WO2010023935A1 - Substrate aligning apparatus, substrate aligning method and method for manufacturing multilayer semiconductor - Google Patents

Abstract

A substrate aligning apparatus is provided with: a first stage which shifts in the surface direction of a substrate while holding one of a pair of substrates facing each other; a second stage which holds the other substrate of the pair of substrates; a first microscope which observes an alignment mark of the substrate held by the second stage; a second microscope which observes an alignment mark of the substrate held by the first stage; a calibration indicator observed from both the first microscope and the second microscope; and an alignment control section which aligns the pair of substrates, based on the relative positions of the first microscope and the second microscope obtained by observing the calibration indicator by the first microscope and the second microscope, first positional information which indicates the position of the alignment mark observed by the second microscope, and second positional information which indicates the position of the alignment mark observed by the first microscope.

Description

Substrate alignment apparatus, substrate alignment method, and laminated semiconductor manufacturing method

The present invention relates to a substrate alignment apparatus, a substrate alignment method, and a stacked semiconductor manufacturing method. This application is related to the following Japanese application and claims priority from the following Japanese application. For designated countries where incorporation by reference of documents is permitted, the contents described in the following application are incorporated into this application by reference and made a part of this application.
1. Japanese Patent Application No. 2008-212265 Filing Date August 29, 2008 Patent application 2008-256804 Application date October 1, 2008

There are stacked semiconductor devices in which substrates each having an element formed thereon are stacked (see Patent Documents 1 and 2). The manufacturing process of the stacked semiconductor device includes a step of aligning and bonding a pair of substrates held in parallel with each other while individually observing with a plurality of microscopes (see Patent Document 3). In addition, there is another method and apparatus for aligning a pair of stacked substrates with each other (see Patent Document 4).

JP-A-11-261000 JP 2007-103225 A JP 2005-251972 A US Pat. No. 6,214,692

Alignment in the manufacturing process of a stacked semiconductor device is required to be as accurate as the line width of elements on the substrate. For this reason, in addition to optical resolution, the microscope used for alignment is required to have high accuracy with respect to the position of the microscope itself. Here, the method described in Patent Document 2 aligns a pair of substrates with each other by matching two reference marks formed on each substrate. However, in a substrate on which a circuit is formed through heat treatment or the like, the positional accuracy of the circuit on the substrate is not always uniform. For this reason, even if alignment is performed with high precision at two specific points on the substrate, alignment accuracy may be deteriorated in other portions of the substrate.

Therefore, an object of one aspect of the present invention is to provide a substrate alignment apparatus, a substrate alignment method, and a stacked semiconductor manufacturing method that can solve the above-described problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous specific examples of the present invention.

According to the first aspect of the present invention, the first stage that moves in the surface direction of the substrate while holding one of the pair of substrates facing each other, the second stage that holds the other of the pair of substrates, and the second A first microscope for observing the alignment mark of the substrate held on the stage, a second microscope for observing the alignment mark of the substrate held on the first stage, and a calibration commonly observed from the first microscope and the second microscope A label, a relative position of the first microscope and the second microscope obtained by observing the calibration marker with the first microscope and the second microscope, first position information indicating a position of the alignment mark observed with the second microscope, and An alignment control unit that aligns a pair of substrates based on second position information indicating the position of the alignment mark observed with the first microscope Substrate alignment apparatus comprising a are provided.

In another aspect of the present invention, a detection unit that detects a plurality of alignment marks formed on two substrates that are aligned with each other, a pair of stages that hold the two substrates, and two stages, respectively A drive unit to be moved, and a control unit for controlling the drive of the drive unit, and based on the position of the alignment mark of the two substrates detected by the detection unit, the displacement of the corresponding alignment mark between the two substrates And a control unit that drives the drive unit to align the two substrates, and the control unit includes three or more alignment marks of the two substrates held on the pair of stages. There is provided a substrate alignment apparatus that drives a drive unit to move a pair of stages so that the position is detected by a detection unit.

In another aspect of the present invention, there is provided a method for manufacturing a stacked semiconductor device comprising any one of the above-described substrate alignment apparatuses and a bonding apparatus that pressurizes and bonds a pair of substrates aligned in the substrate alignment apparatus. Provided.

