JP6847286B2 - Board processing equipment - Google Patents

Description

The present invention relates to a substrate processing apparatus.

Substrate processing equipment (eg, Chemical Mechanical Polishing (CMP))
) In the device), by supplying a gas (for example, nitrogen) at a constant pressure into the elastic film (also referred to as a membrane) of the substrate holding portion (also referred to as a top ring), the elastic film is inflated and adsorbed on the elastic film. The substrate (for example, the wafer) was peeled off (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-258369

However, since the adhesive force of the substrate to the elastic film differs depending on the type of substrate (for example, film type), the time required for the substrate to peel off from the elastic film (hereinafter, also referred to as substrate release time) varies depending on the type of substrate. There is a problem of doing. Occasionally, the substrate does not separate from the elastic membrane. Further, if the adhesive force of the substrate to the elastic film is strong, there is a problem that even if the elastic film swells, the substrate does not peel off and physical stress is applied to the substrate. Occasionally, physical stress can cause the substrate to crack.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a substrate processing apparatus capable of reducing variations in the time required for a substrate to peel off from an elastic film.

The substrate processing apparatus according to the first aspect of the present invention controls a substrate holding portion that holds the substrate, a pressure regulator that adjusts the pressure of the gas supplied into the elastic film of the substrate holding portion, and the pressure regulator. A control unit that changes the pressure of the gas supplied into the elastic film in order to peel the substrate from the elastic film is provided.

According to this configuration, by changing the pressure in the elastic film to control the swelling speed of the elastic film, the elastic film can be swelled at a speed corresponding to the sticking force of the substrate to the elastic film. As a result, it is possible to reduce the variation in the substrate release time regardless of the sticking force of the substrate to the elastic film. Further, by changing the pressure in the elastic film, it is possible to change the pressure to an appropriate level according to the substrate, so that the stress applied to the substrate can be reduced.

The substrate processing apparatus according to the second aspect of the present invention is the substrate processing apparatus according to the first aspect, and the control unit is formed on the elastic film according to the type of substrate currently held by the substrate holding unit. Control the pressure of the supplied gas.

According to this configuration, the swelling time of the elastic film changes depending on the sticking force of the substrate, but by setting the optimum pressure for each different type of substrate, the swelling degree of the elastic film is controlled to control the swelling time. Can be homogenized. Therefore, it is possible to reduce the variation in the substrate release time for each substrate type.

The substrate processing apparatus according to the third aspect of the present invention is the substrate processing apparatus according to the second aspect, the type of the substrate is the film type of the substrate, and the control unit is the substrate holding unit. The pressure of the gas supplied to the elastic film is controlled according to the film type of the substrate currently held.

According to this configuration, the swelling time of the elastic film changes depending on the difference in the sticking force of the substrate, but the swelling time is controlled by controlling the swelling degree of the elastic film by setting the optimum pressure for each substrate of different film type. Can be homogenized. Therefore, it is possible to reduce the variation in the substrate release time for each substrate film type.

The substrate processing apparatus according to the fourth aspect of the present invention is the substrate processing apparatus according to any one of the first to third aspects, and the control unit changes the pressure of the gas stepwise.

According to this configuration, even if the substrate has a strong adhesive force to the elastic film, the physical stress on the substrate can be reduced by changing the gas pressure stepwise. Further, by changing the gas pressure stepwise, it is possible to reduce the variation in the substrate release time.

The substrate processing apparatus according to the fifth aspect of the present invention is the substrate processing apparatus according to the fourth aspect, in which the positions of the release nozzle capable of ejecting the pressurized fluid and the substrate adsorbed on the elastic film are located. The control unit further includes a position detection unit for detecting, and the control unit changes the pressure of the gas when the position of the substrate becomes a position where a pressurized fluid can be ejected from the release nozzle to the back surface of the substrate. ..

According to this configuration, the substrate release pressure can be set to the optimum pressure at the timing when the release nozzle ejects the pressurized fluid, so that the release property of the substrate can be improved.

The inspection method according to the sixth aspect of the present invention is the inspection method according to the fifth aspect, and the control unit can eject a pressurized fluid from the release nozzle to the back surface of the substrate at the position of the substrate. Before reaching such a position, the gas was controlled to be supplied into the elastic film by the first pressure, and the position of the substrate became a position where the pressurized fluid could be ejected from the release nozzle to the back surface of the substrate. In this case, the gas is controlled to be supplied into the elastic film at a second pressure lower than the first pressure, and the pressurized fluid is controlled to be ejected from the release nozzle toward the back surface of the substrate.

According to this configuration, the stress on the substrate can be reduced by reducing the substrate release pressure at the timing when the release nozzle ejects the pressurized fluid.

The inspection method according to the seventh aspect of the present invention is the inspection method according to the sixth aspect, and the position detection unit sets the height of the back surface of the substrate adhering to the elastic film to the position of the substrate. When the height of the back surface of the substrate detected by the position detection unit is equal to or higher than the height of the ejection port of the release nozzle, the control unit applies gas into the elastic film at the first pressure. When the height of the back surface of the substrate detected by the position detection unit is lower than the height of the ejection port of the release nozzle, the elastic film is controlled to be supplied at a second pressure lower than the first pressure. It is controlled to supply gas to the inside and to eject a pressurized fluid from the release nozzle toward the back surface of the substrate.

According to this configuration, the substrate release pressure can be reduced at the timing when the release nozzle ejects the pressurized fluid, so that the stress on the substrate can be reduced.

The inspection method according to the eighth aspect of the present invention is the inspection method according to any one of the first to seventh aspects, and the control unit changes the pressure of the gas according to the degree of swelling of the elastic film. To do.

According to this configuration, when the elastic film swells slowly, the gas pressure can be increased and the substrate release time can be made uniform.

The inspection method according to the ninth aspect of the present invention is the inspection method according to any one of the first to eighth aspects, and the pressure regulator is an electropneumatic regulator.

According to this configuration, the pressure supplied into the elastic membrane can be made variable.

