JP6268702B2 - Substrate processing apparatus and substrate processing method - Google Patents

Description

  The present invention relates to a substrate processing apparatus and a substrate processing method.

In manufacturing a semiconductor element, a substrate or the like is aligned with high accuracy using an interferometer (see Patent Document 1).
[Patent Document 1] JP 2010-147253 A

  When superposing a plurality of substrates, the alignment accuracy of the substrates may decrease due to the vibration of the interferometer itself.

  In the first aspect of the present invention, a substrate processing apparatus for superimposing a first substrate and a second substrate on each other, a first stage for holding the first substrate, a second substrate, A second stage that moves toward the first stage and overlaps the first substrate and the second substrate; an interferometer that is coupled to the first stage and measures the position of the second stage; and A displacement detector that detects displacement of the interferometer caused by contact between the first substrate and the second substrate due to movement, and a correction unit that corrects the measurement result of the interferometer based on the detection result of the displacement detector. A substrate processing apparatus is provided.

  In the second aspect of the present invention, the second stage holding the second substrate is moved toward the first stage holding the first substrate to overlap the first substrate and the second substrate. A substrate processing method for measuring a position of a second stage with an interferometer coupled to a first stage, and detecting displacement of the interferometer caused by contact between the first substrate and the second substrate. There is provided a substrate processing method including a detection stage and a correction stage for correcting the measurement result of the measurement stage using the detection result of the detection stage.

  The above summary of the present invention does not enumerate all necessary features of the present invention. A sub-combination of these feature groups can also be an invention.

1 is a schematic plan view of a substrate bonding apparatus 10. FIG. 2 is a perspective view of a substrate 210. FIG. 5 is a perspective view of a substrate holder 220. FIG. It is sectional drawing which shows the state transition of the board | substrate 210. FIG. It is sectional drawing which shows the state transition of the board | substrate 210. FIG. It is sectional drawing which shows the state transition of the board | substrate 210. FIG. It is sectional drawing which shows the state transition of the board | substrate 210. FIG. 2 is a schematic cross-sectional view of an aligner 150. FIG. 2 is a schematic cross-sectional view of an aligner 150. FIG. 2 is a schematic cross-sectional view of an aligner 150. FIG. 3 is a partially enlarged schematic view of an aligner 150. FIG. 3 is a schematic plan view of an aligner 150. FIG. It is a typical sectional view of other aligner 401. It is a typical sectional view of other aligner 402. It is a typical sectional view of other aligner 403.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a schematic plan view of the substrate bonding apparatus 10. A stacked substrate 230 is manufactured by bonding the pair of substrates 210 together. Examples of the substrate 210 to be bonded include a silicon wafer, a compound semiconductor wafer, and a glass substrate. Further, the substrate 210 to be bonded may be a substrate having a laminated structure manufactured by bonding.

  The substrate bonding apparatus 10 includes an atmospheric environment unit 100 and a vacuum environment unit 300. The atmospheric environment unit 100 includes transfer robots 130, 160, 180, a pre-aligner 140, an aligner 150, a separation unit 170, and a holder rack 190 housed in the environment chamber 110. Inside the environmental chamber 110, the temperature, humidity, etc. of a clean atmosphere are managed.

  A control unit 112 and a substrate cassette 120 are disposed outside the environmental chamber 110. The control unit 112 controls the entire operation of the substrate bonding apparatus 10 and also controls individual operations of the transfer robots 130, 160, 180, the pre-aligner 140, the aligner 150, the separation unit 170, and the like. Therefore, for example, the correction unit 114 that operates as a part of the aligner 150 is also included in the control unit.

  The substrate cassette 120 accommodates a substrate 210 to be bonded and a laminated substrate 230 manufactured by bonding. The substrate cassette 120 can be removed from the substrate bonding apparatus 10 and used as a container when the substrate 210 or the laminated substrate 230 is transported.

  In the atmospheric environment unit 100, the pre-aligner 140 causes the substrate holder 220 to hold the substrate 210 taken out from the substrate cassette 120. The aligner 150 has a fixed stage 151 and a moving stage 152 that face each other, and aligns and superposes a pair of substrates 210 held by the substrate holder 220. The holder rack 190 accommodates unused substrate holders 220.

  The separation unit 170 separates the laminated substrate 230 manufactured by bonding the substrates 210 from the substrate holder 220. The substrate holder 220 separated from the laminated substrate 230 may be stored in the holder rack 190 and waited, or may be transported to the pre-aligner 140 to hold the next substrate 210.