In another aspect of the present invention, a first holding stage in which one of a pair of substrates facing each other is held on a first stage that moves in the surface direction of the substrate, and the other of the pair of substrates is held on a second stage. A second holding stage, a calibration stage for observing with the first microscope and the second microscope to detect a relative position between the first microscope and the second microscope, and a second alignment mark of the substrate held on the first stage. The first detection stage for detecting the first position information indicating the position of the alignment mark observed with a microscope, and the alignment mark of the substrate held on the second stage are observed with the first microscope, and the alignment mark of the alignment mark is detected. A second detection stage for detecting second position information indicating the position, and a position for aligning the pair of substrates according to the difference between the first position information and the second position information; Substrate alignment method comprising the Align step is provided.

In another aspect of the present invention, one of the pair of stages on which each of the pair of substrates is supported is moved, the substrate held on the stage is inserted between the pair of microscopes, and the substrate is paired with the pair of microscopes. The first measurement stage for measuring the relative position of the three or more alignment marks formed on the substrate with respect to the one microscope and the other of the pair of stages are moved and held on the stage. Secondly, the relative position of the three or more alignment marks formed on the substrate with respect to the other microscope is measured by inserting the formed substrate between the pair of microscopes and observing the substrate with the other of the pair of microscopes. Based on the measurement stage and the relative position of the alignment mark relative to the pair of microscopes, the corresponding alignment mark between the pair of substrates Substrate alignment method and an alignment step of moving the pair of the stage so that the position deviation of a minimum throughout is provided.

Note that the above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

1 is a plan view schematically showing the structure of a multilayer substrate manufacturing system 100. FIG. It is a figure which shows typically the transition of the state of the board | substrate 180. FIG. It is a figure which shows typically the transition of the state of the board | substrate 180. FIG. It is a figure which shows typically the transition of the state of the board | substrate 180. FIG. It is a figure which shows typically the transition of the state of the board | substrate 180. FIG. It is a figure which shows typically the transition of the state of the board | substrate 180. FIG. It is a figure which shows the form of the alignment mark 184 typically. 3 is a cross-sectional view schematically showing the structure of the alignment unit 300. FIG. It is a figure which expands and shows a part of alignment part 300 shown in FIG. It is sectional drawing which shows the structure of the reference | standard label | marker 321. FIG. It is sectional drawing which shows the other structure of the reference | standard label | marker 321. FIG. 5 is a flowchart showing an alignment procedure in the alignment unit 300. FIG. 5 is a diagram showing the operation of the alignment unit 300 in contrast to FIG. 4. It is a figure which expands and shows a part of alignment part 300 of the state shown in FIG. FIG. 10 is a diagram illustrating the next operation of the alignment unit 300. It is a figure which shows the next operation | movement of the alignment part 300. FIG. It is a perspective view which shows the structure of the other alignment part 300. FIG. 4 is a plan view of an alignment unit 300. FIG. 6 is a side view showing the operation of the alignment unit 300. FIG. FIG. 11 is a side view showing another operation of the alignment unit 300. FIG. 11 is a side view showing still another operation of the alignment unit 300. FIG. 11 is a side view showing still another operation of the alignment unit 300. It is a top view which shows typically the structure of the other laminated substrate manufacturing apparatus 600 whole. 4 is a perspective view showing a structure of an alignment apparatus 700. FIG. 7 is a perspective view showing one operation of the alignment apparatus 700. FIG. FIG. 11 is a perspective view showing another operation of alignment apparatus 700. FIG. 12 is a perspective view showing still another operation of the alignment apparatus 700. 5 is a flowchart showing a procedure for aligning a substrate 180; It is a figure which shows typically observation of the alignment mark 184. FIG. It is a figure which shows typically observation of the alignment mark 184. FIG. It is a figure which shows typically observation of the alignment mark 184. FIG. It is a figure which shows typically observation of the alignment mark 184. FIG. It is a figure which shows typically observation of the alignment mark 184. FIG. It is a figure which shows typically observation of the alignment mark 184. FIG.