According to the present invention, by changing the pressure in the elastic membrane to control the swelling speed of the elastic membrane, the elastic membrane can be swelled at a speed corresponding to the sticking force of the substrate to the elastic membrane. As a result, the greater the sticking force of the substrate to the elastic membrane, the greater the pressure of the gas supplied into the elastic membrane and the faster the swelling of the elastic membrane, regardless of the sticking force of the substrate to the elastic membrane. It is possible to reduce the variation in the substrate release time.

It is a top view which shows the whole structure of the substrate processing apparatus which concerns on one Embodiment of this invention. It is the schematic which shows the structure of the 1st polishing unit 3A which concerns on this embodiment. FIG. 5 is a schematic cross-sectional view of a top ring 31A constituting a substrate holding device that holds a wafer W to be polished and presses it against a polished surface on a polishing table. It is the schematic which shows the top ring 31A and the substrate delivery device (pusher) 150. It is the schematic which shows the detailed structure of a pusher 150. This is an example of a table stored in the storage unit 51. It is the schematic which shows the state before detaching a wafer from a membrane. It is the schematic which shows the state at the time of the wafer release which detaches a wafer from a membrane. It is a flowchart which shows an example of the flow of the wafer release processing which concerns on this embodiment. It is the schematic sectional drawing which shows the top ring 31A and the 1st linear transporter 6 in the modification of this embodiment. In the modified example of this embodiment, it is a partial schematic cross-sectional view which shows the state at the time of wafer release which detaches a wafer from a membrane.

Hereinafter, the present embodiment will be described with reference to the drawings. The substrate processing apparatus 100 according to the present embodiment is, for example, a polishing apparatus for polishing a substrate. In this embodiment, a wafer will be described as an example as a substrate. FIG. 1 is a plan view showing the overall configuration of the substrate processing apparatus 100 according to the embodiment of the present invention. As shown in FIG. 1, the substrate processing apparatus 100 includes a substantially rectangular housing 1, and the inside of the housing 1 is divided into a load / unload portion 2, a polishing portion 3, and a cleaning portion 4 by partition walls 1a and 1b. It is divided into. The load / unload section 2, the polishing section 3, and the cleaning section 4 are assembled independently and exhausted independently. Further, the substrate processing apparatus 100 has a control unit 5 that controls the substrate processing operation.

The load / unload unit 2 includes two or more (four in this embodiment) front load units 20 on which wafer cassettes for stocking a large number of wafers (boards) are placed. These front load portions 20 are arranged adjacent to the housing 1 and arranged along the width direction (direction perpendicular to the longitudinal direction) of the substrate processing apparatus 100. The front load section 20 has an open cassette, a SMIF (Standard Manufacturing Interface) pod, or a FOU.
P (Front Opening Unified Pod) can be installed. Here, SMIF and FOUP are closed containers that can maintain an environment independent of the external space by storing the wafer cassette inside and covering it with a partition wall.

Further, in the load / unload section 2, a traveling mechanism 21 is laid along the line of the front loading section 20, and a transfer robot (loader) that can move along the arrangement direction of the wafer cassettes on the traveling mechanism 21. 22 is installed. The transfer robot 22 can access the wafer cassette mounted on the front load unit 20 by moving on the traveling mechanism 21. The transfer robot 22 has two upper and lower hands, and the upper hand is used to return the processed wafer to the wafer cassette, and the lower hand is used to take out the unprocessed wafer from the wafer cassette. Therefore, the upper and lower hands can be used properly. Further, the lower hand of the transfer robot 22 is configured to be able to invert the wafer by rotating around its axis.

Since the load / unload section 2 is the area that needs to be kept in the cleanest state, the inside of the load / unload section 2 is higher than the outside of the substrate processing device 100, the polishing section 3, and the cleaning section 4. The pressure is constantly maintained. The polishing unit 3 is the dirtiest region because the slurry is used as the polishing liquid. Therefore, a negative pressure is formed inside the polishing portion 3, and the pressure is maintained lower than the internal pressure of the cleaning portion 4. The load / unload unit 2 is provided with a filter fan unit (not shown) having a clean air filter such as a HEPA filter, a ULPA filter, or a chemical filter, and particles, toxic vapors, and the like from this filter fan unit. Clean air from which toxic gas has been removed is constantly blowing out.

The polishing unit 3 is a region where the wafer is polished (flattened), and includes a first polishing unit 3A, a second polishing unit 3B, a third polishing unit 3C, and a fourth polishing unit 3D. As shown in FIG. 1, these first polishing unit 3A, second polishing unit 3B, third polishing unit 3C, and fourth polishing unit 3D are arranged along the longitudinal direction of the substrate processing apparatus 100.

As shown in FIG. 1, the first polishing unit 3A polishes while holding a polishing table 30A to which a polishing pad 10 having a polishing surface is attached and pressing the wafer against the polishing pad 10 on the polishing table 30A. The top ring (substrate holding portion) 31A, the polishing liquid supply nozzle 32A for supplying the polishing liquid or the dressing liquid (for example, pure water) to the polishing pad 10, and the polishing surface of the polishing pad 10 are dressed. A dresser 33A for this purpose and an atomizer 34A that atomizes a mixed fluid of a liquid (for example, pure water) and a gas (for example, nitrogen gas) or a liquid (for example, pure water) and injects it onto a polished surface.

Similarly, the second polishing unit 3B includes a polishing table 30B to which the polishing pad 10 is attached, a top ring (substrate holding portion) 31B, a polishing liquid supply nozzle 32B, a dresser 33B, and an atomizer 34B. The third polishing unit 3C includes a polishing table 30C to which a polishing pad 10 is attached, a top ring (substrate holding portion) 31C, a polishing liquid supply nozzle 32C, a dresser 33C, and an atomizer 34C. 4 The polishing unit 3D includes a polishing table 30D to which a polishing pad 10 is attached, a top ring (substrate holding portion) 31D, a polishing liquid supply nozzle 32D, a dresser 33D, and an atomizer 34D.

Next, a transport mechanism for transporting the wafer will be described. As shown in FIG. 1, the first linear transporter 6 is arranged adjacent to the first polishing unit 3A and the second polishing unit 3B. The first linear transporter 6 has four transport positions (first transport position TP1 and second transport in order from the load / unload portion side) along the direction in which the first polishing unit 3A and the second polishing unit 3B are arranged. It is a mechanism for transferring the wafer between the position TP2, the third transfer position TP3, and the fourth transfer position TP4).

