Substrate bonding device and substrate bonding method

Abstract

Provided is a substrate bonding device that bonds a first substrate and a second substrate to each other. The substrate bonding device comprises a first stage that holds the first substrate, a second stage that holds the second substrate, a control device that controls the movement of at least the first stage, a first measurement device that measures the position of the first stage, and a second measurement device that measures the position of the first stage. The control device uses a position measurement value from the first measurement device to control the movement during a first time period that is before a time point at which a contact region between the first substrate and the second substrate is formed and uses a position measurement value from the second measurement device to control the movement during a second time period that is after the first time period and includes at least the time point.

Description

Substrate bonding apparatus and substrate bonding method

[0001] The present invention relates to a substrate bonding apparatus and a substrate bonding method.

[0002] Patent Document 1 states, "A stage device including a first measurement device for identifying the stage position, such as a linear encoder that covers the entire area inside the sample chamber, and a second measurement device for the stage position using a laser interferometer and a reflecting mirror so that the measurement areas partially overlap" (paragraph 0012). [Prior art documents] [Patent documents] [Patent document 1] JP 2014-143033 A General disclosure

[0003] A first aspect of the present invention provides a substrate bonding apparatus for bonding a first substrate and a second substrate together, the substrate bonding apparatus comprising: a first stage for holding the first substrate; a second stage for holding the second substrate; a control device for controlling movement of at least the first stage; a first measurement device for measuring the position of the first stage; and a second measurement device for measuring the position of the first stage, the control device controlling the movement using a value measured by the first measurement device during a first time period prior to a time point at which a contact region is formed between the first substrate and the second substrate, and controlling the movement using a value measured by the second measurement device during a second time period after the first time period and including at least the time point.

[0004] In the above substrate bonding apparatus, the second measuring device may measure the position of the first stage with higher measurement accuracy than the first measuring device.

[0005] In any of the above substrate bonding apparatuses, the first measuring device and the second measuring device may each include a detection head that detects a detection target. In any of the above substrate bonding apparatuses, a distance between the detection head of the second measuring device and the detection target during measurement may be smaller than a distance between the detection head of the first measuring device and the detection target during measurement.

[0006] In any of the substrate bonding apparatuses described above, the second time period may include a time period from when the first substrate and the second substrate are brought into contact with each other after being faced to each other.

[0007] In any of the above substrate bonding apparatuses, the first time period may include a time period during which alignment marks provided on the first substrate and the second substrate are measured.

[0008] In any of the above substrate bonding apparatuses, the first measuring device may continue measuring the position while the contact region is being formed between the first substrate and the second substrate.

[0009] In any of the above substrate bonding apparatuses, the second measurement device may include an encoder that measures the position of the first stage.

[0010] In any of the above substrate bonding apparatuses, the encoder may have a scale provided on one of the first stage and the second stage, and a detection head that detects the scale.

[0011] In any of the above substrate bonding apparatuses, the detection head may be provided on at least one of the other of the first stage and the second stage and a frame that holds the other stage.

[0012] In any of the substrate bonding apparatuses described above, the first measurement device may include an interferometer that irradiates light toward the first stage from a side of the first stage. In any of the substrate bonding apparatuses described above, the encoder may be disposed at a position overlapping an optical axis of the interferometer.

[0013] In any of the substrate bonding apparatuses described above, the detection head may detect the scale within a distance range of 0.8 mm or less from the scale.

[0014] In any of the substrate bonding apparatuses described above, the first measurement device may include a first interferometer that measures the position of the first stage from a side of the first stage, and a second interferometer that measures the position of the second stage from a side of the second stage. In any of the substrate bonding apparatuses described above, the control device may control the first stage during the first time period using a measurement value of the position of the second stage measured by the second interferometer.

[0015] In any of the substrate bonding apparatuses described above, the first measurement device may include an interferometer that measures the position of one of the first and second stages that is rotatable. In any of the substrate bonding apparatuses described above, the interferometer may irradiate the one of the stages from a tangential direction of a rotational orbit of the one of the stages.

[0016] In any of the above substrate bonding apparatuses, the control device may start controlling the movement using the measurement value of the position by the second measurement device in response to the first stage moving within a predetermined range in which the position can be measured by the second measurement device.

[0017] In any of the above substrate bonding apparatuses, the control device may start controlling the movement using the position measurement value by the second measuring device in response to the position measurement value by the first measuring device falling within the predetermined range.

[0018] Any of the above substrate bonding apparatuses may further include a gas control unit that controls a gas supplied between the first substrate and the second substrate. In any of the above substrate bonding apparatuses, the gas control unit may not supply the gas between the first substrate and the second substrate until the control device starts to control the movement using the position measurement value by the second measurement device, and may start supplying the gas between the first substrate and the second substrate after the control device starts to control the movement using the position measurement value by the second measurement device.

[0019] In any of the above substrate bonding apparatuses, the gas control unit may supply the gas in a state where the first substrate and the second substrate do not face each other.

[0020] In any of the substrate bonding apparatuses described above, the gas control unit may supply the gas while the first stage is moved to a position outside the predetermined range.

[0021] In any of the substrate bonding apparatuses described above, the control device may record the position measurement value by the second measuring device in response to the first stage moving within the predetermined range or in response to the position measurement value by the first measuring device falling within the predetermined range, move the first stage to widen the gap between the first substrate and the second substrate, cause the gas control unit to supply the gas between the first substrate and the second substrate in response to the first stage moving out of the predetermined range, and move the first stage to the position corresponding to the recorded measurement value in response to the supply of the gas between the first substrate and the second substrate satisfying a predetermined condition, and then control the movement using the position measurement value by the second measuring device to form the contact region between the first substrate and the second substrate.

[0022] In a second aspect of the present invention, there is provided a substrate bonding apparatus for bonding a first substrate and a second substrate together, the substrate bonding apparatus comprising a first stage for holding the first substrate, a second stage for holding the second substrate, a control device for controlling movement of at least the first stage, and an interferometer and an encoder for measuring a position of the first stage, the control device controlling the movement using a value measured by the interferometer for the position during a first time period prior to a time point at which a contact region is formed between the first substrate and the second substrate, and controlling the movement using a value measured by the encoder for the position during a second time period after the first time period and including at least the time point.

[0023] A third aspect of the present invention provides a substrate bonding method for bonding a first substrate and a second substrate together, the substrate bonding method comprising: controlling movement of the stage using measurement values ​​obtained by a first measurement device that measures the position of a stage holding one of the first substrate and the second substrate during a first time period prior to a time point at which a contact region is formed between the first substrate and the second substrate; and controlling the movement using measurement values ​​obtained by a second measurement device that measures the position of the stage during a second time period after the first time period and including at least the time point.

[0024] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions.

[0025] 2 is a schematic plan view of a substrate bonding apparatus 100 according to an embodiment; FIG. 3 is a flowchart of a substrate bonding method according to an embodiment; FIG. 4 is a schematic outline view of a bonding unit 300 for explaining operation of the bonding unit 300 in a first time period according to a substrate bonding method according to an embodiment; FIG. 5 is a partially enlarged view of an area 1000 in FIG. 2; FIG. 6 is a schematic outline view of a bonding unit 300 for explaining operation of the bonding unit 300 in a first time period according to a substrate bonding method according to an embodiment; FIG. 7 is a schematic outline view of a bonding unit 300 for explaining operation of the bonding unit 300 in a second time period according to a substrate bonding method according to an embodiment; FIG. 8 is a schematic outline view of a bonding unit 300 for explaining operation of the bonding unit 300 in a second time period according to a substrate bonding method according to an embodiment; FIG. 9 is a schematic plan view of an arrangement configuration of a first measuring device 370 and a second measuring device 380 in a substrate bonding apparatus 100 according to an embodiment. 1 is a schematic side view of the arrangement of a first measuring device 370 and a second measuring device 380 in a substrate bonding apparatus 100 according to one embodiment; FIG. 2 is a schematic side view of the arrangement of a first measuring device 370 and a second measuring device 380 in a substrate bonding apparatus 100 according to one embodiment; and FIG. 3 is a schematic plan view of the arrangement of a first measuring device 370 and a second measuring device 380 in a substrate bonding apparatus 102 according to another embodiment.

[0026] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0027] 1 is a schematic plan view of a substrate bonding apparatus 100 according to one embodiment. The substrate bonding apparatus 100 bonds at least two substrates 210, 230 together. More specifically, the substrate bonding apparatus 100 bonds at least two substrates 210, 230 together to manufacture a laminated substrate 201. The substrate bonding apparatus 100 includes a control unit 101, a housing 110, substrate cassettes 120, 130, a holder stocker 400, a transport unit 140, a pre-aligner 500, an activation device 170, a bonding unit 300, a control unit 301, a gas control unit 302, and a gas supply unit 350. The substrate bonding apparatus 100 may also be referred to as a substrate bonding system.

[0028] The control unit 101 controls the substrate bonding apparatus 100 in an integrated manner by coordinating the various units of the substrate bonding apparatus 100. The control unit 101 may, for example, receive instructions from an external user and set manufacturing conditions for manufacturing the laminated substrate 201. The control unit 101 may display the operating status of the substrate bonding apparatus 100 to an external user via a user interface of the substrate bonding apparatus 100.

[0029] The housing 110 houses the substrate cassettes 120 and 130, the transport unit 140, the bonding unit 300, the holder stocker 400, and the pre-aligner 500. The temperature inside the housing 110 is controlled by the control unit 101 and is kept at, for example, room temperature.

[0030] The substrate cassette 120 accommodates the substrates 210 and 230 to be bonded together. The substrate cassette 130 accommodates the laminated substrate 201.

[0031] Each of the substrates 210 and 230 has a plurality of structures formed on the surface of the silicon wafer. One example of the plurality of structures is a plurality of circuit regions periodically arranged in the planar direction on the surface of each of the substrates 210 and 230. Each of the plurality of circuit regions is provided with wiring formed by photolithography or the like, a protective film, and connection structures such as pads and bumps that serve as connection terminals when electrically connecting the substrates 210 and 230 to other substrates 230 and 210, lead frames, etc. Another example of the plurality of structures is a plurality of alignment marks that serve as indicators when aligning the substrates 210 and 230 with other substrates 230 and 210. The plurality of alignment marks are provided, for example, on scribe lines arranged between the plurality of circuit regions on the surface of each of the substrates 210 and 230.

[0032] Based on instructions from the control unit 101, the transport unit 140 holds and transports substrates 210, 230, substrate holders 220, 240, laminated substrate 201, etc. individually, or holds and transports substrate holders 220, 240, etc., which hold substrates 210, 230, laminated substrate 201, etc.