Hereinafter, the (1) aspect of the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the scope of claims, and the features described in the embodiments are as follows. Not all combinations are essential for the solution of the invention.

FIG. 1 is a plan view schematically showing the overall structure of the multilayer substrate manufacturing system 100. The multilayer substrate manufacturing system 100 includes a normal temperature part 102 and a high temperature part 202 formed in a common housing 101.

The room temperature unit 102 has a plurality of substrate cassettes 111, 112, 113 and a control panel 120 facing the outside of the housing 101. The control panel 120 includes a calibration control unit 122 and an alignment control unit 124. Moreover, the control part which controls operation | movement of the multilayer substrate manufacturing system 100 whole is also included. Furthermore, the control panel 120 has an operation unit that is operated by the user from the outside when the multilayer substrate manufacturing system 100 is turned on, various settings, and the like are performed.

The substrate cassettes 111, 112, and 113 accommodate the substrates 180 bonded in the multilayer substrate manufacturing system 100 or the substrates 180 bonded in the multilayer substrate manufacturing system 100. The substrate cassettes 111, 112, and 113 are detachably attached to the housing 101. As a result, a plurality of substrates 180 can be loaded into the laminated substrate manufacturing system 100 at once. Further, the substrates 180 bonded in the multilayer substrate manufacturing system 100 can be collected at a time.

The room temperature unit 102 includes a pre-aligner 130, an alignment unit 300, a substrate holder rack 160, and a pair of robot arms 171 and 172 inside the housing 101. The inside of the housing 101 is temperature-controlled so that a specific temperature substantially the same as the room temperature of the environment in which the multilayer substrate manufacturing system 100 is installed is maintained.

Since the alignment unit 300 is highly accurate and has a narrow adjustment range, the pre-aligner 130 temporarily aligns the positions of the individual substrates 180 so that the substrates 180 are within the narrow adjustment range. Thereby, the positioning in the alignment part 300 can be ensured.

The alignment unit 300 includes an upper stage unit 310 and a lower stage unit 320 that face each other, and a pair of measurement units 330 that are arranged orthogonal to each other. In the alignment unit 300, the upper stage unit 310 and the lower stage unit 320 each transport the substrate 180 or the substrate holder 190 that holds the substrate 180. The measuring unit 330 measures the position of the moving upper stage unit 310 or the lower stage unit 320 in the surface direction of the substrate 180.

Further, a heat insulating wall 142 and a shutter 144 are provided so as to surround the alignment unit 300. The space surrounded by the heat insulating wall 142 and the shutter 144 is communicated with an air conditioner or the like, and the temperature is managed, and the alignment accuracy in the alignment unit 300 is maintained. In the alignment unit 300, the pair of substrates 180 are aligned with each other. The detailed structure and operation of the alignment unit 300 will be described later with reference to FIG.

The substrate holder rack 160 accommodates a plurality of substrate holders 190 and stands by. The substrate holder 190 holds the substrates 180 one by one to facilitate handling of the substrates 180. The substrate 180 is held by the substrate holder 190 by, for example, electrostatic adsorption. Further, the substrate holder rack 160 includes a substrate removal unit. The substrate removing unit takes out the substrate 180 sandwiched between the substrate holders 190 from the substrate holder 190 carried out from the pressurizing unit 240 described later.

The substrate 180 loaded in the multilayer substrate manufacturing system 100 may be a single silicon wafer, compound semiconductor wafer, glass substrate, or the like, in which elements, circuits, terminals, and the like are formed. In addition, the loaded substrate 180 may be a laminated substrate that is already formed by laminating a plurality of wafers.

Of the pair of robot arms 171, 172, the robot arm 171 disposed on the side closer to the substrate cassettes 111, 112, 113 transports the substrate 180 between the substrate cassettes 111, 112, 113, the pre-aligner 130, and the alignment unit 300. To do. The robot arm 171 also has a function of turning over one of the substrates 180 to be joined. Accordingly, the surfaces of the substrate 180 on which circuits, elements, terminals, and the like are formed can be opposed to each other.