Further, a second linear transporter 7 is arranged adjacent to the third polishing unit 3C and the fourth polishing unit 3D. The second linear transporter 7 has three transport positions along the direction in which the third polishing unit 3C and the fourth polishing unit 3D are arranged (the fifth transport position TP5 and the sixth transport in order from the load / unload portion side). It is a mechanism for transporting the wafer between the position TP6 and the seventh transport position TP7).

The wafer is conveyed to the first polishing unit 3A and the second polishing unit 3B by the first linear transporter 6. As described above, the top ring 31A of the first polishing unit 3A moves between the polishing position and the second transport position TP2 by the swing operation of the top ring head 60. Therefore, the transfer of the wafer to the top ring 31A is performed at the second transfer position TP2. Similarly, the top ring 31B of the second polishing unit 3B moves between the polishing position and the third transfer position TP3, and the wafer is delivered to the top ring 31B at the third transfer position TP3. The top ring 31C of the third polishing unit 3C moves between the polishing position and the sixth transfer position TP6, and the wafer is delivered to the top ring 31C at the sixth transfer position TP6. The top ring 31D of the 4th polishing unit 3D moves between the polishing position and the 7th transfer position TP7, and the wafer is delivered to the top ring 31D at the 7th transfer position TP7.

At the first transfer position TP1, a lifter 11 for receiving the wafer from the transfer robot 22 is arranged. The wafer is passed from the transfer robot 22 to the first linear transporter 6 via the lifter 11. A shutter (not shown) is provided on the partition wall 1a so as to be located between the lifter 11 and the transfer robot 22 so that the shutter is opened when the wafer is transferred and the wafer is transferred from the transfer robot 22 to the lifter 11. It has become. Further, a swing transporter 12 is arranged between the first linear transporter 6, the second linear transporter 7, and the cleaning unit 4. The swing transporter 12 has a hand that can move between the fourth transport position TP4 and the fifth transport position TP5, and transfers the wafer from the first linear transporter 6 to the second linear transporter 7. Is performed by the swing transporter 12. The wafer is conveyed to the third polishing unit 3C and / or the fourth polishing unit 3D by the second linear transporter 7. Further, the wafer polished by the polishing unit 3 is conveyed to the cleaning unit 4 via the swing transporter 12.

Since the first polishing unit 3A, the second polishing unit 3B, the third polishing unit 3C, and the fourth polishing unit 3D have the same configuration as each other, hereinafter, the first polishing unit 3A
Will be described.

FIG. 2 is a schematic view showing the configuration of the first polishing unit 3A according to the present embodiment. As shown in FIG. 2, the first polishing unit 3A includes a polishing table 30A and a top ring 31A that holds a substrate such as a wafer, which is an object to be polished, and presses it against a polishing surface on the polishing table.

The polishing table 30A is connected to a motor (not shown) arranged below the table shaft 30Aa via a table shaft 30Aa, and is rotatable around the table shaft 30Aa. A polishing pad 10 is attached to the upper surface of the polishing table 30A, and the polishing surface 10a of the polishing pad 10 constitutes a polishing surface for polishing the wafer W. A polishing liquid supply nozzle 102 is installed above the polishing table 30A, and the polishing liquid Q is supplied onto the polishing pad 10 on the polishing table 30A by the polishing liquid supply nozzle 102.

The top ring 31A is basically composed of a top ring main body 202 that presses the wafer W against the polished surface 10a and a retainer ring 203 that holds the outer peripheral edge of the wafer W and prevents the wafer W from popping out from the top ring. It is configured in.

The top ring 31A is connected to the top ring shaft 111, and the top ring shaft 111 moves up and down with respect to the top ring head 110 by the vertical movement mechanism 124. The vertical movement of the top ring shaft 111 raises and lowers the entire top ring 31A with respect to the top ring head 110 for positioning. A rotary joint 125 is attached to the upper end of the top ring shaft 111.

The vertical movement mechanism 124 that moves the top ring shaft 111 and the top ring 31A up and down includes a bridge 128 that rotatably supports the top ring shaft 111 via a bearing 126, a ball screw 132 attached to the bridge 128, and a support column 130. The support base 129 supported by the support base 129 and the servomotor 138 provided on the support base 129 are provided. The support base 129 that supports the servomotor 138 is fixed to the top ring head 110 via the support column 130.

The ball screw 132 includes a screw shaft 132a connected to the servomotor 138 and a nut 132b into which the screw shaft 132a is screwed. The top ring shaft 111 moves up and down integrally with the bridge 128. Therefore, when the servomotor 138 is driven, the bridge 128 moves up and down via the ball screw 132, which causes the top ring shaft 111 and the top ring 31A to move up and down.

Further, the top ring shaft 111 is connected to the rotary cylinder 112 via a key (not shown). The rotary cylinder 112 is provided with a timing pulley 113 on the outer peripheral portion thereof. A top ring rotary motor 114 is fixed to the top ring head 110, and the timing pulley 113 is connected to a timing pulley 116 provided on the top ring rotary motor 114 via a timing belt 115. Therefore, by rotationally driving the rotary motor 114 for the top ring, the rotary cylinder 112 and the top ring shaft 111 rotate integrally via the timing pulley 116, the timing belt 115, and the timing pulley 113, and the top ring 31A rotates. The rotary motor 114 for the top ring includes an encoder 140. The encoder 140 has a function of detecting the rotation angle position of the top ring 31A and a function of integrating the rotation speed of the top ring 31A. Further, a sensor for detecting the rotation angle "reference position (0 degree)" of the top ring 31A may be separately provided. The top ring head 110 is supported by a top ring head shaft 117 rotatably supported by a frame (not shown).

The control unit 5 controls each device in the device, including the rotary motor 114 for the top ring, the servo motor 138, and the encoder 140. The storage unit 51 is connected to the control unit 5 via wiring, and the control unit 5 can refer to the storage unit 51.