  Each of the transfer robots 130, 160, and 180 includes fingers 132, 162, and 182 and arms 134, 164, and 184. The fingers 132, 162, and 182 hold at least one of the substrate 210, the substrate holder 220, and the laminated substrate 230. The arms 134, 164, 184 support and move the fingers 132, 162, 182.

  The transfer robot 130 that is disposed in the immediate vicinity of the substrate cassette 120 and is surrounded by the pre-aligner 140, the aligner 150, and the holder rack 190 sequentially carries the substrate holder 220 and the substrate 210 into the pre-aligner 140. Further, the transfer robot 130 carries the substrate holder 220 holding the substrate 210 in the pre-aligner 140 into the aligner 150. Further, the transfer robot 130 carries the laminated substrate 230 separated from the substrate holder 220 in the separation unit 170 into the substrate cassette 120.

  The transfer robot 160 arranged on the opposite side of the transfer robot 130 with respect to the aligner 150 transfers the stack 201 formed by overlapping the substrate holder 220 holding the substrate 210 in the aligner 150 to the vacuum environment unit 300. To do. Further, the transfer robot 160 carries the laminated body 201 processed in the vacuum environment unit 300 to the atmospheric environment unit 100 again.

  The transfer robot 180 arranged along the side of the aligner 150 in the drawing moves the substrate holder 220 and the stacked substrate 230 separated by the separation unit 170 from the stacked body 201 carried out by the transfer robot 160 to the substrate cassette 120 side. Transport toward you.

  The vacuum environment unit 300 in the substrate bonding apparatus 10 includes a load lock 310, a robot chamber 320, a heating and pressing unit 340, and a cooling chamber 360. The load lock 310 allows communication between the inside of the environmental chamber 110 in the atmospheric environment unit 100 and the inside of the robot chamber 320 of the vacuum environment unit 300.

  The load lock 310 has an access door 312 and a gate valve 314 that open and close individually. Therefore, by supplying or exhausting air while both the access door 312 and the gate valve 314 are closed, the interior of the load lock 310 can be made an atmospheric environment or a vacuum environment.

  When the interior of the load lock 310 is in an atmospheric environment, the load lock 310 and the atmospheric environment unit 100 can be communicated with each other by opening the access door 312 with the gate valve 314 closed. As a result, the transfer robot 160 can carry the laminate 201 into or out of the load lock 310 while maintaining the environment of the atmospheric environment unit 100.

  Further, when the inside of the load lock 310 is in a vacuum environment, the load lock 310 can be communicated with the vacuum environment unit 300 by opening the gate valve 314 with the access door 312 closed. Accordingly, the stacked body 201 can be carried into or out of the load lock 310 from the vacuum environment unit 300 side while the environment of the vacuum environment unit 300 is maintained by the transfer robots 330 and 350.

  The robot chamber 320 includes a pair of transfer robots 330 and 350 that are individually controlled. Each of the transfer robots 330 and 350 includes fingers 332 and 352 that hold the stacked body 201, and arms 334 and 354 that support and move the fingers 332 and 352.

  The plurality of heating and pressurizing units 340 and the single cooling chamber 360 have heat insulating containers 349 and 369, respectively, and communicate with the robot chamber 320 individually. The heating and pressurizing unit 340 and the cooling chamber 360 and the robot chamber 320 can be hermetically blocked by gate valves 342 and 362 that can be individually opened and closed. Thereby, the heating and pressurizing unit 340 and the cooling chamber 360 can independently maintain individual temperature environments.

  The heating and pressing unit 340 includes a heating unit and a pressing unit, and heats and pressurizes the loaded stacked body 201. As a result, the substrates 210 stacked in the stacked body 201 are bonded together to form a single stacked substrate 230. Note that the heating and pressing unit 340 may have a function of cooling the stacked body 201 after heating and pressing to some extent. Thereby, the temperature change which each arises with the laminated body 201 carried out from the heat pressurization part 340 and the laminated body 201 carried in into the heat pressurization part 340 can be suppressed.

  The cooling chamber 360 cools the temperature of the stacked body 201 carried out from the heating and pressurizing unit 340 to a temperature substantially equal to the environmental temperature of the atmospheric environment unit 100. Thereby, while preventing the increase in the thermal load of the atmospheric environment part 100, the temperature change of the laminated body 201 carried in from the vacuum environment part 300 to the atmospheric environment part 100 can be suppressed.

  In the vacuum environment unit 300, when one of the transfer robots 330 and 350 carries out the stacked body 201 from one of the heating and pressurizing units 340, the other of the transfer robots 330 and 350 heats the other stacked body 201. The pressure part 340 can be immediately carried in. Thereby, the waiting time of the heating and pressing unit 340 can be shortened, and the throughput of the substrate bonding apparatus 10 can be improved.