The robot arm 172 arranged on the side far from the substrate cassettes 111, 112, 113 carries the substrate 180 and the substrate holder 190 between the alignment unit 300, the substrate holder rack 160 and the air lock 220. The robot arm 172 is also responsible for loading and unloading the substrate holder 190 with respect to the substrate holder rack 160.

The high temperature unit 202 includes a heat insulating wall 210, an air lock 220, a robot arm 230, and a plurality of pressure units 240. The heat insulating wall 210 surrounds the high temperature part 202 to maintain a high internal temperature of the high temperature part 202 and to block heat radiation to the outside of the high temperature part 202. Thereby, the influence which the heat of the high temperature part 202 has on the normal temperature part 102 can be suppressed.

The robot arm 230 conveys the substrate 180 and the substrate holder 190 between one of the pressurizing units 240 and the air lock 220. The air lock 220 includes shutters 222 and 224 that open and close alternately on the normal temperature part 102 side and the high temperature part 202 side.

When the substrate 180 and the substrate holder 190 are carried into the high temperature unit 202 from the normal temperature unit 102, first, the shutter 222 on the normal temperature unit 102 side is opened, and the robot arm 172 carries the substrate 180 and the substrate holder 190 into the air lock 220. . Next, the shutter 222 on the normal temperature part 102 side is closed, and the shutter 224 on the high temperature part 202 side is opened.

Subsequently, the robot arm 230 unloads the substrate 180 and the substrate holder 190 from the air lock 220 and inserts them into one of the pressurizing units 240. The pressurizing unit 240 presses the substrate 180 carried into the pressurizing unit 240 while being sandwiched between the substrate holders 190 with heat. Thereby, the substrate 180 is permanently bonded.

When carrying out the substrate 180 and the substrate holder 190 from the high temperature part 202 to the normal temperature part 102, the above series of operations are executed in reverse order. Through a series of these operations, the substrate 180 and the substrate holder 190 can be carried into or out of the high temperature part 202 without leaking the internal atmosphere of the high temperature part 202 to the normal temperature part 102 side.

Thus, in many areas in the multilayer substrate manufacturing system 100, the substrate holder 190 is transferred to the robot arms 172, 230, the upper stage unit 310, and the lower stage unit 320 while holding the substrate 180. When the substrate holder 190 holding the substrate 180 is transported, the robot arms 172 and 230 attract and hold the substrate holder 190 by vacuum suction, electrostatic suction or the like.

2a, 2b, 2c, 2d, and 2e are diagrams schematically showing the transition of the state of the substrate 180 in the multilayer substrate manufacturing system 100. FIG. As shown in FIG. 2a, at the beginning of the operation of the multilayer substrate manufacturing system 100, each of the substrates 180 is individually accommodated in one of the substrate cassettes 111 and 112, for example. The substrate holder 190 is also individually accommodated in the substrate holder rack 160.

When the multilayer substrate manufacturing system 100 starts operation, the substrate 180 is loaded one by one by the robot arm 171, pre-aligned by the pre-aligner 130, and then mounted on the substrate holder 190. Thus, the substrates 180 are each held by the substrate holder 190.

Next, as shown in FIG. 2b, a pair of substrate holders 190 each holding the substrate 180 is prepared, and as shown in FIG. 2c, the substrate 180 is loaded into the alignment unit 300 so as to face each other. As shown in FIG. 2d, the substrate 180 and the substrate holder 190 aligned in the alignment unit 300 are connected and positioned by a plurality of fasteners 192 fitted in grooves 191 formed on the side surface of the substrate holder 190. Hold the state. The connected substrate 180 and substrate holder 190 are transported integrally and inserted into the pressure unit 240.

When heated and pressurized in the pressurizing unit 240, the substrates 180 are permanently bonded to each other to form a laminated substrate. Thereafter, the substrate 180 and the substrate holder 190 are unloaded from the pressure unit 240 and separated at the substrate removal unit of the substrate holder rack 160.

The substrate 180 taken out from the substrate holder 190 is accommodated in, for example, the substrate cassette 113 by the robot arms 172 and 171 and the upper stage unit 310 and the lower stage unit 320. The substrate holder 190 from which the substrate 180 has been taken out is returned to the substrate holder rack 160 and stands by.