[0033] The substrates 210 and 230 are transported into the activation device 170 by the transport unit 140. Based on commands from the control unit 101, the activation device 170 generates plasma to clean the bonding surfaces of the substrates 210 and 230. In the activation device 170, oxygen gas, which is a process gas, is excited to generate plasma under reduced pressure, and oxygen ions are irradiated onto the bonding surfaces of the substrates 210 and 230. For example, if the substrate 230 is a wafer with an SiO film formed on Si, the SiO bonds at the bonding surfaces are broken, forming dangling bonds of Si and O. The formation of such dangling bonds on the substrate surface is sometimes referred to as activation. When the substrate is exposed to the atmosphere in this state, moisture in the air bonds with the dangling bonds, covering the substrate surface with OH groups. This makes the substrate surface more susceptible to bonding with water molecules, i.e., hydrophilized. In other words, the activation device 170 hydrophilizes the substrate surface through activation. Although not shown, the activation device 170 cleans the bonding surfaces of the two substrates by applying pure water to each of the bonding surfaces, and in addition, spin-dries the bonding surfaces to which the pure water has been applied, adjusting the amount of water molecules adhering to the bonding surfaces to a predetermined amount.

[0034] In addition to the plasma exposure method, the activation device 170 may activate the surfaces of the substrates 210, 230 by sputter etching using an inert gas, an ion beam, a fast atom beam, or the like. When an ion beam or a fast atom beam is used, the activation device 170 can be generated under reduced pressure. Furthermore, the activation device 170 may activate the substrates 210, 230 by ultraviolet irradiation, an ozone asher, or the like. Furthermore, the activation device 170 may activate the surfaces of the substrates 210, 230 by chemically cleaning them using, for example, a liquid or gas etchant.

[0035] The holder stocker 400 accommodates the substrate holders 220, 240 that hold the substrates 210, 230. The substrate holders 220, 240 are formed from a hard material such as alumina ceramics, and adsorb and hold the substrates 210, 230, the laminated substrate 201, etc. using an electrostatic chuck, a vacuum chuck, or the like. The overall shape of the support surface of the substrate holders 220, 240 may be flat, may have a convex shape in which the center of the surface protrudes more than the surrounding area, or may have a free-form surface that corresponds to, for example, in-plane distortion of the substrates to be held.

[0036] Based on instructions from the control unit 101, the pre-aligner 500 aligns the substrates 210 and 230 with the substrate holders 220 and 240, respectively, and causes the substrates 210 and 230 to be held by the substrate holders 220 and 240, respectively.

[0037] The bonding unit 300 has an opposing upper stage 322 and a lower stage 332. The upper stage 322 holds the activated substrates 210 and 230 via the substrate holders 220 and 240 based on a command from the control device 301. Similarly, the lower stage 332 holds the activated substrates 210 and 230 via the substrate holders 220 and 240 based on a command from the control device 301.

[0038] The upper stage 322 and the lower stage 332 may directly hold the activated substrates 210 and 230, respectively. In this case, a substrate holder may be fixed to the upper stage 322 and the lower stage 332. In other words, the term "substrate holder" may refer to a transportable device such as the substrate holders 220 and 240, or to a non-transportable device that is fixed to the upper stage 322 and the lower stage 332.

[0039] The bonding unit 300 aligns the substrates 210 and 230 held by the upper stage 322 and the lower stage 332, respectively, with respect to each other based on commands from the control device 301. In this embodiment, the upper stage 322 is a fixed stage, and the lower stage 332 is a movable stage. As an example, the lower stage 332 is capable of translational and rotational movement.

[0040] Thereafter, based on a command from the control device 301, the bonding unit 300 maintains the state in which the substrates 210 and 230 are held on the upper stage 322 and the lower stage 332, respectively, and forms a contact area between the aligned substrates 210 and 230. The contact area is a gradually expanding area that is formed between the substrates 210 and 230 by bringing a part of the substrate 210 and a part of the substrate 230 into contact with each other. As an example, the contact area may be a central area within the surface of each of the substrates 210 and 230.

[0041] Then, based on instructions from the control device 301, the bonding section 300 maintains one of the substrates 210, 230 held on one of the upper stage 322 and the lower stage 332, and releases the other of the upper stage 322 and the lower stage 332 from holding the other of the substrates 210, 230, thereby bringing the substrates 210, 230 with activated surfaces into contact with each other and bonding them together.

[0042] Here, the bonded state may refer to a state in which the terminals on the two stacked substrates are connected to each other, thereby ensuring electrical continuity between the two substrates. It may also refer to a state in which the terminals on the two stacked substrates are connected to each other, thereby achieving a predetermined bonding strength between the two substrates or greater. In cases where the terminals of the two stacked substrates are electrically connected by annealing or other treatment, the term may refer to a state in which the two substrates are temporarily bonded, i.e., temporarily bonded, before the annealing or other treatment. In cases where terminals for electrical connection are formed on the two substrates after bonding, the term may refer to a state in which the bonding surfaces of the two substrates on which no terminals are formed are bonded together. In cases where the bonding strength between the two stacked substrates is increased to a predetermined strength or greater by annealing or other treatment, the term may refer to the temporarily bonded state before the annealing or other treatment. The state in which the bonding strength is increased to a predetermined strength or greater by annealing includes, for example, a state in which the surfaces of the two substrates are bonded to each other by covalent bonds. The temporarily bonded state also includes a state in which the two overlapping substrates can be separated and reused.

[0043] The control device 301 controls the movement of the movable stage out of the upper stage 322 and the lower stage 332 using a measurement value of the position of the movable stage. The measurement value may be a value obtained by measuring the position of the movable stage using at least two types of measurement units having different measurement accuracy.

[0044] The control device 301 controls the movement of the movable stage using the measurement value of the position by the first measurement device during a first time period before the time when a contact region is formed between the substrate 210 and the substrate 230. The control device 301 controls the movement of the movable stage using the measurement value of the position by the second measurement device during a second time period after the first time period and including at least the time when a contact region is formed between the substrate 210 and the substrate 230. The second measurement device may measure the position with higher measurement accuracy than the first measurement device. In this embodiment, the control device 301 controls the movement of the lower stage 332 using the measurement value of the position by the first measurement device during the first time period, and controls the movement of the lower stage 332 using the measurement value of the position by the second measurement device during the second time period. In the following description, the first time period before the time when a contact region is formed between the substrate 210 and the substrate 230 may be simply referred to as the first time period, and the second time period after the first time period and including at least the time when a contact region is formed between the substrate 210 and the substrate 230 may be simply referred to as the second time period. In addition, the control device 301 may use the measurement value of the position by the first measurement device even during the second time period, that is, may control the movement of the lower stage 332 using the measurement values ​​of the position by the second measurement device and the first measurement device.

[0045] Measuring the position of the movable stage with higher measurement accuracy as described above is intended to measure the position with higher absolute accuracy, and may mean that the error from a certain ideal length caused by, for example, external disturbances or internal factors such as noise in the sensor itself is small. A second measurement device that measures the position of the movable stage with higher measurement accuracy than the first measurement device may be more resistant to external disturbances than the first measurement device.

[0046] The control device 301 controls translational movement of the movable stage in three mutually orthogonal directions. In addition, the control device 301 may control rotational movement of the movable stage in at least one of the three directions of pan, tilt, and roll. In this embodiment, the control device 301 controls translational movement of the lower stage 332 in three-dimensional directions and rotational movement in the three directions of pan, tilt, and roll.

[0047] Based on a command from the control device 301, the gas control unit 302 controls, via the gas supply unit 350, the gas to be supplied between the substrates 210 and 230 to be bonded in the bonding unit 300. The gas control unit 302 does not need to supply gas between the substrates 210 and 230 until the control device 301 starts to control the movement of the movable stage using the measurement value of the position of the movable stage obtained by the second measurement device. The gas control unit 302 may start supplying gas between the substrates 210 and 230 after the control device 301 starts to control the movement of the movable stage using the measurement value of the position of the movable stage obtained by the second measurement device. For example, the gas control unit 302 may start supplying gas between the substrates 210 and 230 in response to the control device 301 starting stage movement control using the measurement value obtained by the second measurement device, or several seconds after the control device 301 starts stage movement control.

[0048] The gas supply unit 350 is connected to the bonding unit 300 and supplies gas into the bonding unit 300 based on a command from the gas control unit 302. More specifically, the gas supply unit 350 supplies the gas between the substrates 210 and 230 to be bonded before they come into contact with each other. The gas supply unit 350 continues to supply the gas between the substrates 210 and 230 after they come into contact with each other. The gas supply unit 350 according to this embodiment may replace the atmosphere present between the substrates 210 and 230 with the gas before they come into contact with each other, and may continue to supply the gas between the substrates 210 and 230 until the contact area reaches the outer periphery of the substrates 210 and 230 after they come into contact with each other. Examples of the gas include inert gases such as helium (He) gas, argon (Ar) gas, and a mixed gas of helium and argon, and nitrogen (N ２ The gas may be a humidity-controlled gas such as a humidified air (CDA) or a clean dry air (CDA). In this embodiment, the gas is helium, which has a specific gravity lighter than air.

[0049] The gas supply unit 350 may be capable of adjusting the supply conditions of the gas based on a command from the gas control unit 302. The gas supply unit 350 may have, for example, a heater, a mass flow controller, a regulator, etc., and is capable of adjusting the temperature, flow rate, pressure, etc. of the gas.

[0050] In this embodiment, in addition to the gas supplied by the gas supply unit 350, air flows in one direction from the side of the substrates 210, 230 toward the substrates 210, 230 in the bonding unit 300 to maintain a constant temperature between the substrates 210, 230 being bonded. This unidirectional air flow may be referred to as a side flow. The humidity of this air may be maintained constant.

[0051] In the substrate bonding apparatus 100 described above, in addition to the substrates 210, 230 on which elements, circuits, terminals, etc. are formed as described above, it is also possible to bond bare silicon, which is an unprocessed silicon wafer without any structures formed thereon, a Ge-doped SiGe substrate, a Ge single crystal substrate, a III-V or II-VI compound semiconductor wafer, and a glass substrate. The substrates to be bonded may be a circuit board and an unprocessed substrate, or two unprocessed substrates. The substrates 210, 230 to be bonded may themselves be a laminated substrate 201 having multiple substrates already stacked one on top of another. The substrates 210, 230 to be bonded may have, for example, approximately the same outer dimensions when not distorted. The outer shapes of the substrates 210, 230 may be approximately circular or may have other shapes.

[0052] 2 is a flowchart of a substrate bonding method according to one embodiment. The flowchart shown in FIG. 2 will be described with reference to FIGS. 3 to 7. As an example, this flow may start with activated substrates 210 and 230 being carried into the bonding unit 300.

[0053] 3 and 5 are schematic diagrams of the bonding unit 300 for explaining the operation of the bonding unit 300 during a first time period in accordance with an embodiment of the substrate bonding method. As shown in FIG. 3 , mutually orthogonal X-, Y-, and Z-axes are defined. The left-right direction as viewed from the page is defined as the X-axis direction, and the rightward direction as the positive X-axis direction. Similarly, the front-rear direction as viewed from the page is defined as the Y-axis direction, and the forward direction, i.e., the depth direction, is defined as the positive Y-axis direction. Similarly, the up-down direction as viewed from the page is defined as the Z-axis direction, and the upward direction as the positive Z-axis direction. The origin of these three-dimensional Cartesian coordinate systems may be the center of the bonding surface of the substrate 210 held on the upper stage 322 in alignment with the center of the substrate holding surface of the upper stage 322. In FIG. 3 , the origin is shown outside the bonding unit 300 simply for clarity of explanation. This applies similarly to subsequent figures, and redundant explanations will be omitted. In the following description, the positive side of the Z axis may be referred to as "upper" and the negative side of the Z axis may be referred to as "lower."