  FIG. 2 is a conceptual perspective view of a pair of substrates 210 to be bonded together in the substrate bonding apparatus 10. Each of the substrates 210 has a disk shape that is partially cut out by the notch 214. Each of the substrates 210 has a plurality of element regions 216 and a plurality of alignment marks 218.

  The notch 214 is provided as an index indicating the crystal orientation of the substrate 210 and the like. Therefore, the pre-aligner 140 detects the direction of the element region 216 formed in the substrate 210 by detecting the position of the notch 214.

  The element region 216 is periodically arranged on the surface of the substrate 210. Each element region 216 is provided with a semiconductor element formed by a photolithography technique or the like. Each element region 216 also includes pads, bumps, and the like that serve as connection terminals when the substrate 210 is bonded to another substrate 210.

  In the substrate 210, there is a blank area where no functional elements such as elements and circuits are arranged between the plurality of element areas 216. A scribe line 212 that is cut when the substrate 210 is cut into the element regions 216 is disposed in the blank region.

  Furthermore, on the scribe line 212, an alignment mark 218 serving as an index when the substrate 210 to be bonded is aligned is disposed. Since the scribe line 212 disappears as a saw margin in the process of cutting the substrate 210 into a die, the effective area of the substrate 210 is not pressed by providing the alignment mark 218.

  Although the element regions 216 and the alignment marks 218 are drawn large in the drawing, the number of element regions 216 formed on the substrate 210 having a diameter of 300 mm, for example, may reach several hundreds or more. In some cases, a wiring pattern or the like formed in the element region 216 is used as the alignment mark 218.

  FIG. 3 is a perspective view of a pair of substrate holders 220 used when a pair of substrates 210 are bonded inside the substrate bonding apparatus 10. The aligner 150 is an example of a substrate processing apparatus.

  The substrate holder 220 is formed of a hard material such as alumina ceramics. Each of the substrate holders 220 has circular holding surfaces 227 and 228 that are in contact with the substrate 210 to be held, and edge portions 221 and 222 that extend radially outward of the holding surfaces 227 and 228.

  In each of the substrate holders 220, electrostatic chuck electrodes 225 and 226 that attract the substrate 210 are embedded in the holding surfaces 227 and 228. Thereby, the substrate holder 220 adsorbs and holds the substrate 210, respectively.

  In the set of substrate holders 220, one has a magnet piece 223 disposed on the edge portion 221, and the other has a magnetic piece 224 disposed on the edge portion 222. Accordingly, the pair of substrate holders 220 can autonomously maintain a state of being coupled to each other with the substrate 210 interposed therebetween.

  4, FIG. 5, FIG. 6 and FIG. 7 are diagrams showing the transition of the substrate 210 to the laminated substrate 230 in the substrate bonding apparatus 10 step by step. The operation of the substrate bonding apparatus 10 will be described with reference to these drawings.

  As shown in FIG. 4, each of the substrates 210 to be bonded is mounted on the substrate holder 220 one by one in the pre-aligner 140. At this stage, the substrate 210 is held on the substrate holder 220 by the electrostatic force of the electrostatic chuck.

  The substrate holder 220 holding the substrate 210 in the pre-aligner 140 is carried into the aligner 150 by the transfer robot 130. In the aligner 150, the substrate holder 220 held by the fixed stage 151 and the substrate holder 220 held by the moving stage face each other as shown in FIG. Accordingly, the pair of substrates 210 to be bonded also face each other.

  Subsequently, in the aligner 150, the pair of substrates 210 are aligned and overlapped. Thereby, as shown in FIG. 6, a laminate 201 is formed by the pair of substrates 210 and the pair of substrate holders 220.

  In the stacked body 201, the pair of substrate holders 220 are coupled by the magnet pieces 223 and the magnetic body pieces 224 that are attracted to each other, and maintain the relative position of the pair of stacked substrates 210. However, in the stacked body 201 at the stage of being unloaded from the aligner 150, the pair of substrates 210 is merely overlapped, and is not bonded.

  Such a laminate 201 is heated and pressurized in the heating and pressing unit 340. Thus, the pair of substrates 210 included in the stacked body 201 are bonded to each other to form the stacked substrate 230. As shown in FIG. 7, the substrate 210 that has become the laminated substrate 230 is separated from the substrate holder 220 by the separation unit 170 and stored in the substrate cassette 120.