FIG. 3 is a plan view schematically showing the form of the substrate 180 as a material of the laminated substrate. As illustrated, a plurality of element regions 186 are formed on the substrate 180, and alignment marks 184 are disposed in the vicinity of each of the element regions 186. Further, the substrate 180 has a notch 182 formed at a specific portion of the edge. The notches 182 are arranged corresponding to the crystal orientation of the substrate 180 and the like, and show the physical properties and the anisotropy of the arrangement in the substrate 180 having a substantially circular shape as a whole.

The alignment mark 184 is used as an index when the element region 186 is formed on the substrate 180. For this reason, the position of the alignment mark 184 is closely related to the position of the element region 186 displaced by the deformation of the substrate 180 or the like. Therefore, when the substrates 180 are stacked, the distortion generated in each substrate 180 can be effectively compensated by using the alignment mark 184 as an alignment index.

In the drawing, the element regions 186 and the alignment marks 184 are drawn large, but the number of element regions 186 formed on a large substrate 180 such as 300 mmφ is several hundred or more. Accordingly, the number of alignment marks 184 arranged on the substrate 180 also increases. Furthermore, the alignment mark 184 can be substituted by wiring, bumps, scribe lines, etc. formed on the substrate 180.

FIG. 4 is a cross-sectional view schematically showing the structure of the alignment unit 300. The alignment unit 300 includes an upper stage unit 310 and a lower stage unit 320 disposed inside the frame body 301. Also, in FIG. 4, one measurement unit 330 is also visible. The measurement unit 330 includes interferometers 332 and 334 having different heights.

The frame body 301 includes a top plate 302 and a bottom plate 306 that are parallel to each other and a plurality of columns 304 that couple the top plate 302 and the bottom plate 306 together. The top plate 302, the support column 304, and the bottom plate 306 are each formed of a highly rigid material, and are not deformed even when a reaction force related to the operation of the internal mechanism is applied.

The upper stage unit 310 includes a drive unit 350, a substage 314, a spacer 311 and a main stage 312 that are sequentially suspended on the lower surface of the top plate 302. The substage 314 suspends the upper reflecting mirror 316 and the upper microscope 318. The main stage 312 sucks and holds the substrate holder 190 that holds the substrate 180.

The driving unit 350 includes an X driving unit 351 and a Y driving unit 352 that move the substage 314 in the X direction and the Y direction indicated by arrows in the drawing. Further, the substage 314 is integrally coupled to the main stage 312 via the spacer 311. Accordingly, the upper reflecting mirror 316 and the upper microscope 318 move in the X direction and the Y direction together with the substrate 180 while maintaining a certain relative position with respect to the substrate 180 held on the main stage 312.

The lower stage unit 320 includes a drive unit 340, a substage 324, and a main stage 322 mounted on the upper surface of the bottom plate 306. The substage 324 includes a lower reflecting mirror 326 and a lower microscope 328. The main stage 322 sucks and holds the substrate holder 190 that holds the substrate 180.

In the lower stage unit 320, the lower microscope 328 is mounted on the substage 324 via the vertical actuator 329. As a result, the lower microscope 328 moves up and down with respect to the substage 324 only in the vertical direction. A reference mark 321 is also mounted on the main stage 322.

The drive unit 340 includes an X drive unit 341, a Y drive unit 342, and a Z drive unit 348 that move the substage 324 in the X direction, the Y direction, and the Z direction indicated by arrows in the drawing. Further, a θ drive unit 344 that rotates the substage 324 in a horizontal plane and a φ drive unit 346 that swings the substage 324 are included. Note that the Z drive unit 348 is disposed between the substage 324 and the main stage 322, and also has a function corresponding to the spacer 311 in the upper stage unit 310.

The sub-stage 324 is integrally coupled with the main stage 322 by the Z driving unit 348. Accordingly, the lower reflecting mirror 326 and the lower microscope 328 rotate and swing together with the substrate 180 while maintaining a certain relative position with respect to the substrate 180 held on the main stage 322, and in the X direction and Y direction. Move in the direction and Z direction.