[0054] In addition to the upper stage 322 and the lower stage 332, the bonding section 300 includes a frame 310 that holds the upper stage 322 and the lower stage 332, an X-direction drive section 331, a Y-direction drive section 333, a lifting drive section 338, a microscope 324, a plurality of fixed piping sections 321, a filling top plate 323, a filling cover section 327, a sealing member 328, an air cylinder section 326, a lifting arm section 325, a first measuring device 370, and a second measuring device 380.

[0055] 3 , in this embodiment, the control device 301 causes the upper stage 322 of the bonding unit 300 to hold the substrate 210 via the substrate holder 220, and causes the lower stage 332 to hold the substrate 230 via the substrate holder 240 (step S101). The substrate holder 220 holding the substrate 210 is carried into the bonding unit 300 and placed on the upper stage 322 by the transport unit 140, and the substrate holder 240 holding the substrate 230 is carried into the bonding unit 300 and placed on the lower stage 332.

[0056] The upper stage 322 has a holding function such as a vacuum chuck or electrostatic chuck, and is fixed facing downward to the top plate 316 of the frame 310. The lower stage 332 has a holding function such as a vacuum chuck or electrostatic chuck. The lower stage 332 is mounted on the upper surface of an elevation drive unit 338 that is supported so as to be able to move up and down in the Z-axis direction by at least a part of an X-direction drive unit 331 disposed on the bottom plate 312 of the frame 310 and a Y-direction drive unit 333 overlapped on the positive side of the X-direction drive unit 331 on the Z-axis direction.

[0057] The X-direction driving unit 331 is capable of moving in the X-axis direction parallel to the bottom plate 312 based on a command from the control device 301. The Y-direction driving unit 333 is capable of moving in the Y-axis direction parallel to the bottom plate 312 on the X-direction driving unit 331 based on a command from the control device 301. Thus, the control device 301 moves the lower stage 332 two-dimensionally parallel to the bottom plate 312 by combining the operations of the X-direction driving unit 331 and the Y-direction driving unit 333.

[0058] Furthermore, the lower stage 332 is supported by an elevation drive unit 338, and can be raised and lowered in the Z-axis direction by driving the elevation drive unit 338 based on commands from the control device 301. In this way, the lower stage 332 displaces the relative positions of the substrate 230 held by the substrate holder 240 and the substrate 210 held by the substrate holder 220, between the lower stage 332 and the upper stage 322 that holds the substrate 210 via the substrate holder 220, based on commands from the control device 301.

[0059] Therefore, the control device 301 controls the translational movement of the lower stage 332 in three dimensions, in the X-axis direction, the Y-axis direction, and the Z-axis direction. In addition, the control device 301 controls the rotational movement of the lower stage 332 in three directions around the X-axis, the Y-axis, and the Z-axis, i.e., in three directions of tilt, roll, and pan, by using a rotation drive unit (not shown). The control device 301 may translate the lower stage 332 and rotate the lower stage 332 to make the lower stage 332 parallel to the upper stage 322 and rotate the substrate 230 held on the lower stage 332. In this way, the control device 301 aligns the substrate 230 with the substrate 210 held on the upper stage 322.

[0060] The microscope 324 is fixed to the side of the upper stage 322 on the top plate 316 of the frame 310. The microscope 324 can observe the surface of the substrate 230 held facing upward on the lower stage 332.

[0061] The microscope 334 is fixed to the side of the lower stage 332 on the upper surface of the Y-direction driving unit 333. The microscope 334 can observe the surface of the substrate 210 held on the upper stage 332 facing downward.

[0062] The microscopes 324, 334 are calibrated by the control device 301 at any timing by aligning the focal points F with each other or by having the microscopes observe a common index. This allows the relative positions of the pair of microscopes 324, 334 in the bonding section 300 to be measured. The control device 301 uses the pair of microscopes 324, 334 whose relative positions are known to measure the above-mentioned alignment marks for each of the substrates 210, 230 held on the upper stage 322 and the lower stage 332.

[0063] The plurality of fixed pipe sections 321 are fixed to the side of the upper stage 322 on the top plate 316 of the frame 310. One end of each of the plurality of fixed pipe sections 321 is connected to the gas supply section 350, and the other end is exposed to the side of the upper stage 322 in the bonding section 300, and the gas supplied from the gas supply section 350 can be delivered into the bonding section 300. In this embodiment, the plurality of fixed pipe sections 321 are each provided with a flow rate adjustment valve at the one end, and the flow rate of the gas supplied into the bonding section 300 is adjusted individually or collectively by the gas supply section 350.

[0064] As an example, as shown in FIG. 3 , a filling top plate 323 is coupled to the other end of the fixed pipe unit 321, covering the back surface of the upper stage 322 opposite the surface that holds the substrate holder 220. As another example, a filling cover unit 327 that surrounds the side of the upper stage 322 may be coupled to the other end of the fixed pipe unit 321. As another example, some of the multiple fixed pipe units 321 may have the filling top plate 323 coupled to the other end, and some of the multiple fixed pipe units 321 may have the filling cover unit 327 coupled to the other end. Some or all of the multiple fixed pipe units 321 may be capable of delivering gas supplied from the gas supply unit 350 into the bonding unit 300 by an arrangement configuration other than the arrangement configuration illustrated here. Note that in FIG. 3 , some of the fixed pipe units 321 are omitted from the illustration simply for the purpose of clarity.

[0065] The filling top plate 323 is a disk-shaped member with an opening formed in the center for passing the upper stage 322 through. When the substrate holder 220 is held on the upper stage 322, the filling top plate 323 is disposed on the back side of the substrate holder 220, i.e., the side on which the substrate 210 is not placed, so as to face one surface of the upper stage 322. The filling top plate 323 is coupled to the fixed piping unit 321 so that the other end of the fixed piping unit 321 is exposed between the filling top plate 323 and the upper stage 322 when the substrate holder 220 is held on the upper stage 322. A flat, annular sealing member 328 is fixed to the top surface of the filling top plate 323 along the outer periphery of the filling top plate 323. The sealing member 328 may be made of rubber, for example. The sealing member 328 may also be an O-ring.

[0066] The filling cover part 327 is a generally rectangular cylindrical member having an opening formed in the center for passing the upper stage 322, etc. Here, as shown in Fig. 4, which is a partial enlargement of the area 1000 enclosed by the dashed line circle in Fig. 3, the filling cover part 327 has a side wall 341, a top plate 343 extending from an upper end of the side wall 341 on the positive side in the Z axis direction toward the center in the XY plane, and a bottom plate 345 extending from a lower end of the side wall 341 on the negative side in the Z axis direction toward the center in the XY plane.

[0067] The filling cover part 327 is held by the fixed piping part 321 via the air cylinder part 326 and the lifting arm part 325. The air cylinder part 326 is connected to the fixed piping part 321, and expands and contracts in the Z-axis direction by the energy of compressed air based on commands from the control device 301. The lifting arm part 325 is connected to the air cylinder part 326, and can be raised and lowered in the Z-axis direction by the expansion and contraction of the air cylinder part 326. Therefore, the filling cover part 327 can be raised and lowered in the Z-axis direction as the lifting arm part 325 is raised and lowered.

[0068] When the filling cover part 327 is raised to the most positive side in the Z axis direction, the lower end of the filling cover part 327 in the Z axis direction is located on the more positive side of the Z axis direction than the bonding surface of the substrate 210 held by the upper stage 322. Therefore, when raised to the most positive side in the Z axis direction, the filling cover part 327 does not come into contact with components such as the substrate 230 on the lower stage 332 that moves within the XY plane on the more negative side of the Z axis direction than the bonding surface of the substrate 210 held by the upper stage 322. Note that, as shown in Figures 3 and 5, during the first time period, the lifting arm part 325 and the filling cover part 327 remain positioned on the most positive side in the Z axis direction.

[0069] Furthermore, when the filling cover part 327 is lowered to the most negative side in the Z-axis direction with the substrates 210 and 230 held by the upper stage 322 and the lower stage 332 facing each other, it can surround the substrates 210 and 230 from the sides around the entire periphery of the substrates 210 and 230. When lowered to the most negative side in the Z-axis direction, the bottom plate 345 of the filling cover part 327 is in approximately the same position as the substrate holder 240 in the Z-axis direction, and the top plate 343 of the filling cover part 327 is connected to the filling top plate 323 via the sealing member 328. In this case, the sealing member 328 may be in close contact with the underside of the top plate 343 of the filling cover part 327 around the entire periphery.

[0070] The first measuring device 370 is an example of the first measuring device described above. According to the substrate bonding method of this embodiment, during a first time period before the formation of a contact region between the substrates 210 and 230, the movement of the stage is controlled using a measurement value obtained by the first measuring device 370 that measures the position of the stage holding one of the substrates 210 and 230. More specifically, the substrate bonding method of this embodiment controls the movement of the lower stage 332 using a measurement value obtained by the first measuring device 370 that measures the position of the lower stage 332 that holds the substrate 230 during the first time period.

[0071] The first measurement device 370 according to this embodiment also measures the position of the upper stage 322. The measurement values ​​of the positions of the upper stage 322 and the lower stage 332 by the first measurement device 370 are used by the control device 301 at least during a first time period to control the movement of the lower stage 332. The first time period includes, for example, a time period during which alignment marks provided on the first substrate 210 and the second substrate 230 are measured.

[0072] The start point of the first time period may be, for example, the point when the substrates 210 and 230 are carried into the bonding unit 300 and held by the upper stage 322 and the lower stage 332. The end point of the first time period may be, for example, the point when the substrates 210 and 230 are aligned and face each other. The point when they face each other may be the point when the lower stage 332 moves within a predetermined range within which the position of the lower stage 332 can be measured by the second measuring device 380, or the point when the measurement value of the position of the lower stage 332 by the first measuring device 370 falls within the predetermined range.

[0073] The first measuring device 370 may be controlled to turn on or off the power or measurement by the control device 301. For example, the first measuring device 370 may be switched from off to on in response to the substrates 210, 230 being carried into the bonding unit 300 and held by the upper stage 322 and the lower stage 332, or may be switched from on to off in response to the substrates 210, 230 being bonded and carried out of the bonding unit 300, or the power or measurement may be kept on until the next substrates 210, 230 to be bonded are carried into the bonding unit 300, that is, all the time.

[0074] The first measurement device 370 may continue to measure the positions of the lower stage 332 and the upper stage 322 during the second time period, i.e., while a contact region is being formed between the substrate 210 and the second substrate 230, in order to back up the second measurement device 380 in case, for example, the power or measurement of the second measurement device 380 is unintentionally turned off. When the power or measurement is kept on during the second time period, the first measurement device 370 may, for example, continue to output measurement values ​​to the control device 301 but may not be used by the control device 301. Alternatively, when the first measurement device 370 does not measure the positions of the upper stage 322 and the lower stage 332 during the second time period, the power or measurement may be switched from on to off in response to the start of controlling the movement of the lower stage 332 using the measurement values ​​of the position of the lower stage 332 by the second measurement device 380.