  In the above example, the substrate holder 220 having the magnet piece 223 is drawn on the upper side, and the substrate holder 220 having the magnetic piece 224 is drawn on the lower side. However, the arrangement of the substrate holder 220 is not limited to this. Further, the member that couples the pair of substrate holders 220 is not limited to the combination of the magnet piece 223 and the magnetic piece 224, and a clip or the like that elastically holds the pair of substrate holders 220 may be used. .

  Further, in the above-described substrate bonding apparatus 10, the laminated substrate 230 is formed by bonding the substrates 210 overlapped in the aligner 150 in the heating and pressing unit 340. However, for example, if the substrate 210 is highly mirror-polished, the laminated substrate 230 can be formed by superposition in the aligner 150 without heating and pressing. Alternatively, the stacked substrate 230 can be formed by bonding the substrates 210 using an adhesive.

  FIG. 8 is a schematic longitudinal sectional view of an aligner 150 included in the substrate bonding apparatus 10. The aligner 150 includes a frame body 159, a fixed stage 151, a moving stage 152, and an upper interferometer unit 410. The correction unit 114 provided in the control unit 112 also forms part of the aligner 150.

  The frame 159 forms a rectangular parallelepiped space that accommodates other members. The fixed stage 151 is fixed downward in the figure with respect to the ceiling surface of the frame body 159 via the load cell 259. Further, the microscope 255 and the reflecting mirror 412 are fixed to the side of the fixed stage 151.

  The fixed stage 151 has an adsorption device such as an electrostatic chuck or a vacuum chuck, and adsorbs and holds the substrate holder 220 holding the substrate 210. As a result, in the aligner 150, the substrate 210 is held downward on the fixed stage 151.

  The load cell 259 detects the magnitude of the load by detecting deformation that occurs in the strain generating body when a load is applied from below to the substrate 210 held on the fixed stage 151. The microscope 255 observes the alignment mark 218 on the substrate 210 that passes under the fixed stage 151.

  The moving stage 152 is supported by a coarse movement unit 251, a fine movement unit 252, an elevating unit 253, and a swinging unit 254 that are sequentially stacked from the bottom surface of the frame body 159. The coarse moving unit 251 and the fine moving unit 252 move the moving stage 152 in the X direction and the Y direction indicated by arrows in the drawing, respectively. Thereby, the moving stage 152 can move two-dimensionally in the aligner 150. The coarse moving unit 251 and the fine moving unit 252 preferably set the horizontal driving position for transmitting the horizontal driving force to the moving stage 152 at the same height as the center of gravity of the moving stage 152.

  The elevating unit 253 moves the moving stage 152 in the Z direction indicated by an arrow in the drawing. Further, the swinging part 254 changes the inclination of the moving stage 152 with respect to the horizontal plane. By controlling the coarse movement unit 251, the fine movement unit 252, the elevating unit 253, and the swinging unit 254 as control targets, the substrate 210 mounted on the moving stage 152 can be moved toward the target position.

  A microscope 255 is fixed upward on the side of the moving stage 152. The microscope 255 can observe the alignment mark 218 on the substrate 210 at a position facing the moving stage 152. A reflecting mirror 414 is also fixed to the side of the moving stage 152.

  The reflecting mirror 414 fixed to the moving stage 152 reflects the measurement beam generated by the upper interferometer unit 410 and returns it to the upper interferometer unit 410 again. The upper interferometer unit 410 also receives the reflected light by irradiating the length measuring beam to the reflecting mirror 412 of the fixed stage 151. Thereby, the upper interferometer unit 410 can detect the relative position of the fixed stage 151 and the movable stage 152 with high accuracy.

  The reflecting mirror 414 has a height that covers the amount of movement of the moving stage 152. Therefore, even if the moving stage 152 moves up and down, the upper interferometer unit 410 can receive the measurement beam reflected by the reflecting mirror 414.

  The moving stage 152 has a suction device such as an electrostatic chuck or a vacuum chuck, and sucks and holds the substrate holder 220 holding the substrate 210. As a result, in the aligner 150, the substrate 210 is held upward on the moving stage 152.

  In the board | substrate bonding apparatus 10, the control part 112 refers to the length measurement value by the upper interferometer unit 410, and controls the movement amount of the fine movement part 252 with high precision. However, the movement speed of fine movement part 252 is lower than the movement speed of coarse movement part 251.

  The moving stage 152 is supported from the elevating unit 253 via a spherical seat. Therefore, the moving stage 152 can be rotated around the X, Y, and Z axes in addition to translational movements in the X, Y, and Z directions indicated by arrows in the drawing.