In the first polishing unit 3A configured as shown in FIG. 2, the top ring 31A can hold a substrate such as a wafer W on the lower surface thereof. The top ring head 110 is configured to be rotatable around the top ring head shaft 117, and the top ring 31A holding the wafer W on the lower surface is a polishing table 30A from the receiving position of the wafer W due to the rotation of the top ring head 110. Moved upwards. Then, the top ring 31A is lowered to press the wafer W against the surface (polished surface) 10a of the polishing pad 10. At this time, the top ring 31A and the polishing table 30A are rotated, respectively, to rotate the polishing table 30.
The polishing liquid is supplied onto the polishing pad 10 from the polishing liquid supply nozzle 32A provided above A. In this way, the wafer W is brought into sliding contact with the polishing surface 10a of the polishing pad 10 to polish the surface of the wafer W.

Next, the top ring (board holding portion) in the polishing apparatus of the present invention will be described. FIG. 3 is a schematic cross-sectional view of a top ring 31A constituting a substrate holding device that holds a wafer W, which is an object to be polished, and presses it against a polished surface on a polishing table. In FIG. 3, only the main components constituting the top ring 31A are shown.

As shown in FIG. 3, the top ring 31A is basically composed of a top ring main body (also referred to as a carrier) 202 that presses the wafer W against the polished surface 10a and a retainer ring 203 that directly presses the polished surface 101a. Has been done. The top ring main body (carrier) 202 is formed of a substantially disk-shaped member, and the retainer ring 203 is attached to the outer peripheral portion of the top ring main body 202. The top ring body 202 is made of a resin such as engineering plastic (for example, PEEK). An elastic film (membrane) 204 that comes into contact with the back surface of the wafer is attached to the lower surface of the top ring main body 202. The elastic film (membrane) 204 is formed of a rubber material having excellent strength and durability, such as ethylene propylene rubber (EPDM), polyurethane rubber, and silicon rubber.

The elastic membrane 204 has a plurality of concentric partition walls 204a, and the partition walls 204a provide a circular center chamber 205 and an annular ripple between the upper surface of the elastic film 204 and the lower surface of the top ring body 202. A chamber 206, an annular outer chamber 207, and an annular edge chamber 208 are formed. That is, the center chamber 205 is formed in the central portion of the top ring main body 202, and the ripple chamber 206, the outer chamber 207, and the edge chamber 208 are sequentially and concentrically formed from the center toward the outer peripheral direction. The elastic film (membrane) 204 has a plurality of holes 204h penetrating in the ripple area (ripple chamber 206) in the thickness direction of the elastic film for adsorbing the wafer. In this embodiment, the hole 204h is provided in the ripple area, but it may be provided in a region other than the ripple area.

In the top ring main body 202, a flow path 211 communicating with the center chamber 205, a flow path 212 communicating with the ripple chamber 206, a flow path 213 communicating with the outer chamber 207, and a flow path 214 communicating with the edge chamber 208 are formed. Has been done. The flow path 211 communicating with the center chamber 205, the flow path 213 communicating with the outer chamber 207, and the flow path 214 communicating with the edge chamber 208 are connected to the flow paths 221, 223, 224 via the rotary joint 225, respectively. ing. The flow paths 221, 223, 224 are connected to the pressure adjusting unit 230 via valves V1-1, V3-1, V4-1 and pressure regulators R1, R3, R4, respectively. Further, the flow paths 221, 223, 224 are connected to the vacuum source 231 via valves V1-2, V3-2, V4-2, respectively, and are connected to the vacuum source 231 via valves V1-3, V3-3, V4-3, respectively. It is possible to communicate with the atmosphere.

On the other hand, the flow path 212 communicating with the ripple chamber 206 is connected to the flow path 222 via the rotary joint 225. The flow path 222 is connected to the pressure adjusting unit 230 via the steam separation tank 235, the valve V2-1, and the pressure regulator R2. Further, the flow path 222 is connected to the vacuum source 131 via the steam separation tank 235 and the valve V2-2, and can communicate with the atmosphere via the valve V2-3. Further, the flow path 222 is connected to the pressure regulator R6 via the steam separation tank 235 and the valve V2-1. The pressure regulator R6 is, for example, an electropneumatic regulator. Thereby, the pressure supplied into the membrane 204 can be made variable. The pressure regulator R6 is connected to the control unit 5 via a control line, and the control unit 5 controls the pressure regulator R6 to make the pressure of the gas supplied into the membrane 204 variable. In this way, the pressure regulator R6 has a flow path 2
It communicates with the ripple chamber 206 via the 22 and the flow path 212, and regulates the pressure of the gas (for example, nitrogen) supplied to the ripple chamber 206 in the membrane 204 of the top ring 31A.

As a result, the wafer W adsorbed on the membrane 204 can be peeled off by varying the pressure in the ripple chamber 206 in the membrane 204 to control the swelling of the membrane 204. As a result, the pressure of the gas supplied into the membrane 204 can be changed according to the sticking force of the wafer W to the membrane 204 to control the swelling of the membrane 204, which is required for the wafer W to peel off from the membrane 204. The time (hereinafter, also referred to as wafer release time) can be stabilized. Further, by varying the pressure in the membrane 204, the pressure can be changed to an appropriate pressure according to the wafer W, so that the stress applied to the wafer W can be reduced.

Further, a retainer ring pressurizing chamber 209 made of an elastic film is also formed directly above the retainer ring 203, and the retainer ring pressurizing chamber 209 is a flow path 215 and a rotary formed in the top ring main body (carrier) 202. It is connected to the flow path 226 via a joint 225. The flow path 226 is connected to the pressure adjusting unit 230 via the valve V5-1 and the pressure regulator R5. Further, the flow path 226 is connected to the vacuum source 231 via the valve V5-2 and can communicate with the atmosphere via the valve V5-3. The pressure regulators R1, R2, R3, R4, and R5 adjust the pressure of the pressure fluid supplied from the pressure adjusting unit 230 to the center chamber 205, the ripple chamber 206, the outer chamber 207, the edge chamber 208, and the retainer ring pressurizing chamber 209, respectively. It has a pressure adjustment function. Pressure regulators R1, R2, R3, R4, R5 and each valve V1-1 to V1-3, V2-1 to V2-3, V3-1 to V3, V4-1 to V4-3, V5-1 to V5-3 is connected to control units 5 (see FIGS. 1 and 2) so that their operations are controlled. Further, pressure sensors P1, P2, P3, P4, P5 and flow rate sensors F1, F2, F3, F4, F5 are installed in the flow paths 221,222, 223, 224, and 226, respectively.