[0075] As an example, the first measuring device 370 can measure a larger range than the second measuring device 380. The first measuring device 370 includes an interferometer that irradiates light from the side of the lower stage 332 toward the lower stage 332. The first measuring device 370 may include a linear scale in addition to or instead of the interferometer. In this embodiment, the first measuring device 370 includes a first interferometer 371 and a second interferometer 376 that are fixed to the side walls of the frame 310 of the bonding unit 300. The first interferometer 371 and the second interferometer 376 are examples of detection heads that detect the detection target.

[0076] The first interferometer 371 measures the position of the lower stage 332 by irradiating light toward the lower stage 332 from a side of the lower stage 332. More specifically, the first interferometer 371 may measure the X coordinate, Y coordinate, rotation angle about the X axis, rotation angle about the Y axis, rotation angle about the Z axis, etc. of the lower stage 332 by irradiating light toward the lower stage 332 from a side in the horizontal direction of the lower stage 332 and receiving light reflected from the side surface of the lower stage 332. In addition, the first interferometer 371 may measure the Z coordinate of the lower stage 332 by irradiating light toward the lower stage 332 from the upper stage 322 or from a side of the upper stage 322 on the top plate 316 of the frame 310 and receiving light reflected from the upper surface of the lower stage 332, which is the surface that holds the substrate holder 240. Instead of reflecting light on the surface of the lower stage 332 , the first interferometer 371 may reflect light from a reflecting mirror appropriately arranged on the surface of the lower stage 332 .

[0077] Similarly, the second interferometer 376 measures the position of the upper stage 322 by irradiating light toward the upper stage 322 from the side of the upper stage 322. More specifically, the second interferometer 376 may measure the X coordinate, Y coordinate, rotation angle about the X axis, rotation angle about the Y axis, rotation angle about the Z axis, etc. of the upper stage 322 by irradiating light toward the upper stage 322 from the side in the horizontal direction of the upper stage 322 and receiving light reflected from the side surface of the upper stage 322. In addition to this, the second interferometer 376 may measure the Z coordinate of the upper stage 322; for example, the Z coordinate of the upper stage 322 may be measured by a WTD interferometer. The WTD interferometer irradiates a reference beam horizontally toward the upper stage 322 from the side of the upper stage 322 and receives the reference beam reflected by the side surface of the upper stage 322, and also irradiates a light obliquely from the side of the upper stage 322 toward a sloped mirror (movable mirror) provided on the upper stage 322, causes the light reflected by the sloped mirror to be further reflected by a roof mirror (WTD fixed mirror) fixed to the top plate 316 of the frame 310, and receives the return beam further reflected by the sloped mirror. The WTD interferometer causes interference between the reference beam and the return beam, and measures the Z coordinate of the upper stage 322 from the phase change. Furthermore, the optical path length of the reference light does not change even if the Z coordinate of the upper stage 322 changes, while the optical path length of the return light changes when the Z coordinate of the upper stage 322 changes.Therefore, the WTD interferometer can calculate the Z coordinate of the upper stage 322 based on the difference between the optical path length of the reference light and the optical path length of the return light.

[0078] The first interferometer 371 and the second interferometer 376 may be, for example, a Michelson interferometer using a coherent light source. For the sake of clarity, FIG. 3 only shows an example of the first interferometer 371 that irradiates light from a horizontal side of the lower stage 332 toward the lower stage 332 and an example of the second interferometer 376 that irradiates light from a horizontal side of the upper stage 322 toward the upper stage 322, and does not illustrate other components of the first interferometer 371 and the second interferometer 376. FIG. 3 also shows, with dashed dotted lines, examples of light beams 372 and 377 extending between the first interferometer 371 and the second interferometer 376 and the lower stage 332 and the upper stage 322. The same applies to the subsequent figures, and redundant explanations will be omitted.

[0079] The first interferometer 371 and second interferometer 376 of the first measurement device 370 output the measurement values ​​of the positions of the lower stage 332 and upper stage 322, that is, the absolute coordinates in the above-mentioned Cartesian coordinate system, to the control device 301.

[0080] During the first time period, the control device 301 controls the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 obtained by the first interferometer 371 and the measurement value of the position of the upper stage 322 obtained by the second interferometer 376. The control device 301 records the measurement values ​​of the positions of the lower stage 332 and the upper stage 322 obtained by the first interferometer 371 and the second interferometer 376, i.e., the absolute coordinates in the above-mentioned Cartesian coordinate system, in accordance with the movement of the lower stage 332. The control device 301 may calculate the relative position of the lower stage 332 with respect to the upper stage 322 from the difference between the absolute coordinates of the lower stage 332 and the upper stage 322.

[0081] The control device 301 moves the lower stage 332 by operating the X-direction driver 331 and the Y-direction driver 333 while referring to the measurement value of the position of the lower stage 332 by the first interferometer 371 and the measurement value of the position of the upper stage 322 by the second interferometer 376, and causes the microscopes 324 and 334, whose relative positions are known, to detect the alignment marks provided on the substrates 210 and 230, respectively, and calculates the relative positions of the substrates 210 and 230 (step S102).The control device 301 then calculates the amount of relative movement between the substrates 210 and 230 based on the relative positions of the microscopes 324 and 334, the relative positions of the substrates 210 and 230, and the relative position of the lower stage 332 with respect to the upper stage 322, so that the amount of misalignment between corresponding alignment marks on the substrates 210 and 230 is equal to or less than a predetermined threshold and the amount of misalignment between corresponding connection structures on the substrates 210 and 230 is equal to or less than a predetermined threshold.

[0082] The misalignment may refer to misalignment between corresponding alignment marks between the bonded substrates 210 and 230, or may refer to misalignment between corresponding connection structures between the bonded substrates 210 and 230. The misalignment may be caused by a difference in the amount of strain generated in each of the two substrates 210 and 230.

[0083] Here, the threshold value may be the amount of misalignment that allows electrical conduction between the substrates 210 and 230 when the bonding of the substrates 210 and 230 is completed, or may be the amount of misalignment that causes at least partial contact between the structures provided on the substrates 210 and 230. When the positional misalignment between the substrates 210 and 230 becomes larger than the threshold value, the control device 301 may determine that the connection structures are not in contact with each other or that appropriate electrical conduction is not achieved, or that a predetermined bonding strength is not achieved between the connection structures.

[0084] 3 , the control device 301 operates the X-direction driver 331 and the Y-direction driver 333 while referring to the measurement values ​​from the first measurement device 370, i.e., the measurement value of the position of the lower stage 332 from the first interferometer 371 and the measurement value of the position of the upper stage 322 from the second interferometer 376, to move the lower stage 332 by the movement amounts in the X-axis direction and the Y-axis direction included in the relative movement amount calculated as described above, as shown in FIG. 5 . In this way, the control device 301 aligns the substrate 210 and the substrate 230 with respect to each other in the XY plane (step S103). In addition, in step S103, the control device 301 may operate a rotational drive unit (not shown) while referring to the measurement value of the position of the lower stage 332 taken by the first interferometer 371 and the measurement value of the position of the upper stage 322 taken by the second interferometer 376, thereby moving the lower stage 332 by at least one rotational movement amount around the X-axis, Y-axis, or Z-axis included in the relative movement amount calculated as described above.

[0085] As shown in Fig. 5, the substrates 210 and 230 are aligned in the XY plane and face each other, and in this state, the second measuring device 380 may be able to measure the position of the lower stage 332. In this case, Fig. 5 can also be said to show the operation of the bonding unit 300 in the second time period. Note that the second measuring device 380 is an example of the second measuring device described above.

[0086] On the other hand, when the substrates 210 and 230 are aligned with each other in the XY plane, if the second measuring device 380 is unable to measure the position of the lower stage 332, i.e., if the lower stage 332 is not located within the measurable range of the second measuring device 380, the control device 301 may further operate the lifting and lowering drive unit 338 to move the lower stage 332 in the positive direction of the Z axis, thereby bringing the substrates 210 and 230 closer to each other until the second measuring device 380 can measure the position of the lower stage 332.

[0087] According to the substrate bonding method of this embodiment, during the second time period, the movement of the stage holding either the substrate 210 or the substrate 230 is controlled using a measurement value obtained by the second measuring device 380 to determine the position of the stage. More specifically, the substrate bonding method of this embodiment controls the movement of the lower stage 332 holding the substrate 230 during the second time period using a measurement value obtained by the second measuring device 380 that measures the position of the lower stage 332. As an example, if the second measuring device 380 can measure the position of the lower stage 332 while the substrates 210 and 230 are aligned with each other in the XY plane, the second time period includes the time period from when the first substrate 210 and the second substrate 230 are brought into contact with each other until they are brought face to face with each other. The second measuring device 380 may measure the position of the lower stage 332 with higher measurement accuracy than the first measuring device 370.

[0088] The start point of the second time period may be, for example, the point when the lower stage 332 moves within a predetermined range in which the position of the lower stage 332 can be measured by the second measurement device 380, or the point when the measurement value of the position of the lower stage 332 by the first measurement device 370 falls within the predetermined range. In other words, the control device 301 may start controlling the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 by the second measurement device 380 in response to the lower stage 332 moving within a predetermined range in which the position of the lower stage 332 can be measured by the second measurement device 380, or in response to the measurement value of the position of the lower stage 332 by the first measurement device 370 falling within the predetermined range. The predetermined range may be a range within the XY plane or a range in the Z-axis direction. As described above, the Z-axis range is a range in which the position of the lower stage 332 can be measured by the second measurement device 380, and may be, for example, a distance range of 0.8 mm or less.

[0089] The end point of the second time period may be, for example, the point at which the control device 301 releases the upper stage 322 from holding the substrate 210. In other words, after a contact area is formed between the substrate 210 and the substrate 230 and sufficient bonding strength is ensured between the substrate 210 and the substrate 230, the control device 301 may continue to control the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 by the second measurement device 380 until the upper stage 322 releases the substrate 210. The control device 301 may also determine whether sufficient bonding strength is ensured between the substrate 210 and the substrate 230 based on whether a predetermined time has elapsed since the contact area was formed between the substrate 210 and the substrate 230.

[0090] The second measuring device 380 may be controlled to turn on or off the power or measurement by the control device 301. For example, the second measuring device 380 may be switched from off to on in response to start of controlling the movement of the lower stage 332 using a measurement value of the position of the lower stage 332 by the second measuring device 380, and may be switched from on to off in response to the substrates 210 and 230 being bonded and carried out of the bonding unit 300.

[0091] The second measurement device 380 includes an encoder that measures the position of the lower stage 332. The encoder detects the physical quantity or changes in the physical quantity of a scale placed on the target using a detection head that is provided close to the scale, for example, on the order of μm to mm, to obtain the linear or rotational position and amount of movement of the target. Examples of such encoders include an optical encoder using a laser scale and a magnetic encoder using a magnetoscale.

[0092] In this embodiment, multiple second measuring devices 380 are provided on the substrate holding surfaces of the upper stage 322 and the lower stage 332. The second measuring devices 380 measure the relative position of the lower stage 332 with respect to the upper stage 322. Based on the relative position, the second measuring device 380 may calculate absolute coordinates of the lower stage 332 in the above-mentioned Cartesian coordinate system, such as the X coordinate, Y coordinate, and rotation angle around the Z axis.