  FIG. 9 shows a state where the moving stage 152 has moved to a position facing the fixed stage 151 in the aligner 150. That is, in the substrate bonding apparatus 10, the control unit 112 first moves the moving stage 152 to a position facing the fixed stage 151 using the coarse moving unit 251. In addition, the control unit 112 detects misalignment between the substrate 210 held on the fixed stage 151 and the substrate 210 held on the moving stage 152 using the microscopes 255 and 255 in the process of moving the moving stage 152. To do.

  The relative position of the upper microscope 255 with respect to the fixed stage 151 is known in advance and does not change due to the operation of the aligner 150. Therefore, the control unit 112 can accurately detect the relative position between the substrate 210 and the fixed stage 151 by observing the alignment mark 218 of the substrate 210 held on the moving stage 152 with the microscope 255.

  Similarly, the relative position of the lower microscope 255 with respect to the moving stage 152 is known in advance and does not change due to the operation of the aligner 150. Therefore, the control unit 112 can detect the relative position between the substrate 210 and the moving stage 152 by observing the alignment mark 218 of the substrate 210 held on the fixed stage 151 with the microscope 255.

  Furthermore, the control unit 112 can initialize the relative positions of the microscopes 255 and 255 by causing the pair of microscopes 255 and 255 to face each other. Therefore, the control unit 112 can calculate the positional deviation amount of the pair of substrates 210 based on the initialized relative position. Further, the control unit 112 moves and swings the moving stage 152 by the fine moving unit 252 and the swinging unit 254 so as to compensate for the detected positional deviation amount, and the substrate 210 held on the fixed stage 151 and the moving stage. The substrate 210 held by 152 is aligned.

  FIG. 10 is a schematic cross-sectional view of the aligner 150. In the aligner 150, the elevating unit 253 moves the moving stage 152 up and down in the Z direction indicated by an arrow in the drawing. When the pair of opposing substrates 210 are aligned, the control unit 112 raises the moving stage 152 by the elevating unit 253 so that the pair of substrates 210 are in close contact with each other and overlap each other. In this way, the stacked body 201 is formed by the pair of substrates 210 and the pair of substrate holders 220 sandwiching the substrates.

  In the formation of the stacked body 201, the elevating unit 253 raises the substrate 210 mounted on the moving stage 152 toward the substrate 210 held on the fixed stage 151. Thereby, a pair of board | substrates are piled up. Therefore, in the aligner 150, the lower surface of the substrate 210 held on the fixed stage 151 coincides with the overlapping surface of the substrate 210.

  When the substrate 210 is superimposed on the aligner 150, the control unit 112 lowers the moving stage 152 after releasing the suction of the substrate holder 220 by the fixed stage 151. As a result, the stacked body 201 is separated from the fixed stage 151, so that it can be unloaded from the aligner 150 by the transfer robot 160. The stacked body 201 carried out is carried into the load lock 310 by the transfer robot 160.

  Note that the control unit 112 detects the position of the moving stage 152 by length measurement using the upper interferometer unit 410 and the moving stage 152 based on the detected position while the moving stage 152 rises toward the fixed stage 151. Continue feedback control. For this reason, in the process of superimposing the substrates 210, the moving stage 152 may move while the substrate 210 held by the fixed stage 151 and the substrate 210 held by the moving stage 152 are in contact with each other. In such a case, the strain body of the load cell 259 undergoes elastic deformation due to the displacement of the moving stage 152, and the fixed stage 151 vibrates.

  The vibration of the fixed stage 151 is also transmitted to the upper interferometer unit 410 through the frame body 159. When the upper interferometer unit 410 vibrates, the position detection accuracy of the moving stage 152 by the upper interferometer unit 410 decreases, and the alignment accuracy of the substrate 210 also decreases. Further, when waiting for the vibration of the fixed stage 151 to be attenuated for the purpose of avoiding a decrease in detection accuracy of the upper interferometer unit 410, the processing time in the aligner 150 increases, and the overall throughput of the substrate bonding apparatus 10 decreases. . However, by correcting the measurement value of the upper interferometer unit 410 by the correction unit 114, it is possible to prevent a decrease in detection accuracy.

  FIG. 11 is a schematic diagram for explaining a correction method by the correction unit 114. In the aligner 150, the upper interferometer unit 410 has a plurality of interferometers that irradiate at least four length measuring beams UTYR, UYR, WYR, and WTYR toward reflecting mirrors 412 and 414 as subjects.

  The four measurement beams UTYR, UYR, WYR, and WTYR are irradiated toward the reflecting mirrors 412 and 414 in parallel within a common vertical plane. The two length measuring beams UTYR and UYR are applied to the reflecting mirror 412 fixed to the fixed stage 151, and the other two length measuring beams WYR and WTYR are reflected to the reflecting mirror 414 fixed to the moving stage 152. Irradiated towards.