In the top ring 31A configured as shown in FIG. 3, as described above, the center chamber 205 is formed in the center of the top ring main body 202, and the ripples are sequentially concentrically from the center toward the outer circumference. A chamber 206, an outer chamber 207, and an edge chamber 208 are formed, and the pressure of the fluid supplied to the center chamber 205, the ripple chamber 206, the outer chamber 207, the edge chamber 208, and the retainer ring pressurizing chamber 209 is applied to the pressure adjusting unit 230 and the pressure. The regulators R1, R2, R3, R4, and R5 can be adjusted independently. With such a structure, the pressing force for pressing the wafer W against the polishing pad 10 can be adjusted for each region of the wafer W, and the pressing force for the retainer ring 203 to press the polishing pad 10 can be adjusted.

Next, a series of polishing processing steps by the substrate processing apparatus 100 configured as shown in FIGS. 1 to 3 will be described. The top ring 31A receives the wafer W from the first linear transporter 6 and holds it by vacuum suction. The elastic membrane 204 is provided with a plurality of holes 204h for vacuum-adsorbing the wafer W, and these holes 204h are communicated with the vacuum source 131. The top ring 31A holding the wafer W by vacuum suction descends to a preset position at the time of polishing of the top ring. At this polishing setting position, the retainer ring 203 is in contact with the surface (polishing surface) 10a of the polishing pad 10, but before polishing, the top ring 31A sucks and holds the wafer W, so that the lower surface of the wafer W is held. There is a slight gap (for example, about 1 mm) between the (polished surface) and the surface (polished surface) 10a of the polishing pad 10. At this time, both the polishing table 30A and the top ring 31A are rotationally driven. In this state, the elastic film (membrane) 204 on the back surface side of the wafer is inflated, the lower surface (polishing surface) of the wafer is brought into contact with the surface (polishing surface) of the polishing pad 10, and the polishing table 30A and the top ring 31A are formed. By relatively moving the wafer W, the wafer W is polished until the surface (surface to be polished) is in a predetermined state (for example, a predetermined film thickness).

After the wafer processing process on the polishing pad 10 is completed, the wafer W is attracted to the top ring 31A to raise the top ring 31A, and the substrate delivery device (also referred to as a pusher) included in the first linear transporter (board transfer unit) 6 is provided. ) Move to 150. After the movement, gas (for example, nitrogen) is supplied to the ripple chamber 206 in the membrane 204 to inflate the membrane 204 to a predetermined degree to reduce the sticking area with the wafer W, and the pressure of this gas causes the wafer W to be removed from the membrane 204. Peel off. As an example, the predetermined degree is such that the position of the wafer W becomes a position where the pressurized fluid can be ejected from the release nozzle described later to the back surface of the wafer W. When the wafer W is peeled off from the membrane 204, a pressurized fluid is blown between the membrane 204 and the wafer W with the elastic film inflated to a predetermined degree. This assists the release of the wafer W and makes it easier to peel off the wafer W. The release of the wafer W from the membrane 204 is also referred to as wafer release. The details of the wafer release will be described below.

FIG. 4 is a schematic view showing the top ring 31A and the substrate delivery device (pusher) 150. It is a schematic diagram which shows the state which raised the pusher in order to transfer a wafer W from a top ring 31A to a pusher 150. As shown in FIG. 3, the pusher 150 is located between the top ring guide 151, which can be fitted to the outer peripheral surface of the top ring 31A for centering with the top ring 31A, and between the top ring 31A and the pusher 150. To move the push stage 152 for supporting the wafer, the air cylinder (not shown) for moving the push stage 152 up and down, and the push stage 152 and the top ring guide 151 up and down when the wafer is delivered. It is equipped with an air cylinder (not shown).

Hereinafter, the operation of transferring the wafer W from the top ring 31A to the pusher 150 will be described. After the wafer processing step on the polishing pad 10 is completed, the top ring 31A adsorbs the wafer W. The wafer W is adsorbed by communicating the pores 204h of the membrane 204 with the vacuum source 131. As described above, the top ring 31A has a membrane 204 having holes 204h on its surface, and by sucking the wafer W through the holes 204h, the wafer W is adsorbed on the surface of the membrane 204.

After the wafer W is adsorbed, the top ring 31A is raised and moved to the pusher 150 to release the wafer W. After moving to the pusher 150, the top ring 31A may be rotated to perform a cleaning operation while supplying pure water or a chemical solution to the wafer W adsorbed and held on the top ring 31A.

After that, the push stage 152 and the top ring guide 151 of the pusher 150 are raised, and the top ring guide 151 is fitted with the outer peripheral surface of the top ring 31A to center the top ring 31A and the pusher 150. At this time, the top ring guide 151 pushes up the retainer ring 203, but at the same time, the retainer ring pressurizing chamber 209 is evacuated so that the retainer ring 203 is quickly raised. When the pusher rise is completed, the bottom surface of the retainer ring 203 is pressed by the upper surface of the top ring guide 151 and pushed up above the lower surface of the membrane 204, so that the space between the wafer and the membrane is exposed. It has become. In the example shown in FIG. 4, the bottom surface of the retainer ring 203 is located 1 mm above the bottom surface of the membrane. After that, the vacuum suction of the wafer W by the top ring 31A is stopped, and the wafer release operation is performed. In addition, you may move to a desired positional relationship by lowering the top ring instead of raising the pusher.

FIG. 5 is a schematic view showing the detailed structure of the pusher 150. As shown in FIG. 5, the pusher 150 includes a top ring guide 151, a push stage 152, and two release nozzles (substrate peeling promoting portions) formed in the top ring guide 151 and capable of injecting a pressurized fluid F.
153 is provided. The pressurized fluid F may be only a pressurized gas (for example, pressurized nitrogen), may be only a pressurized liquid (for example, pressurized water), or may be a pressurized gas (for example, pressurized nitrogen). It may be a mixed fluid of liquid (for example, pure water). The release nozzle 153 is connected to the control unit 5 via a control line and is controlled by the control unit 5. Further, the pusher 150 includes a position detection unit 154 that detects the position of the wafer W adhering to the membrane 204. In the present embodiment, as an example thereof, the position detection unit 154 detects the height of the back surface of the wafer W adhering to the membrane 204. The position detection unit 154 has, for example, an image pickup unit that images the inside of the top ring guide 151, and detects the height of the back surface of the wafer W from the captured image.