[0093] The second measurement device 380 outputs a measurement value of the position of the lower stage 332, such as the relative position of the lower stage 332 with respect to the upper stage 322, or absolute coordinates in the above-mentioned Cartesian coordinate system, to the control device 301. If the control device 301 determines from the measurement value of the position of the lower stage 332 input from the second measurement device 380 after step S103 that further alignment of the substrates 210 and 230 with respect to each other in the XY plane is necessary, i.e., the amount of misalignment between the substrates 210 and 230 is greater than the above-mentioned threshold (step S104: YES), the control device 301 moves the lower stage 332 by the movement amounts in the X-axis and Y-axis directions included in the relative movement amount calculated as above, by operating the X-direction driver 331 and the Y-direction driver 333 while referring to the measurement value of the position of the lower stage 332 obtained by the second measurement device 380. As a result, the control device 301 again aligns the substrates 210 and 230 with respect to each other in the XY plane (step S105). In step S104, if it is determined that there is no need to further align the substrates 210 and 230 with each other, that is, if it is determined that the amount of misalignment between the substrates 210 and 230 is equal to or less than the threshold value, the process proceeds to step S106, which will be described later. Note that the control device 301 records the measurement value of the position of the lower stage 332 measured by the second measurement device 380 in accordance with the movement of the lower stage 332.

[0094] In addition, in step S105, the control device 301 may operate a rotation drive unit (not shown) while referring to the measurement value of the position of the lower stage 332 by the second measuring device 380, thereby moving the lower stage 332 by an amount of rotational movement around the Z axis included in the relative movement amount calculated as described above, thereby aligning the substrates 210 and 230 with each other.

[0095] In addition, in step S105, if the control device 301 continues to measure the position of the lower stage 332 by the first measuring device 370 even during the second time period, the control device 301 may operate a rotation drive unit (not shown) while referring to the measurement value of the position of the lower stage 332 by the first measuring device 370, thereby moving the lower stage 332 by at least one of the rotational movement amounts around the X axis and the Y axis included in the relative movement amount calculated as above, thereby aligning the substrate 210 and the substrate 230 with each other.

[0096] In this case, the control device 301 may also align the substrates 210 and 230 with each other during the second time period by operating the lifting drive unit 338 while referring to the measurement value of the Z coordinate of the lower stage 332 by the first measuring device 370, thereby moving the lower stage 332 by the amount of movement in the Z-axis direction included in the relative movement amount calculated as described above.

[0097] 6 and 7 are schematic diagrams of the bonding unit 300 for explaining the operation of the bonding unit 300 in the second time period according to the substrate bonding method according to one embodiment.

[0098] 5, as shown in Fig. 6, the control device 301 operates the air cylinder unit 326 to move the lifting arm unit 325 and the filling cover unit 327 in the direction indicated by the white arrow in Fig. 6, thereby lowering the lifting arm unit 325 and the filling cover unit 327 to the most negative side in the Z-axis direction. As a result, the filling cover unit 327 surrounds the substrates 210 and 230 from the sides, all around the entire periphery of the substrates 210 and 230, which are held facing each other by the upper stage 322 and the lower stage 332.

[0099] The control device 301 according to this embodiment outputs a command to the gas control unit 302, and replaces the gas supplied by the gas supply unit 350 into the bonding unit 300 via the fixed piping unit 321 with the atmosphere present between the substrates 210 and 230 before the substrates 210 and 230 to be bonded come into contact with each other (step S106).

[0100] As an example of a specific method for replacing the atmosphere between the substrates 210 and 230 with the above-mentioned gas, the control device 301 outputs a command to the gas control unit 302 to stop supplying gas between the substrates 210 and 230 until the control device 301 starts to control the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 by the second measuring device 380. The control device 301 further outputs a command to the gas control unit 302 to start supplying gas between the substrates 210 and 230 after the control device 301 starts to control the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 by the second measuring device 380.

[0101] Here, when aligning the substrates 210 and 230, the distance between the substrates 210 and 230 is typically narrowed to minimize stage movement after alignment and prevent misalignment between the substrates 210 and 230. If the distance is narrow, there is a risk that the gas supplied between the substrates 210 and 230 by the gas supply unit 350 will not fill the space between the substrates 210 and 230 quickly and sufficiently due to viscosity.

[0102] Therefore, as a specific example, after bringing the substrates 210 and 230 to be bonded together face to face, the control device 301 may widen the gap between the substrates 210 and 230 held by the upper stage 322 and the lower stage 332 before replacing the atmosphere between the substrates 210 and 230 with gas from the gas supply unit 350. For example, the control device 301 may cause the gas control unit 302 to supply gas while the lower stage 332 is moved outside the above-mentioned predetermined range. For example, the control device 301 may move the lower stage 332 in the negative direction of the Z axis to widen the gap between the substrates 210 and 230 from 0.8 mm to several tens of mm, and then issue a command to the gas control unit 302 to supply gas between the substrates 210 and 230.

[0103] As a specific processing procedure in this case, the control device 301 first records the measurement value of the position of the lower stage 332 by the second measurement device 380 in response to the lower stage 332 having moved into the above-mentioned predetermined range, or in response to the measurement value of the position of the lower stage 332 by the first measurement device 370 having fallen into the predetermined range. The control device 301 then moves the lower stage 332 to increase the distance between the substrate 210 and the substrate 230.

[0104] The control device 301 then controls the gas control unit 302 to supply gas between the substrate 210 and the substrate 230 in response to the lower stage 332 moving outside the predetermined range. The control device 301 then controls the gas control unit 302 to supply gas between the substrate 210 and the substrate 230 in response to the supply of gas between the substrate 210 and the substrate 230 satisfying the predetermined condition, and then controls the movement of the lower stage 332 using the measurement value of the second measurement device 380 to form a contact area between the substrate 210 and the substrate 230. The predetermined condition may be, for example, that the amount of gas supplied has reached a predetermined threshold amount, or alternatively or additionally, that the elapsed time since the supply of gas between the substrate 210 and the substrate 230 began, i.e., the gas supply time, has reached a predetermined threshold length.

[0105] Measurement using an interferometer is capable of measuring over a wide range, but is susceptible to the effects of air fluctuations and changes in the environmental refractive index. On the other hand, measurement using an encoder has a measurable range of close distances, such as 0.8 mm or less, and is therefore less susceptible to disturbances such as air fluctuations. If an attempt were made to control all of the movements of the lower stage 332 using only the second measurement device 380 including an encoder, without using the first measurement device 370 including an interferometer, a long scale would be required, which would not only reduce design freedom but also increase costs due to its complex structure.

[0106] In contrast, as described above, the control device 301 does not supply gas between the substrates 210 and 230 until it starts to control the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 by the second measurement device 380 including an encoder, that is, while it is controlling the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 by the first measurement device 370 including an interferometer. The control device 301 further switches the means for measuring the position of the lower stage 332 from the first measurement device 370 including an interferometer to the second measurement device 380 including an encoder before gas is filled between the substrates 210 and 230 to be bonded. This allows the substrate bonding apparatus 100 to align the substrates 210 and 230 with high precision by suppressing the influence of disturbances such as air fluctuations, while preventing a complex structure and increased costs.

[0107] The substrate bonding apparatus 100 also widens the gap between the substrates 210 and 230 before replacing the atmosphere between the substrates 210 and 230 to be bonded with gas from the gas supply unit 350, thereby enabling the gas from the gas supply unit 350 to quickly and sufficiently fill the gap between the substrates 210 and 230.

[0108] However, if the gap between the substrates 210 and 230 is large enough to allow gas to be filled when the alignment of the two substrates 210 and 230 is complete, or when the detection of the alignment marks on the two substrates 210 and 230 is complete, it is not necessary to further widen the gap between the substrates 210 and 230 before replacing the gas.

[0109] As a specific example of a case where the gap between the substrates 210 and 230 is not further widened before the gas is replaced, the gas control unit 302 may start supplying gas between the substrates 210 and 230 when the filling cover unit 327 surrounds the substrates 210 and 230 from the sides, without moving the lower stage 332 after the alignment of the two substrates 210 and 230 is completed, as shown in FIG. 6 .

[0110] As another example of a case where the gap between the substrates 210 and 230 is not further increased before gas replacement, the gas control unit 302 may start supplying gas when detection of the alignment marks of the two substrates 210 and 230 is completed, i.e., when the substrates 210 and 230 are not facing each other in a plan view from the positive side of the Z axis. In this case, the measurable range of the position of the lower stage 332 by the second measurement device 380 in at least one of the X-axis and Y-axis directions may be increased to, for example, approximately the width of the substrate holding surface of the lower stage 332, so that the control device 301 starts controlling the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 by the second measurement device 380 before starting gas supply. Note that when gas is supplied when the substrates 210 and 230 are not facing each other, the control device 301 does not need to lower the lifting arm unit 325 and the filling cover unit 327 to the negative side of the Z axis.

[0111] 6 , as shown in FIG. 7 , the control device 301, while at least referring to the measurement value of the position of the lower stage 332 by the second measurement device 380, operates the elevation driver 338 to move the lower stage 332, thereby bringing a portion of the substrate 230 into contact with a portion of the substrate 210. As a result, the control device 301 forms a contact area between the substrate 210 and the substrate 230, and further expands the contact area to bond the substrates 210 and 230 together (step S107), and this flow ends. In addition, in step S107, if the first measurement device 370 continues to measure the position of the lower stage 332 during the second time period, the control device 301 may operate the elevation driver 338 to move the lower stage 332 while referring to the measurement value of the Z coordinate of the lower stage 332 by the first measurement device 370.

[0112] More specifically, first, the substrates 210 and 230 are brought close to each other, and portions of the substrates 210 and 230 are brought into contact with each other, forming a contact region at the already activated contact point. Furthermore, by releasing the substrate 210 from the upper stage 322 via the substrate holder 220, the regions adjacent to the contact point autonomously adhere to each other due to the intermolecular forces between the activated surfaces, and a bonding wave (also called a bonding wave) is generated in which the contact region gradually spreads radially outward from the substrates 210 and 230. As a result, the substrates 210 and 230 are bonded together in a state in which the substrate 230 is deformed to conform to the central convex shape of the substrate holder 240, for example.

[0113] Fig. 8 is a schematic plan view of the arrangement of the first measuring device 370 and the second measuring device 380 in the substrate bonding apparatus 100 according to one embodiment. Figs. 9 and 10 are schematic side views of the arrangement of the first measuring device 370 and the second measuring device 380 in the substrate bonding apparatus 100 according to one embodiment, and correspond to the plan view of Fig. 8. Fig. 9 is a side view of the arrangement shown in Fig. 8 as seen from the negative side of the X axis, and Fig. 10 is a side view of the arrangement shown in Fig. 8 as seen from the positive side of the Y axis. In Figs. 8 to 10, the substrate holder 240 and the substrate 230 held on the lower stage 332 are indicated by dashed lines for reference of their positional relationship.