Here, the second measuring beam UYR has a vertical interval Δh ₁ with respect to the measuring beam UTYR having the optical path at the top in the drawing. Similarly, the third length measuring beam WYR has a vertical interval Δh ₂ with respect to the length measuring beam UTYR. Further, the bottom measurement beam WTYR has a vertical interval Δh ₃ with respect to the measurement beam UTYR.

When the upper interferometer unit 410 as described above is tilted by vibration, the distance to the reflecting mirror 412 measured by the measuring beam UYR is relative to the distance to the reflecting mirror 412 measured by the measuring beam UTYR. The difference Δx _{1 is} excessive. Similarly, the distance to the reflecting mirror measured by the length measuring beam WYR is larger than the difference Δx _{2 with} respect to the distance to the reflecting mirror 412 measured by the measuring beam UTYR. Further, the distance to the reflecting mirror measured by the length measuring beam WTYR becomes a difference Δx ₃ excessively with respect to the distance to the reflecting mirror 412 measured by the length measuring beam UTYR.

Here, the value of the difference [Delta] x ₁ includes a length measurement value _{D (UYR)} by measurement beams UYR, nothing but the difference between _{D (UTYR)} by measurement beam UTYR. Therefore, when the distance to the reflecting mirror 412 measured by the length measuring beam UYR is a measured value to the reflecting mirror 412 measured by the length measuring beam UTYR, the difference Δx ₁ is expressed by the following formula 1. Can be calculated.
Δx ₁ = D _(UYR) −D _(UTYR) Equation 1

Further, the difference Δx ₂ can be calculated from the difference Δx ₁ by the following equation 2 in consideration of the vertical interval Δh ₂ that changes depending on the position of the moving stage 152.
Δx ₂ = (Δx ₁ / Δh ₁ ) × Δh ₂ Formula 2

Similarly, the difference Δx ₃ can be calculated from the difference Δx ₁ by the following expression 3 in consideration of the vertical interval Δh ₃ that changes depending on the position of the moving stage 152.
Δx ₃ = (Δx ₁ / Δh ₁ ) × Δh ₃ ...

Thus, when the differences Δx ₁ , Δx ₂ , and Δx ₃ generated in the length measurement values due to the vibration of the upper interferometer unit 410 are calculated, the correction unit 114 corrects the length measurement values by the respective interferometers, and the fixed stage 151 And a correction value that accurately reflects the relative position of the moving stage 152 can be calculated. That is, the correction value A _(UYR) of the length measurement value D _(UYR) by the length measurement beam UYR can be calculated by the following equation 4.
A _(UYR) = D _(UYR) −Δx _1.

Further, the correction value A _(WYR) of the length measurement value D _(WYR) by the length measurement beam WYR can be calculated by the following equation ₍₅₎ .
A _(WYR) = D _(WYR) −Δx ₂ Expression 5

Further, the correction value A _(WTYR) of the length measurement value D _(WTYR) by the length measurement beam WTYR can be calculated by the following equation ₍₆₎ .
A _(WTYR) = D _(WTYR) −Δx _3.

The control unit 112 uses the correction values A _(UYR) , A _(WYR) , and A _(WTYR) calculated as described above, and uses the correction value A _(WTYR) as a reference to correct the correction value A _(UYR) and the correction value A _(UYR). By executing the feedback control so that the value A _(WYR) coincides with the value A _(WYR) , a decrease in accuracy due to vibration of the upper interferometer unit 410 can be avoided.

  When the upper interferometer unit 410 is tilted by vibration, the length measurement beam is also tilted. However, the inclination of the upper interferometer unit 410 due to vibration is small, and the error of the measurement value caused by the inclination is extremely small compared to the measurement value. Therefore, the above example has been described without considering the inclination of the measurement beam.

  Note that a heterodyne interferometer may be used as the upper interferometer unit 410. The heterodyne interferometer converts the phase of the interference fringes into the phase of the electrical signal by measuring the optical heterodyne by applying a frequency shift between a pair of interfering beams. Thereby, the heterodyne interferometer can suppress the influence of the spatial or temporal fluctuation of the light intensity and can obtain a high accuracy exceeding 1/100 of the wavelength of the length measurement beam.

  FIG. 12 is a schematic plan view showing a planar layout of the upper interferometer units 410, 411, and 413 in the aligner 150. The aligner 150 is provided with other upper interferometer units 411 and 413 in addition to the upper interferometer unit 410 described above.