Measure unit 330 includes a pair of interferometers 332 and 334. One interferometer 332 is disposed at the same height as the reflecting mirror 316 of the upper stage unit 310. Thereby, the interferometer 332 uses the reflecting mirror 316 to accurately measure the position of the substage 314 in the X direction. Note that the measurement unit 330 that does not appear in this figure has the same structure, and measures the position of the substage 314 in the Y direction.

The other interferometer 334 is arranged at the same height as the reflecting mirror 326 of the lower stage unit 320. Thereby, the interferometer 334 accurately measures the position of the substage 324 in the X direction using the reflecting mirror 326. The measurement unit 330 that does not appear in this figure also has the same structure, and measures the position of the substage 324 in the Y direction.

FIG. 5 is an enlarged view showing the vicinity of the reference sign 321 in a state where the upper stage part 310 and the lower stage part are moved to a position where the reference sign 321 can be observed from the upper microscope 318. As shown in the drawing, the reference marker 321 can be put into the field of view from the upper microscope 318 by appropriately moving the upper stage portion 310 and the lower stage portion 320 as shown in the drawing.

Further, the reference mark 321 is disposed on the through hole 323 formed in the main stage 322 immediately above the lower microscope 328. As a result, the reference mark 321 also enters the field of view of the lower microscope 328.

Further, the height of the reference mark 321 is adjusted to be the same height as the surface of the substrate 180 mounted on the main stage 322 of the lower stage unit 320. In the state shown in FIG. 5, the lower microscope 328 is lowered by the vertical actuator 329 and focuses on the reference mark 321. The upper microscope 318 observes the substrate 180 mounted on the lower stage unit 320, as will be described later. Therefore, in the above state, both the upper microscope 318 and the lower microscope 328 are in a state of focusing on the same reference mark 321.

FIG. 6 is a cross-sectional view showing the structure of the reference mark 321 described above. The reference mark 321 includes a support frame 421, a transparent substrate 422, and an opaque thin film 423.

More specifically, the transparent substrate 422 can be formed using a glass substrate or the like. An example of the opaque thin film 423 is a metal film. By thinning the opaque thin film 423, the observed position does not shift both when observed from the upper microscope 318 and when observed from the lower microscope 328. Note that the effective height of the reference mark 321 can be finely adjusted by adopting a structure in which the transparent substrate 422 is mounted on the main stage 322 via the support frame 421.

Also, the reference mark 321 has a transparent area where the transparent substrate 422 is exposed. Thus, the alignment mark 184 and the like positioned therethrough can be observed through the reference mark 321, which will be described later with reference to FIG.

FIG. 7 is a cross-sectional view showing another structure of the reference mark 321. This reference mark 321 is formed by an opaque substrate 425 having a knife edge 427. The knife edge 427 is formed by a pair of surfaces intersecting with a line connecting the upper microscope 318 and the lower microscope 328.

Such an opaque substrate 425 can be manufactured, for example, by processing a silicon wafer by dry etching. Since the tip of the knife edge 427 is very thin, the observed position does not shift both when observed from the upper microscope 318 and when observed from the lower microscope 328. Further, since the inside of the knife edge 427 penetrates, the lower microscope 328 can also observe the other side of the reference mark 321.

FIG. 8 is a flowchart showing a procedure in the case of aligning the substrate 180 using the alignment unit 300 as described above. First, as shown in FIG. 4, the upper stage unit 310 and the lower stage unit 320 are opened so that the lower side of the main stage 312 of the upper stage unit 310 and the upper side of the main stage 322 of the lower stage unit 320 are opened. Shifting to different positions, the substrate 180 held by the substrate holder 190 is loaded on each of the main stages 312, 322 (step S101).

Next, while observing the substrate 180 with a microscope (not shown) or the like, the φ driving unit 346 of the lower stage unit 320 is operated to make the pair of substrates 180 parallel (step S102). Hereinafter, the substrate 180 is aligned exclusively in the X direction and the Y direction.