[0114] 8 , the substrate bonding apparatus 100 of this embodiment includes four first interferometers 371A, 371B, 371C, and 371D as first interferometers 371 of the first measuring device 370 that measure the position of the lower stage 332. The substrate bonding apparatus 100 of this embodiment further includes three second measuring devices 380A, 380B, and 380C as second measuring devices 380 that measure the position of the lower stage 332.

[0115] The first interferometers 371A, 371B, and 371C are fixed to the side walls of the frame 310 of the bonding unit 300. The first interferometer 371D is fixed to an area of ​​the substrate holding surface of the upper stage 322 where the substrate holder 220 and the like are not located.

[0116] At least the side surface on the negative side of the X axis, the side surface on the positive side of the Y axis, and the substrate holding surface on the positive side of the Z axis of the lower stage 332 are flat reflective surfaces that totally reflect the light beam 372. Alternatively, mirrors may be provided on these surfaces of the lower stage 332.

[0117] 8 to 10 , the first interferometer 371A is, for example, a double-pass interferometer, and irradiates four light beams 372 along the X axis in the above-described Cartesian coordinate system onto the side surface of the lower stage 332 on the negative side of the X axis. As shown in Fig. 9 , of the four light beams 372 from the first interferometer 371A, two light beams 372 are spaced apart from each other in the Z axis direction. Note that, in a plan view from the positive side of the Z axis, the four light beams 372 from the first interferometer 371A pass through the origin of the Cartesian coordinate system, i.e., near the center point of the substrate 210 held by the upper stage 322.

[0118] 8 to 10, the first interferometer 371B is disposed offset to the positive Y-axis side of the first interferometer 371A, and irradiates two light beams 372 along the X-axis in the Cartesian coordinate system onto the negative X-axis side surface of the lower stage 332. Note that, in a plan view from the positive Z-axis side, the two light beams 372 from the first interferometer 371B do not pass near the origin of the Cartesian coordinate system.

[0119] 8 to 10 , the first interferometer 371C is, for example, a double-pass interferometer, and irradiates four light beams 372 along the Y axis of a Cartesian coordinate system onto the side surface of the lower stage 332 on the Y-axis positive side. As shown in Fig. 10 , of the four light beams 372 from the first interferometer 371C, two light beams 372 are spaced apart from each other in the Z-axis direction. Note that, in a plan view from the Z-axis positive side, the four light beams 372 from the first interferometer 371C pass near the origin of the Cartesian coordinate system.

[0120] 8 to 10 , the first interferometer 371D irradiates a light beam 372 along the Z axis of the Cartesian coordinate system onto the substrate holding surface on the Z axis positive side of the lower stage 332. In a plan view from the Z axis positive side, the light beam 372 from the first interferometer 371D does not pass near the origin of the Cartesian coordinate system and does not interfere with the substrate holder 240 and the substrate 230.

[0121] The first interferometer 371A and the first interferometer 371B having the above configuration measure the X coordinate of the lower stage 332 in the Cartesian coordinate system and output it to the control device 301. The first interferometer 371C having the above configuration measures the Y coordinate of the lower stage 332 in the Cartesian coordinate system and output it to the control device 301. The first interferometer 371D having the above configuration measures the Z coordinate of the lower stage 332 in the Cartesian coordinate system and output it to the control device 301.

[0122] The control device 301 may acquire, at least during the first time period, an X coordinate based on two sets of light rays 372 spaced apart in the Z-axis direction of the first interferometer 371A as the X coordinate of the lower stage 332. The X coordinate based on the two sets of light rays 372 may be a coordinate intermediate between the X coordinate based on one set of light rays 372 and the X coordinate based on the other set of light rays 372.

[0123] The control device 301 may calculate the rotation angle around the Y axis of the lower stage 332 from the difference between the X coordinate based on one of two sets of light rays 372 spaced apart in the Z axis direction of the first interferometer 371A and the X coordinate based on the other set, at least during the first time period.

[0124] The control device 301 may calculate, at least during the first time period, the rotation angle of the lower stage 332 about the Z axis based on the difference between the X coordinate from the first interferometer 371A and the X coordinate from the first interferometer 371B. The X coordinate from the first interferometer 371A here refers to the pair of light rays 372 that are located in approximately the same XY plane as the light rays 372 from the first interferometer 371B, out of two pairs of light rays 372 that are spaced apart in the Z axis direction of the first interferometer 371A.

[0125] The control device 301 may acquire, at least during the first time period, a Y coordinate based on two sets of light rays 372 spaced apart in the Z-axis direction of the first interferometer 371C as the Y coordinate of the lower stage 332. The Y coordinate based on the two sets of light rays 372 may be a coordinate intermediate between the Y coordinate based on one set of light rays 372 and the Y coordinate based on the other set of light rays 372.

[0126] The control device 301 may calculate the rotation angle of the lower stage 332 around the X axis from the difference between the Y coordinate based on one of two sets of light rays 372 spaced apart in the Z axis direction of the first interferometer 371C and the Y coordinate based on the other set, at least during the first time period.

[0127] The control device 301 may acquire the Z coordinate from the first interferometer 371D as the Z coordinate of the lower stage 332 at least during the first time period.

[0128] The encoder of the second measurement device 380 may be disposed at a position overlapping the optical axis of the interferometer of the first measurement device 370, for example, the first interferometer 371, in a plan view from the positive side of the Z axis. More specifically, as shown in FIG. 8 , the encoders of the second measurement device 380A, the second measurement device 380B, and the second measurement device 380C may be disposed at a position overlapping the optical axis of the first interferometer 371A, the first interferometer 371B, and the first interferometer 371C, respectively, in a plan view from the positive side of the Z axis. This enables the control device 301 to easily perform a transfer calculation from the measurement value of the position of the lower stage 332 measured by the first measurement device 370 to the measurement value of the position of the lower stage 332 measured by the second measurement device 380. Furthermore, if it is possible to convert the measurement value of the position of the lower stage 332 by the first measurement device 370 into the measurement value of the position of the lower stage 332 by the second measurement device 380, that is, if the relative positions of the coordinates of the measurement point of the lower stage 332 by the first measurement device 370 and the coordinates of the measurement point of the lower stage 332 by the second measurement device 380 are known, the encoder of the second measurement device 380 does not need to be positioned in a position that overlaps with the optical axis of the interferometer of the first measurement device 370 when viewed in a plane from the positive side of the Z axis.

[0129] The second measuring device 380A having the above configuration measures the relative position of the lower stage 332 with respect to the upper stage 322 in the X-axis direction, and outputs the result to the control device 301. The second measuring device 380B having the above configuration measures the relative rotation angle of the lower stage 332 with respect to the upper stage 322 about the Z-axis, and outputs the result to the control device 301. The second measuring device 380C having the above configuration measures the relative position of the lower stage 332 with respect to the upper stage 322 in the Y-axis direction, and outputs the result to the control device 301.

[0130] The control device 301 may acquire, during the second time period, a measurement value from the second measuring device 380A as the relative position in the X-axis direction of the lower stage 332 with respect to the upper stage 322. The control device 301 may acquire, during the second time period, a measurement value from the second measuring device 380B as the relative rotation angle about the Z-axis of the lower stage 332 with respect to the upper stage 322. The control device 301 may acquire, during the second time period, a measurement value from the second measuring device 380C as the relative position in the Y-axis direction of the lower stage 332 with respect to the upper stage 322.

[0131] The encoder of the second measuring device 380 has a scale 382 provided on the surface of one of the lower stage 332 and the upper stage 322, and a detection head 383 that detects the scale 382. The detection head 383 is provided on at least one of the other of the lower stage 332 and the upper stage 322, and the frame 310 that holds the other stage. In this embodiment, the encoders of the second measuring device 380A, the second measuring device 380B, and the second measuring device 380C each have a scale 382 provided on the lower stage 332 and a detection head 383 provided on the upper stage 322. As an example, the scale 382 of the encoder is provided on the surface of the lower stage 332. The detection head 383 of the encoder may measure the relative position of the lower stage 332 with respect to the upper stage 322 as in this embodiment, or alternatively, may measure the absolute position of the lower stage 332. For example, if the upper stage 322 is movable, for example, rotatable, the detection head 383 may measure the absolute position of the lower stage 332. When the detection head 383 measures the absolute position of the lower stage 332, the detection head 383 may be provided, for example, on the frame 310 that holds the upper stage 322. Note that, for the sake of clarity of explanation, Figures 8 to 10 do not show the upper stage 322, and instead show the detection head 383 fixed to the upper stage 322. Note that the detection head 383 is an example of a detection head that detects a detection target.

[0132] During measurement, the distance between a detection head of the second measurement device 380, for example, the detection head 383, and the detection target, for example, the scale 382, ​​is shorter than the distance between a detection head of the first measurement device 370, for example, the first interferometer 371 or the second interferometer 376, and the detection target, for example, the lower stage 332 or the upper stage 322 (or a reflecting mirror if the lower stage 332 and the upper stage 322 are provided with a reflecting mirror). As a more specific example, in the second measurement device 380, the detection head 383 detects the scale 382 within a distance range of 0.8 mm or less from the scale 382. The scale 382 is one-dimensional and capable of measuring the position in one direction. Alternatively, a two-dimensional scale 382 may be used and capable of measuring the position in two directions. The scale 382 has a length such that at least a portion of the measurable range of the second measuring device 380 overlaps with the range measured by the first measuring device 370, so that when switching from measurement by the first measuring device 370 to measurement by the second measuring device 380, the coordinates of the lower stage 332 measured by the first measuring device 370 can be carried over to measurement by the second measuring device 380.

[0133] As described above, according to the substrate bonding apparatus 100 of this embodiment, at least at the time of forming the contact area between the substrates 210 and 230, the movement of the lower stage 332 is controlled using the measurement values ​​from the second measuring device 380, which is different from the first measuring device 370 used before forming the contact area. As a result, even if a disturbance that affects the measurement accuracy of the first measuring device 370 occurs when forming the contact area, there may be cases where the disturbance does not affect the second measuring device 380. In this case, the measurement accuracy can be improved compared to when the first measuring device 370 is used continuously before and after forming the contact area.

[0134] Furthermore, at least at the time when a contact area is formed between the substrates 210 and 230, the movement of the lower stage 332 is controlled using measurement values ​​from the second measuring device 380, which has higher measurement accuracy than the first measuring device 370 used before the contact area is formed. This makes it possible for the substrate bonding apparatus 100 to be less susceptible to the influence of disturbances at the time when the contact area is formed, compared to when the same measuring means, for example, an interferometer, is used to control the movement of the movable stage before the stages are brought face to face and the substrates are bonded.

[0135] 11 is a schematic plan view of the arrangement of a first measuring device 370 and a second measuring device 380 in a substrate bonding apparatus 102 according to another embodiment. The substrate bonding apparatus 102 according to this embodiment differs from the substrate bonding apparatus 100 according to the embodiment described with reference to FIGS. 1 to 9 in that the bonding unit 300 includes an upper stage 622 that is rotatably supported by the top plate 316 of the frame 310, instead of the upper stage 322 fixed to the top plate 316 of the frame 310, and the second interferometer 376 of the first measuring device 370 irradiates light toward the upper stage 622 from a direction intersecting the axes of the Cartesian coordinate system. Other components of the substrate bonding apparatus 102 according to this embodiment are similar to the corresponding components of the substrate bonding apparatus 100, and therefore the same reference numerals as those of the substrate bonding apparatus 100 are used, and redundant description will be omitted.