  The upper interferometer unit 411 located on the left side in the drawing with respect to the moving stage 152 irradiates a measuring beam parallel to the measuring beam of the upper interferometer unit 410 toward the reflecting mirror 414. Thereby, based on the measurement results of the two upper interferometer units 410 and 411, the amount of rotation of the moving stage 152 around the rotation axis perpendicular to the paper surface indicated by the arrow θ in the drawing can be detected.

  In addition, the upper interferometer unit 413 positioned below the moving stage 152 in the drawing has a length measurement beam in a direction orthogonal to the length measurement beam of the upper interferometer unit 410 as another reflection fixed to the movement stage 152. Irradiate towards mirror 416. The reflecting mirror 416 has a reflecting surface orthogonal to the reflecting mirror 414 on which the upper interferometer units 410 and 411 emit the measurement beam on the surface of the moving stage 152. Therefore, the upper interferometer unit 413 can detect the displacement of the moving stage 152 in the vertical direction of the paper, indicated by the arrow Y in the drawing.

  As described above, in the aligner 150, the control unit 112 includes the plurality of upper interferometer units 410, 411, and 413, thereby detecting the translational motion and the rotational motion of the moving stage 152 in the XY plane and performing feedback control. Can be executed. In each of the plurality of upper interferometer units 410, 411, and 413, feedback control can be executed with high accuracy by correcting the length measurement result by the method shown in FIG.

  FIG. 13 is a schematic cross-sectional view of an aligner 401 having another structure. The aligner 401 includes a lower interferometer unit 420 in addition to the upper interferometer unit 410 that measures the position of the moving stage 152.

  The lower interferometer unit 420 has an interferometer that is fixed to the bottom surface of the frame body 159 and irradiates the upper interferometer unit 410 with a measurement beam. Accordingly, the lower interferometer unit 420 detects the displacement of the upper interferometer unit 410 with respect to the frame body 159.

  Therefore, the correction unit 114 refers to the measurement result of the lower interferometer unit 420 and corrects the measurement result of the upper interferometer unit 410, thereby eliminating the influence of vibration of the upper interferometer unit 410 and moving stage 152. Can be accurately feedback controlled. Thus, apart from the upper interferometer unit 410 that measures the position of the moving stage 152, the lower interferometer unit 420 that detects displacement due to vibration of the upper interferometer unit 410 itself is provided, and the displacement of the upper interferometer unit 410 is changed. May be measured.

  FIG. 14 is a schematic cross-sectional view of an aligner 402 having another structure. The aligner 402 includes an acceleration sensor 430 together with the upper interferometer unit 410 that measures the position of the moving stage 152. The acceleration sensor 430 is integrally fixed to the upper interferometer unit 410, and detects the acceleration of the upper interferometer unit 410 itself when the upper interferometer unit 410 vibrates.

  Therefore, the correction unit 114 in the aligner 402 calculates the displacement of the upper interferometer unit 410 based on the acceleration of the upper interferometer unit 410 detected by the acceleration sensor 430, and uses the calculation result to measure the upper interferometer unit 410. Correct the result. Thereby, the influence of the vibration of the upper interferometer unit 410 can be eliminated, and the moving stage 152 can be accurately feedback-controlled. Thus, apart from the upper interferometer unit 410 that measures the position of the moving stage 152, the lower interferometer unit 420 that detects displacement due to vibration of the upper interferometer unit 410 itself is provided, and the displacement of the upper interferometer unit 410 is changed. May be measured.

  FIG. 15 is a schematic cross-sectional view of an aligner 403 having another structure. The aligner 403 is different from the other aligners 150, 401, and 402 in that it includes a reflecting mirror 418. The reflecting mirror 418 is fixed to the top plate of the frame body 159 in the direction facing the upper interferometer unit 410.

  The upper interferometer unit 410 includes three reflecting mirrors 412 and 414 including a reflecting mirror 412 fixed to the fixed stage 151, a reflecting mirror 414 fixed to the moving stage 152, and a reflecting mirror 418 fixed to the frame body 159. A length measurement beam is projected using 418 as a subject. Thereby, the upper interferometer unit 410 measures the position of the fixed stage 151 as the relative position of the fixed stage 151 with respect to the reflecting mirror 418. The upper interferometer unit 410 measures the position of the moving stage 152 as the relative position of the moving stage 152 with respect to the reflecting mirror 418.

  Thus, in the aligner 403, the upper interferometer unit 410 measures the positions of the fixed stage 151 and the moving stage 152 with respect to the reflecting mirror 418, which is a common reference. Therefore, when the measurement value of the upper interferometer unit 410 is corrected, the measurement beam projected toward the reflecting mirror 418 is also corrected. Thereby, the influence of the vibration of the upper interferometer unit 410 can be eliminated, and the moving stage 152 can be accurately feedback-controlled.