Subsequently, as shown in FIGS. 4 and 5, the reference marker 321 is simultaneously observed by the lower microscope 328 and the upper microscope 318, thereby specifying the relative positions of the lower microscope 328 and the upper microscope 318 (step S103). In this state, the calibration control unit 122 measures the positions of the upper stage unit 310 and the lower stage unit 320, and initializes the interferometers 332 and 334 using the measured values as initial values (step S104).

Subsequently, the upper stage unit 310 and the lower stage unit are operated, and the alignment mark 184 of the substrate 180 held on the lower stage unit 320 is aligned with the alignment mark 184 of the substrate 180 held on the lower stage unit 320 by the upper microscope 318. Are detected three or more by the lower microscope 328 (step S105).

FIG. 9 is a diagram showing the state of the alignment unit 300 that executes step S105 in contrast to FIG. As illustrated, the surface of the substrate 180 held by the lower stage unit 320 is brought into the field of view of the upper microscope 318 by operating the driving unit 350 of the upper stage unit 310 and the driving unit 340 of the lower stage unit 320, respectively. The surface of the substrate 180 held on the upper stage unit 310 can be put into the field of view of the lower microscope 328, respectively.

FIG. 10 is an enlarged view showing the vicinity of the lower microscope 328 in the state shown in FIG. As shown in the drawing, the focus of the lower microscope 328 is moved to the surface of the substrate 180 held by the upper stage unit 310 by operating the vertical actuator 329. Accordingly, the lower microscope 328 can accurately observe the surface of the substrate 180 held on the upper stage unit 310 through the reference mark 321.

Although not shown, the alignment unit 300 includes a low-power microscope that observes a wide range of the surface of the substrate 180 separately from the upper microscope 318 and the lower microscope 328. The resolution of the low-magnification microscope is less than the alignment accuracy of the substrate 180, but the approximate positions of the alignment mark 184 and the element region 186 on the substrate 180 can be recognized. By using such a low-magnification microscope in combination, the upper microscope 318 and the lower microscope 328 can efficiently detect the alignment mark 184.

Returning to the procedure shown in FIG. 8 again, when the upper microscope 318 and the lower microscope 328 detect the alignment mark 184 of the opposing substrate 180, the positions of the main stages 312 and 322 at that time are interferometers 332 and 334, respectively. The relative position of the alignment mark 184 with respect to the initial value can be determined by measuring at The relative position of the detected alignment mark 184 is stored by the alignment control unit 124 (step S106).

Thus, when the alignment control unit 124 acquires the position information of the three or more alignment marks 184 for each of the pair of substrates 180, the drive unit required when aligning the substrate 180 based on the position information. The movement amounts of 340 and 350 can be calculated (step S107).

That is, the substrate 180 used for bonding is formed with elements and the like through a lot of processing and processing. For this reason, various distortions are generated in the substrate 180. Further, the strain distribution on one substrate 180 is not uniform. For this reason, when aligning the substrates 180, even if the positions of the specific alignment marks 184 corresponding to the pair of substrates 180 are matched, misalignment may increase in other portions of the substrate 180.

However, by performing the following processing on the relative position information of each of the three or more alignment marks 184 corresponding to each other between the pair of substrates 180, the positional deviation of the alignment marks 184 generated in the entire substrate 180 is minimized. You can stay.

Hereinafter, the alignment method will be described. In a pair of wafers, a translation amount (T _x , T _y ) that one of the wafers should translate relative to the other and a rotation amount θ that should be rotated are calculated as follows. The following relationship exists between the position coordinates (A _xi , A _yi ) of the measured alignment mark with respect to the reference coordinate system and the converted position coordinates (M _xi , M _yi ). “I” indicates the number of the alignment mark.

Next, assuming that the position coordinate of one substrate 180 with respect to the reference coordinate system is (D _xi , D _yi ), the movement amount (T _x , T _y ) of the other substrate 180 and the following function F are _minimized. The rotation amount θ is determined.

FIG. 11 is a diagram illustrating the next operation of the alignment unit 300. As illustrated, the alignment control unit 124 uses the initial values based on the relative positions of the upper microscope 318 and the lower microscope 328 as a reference, and the driving unit 340 according to the calculated movement amount (T _x , T _y ) and rotation amount θ. , 350 can be operated to align the pair of substrates 180 (step S108).