A plurality of release nozzles 153 are provided at predetermined intervals in the circumferential direction of the top ring guide 151, and the pressurized fluid F is ejected inward in the radial direction of the top ring guide 151. As a result, it is possible to inject a release shower made of the pressurized fluid F between the wafer W and the membrane 204 to release the wafer W from the membrane 204.

The storage unit 51 stores the type of wafer and the recipe of the pressure of the gas supplied into the membrane in association with each other. In the present embodiment, as an example thereof, as shown in FIG. 6, the storage unit 51 stores the film type of the wafer and the recipe of the pressure of the gas supplied into the membrane in association with each other. FIG. 6 is an example of the table T1 stored in the storage unit 51. Table T1 of FIG. 6 contains records of a set of recipes for the film type of the wafer and the pressure of the gas supplied into the membrane. For example, when the film type of the wafer is Th-SiO2, the first pressure PS1 can be set to 0.5 MPa and the second pressure PS2 can be set to 0.1 MPa. In this way, the first pressure PS1 and the second pressure PS2 can be set according to the film type of the wafer.

The control unit 5 controls the pressure of the gas supplied to the membrane 204 according to the type of wafer W currently held by the top ring 31A. As a result, the swelling time of the membrane 204 changes depending on the difference in the adhesive force of the wafer, but by adjusting the pressure to the optimum pressure for each different type of wafer, the swelling condition of the membrane can be controlled to make the swelling time uniform. Can be done. Therefore, it is possible to reduce the variation in the wafer release time for each type of wafer. As an example, in the present embodiment, the control unit 5 controls the pressure of the gas supplied to the membrane 204 according to the film type of the wafer W currently held by the top ring 31A. As a result, the swelling time of the membrane 204 changes depending on the difference in the adhesive force of the wafers, but by setting the optimum pressure for each wafer of different film type, the swelling condition of the membrane is controlled to make the swelling time uniform. be able to. Therefore, it is possible to reduce the variation in the wafer release time for each wafer film type. Specifically, for example, the control unit 5 refers to the storage unit 51 and uses a recipe (for example, a first pressure PS1 and a second pressure) corresponding to the film type of the wafer W currently held, to form a membrane. Controls the pressure of the gas supplied to 204.

Further, if the adhesive force of the substrate to the elastic film is strong, there is a problem that even if the elastic film swells, the substrate does not peel off and physical stress is applied to the substrate. Furthermore, the substrate may crack due to physical stress. On the other hand, the control unit 5 according to the present embodiment changes the pressure of the gas supplied to the membrane 204 stepwise (for example, with the passage of time). As a result, even if the wafer has a strong attachment force to the membrane 204, the physical stress on the substrate can be reduced by changing the gas pressure stepwise. Further, by changing the gas pressure stepwise, it is possible to reduce the variation in the wafer release time. Further, when the position of the wafer W becomes a position where the pressurized fluid can be ejected from the release nozzle 153 to the back surface of the wafer W, the control unit 5 changes the pressure of the gas supplied to the membrane 204. As a result, the wafer release pressure can be adjusted to the optimum pressure at the timing when the release nozzle 153 ejects the pressurized fluid, so that the release property of the wafer W can be improved.

The control unit 5 controls the pressure of the gas supplied into the membrane 204 by using the position of the wafer W detected by the position detection unit 154 (for example, the height of the back surface of the wafer W). As an example, in the present embodiment, the control unit 5 uses the first pressure PS1 to gas in the membrane 204 before the position of the wafer W becomes a position where the pressurized fluid can be ejected from the release nozzle 153 to the back surface of the wafer. Is controlled to supply. On the other hand, when the position of the wafer W is such that the pressurized fluid can be ejected from the release nozzle 153 to the back surface of the wafer W, the control unit 5 has a second pressure PS2 lower than the first pressure PS1 in the membrane 204. Control to supply gas to the wafer. At the same time, the control unit 5 controls the release nozzle 153 to eject the pressurized fluid toward the back surface of the wafer W.

According to this configuration, the stress on the wafer W can be reduced by reducing the wafer release pressure at the timing when the release nozzle 153 ejects the pressurized fluid.

Subsequently, a specific example of the processing of the control unit 5 related to the release of the wafer W described above will be described with reference to FIGS. 7 and 8. FIG. 7 is a schematic view showing a state before the wafer is detached from the membrane. As shown in FIG. 7, when the pusher is completely raised, the bottom surface of the retainer ring 203 is pressed against the upper surface of the top ring guide 151 and pushed up above the lower surface of the membrane 204, exposing the space between the wafer W and the membrane 204. It is in the state of being. In FIG. 7, the height of the back surface of the wafer W is higher than the height H0 of the ejection port of the release nozzle.

As shown in FIG. 7, when the height of the back surface of the wafer W detected by the position detection unit 154 is equal to or higher than the height H0 of the ejection port of the release nozzle 153, the control unit 5 applies the first pressure PS1 to the membrane 204. Control to supply gas inside. As a result, gas is supplied to the ripple area (ripple chamber 206) in the membrane 204 at the first pressure PS1.

FIG. 8 is a schematic view showing a state at the time of wafer release in which the wafer is separated from the membrane. In FIG. 8, the height of the back surface of the wafer W is lower than the height H0 of the ejection port of the release nozzle. As shown in FIG. 8 when the membrane 204 swells, when the height of the back surface of the wafer W detected by the position detection unit 169 becomes lower than the height H0 of the ejection port of the release nozzle 153, the control unit 5 is the first. A second pressure PS2, which is lower than the pressure PS1, is controlled to supply gas into the membrane 204. At the same time, the control unit 5 controls the release nozzle 153 to eject the pressurized fluid toward the back surface of the wafer W.

According to this configuration, the wafer release pressure can be reduced at the timing when the release nozzle 153 ejects the pressurized fluid, so that the release property of the wafer W can be improved.