  As described above, by providing the correction unit 114 that detects the vibration of the upper interferometer unit 410 and corrects the measurement result of the upper interferometer unit 410, the vibration of the fixed stage 151 is suppressed, attenuated, and further propagated. Can be prevented. However, when the control system that controls the movement of the moving stage 152 vibrates or oscillates, even if the vibration of the upper interferometer unit 410 is suppressed or prevented, the alignment of the substrate 210 cannot be completed. Therefore, when vibration or oscillation of the control system is detected or predicted, it is preferable to stop the alignment of the substrate 210.

  In such a case, the control unit 112 lowers the moving stage 152 by the elevating unit 253, and once separates the substrate 210 held by the moving stage 152 and the substrate 210 held by the fixed stage 151. Then, the moving stage 152 may be raised again, and alignment and superposition may be retried.

  When oscillation occurs, the substrate 210 involved in the bonding may be temporarily stored, and the bonding may be retried in combination with, for example, another substrate holder 220 or another substrate 210.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output of the previous process may be realized in any order unless used in a subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 10 Board | substrate bonding apparatus, 100 Atmosphere environment part, 110 Environment chamber, 112 Control part, 114 Correction part, 120 Board cassette, 130, 160, 180, 330, 350 Transfer robot, 132, 162, 182, 332, 352 Finger, 134, 164, 184, 334, 354 Arm, 140 Pre-aligner, 150, 401, 402, 403 Aligner, 151 Fixed stage, 152 Moving stage, 159 Frame, 170 Separating part, 190 Holder rack, 201 Laminate, 210 Substrate, 212 Scribe line, 214 Notch, 216 Element region, 218 Alignment mark, 220 Substrate holder, 221, 222 Edge, 223 Magnet piece, 224 Magnetic body piece, 225, 226 Electrostatic chuck electrode, 227, 228 Holding surface, 23 Laminated substrate, 251 Coarse moving part, 252 Fine moving part, 253 Lifting part, 254 Oscillating part, 255 Microscope, 259 Load cell, 300 Vacuum environment part, 310 Load lock, 312 Access door, 314, 342, 362 Gate valve, 320 Robot Chamber, 340 Heating and pressurizing unit, 349, 369 Thermal insulation container, 360 Cooling chamber, 410, 411, 413 Upper interferometer unit, 412, 414, 416, 418 Reflector, 420 Lower interferometer unit, 430 Acceleration sensor

Claims (5)

A substrate processing apparatus for overlapping a first substrate and a second substrate,
A first stage for holding the first substrate;
A second stage for holding the second substrate and moving toward the first stage to superimpose the first substrate and the second substrate;
A reference object provided separately from the first stage and the second stage ;
A measurement unit for measuring the relative positions of the first stage and the second stage with respect to the reference object ;
A displacement detection unit that detects a displacement of a relative position of the measurement unit with respect to the reference object ;
A correction unit that corrects the positions of the first stage and the second stage measured by the measurement unit based on the detection result of the displacement detection unit;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 1, wherein the reference object is fixed to a frame body on which the first stage is fixed. The displacement detection unit includes an interferometer that irradiates a subject whose position is fixed with respect to the first stage with a length measurement beam,
Wherein the correction unit includes a substrate processing apparatus according to claim 1 or 2, wherein correcting the measurement result of the measurement section based on the relative values of the measurement result by the measuring unit for the measurement result of the subject by the interferometer. The measurement unit is an interferometer that irradiates a measuring beam to a reflecting mirror provided on the second stage,
The subject is a reflecting mirror provided on the first stage;
The displacement detection unit is provided in the measurement unit, and is based on a difference between a distance to the reflecting mirror provided on the first stage and a distance to the reflecting mirror provided on the second stage. To calculate the displacement,
The substrate processing apparatus according to claim 3 , wherein the correction unit corrects a measurement result by the measurement unit based on the difference. A substrate processing method in which a second stage holding a second substrate is moved toward a first stage holding a first substrate to overlap the first substrate and the second substrate,
A measurement stage in which a measurement unit measures a relative position of each of the first stage and the second stage with respect to a reference object provided separately from the first stage and the second stage;
A detection step of detecting a displacement of a relative position of the measurement unit with respect to the reference object ;
A correction step of correcting the positions of the first stage and the second stage measured by the measurement unit using a detection result of the detection step;
A substrate processing method comprising:

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