[0136] Unlike Fig. 8, Fig. 11 illustrates a portion of the upper stage 622. As shown in Fig. 11, the detection head 383 of the second measuring device 380 is fixed to the top plate 316 of the frame 310 on the side of the upper stage 622. In Fig. 11, as in Fig. 8, the substrate holder 240 and the substrate 230 held on the lower stage 332 are indicated by dashed lines for reference of the positional relationship.

[0137] The upper stage 622 has a generally circular outline centered on the Z axis when viewed from the positive Z axis side, and has three corner cube mirrors 378 arranged at 120-degree intervals around its outer periphery. All three corner cube mirrors 378 are positioned at a distance r from the center of the upper stage 622. In FIG. 11 , the distance r from the center of the upper stage 622 for each corner cube mirror 378 is indicated by a hollow arrow. Note that at least one of the three corner cube mirrors 378 does not necessarily have to be positioned at the distance r from the center of the upper stage 622; that is, two or all of the three corner cube mirrors 378 may be positioned at different distances from the center of the upper stage 622. Note that the upper stage 622 may include a prism instead of the corner cube mirrors 378.

[0138] The first measurement device 370 includes an interferometer that measures the position of one of the rotatable stages, the lower stage 332 and the upper stage 622, and the interferometer irradiates light toward the one stage from a tangential direction of the rotational orbit of the one stage. In this embodiment, the first measurement device 370 includes a second interferometer 376 that measures the position of the rotatable upper stage 622, and the second interferometer 376 irradiates light beam 377 toward the upper stage 622 from a tangential direction of the rotational orbit of the upper stage 622 about the Z axis. More specifically, the first measurement device 370 includes three second interferometers 376: second interferometer 376A, second interferometer 376B, and second interferometer 376. The second interferometers 376A and 376B are, for example, linear interferometers. Note that the tangential direction may be a direction that coincides with a tangent to the rotational orbit of the rotatable stage, or may be a direction that forms an angle of less than 90 degrees with respect to the tangent.

[0139] The second interferometers 376A, 376B, and 376 correspond to the three corner cube mirrors 378 provided on the upper stage 622, respectively. The second interferometers 376A, 376B, and 376 are configured to irradiate light beams 377 toward the corresponding corner cube mirrors 378 and receive the light beams 377 reflected by the corner cube mirrors 378. The second interferometers 376A, 376B, and 376 are each positioned so that the angle between the light beams 377 is 60 degrees, in accordance with the three corner cube mirrors 378 that are arranged at 120-degree intervals around the Z axis. Note that the second interferometers 376A and 376B may be arranged in a manner other than that shown in FIG. 11 . For example, they may be arranged at 120-degree intervals or 90-degree intervals around the Z axis.

[0140] In this embodiment, the first measurement device 370 has three second interferometers 376A and the like configured so that the angle formed between the mutual light rays 377 is 60 degrees, but instead, the first measurement device 370 may have a combination of one or two second interferometers 376 that irradiate light toward the upper stage 622 from a tangential direction of the rotational orbit of the upper stage 622 about the Z axis, and two or one second interferometers 376 that irradiate the light rays 377 onto the side surface of the upper stage 622 along any axis of the Cartesian coordinate system, similar to the first interferometer 371. When the first measurement device 370 has two or more second interferometers 376 that irradiate light toward the upper stage 622 from a tangential direction of the rotational orbit of the upper stage 622 about the Z axis, the two or more second interferometers 376 are arranged so that the angle formed between the light rays 377 from the two or more second interferometers 376 is equal to or greater than 0 degrees and less than 90 degrees.

[0141] The control device 301 controls the rotational movement of the upper stage 622 about the Z axis by a rotation drive unit (not shown) using the measurement values ​​of the position of the upper stage 622 obtained by the second interferometer 376A, the second interferometer 376B, and the second interferometer 376. The control device 301 calculates a change in the rotation angle of the upper stage 622 about the Z axis with respect to a Cartesian coordinate system from the measurement values ​​of the position of the upper stage 622 obtained by the second interferometer 376A, the second interferometer 376B, and the second interferometer 376. The control device 301 may additionally calculate changes in the X coordinate and the Y coordinate of the upper stage 622 with respect to the Cartesian coordinate system from the measurement values ​​of the position of the upper stage 622 obtained by the second interferometer 376A, the second interferometer 376B, and the second interferometer 376.

[0142] Specifically, if the converted length measurement values ​​of second interferometer 376A, second interferometer 376B, and second interferometer 376 are defined as U3, U1, and U2, control device 301 may calculate a rotation angle change ΔTz about the Z axis relative to the Cartesian coordinate system using the formula: ΔTz = arcsin((U1 + U2 + U3) / (3 × r)). Control device 301 may calculate an X coordinate change ΔX relative to the Cartesian coordinate system using the formula: ΔX = (U3 - U2) / √3. Control device 301 may calculate a Y coordinate change ΔY relative to the Cartesian coordinate system using the formula: ΔY = (2 × U1 - U2 - U3) / 3.

[0143] In the substrate bonding apparatus 102 of this embodiment, after measuring the alignment of the substrates 210 and 230, the control device 301 corrects the rotational positional deviation between the substrates 210 and 230 by rotating the upper stage 622, then fixes the upper stage 622 and again measures the alignment of the substrates 210 and 230. Then, as in the above-described substrate bonding apparatus 100, the control device 301 aligns and bonds the substrates 210 and 230 by finely controlling the six-axis movement of the lower stage 332 so as to reduce the positional deviation between the substrates 210 and 230. As a result, the substrate bonding apparatus 102 of this embodiment can reduce the amount of drive error of the lower stage 332 when bonding the substrates 210 and 230, and can further reduce the bonding error of the substrates 210 and 230.

[0144] The substrate bonding apparatus 102 according to this embodiment also achieves the same effects as the substrate bonding apparatus 100 according to the embodiment described with reference to Figures 1 to 9. According to the substrate bonding apparatus 102 according to this embodiment, since the upper stage 622 is rotatable about the Z axis, the second interferometer 376 of the first measurement device 370 uses second interferometers 376A, 376B, and 376C that measure the position of the upper stage 622 by irradiating light toward the upper stage 622 from a tangential direction of the rotational orbit of the upper stage 622. As a result, according to the substrate bonding apparatus 102 according to this embodiment, even when there is a large positional deviation between the substrates 210 and 230 in the rotational direction and it is necessary to increase the amount of rotation of the upper stage 622 about the Z axis to correct the positional deviation, it is possible to measure the position of the upper stage 622 with high accuracy.

[0145] In this embodiment, only the second interferometer 376, which measures the position of the upper stage 622, is configured to have an interferometer that measures the position of the rotatable stage by irradiating light toward the stage from the tangent direction of the rotational orbit of the stage, but the first interferometer 371, which measures the position of the lower stage 332, may also have such an interferometer.

[0146] In the above embodiments, the gas control unit 302 may start supplying gas when the substrate 210 and the substrate 230 do not face each other in a plan view from the positive side of the Z axis, and in this case, the measurable range of the position of the lower stage 332 by the second measuring device 380 in at least one of the X-axis and Y-axis directions may be increased to, for example, approximately the width of the substrate holding surface of the lower stage 332 so that the control device 301 starts controlling the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 by the second measuring device 380 before starting gas supply. Alternatively, it is not necessary to start controlling the movement of the lower stage 332 using the measurement value of the position of the lower stage 332 by the second measuring device 380 before supplying gas when the substrates 210 and 230 do not face each other, and in this case, control of the movement of the lower stage 332 may continue using the measurement value of the position of the lower stage 332 by the first measuring device 370 even when gas is filled between the substrates 210 and 230.

[0147] In the above embodiments, it has been described that, during the second time period, the second measurement device 380 measures the relative position in the X-axis direction, the relative rotation angle about the Z-axis, and the relative position in the Y-axis direction of the lower stage 332 with respect to the upper stage 322, and in addition, the first measurement device 370 may measure the Z coordinate in a Cartesian coordinate system of the lower stage 332 and values ​​for calculating the rotation angle about the X-axis and the rotation angle about the Y-axis. Alternatively, during the second time period, the second measurement device 380 may measure the relative position in the X-axis direction and the Y-axis direction of the lower stage 332 with respect to the upper stage 322, and the first measurement device 370 may measure the Z coordinate in the Cartesian coordinate system of the lower stage 332. Alternatively, during the second time period, the second measurement device 380 may measure the relative position in the X-axis direction, the relative rotation angle about the Z-axis, the relative position in the Y-axis direction, and the relative position in the Z-axis direction of the lower stage 332 with respect to the upper stage 322, and the first measurement device 370 may measure values ​​for calculating the rotation angle about the X-axis and the rotation angle about the Y-axis. In order to measure the relative position in the Z-axis direction of the lower stage 332 with respect to the upper stage 322, the second measurement device 380 may have a scale 382 provided on a side surface of one of the upper stage 322 and the lower stage 332, a detection head 383 provided on a side surface of the other stage, and an encoder in which the detection surface of the detection head 383 faces the scale 382.

[0148] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0149] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order.

