating with a second area different from the first area of the plurality of areas and capable of pressurizing or depressurizing the second area;
A determination unit that determines whether the substrate is adsorbed on the second surface based on the measurement value when the substrate is adsorbed on the second surface ;
The top ring body is provided with a convex portion toward the first surface,
The convex portion is formed in an annular shape, and is located outside a hole communicating with the first line of the top ring body and inside a hole communicating with the second line of the top ring body. . The top ring body,
An elastic film having a first surface that forms a plurality of areas between the top ring body and a second surface that is opposite to the first surface and can hold a substrate;
A first line communicating with a first area of the plurality of areas and capable of pressurizing the first area;
A second line communicating with the first area and capable of exhausting from the first area;
A measuring device whose measurement value changes based on the flow rate of the first area;
A third line communicating with a second area different from the first area of the plurality of areas and capable of pressurizing or depressurizing the second area;
And a controller that controls the pressure in the second area via the third line based on the measurement value.   The substrate holding apparatus according to claim 5, wherein the control unit controls the pressure in the second area so that the measurement value falls within a predetermined range.   When the controller releases the substrate held on the second surface, the controller pressurizes the first area via the first line and distributes the fluid to the first area via the second line. The substrate holding apparatus according to claim 5, wherein the pressure in the second area is controlled via the third line based on the measurement value.   The substrate holding apparatus according to claim 5, wherein the control unit controls the pressure in the second area so that fluid is ejected from the release nozzle to a predetermined position.   The substrate holding apparatus according to claim 8, wherein the predetermined position is between the second surface and the held substrate.   The substrate holding apparatus according to claim 1, wherein the measuring device is a flow meter capable of measuring a flow rate of the second line.   The substrate holding apparatus according to claim 1, wherein the measuring instrument is a pressure gauge capable of measuring the pressure of the first line or the second line.   The determination unit determines whether or not the substrate is adsorbed on the second surface based on a measurement value measured by the measuring device after a predetermined time has elapsed from the start of decompression of the second area. Item 2. The substrate holding apparatus according to Item 1.   The substrate holding apparatus according to claim 1, wherein the second area is not adjacent to the first area.   The substrate holding apparatus according to claim 1, further comprising a retainer ring provided on an outer periphery of the elastic film.   The substrate holding apparatus according to claim 14, wherein the retainer ring includes an inner ring and an outer ring provided outside the inner ring. A substrate holding device according to any one of claims 1 to 15,
A substrate polishing apparatus comprising: a polishing table configured to polish a substrate held by the substrate holding apparatus. The second area formed between the top ring main body and the first surface of the elastic film in the substrate holding device is decompressed, and formed between the top ring main body and the first surface of the elastic film, Pressurizing the first area different from the second area through the first line and circulating the fluid through the second line communicating with the first area ;
A substrate in a substrate holding device that determines whether or not the substrate is adsorbed on a second surface of the elastic film opposite to the first surface based on a measurement value corresponding to a flow rate of the first area. Adsorption determination method.   The substrate adsorption | suction determination method of Claim 17 which the convex part provided in the 1st surface of the said elastic film closely_contact | adheres to the said top ring main body, and seals the said 1st area.   The substrate suction determination method according to claim 17, wherein the first surface of the elastic film is in close contact with a convex portion provided on the top ring body to seal the first area. A first area formed between the top ring body and the first surface of the elastic film in the substrate holding device is pressurized through the first line and fluid is circulated through the second line communicating with the first area. while,
Based on the measured value corresponding to the flow rate of the first area, the pressure in the second area different from the first area, which is formed between the top ring body and the first surface of the elastic membrane, is controlled. , Pressure control method in substrate holding device. A top ring body provided with a first hole and a second hole on the outer side and the inner side of the first part, respectively;
A second portion that can be engaged with the first portion is provided, and a first surface that forms a plurality of areas between the top ring main body and a substrate opposite to the first surface can be held. An elastic membrane having a second surface;
The first hole is located in a first area of the plurality of areas, and a first line capable of pressurizing the first area through the first hole;
The second hole is located in the first area, and a second line capable of exhausting from the first area through the second hole;
A measuring device whose measurement value changes based on the flow rate of the first area;
A third line communicating with a second area different from the first area of the plurality of areas and capable of pressurizing or depressurizing the second area;
A determination unit that determines whether the substrate is adsorbed on the second surface based on the measurement value when the substrate is adsorbed on the second surface ;
A substrate holding apparatus, wherein a portion corresponding to the first area of the top ring body is provided with a radially expanding groove. A top ring body provided with a first hole and a second hole on the outer side and the inner side of the first part, respectively;
A second portion that can be engaged with the first portion is provided, and a first surface that forms a plurality of areas between the top ring main body and a substrate opposite to the first surface can be held. An elastic membrane having a second surface;
The first hole is located in a first area of the plurality of areas, and a first line capable of pressurizing the first area through the first hole;
The second hole is located in the first area, and a second line capable of exhausting from the first area through the second hole;
A measuring device whose measurement value changes based on the flow rate of the first area;
A third line communicating with a second area different from the first area of the plurality of areas and capable of pressurizing or depressurizing the second area;
A bypass line that bypasses the first line and the second line;
A valve provided on the bypass line;
And a determination unit that determines whether the substrate is adsorbed to the second surface based on the measurement value when the substrate is adsorbed to the second surface .