FIG. 9 is a flowchart showing an example of the flow of the wafer release process according to the present embodiment.
(Step S101) Next, the control unit 5 acquires the first pressure PS1 and the second pressure PS2 according to the film type of the wafer W currently held by the top ring 31A from the storage unit 51.

(Step S102) Next, the control unit 5 supplies gas into the membrane 204 at the first pressure PS1.

(Step S103) Next, the control unit 5 determines whether or not the height of the back surface of the wafer W is lower than the height of the ejection port of the release nozzle 153. The control unit 5 waits until the height of the back surface of the wafer W becomes lower than the height of the ejection port of the release nozzle 153.

(Step S104) When it is determined in step S103 that the height of the back surface of the wafer W is lower than the height of the ejection port of the release nozzle 153, the control unit 5 presses the gas in the membrane 204 at the second pressure PS2. Is supplied, and the pressurized fluid is ejected from the release nozzle 153 toward the back surface of the wafer W.

As described above, the substrate processing apparatus 100 according to the present embodiment has a membrane 204 having holes 204h on its surface, and by sucking the wafer W through the holes 204h, the wafer W is attached to the surface of the membrane 204. A top ring 31A for adsorption is provided. Further, the substrate processing apparatus 100 includes a pressure regulator R6 that adjusts the pressure of the gas supplied into the membrane. Further, the substrate processing apparatus 100 includes a control unit 5 that controls the pressure regulator R6 to change the pressure of the gas supplied into the membrane 204 in order to peel the wafer W from the membrane 204.

According to this configuration, the pressure in the ripple chamber 206 in the membrane 204 is changed to control the swelling speed of the membrane 204, so that the membrane 204 can be moved at a speed corresponding to the sticking force of the wafer W to the membrane 204. Can be inflated. As a result, the greater the sticking force of the wafer W to the membrane 204, the greater the pressure of the gas supplied into the membrane 204 and the faster the swelling of the membrane 204, and the stronger the sticking force of the wafer W to the membrane 204. Therefore, it is possible to reduce the variation in the wafer release time.

The control unit 5 may change the pressure of the gas supplied into the membrane 204 according to the degree of swelling of the membrane 204. As a result, when the swelling of the membrane 204 is slow, the gas pressure can be increased and the wafer release time can be made uniform.

Further, the position detection unit 154 is located at the same height as the release nozzle 153, has a light projecting unit and a light receiving unit, and even if the light projecting unit irradiates light and the light receiving unit detects this reflected light. Good. In that case, when the time from the start of projection to the detection of the reflected light becomes shorter than the set time, the control unit 5 can eject the pressurized fluid from the release nozzle 153 to the back surface of the wafer W at the position of the wafer W. It may be judged that the position has been reached.

In the present embodiment, an example in which the substrate processing apparatus includes the pusher 150 has been described, but the present invention is not limited to this, and the substrate processing apparatus does not include the pusher 150, but instead the first linear transporter 6 and the first linear transporter No. 6 and the first linear transporter 150. 2 The linear transporter 7 may perform the function of the pusher 150.

FIG. 10 is a schematic cross-sectional view showing the top ring 31A and the first linear transporter 6 in the modified example of the present embodiment. As shown in FIG. 10, in the first linear transporter 6, the linear stage 160, the transport hand 161 that moves up and down, the holding portion 162 that holds the transport hand 161 so that it can move up and down, and the transport hand 161 are connected. The plate member 163, the elastic members 164 and 165 whose one end is connected to the front surface of the plate member 163, the plate member 166 and the plate member 166 whose other ends of the elastic members 164 and 165 are connected to the back surface. It is provided with an annular member 167 provided on the top.

As shown in FIG. 10, when the wafer W is released, the top ring 31A first descends as shown by the arrow A3, and the first linear transporter 6 rises as shown by the arrow A4. Subsequently, when the first linear transporter 6 rises as shown by the arrow A4, the annular member 167 of the first linear transporter 6 presses the linear stage 160. Along with this, the linear stage 160 is pressed against the retainer ring 203 of the top ring 31A, so that the retainer ring 203 rises. The first linear transporter 6 stops at the wafer W delivery position.

FIG. 11 is a partial schematic cross-sectional view showing a state at the time of wafer release in which the wafer is separated from the membrane in the modified example of the present embodiment. As shown in FIG. 11, a release nozzle (substrate peeling promoting portion) 168 capable of injecting a pressurized fluid is provided in the annular member 167. A plurality of release nozzles 168 are provided at predetermined intervals in the circumferential direction of the annular member 167 so as to eject the pressurized fluid F inward in the radial direction of the annular member 167. As a result, it is possible to inject a release shower made of the pressurized fluid F between the wafer W and the membrane 204 to release the wafer W from the membrane 204. The pressurized fluid F may be only a pressurized gas (for example, pressurized nitrogen), may be only a pressurized liquid (for example, pressurized water), or may be a pressurized gas (for example, pressurized nitrogen). It may be a mixed fluid of liquid (for example, pure water).

The release nozzle 168 is connected to the control unit 5 via a control line and is controlled by the control unit 5. Further, a position detection unit 169 for detecting the position of the wafer W adhering to the membrane 204 is provided in the annular member 167. In the modified example of this embodiment, as an example, the position detection unit 169 detects the height of the back surface of the wafer W adhering to the membrane 204. The position detection unit 169 has, for example, an image pickup unit that images the inside of the top ring guide 151, and detects the height of the back surface of the wafer W from the captured image.

The control unit 5 controls the pressure of the gas supplied into the membrane 204 by using the position of the wafer W detected by the position detection unit 169 (for example, the height of the back surface of the wafer W). As an example, in the present embodiment, the control unit 5 uses the first pressure PS1 to gas in the membrane 204 before the position of the wafer W becomes a position where the pressurized fluid can be ejected from the release nozzle 168 to the back surface of the wafer. Is controlled to supply. On the other hand, when the position of the wafer W is such that the pressurized fluid can be ejected from the release nozzle 168 to the back surface of the wafer W, the control unit 5 has a second pressure PS2 lower than the first pressure PS1 in the membrane 204. Control to supply gas to the wafer. At the same time, the control unit 5 controls the release nozzle 168 to eject the pressurized fluid toward the back surface of the wafer W.