[0150] 100, 102 Substrate bonding apparatus 101 Control unit 110 Housing 120, 130 Substrate cassette 140 Transport unit 170 Activation device 201 Laminated substrate 210, 230 Substrate 220, 240 Substrate holder 300 Bonding unit 301 Control unit 302 Gas control unit 310 Frame 312 Bottom plate 316 Top plate 321 Fixed piping unit 322, 622 Upper stage 323 Filling top plate 324, 334 Microscope 325 Lifting arm unit 326 Air cylinder unit 327 Filling cover unit 328 Sealing member 331 X-direction driving unit 332 Lower stage 333 Y-direction driving unit 338 Lifting driving unit 341 Side wall 343 Top plate 345 1000 Region [Other Possible Items] [Item 1] A substrate bonding apparatus for bonding a first substrate and a second substrate together, comprising: a first stage that holds the first substrate; a second stage that holds the second substrate; a control device that controls movement of at least the first stage; a first measurement device that measures the position of the first stage; and a second measurement device that measures the position of the first stage, wherein the control device 2. A substrate bonding apparatus according to claim 1, wherein the movement is controlled using a measurement value of the position by the first measuring device during a first time period prior to a time point at which a contact region is formed between the first substrate and the second substrate, and the movement is controlled using a measurement value of the position by the second measuring device during a second time period after the first time period and including at least the time point.[Item 3] The substrate bonding apparatus of item 1, wherein the first measuring device and the second measuring device each include a detection head that detects a detection target, and wherein the distance between the detection head of the second measuring device and the detection target during measurement is smaller than the distance between the detection head of the first measuring device and the detection target during measurement. [Item 4] The substrate bonding apparatus of item 1, wherein the second time period includes a time period from when the first substrate and the second substrate are brought face to face until they are brought into contact. [Item 5] The substrate bonding apparatus of item 1, wherein the first time period includes a time period for measuring alignment marks provided on the first substrate and the second substrate. [Item 6] The substrate bonding apparatus of item 1, wherein the first measuring device continues measuring the position while forming the contact region between the first substrate and the second substrate. [Item 7] The substrate bonding apparatus of item 1, wherein the second measuring device includes an encoder that measures the position of the first stage. [Item 8] The substrate bonding apparatus according to item 7, wherein the encoder has a scale provided on one of the first stage and the second stage, and a detection head that detects the scale. [Item 9] The substrate bonding apparatus according to item 8, wherein the detection head is provided on at least one of the other of the first stage and the second stage and a frame that holds the other stage. [Item 10] The substrate bonding apparatus according to item 8 or 9, wherein the first measurement device includes an interferometer that irradiates light from a side of the first stage toward the first stage, and the encoder is disposed at a position overlapping with the optical axis of the interferometer. [Item 11] The substrate bonding apparatus according to item 8, wherein the detection head detects the scale within a distance range of 0.8 mm or less from the scale.[Item 12] The substrate bonding apparatus of item 1, wherein the first measurement device includes a first interferometer that measures the position of the first stage from a side of the first stage and a second interferometer that measures the position of the second stage from a side of the second stage, and the control device controls the first stage during the first time period using a measurement value of the position of the second stage measured by the second interferometer. [Item 13] The substrate bonding apparatus of item 1, wherein the first measurement device includes an interferometer that measures the position of one of the first and second stages that is rotatable, and the interferometer irradiates the one stage with light from a tangential direction of a rotational orbit of the one stage. [Item 14] The substrate bonding apparatus of item 1, wherein the control device starts controlling the movement using the measurement value of the position measured by the second measurement device in response to the first stage moving within a predetermined range in which the position can be measured by the second measurement device. [Item 15] The substrate bonding apparatus of Item 14, wherein the control device starts controlling the movement using the position measurement value by the second measuring device in response to the position measurement value by the first measuring device falling within the predetermined range. [Item 16] The substrate bonding apparatus of Item 14, further comprising a gas control unit that controls gas supplied between the first substrate and the second substrate, wherein the gas control unit does not supply the gas between the first substrate and the second substrate until the control device starts controlling the movement using the position measurement value by the second measuring device, and starts supplying the gas between the first substrate and the second substrate after the control device starts controlling the movement using the position measurement value by the second measuring device. [Item 17] The substrate bonding apparatus of Item 16, wherein the gas control unit supplies the gas when the first substrate and the second substrate do not face each other. [Item 18] The substrate bonding apparatus of Item 16, wherein the gas control unit supplies the gas when the first stage is moved outside the predetermined range.Item 19. The substrate bonding apparatus according to Item 16, wherein the control device records the measurement value of the position by the second measuring device in response to the first stage moving into the predetermined range or in response to the measurement value of the position by the first measuring device falling within the predetermined range, moves the first stage to increase the gap between the first substrate and the second substrate, causes the gas control unit to supply the gas between the first substrate and the second substrate in response to the first stage moving out of the predetermined range, and moves the first stage to the position corresponding to the recorded measurement value in response to the supply of the gas between the first substrate and the second substrate satisfying a predetermined condition, and then forms the contact region between the first substrate and the second substrate by controlling the movement using the measurement value of the position by the second measuring device. [Item 20] A substrate bonding apparatus that bonds a first substrate and a second substrate together, comprising: a first stage that holds the first substrate; a second stage that holds the second substrate; a control device that controls movement of at least the first stage; and an interferometer and an encoder that measure a position of the first stage, wherein the control device controls the movement using a value measured by the interferometer of the position during a first time period before a point in time when a contact region is formed between the first substrate and the second substrate, and controls the movement using a value measured by the encoder of the position during a second time period after the first time period and including at least the point in time. [Item 21] A substrate bonding method for bonding a first substrate and a second substrate together, comprising: controlling movement of the stage using a measurement value obtained by a first measurement device that measures the position of a stage holding one of the first substrate and the second substrate during a first time period before a time point at which a contact region is formed between the first substrate and the second substrate; and controlling the movement using a measurement value obtained by a second measurement device that measures the position of the stage during a second time period after the first time period and including at least the time point.

Claims

1. A substrate bonding apparatus for bonding a first substrate and a second substrate together, comprising: a first stage for holding the first substrate; a second stage for holding the second substrate; a first measurement device for measuring a position of the first stage; and a second measurement device for measuring the position of the first stage, wherein the first measurement device includes a first detection head for detecting a first detection object, one of the first detection object and the first detection head is located on the first stage, and the other of the first detection object and the first detection head is located outside the first stage, the second measurement device includes a second detection head for detecting a second detection object, one of the second detection object and the second detection head is located on the first stage, and the other of the second detection object and the second detection head is located on the second stage, and the second measurement device measures the position of the first stage in a state where a distance between the second detection object and the second detection head is smaller than a distance between the first detection object and the first detection head.

2. A substrate bonding apparatus as described in claim 1, further comprising a control device which switches measurement of the position of the first stage from measurement by the first measuring device to measurement by the second measuring device when the distance between the second detection object and the second detection head is smaller than the distance between the first detection object and the first detection head.

3. A substrate bonding apparatus that bonds a first substrate and a second substrate together, comprising: a first stage that holds the first substrate; a second stage that holds the second substrate; a first measuring device that measures a position of the first stage; and a second measuring device that measures the position of the first stage, wherein the first stage is movable between a first range in which the second measuring device can measure the position of the first stage and a second range in which the second measuring device cannot measure the position of the first stage, and the first measuring device is capable of measuring the position of the first stage in each of the first range and the second range.

4. A substrate bonding apparatus as described in claim 3, further comprising a control device which uses the position of the first stage measured by the first measuring device to move the first stage to the first range, and which uses the position of the first stage measured by the second measuring device to bond the first substrate and the second substrate together.

5. The substrate bonding apparatus of claim 4, further comprising a detection device that detects an index of the first substrate held by the first stage, the detection device detecting the index when aligning the first substrate and the second substrate to be bonded together, wherein the control device uses the index to bond the first substrate and the second substrate to each other when the first stage is positioned within the first range, and the detection device detects the index when the first stage is positioned within the second range.

6. A substrate bonding apparatus for bonding a first substrate and a second substrate together, comprising: a first stage for holding the first substrate; a second stage for holding the second substrate; a control device for controlling at least movement of the first stage; a first measuring device for measuring a position of the first stage; and a second measuring device for measuring the position of the first stage, wherein the control device controls the movement using a measurement value of the position by the first measuring device during a first time period prior to a time point at which a contact area is formed between the first substrate and the second substrate, and controls the movement using a measurement value of the position by the second measuring device during a second time period after the first time period and including at least the time point.

7. The substrate bonding apparatus according to any one of claims 1 to 6, wherein the second measuring device measures the position of the first stage with higher measurement accuracy than the first measuring device.

8. A substrate bonding apparatus according to any one of claims 1 to 6, wherein the first measuring device and the second measuring device each include a detection head that detects a detection object, and the distance between the detection head of the second measuring device and the detection object during measurement is smaller than the distance between the detection head of the first measuring device and the detection object during measurement.

9. The substrate bonding apparatus according to claim 6, wherein the second time period includes a time period from when the first substrate and the second substrate are brought face to face with each other until they are brought into contact with each other.

10. The substrate bonding apparatus according to claim 6, wherein the first time period includes a time period for measuring alignment marks provided on the first substrate and the second substrate.

11. The substrate bonding apparatus according to any one of claims 1 to 6, wherein the first measuring device continues measuring the position while a contact area is being formed between the first substrate and the second substrate.

12. The substrate bonding apparatus according to any one of claims 1 to 6, wherein the second measurement device includes an encoder that measures the position of the first stage.

13. The substrate bonding apparatus according to claim 12, wherein the encoder comprises: a scale provided on one of the first stage and the second stage; and a detection head for detecting the scale.

14. The substrate bonding apparatus according to claim 13, wherein the detection head is provided on at least one of the other of the first stage and the second stage, and a frame that holds the other stage.

15. A substrate bonding apparatus as described in claim 13 or 14, wherein the first measurement device includes an interferometer that irradiates light toward the first stage from the side of the first stage, and the encoder is positioned so as to overlap with the optical axis of the interferometer.

16. The substrate bonding apparatus according to claim 13, wherein the detection head detects the scale within a distance range of 0.8 mm or less from the scale.

17. The substrate bonding apparatus described in claim 6, wherein the first measurement device includes a first interferometer that measures the position of the first stage from a side of the first stage, and a second interferometer that measures the position of the second stage from a side of the second stage, and the control device controls the first stage using a measurement value of the position of the second stage measured by the second interferometer during the first time period.

18. A substrate bonding apparatus as described in any one of claims 1 to 6, wherein the first measurement device includes an interferometer that measures the position of one of the first and second stages which is rotatably movable, and the interferometer irradiates light towards the one of the stages from a tangential direction of the rotational orbit of the one of the stages.

19. The substrate bonding apparatus according to claim 6, wherein the control device starts controlling the movement using a measurement value of the position by the second measuring device in response to the first stage moving into a predetermined range within which the position can be measured by the second measuring device.

20. The substrate bonding apparatus according to claim 19, wherein the control device starts controlling the movement using the position measurement value obtained by the second measuring device in response to the position measurement value obtained by the first measuring device falling within the predetermined range.

21. A substrate bonding apparatus as described in claim 19, further comprising a gas control unit that controls the gas supplied between the first substrate and the second substrate, wherein the gas control unit does not supply the gas between the first substrate and the second substrate until the control device starts to control the movement using the position measurement value by the second measuring device, and starts supplying the gas between the first substrate and the second substrate after the control device starts to control the movement using the position measurement value by the second measuring device.

22. The substrate bonding apparatus according to claim 21, wherein the gas control unit supplies the gas in a state in which the first substrate and the second substrate do not face each other.

23. The substrate bonding apparatus according to claim 21, wherein the gas control unit supplies the gas in a state in which the first stage is moved outside the predetermined range.

24. The substrate bonding apparatus of claim 21, wherein the control device records the measurement value of the position by the second measuring device in response to the first stage moving into the predetermined range or in response to the measurement value of the position by the first measuring device falling within the predetermined range, moves the first stage to widen the gap between the first substrate and the second substrate, causes the gas control unit to supply the gas between the first substrate and the second substrate in response to the first stage moving out of the predetermined range, and moves the first stage to the position corresponding to the recorded measurement value in response to the supply of the gas between the first substrate and the second substrate satisfying a predetermined condition, and then forms the contact area between the first substrate and the second substrate by controlling the movement using the measurement value of the position by the second measuring device.

25. The substrate bonding apparatus according to claim 6, wherein the first measurement device includes an interferometer, and the second measurement device includes an encoder.

26. A substrate bonding method for bonding a first substrate and a second substrate together, comprising: controlling movement of the stage using a measurement value obtained by a first measuring device that measures a position of a stage holding either the first substrate or the second substrate during a first time period prior to a time when a contact region is formed between the first substrate and the second substrate; and controlling the movement using a measurement value obtained by a second measuring device that measures the position of the stage during a second time period after the first time period and including at least the first time period.

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