According to this configuration, the stress on the wafer W can be reduced by reducing the wafer release pressure at the timing when the release nozzle 168 ejects the pressurized fluid.

Subsequently, a specific example of the processing of the control unit 5 related to the release of the wafer W described above will be described. When the height of the back surface of the wafer W detected by the position detection unit 169 is equal to or higher than the height H1 of the ejection port of the release nozzle 168, the control unit 5 supplies gas into the membrane 204 at the first pressure PS1. Control. As a result, gas is supplied to the ripple area (ripple chamber 206) in the membrane 204 at the first pressure PS1.

As shown in FIG. 11 when the membrane 204 swells, the height of the back surface BS (see FIG. 11) of the wafer W detected by the position detection unit 169 is higher than the height H1 (see FIG. 11) of the ejection port of the release nozzle 168. When it becomes low, the control unit 5 controls, for example, to supply gas into the membrane 204 at a second pressure PS2 lower than the first pressure PS1. At the same time, the control unit 5 controls the release nozzle 168 to eject the pressurized fluid F2 (see FIG. 11) toward the back surface of the wafer W.

According to this configuration, the wafer release pressure can be reduced at the timing when the release nozzle 168 ejects the pressurized fluid, so that the release property of the wafer W can be improved.

As described above, the present invention is not limited to the above-described embodiment as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. Furthermore, components over different embodiments may be combined as appropriate.

1 Housing 2 Load / unload part 3 Polishing part 3A, 3B, 3C, 3D Polishing unit 4 Cleaning part 5 Control part 6 1st linear transporter 7 2nd linear transporter 10 Polishing pad 10a Polishing surface 11 Lifter 12 Swing transporter 20 Front load section 21 Traveling mechanism 22 Conveying robot 30A, 30B, 30C, 30D Polishing table 31A, 31B, 31C, 31D Top ring (board holding section)
32A, 32B, 32C, 32D Polishing liquid supply nozzle 33A, 33B, 33C, 33D Dresser 34A, 34B, 34C, 34D Atomizer 30Aa Table shaft 51 Storage unit 100 Substrate processing device 102 Polishing liquid supply nozzle 111 Top ring shaft 112 Rotating cylinder 113 Timing pulley 114 Rotating motor for top ring 115 Timing belt 116 Timing pulley 117 Top ring head shaft 124 Vertical movement mechanism 125 Rotary joint 126 Bearing 128 Bridge 129 Support base 130 Support 131,231 Vacuum source 132 Ball screw 132a Screw shaft 132b Nut 138 Servo Motor 140 Encoder 150 Board delivery device (pusher)
151 Top ring guide 152 Push stage 153 Release nozzle (Substrate peeling promotion part)
154 Position detection unit 160 Linear stage 161 Conveying hand 162 Holding unit 163 Plate member 164, 165 Elastic member 166 Plate member 167 Ring member 168 Release nozzle (Substrate peeling promotion unit)
169 Position detector 202 Top ring body 203 Retainer ring 204 Elastic membrane (membrane)
204a Partition 204h Hole 205 Center chamber 206 Ripple chamber 207 Outer chamber 208 Edge chamber 209 Retaining pressurizing chamber 211,212,213,214,215,221,222,223,224,226
Flow path 225 Rotary joint 230 Pressure adjustment unit 235 Air-water separation tank F1 to F5 Flow sensor R1 to R6 Pressure regulator P1 to P5 Pressure sensor SH release shower V1-1 to V1 to 3, V2-1 to V2 to 3, V3 1-V3-3, V4-1-1 V4-1, V5-1-1 V5-3 valve

Claims (7)

A board holder configured to hold the board,
Storage configured to store information that indicates multiple board types and the pressure associated with each board type.
A pressure regulator configured to adjust the pressure of the gas supplied into the elastic membrane of the substrate holding portion, and
Wherein by controlling the pressure regulator, upon the release of the substrate from the elastic film, to be able to inflate the elastic membrane at a speed corresponding to the sticking force to the elastic layer of the substrate, said elastic membrane A control unit that changes the pressure of the gas supplied inside,
With
The control unit uses information indicating a plurality of substrate types and the respective pressures associated with the substrate types, and uses the elastic film according to the type of substrate currently held by the substrate holding unit. It is further configured to control the pressure of the gas supplied inside ,
The control unit is a substrate processing device configured to change the pressure of the gas stepwise. The substrate processing apparatus according to claim 1, wherein the type of the substrate is a film type of the substrate. With a nozzle configured to eject a pressurized fluid,
A position detector configured to detect the position of the substrate adhering to the elastic film, and
Further prepare
The control unit is further configured to change the pressure of the gas when the position of the substrate reaches a position where the nozzle is configured to eject a pressurized fluid onto the back surface of the substrate. Item 2. The substrate processing apparatus according to Item 1 or 2. The control unit is configured to supply gas into the elastic film at a first pressure before the position of the substrate becomes a position where the pressurized fluid is ejected from the nozzle to the back surface of the substrate. When the position of the substrate reaches the position where the pressurized fluid is ejected from the nozzle to the back surface of the substrate, the gas is controlled to be supplied into the elastic film at a second pressure lower than the first pressure, and the gas is supplied. The substrate processing apparatus according to claim 3 , which is configured to eject a pressurized fluid from a nozzle toward the back surface of the substrate. The position detector is configured to detect the height of the back surface of the substrate adhering to the elastic film as the position of the substrate.
The control unit is configured to supply gas into the elastic film at a first pressure when the height of the back surface of the substrate detected by the position detector is equal to or higher than the height of the ejection port of the nozzle. When the height of the back surface of the substrate detected by the position detector becomes lower than the height of the nozzle outlet, the gas is supplied into the elastic film at a second pressure lower than the first pressure. The substrate processing apparatus according to claim 4 , which is configured to be such that the pressurized fluid is ejected from the nozzle toward the back surface of the substrate. The substrate processing apparatus according to any one of claims 1 to 5 , wherein the control unit changes the pressure of the gas according to the degree of swelling of the elastic film. The substrate processing apparatus according to any one of claims 1 to 6 , wherein the pressure regulator is an electropneumatic pressure regulator.

Images