For the purpose of further improving the alignment accuracy, a plurality of reference markers 321 may be provided and the step of calibrating the relative positions of the upper microscopes 318 and 328 (step S104) may be executed several times. In particular, when the upper stage unit 310 or the lower stage unit 320 moves greatly, when the operation direction is switched to the X direction or the Y direction, the procedure from the stage 104 may be repeated.

FIG. 12 is a diagram showing the alignment unit 300 and the next operation. As illustrated, the Z driving unit 348 can be operated to bond the substrates 180 that are aligned in the X direction and the Y direction and face each other. That is, the substrate 180 can be temporarily joined by raising the main stage 322 of the lower stage unit 320 to contact the pair of substrates 180 and further increasing the driving force of the Z driving unit 348 (step S109). .

As described above, the pair of substrates 180 bonded after being aligned in this way are carried out of the alignment unit 300 (step S110) and transferred to the pressurizing unit 240. While being conveyed from the alignment unit 300 to the pressurizing unit 240, as described with reference to FIG. 2b, the aligned state is held by the substrate holder 190 and the fastener 192.

In the above example, the upper stage unit 310 and the lower stage unit 320 both have the driving units 350 and 340 to move the main stages 312 and 322. In this case, it is also preferable to distribute the operation amounts of the drive units 350 and 340 so that the movement amounts of both the upper stage unit 310 and the lower stage unit 320 are equal. As a result, the wear of the members can be made uniform, and the life of the device can be extended.

Further, the substrate 180 can be aligned even in a state where the main stage 312 is fixed by omitting the driving unit 350 of the upper stage unit 310, for example, the upper stage unit 310, or the upper stage unit 310. Further, for example, the Y drive unit 352 of the upper stage unit 310 may be omitted, and the upper stage unit 310 may be aligned exclusively in the X direction, and the lower stage unit 320 may be aligned exclusively in the Y direction.

However, by moving both main stages 312, 322, the time required to move the required amount of movement can be reduced by half. Therefore, by providing the drive units 350 and 340 in both the upper stage unit 310 and the lower stage unit 320, the throughput in the alignment unit 300 can be improved.

In the above example, the reference mark 321 is fixed and the lower microscope 328 is moved up and down. However, in addition to a structure in which the lower microscope 328 is fixed and the focal length is optically changed, various modifications can be made such as a structure in which the reference marker is advanced and retracted from the field of view of the upper microscope 318 or the lower microscope 328. Furthermore, it is also possible to employ a structure in which the measurement of each alignment mark 184 of the substrate 180 and the alignment of the pair of substrates 180 are performed by separate facilities.

FIG. 13 is a perspective view showing an alignment unit 300 having another structure. The alignment unit 300 includes a measurement unit 360, a pair of microscope units 370, and a joint unit 380 mounted on the bottom plate 303. Further, although not shown in FIG. 13 for the purpose of avoiding complicated drawing, a robot arm 390 is disposed between the measurement unit 360 and the joint unit 380 (see FIG. 14).

The measurement unit 360 is formed inside a rectangular frame formed by a pair of support columns 361 standing upright from the bottom plate 303 and a pair of horizontal guide units 363 that respectively connect the upper end and the lower end of the support column 361. Each of the guide units 363 suspends or supports the X drive unit 362, the Z drive unit 364, and the main stages 312, 322, respectively.

In the measurement unit 360, the X drive unit 362 individually connects the Z drive unit 364 and the main stages 312 and 322, and the substrate holder 190 and the substrate 180 mounted on the main stages 312 and 322 along the guide unit 363. Move. The Z driving unit 364 vertically moves the main stages 312 and 322 and the substrate holder 190 and the substrate 180 mounted on the main stages 312 and 322 up and down.

A substrate holder 190 holding the substrate 180 is mounted on each of the main stages 312, 322. Each of the substrates 180 has a pair of alignment marks 184.

Furthermore, a reference sign 321 is also mounted on one main stage 322. The reference mark 321 is fixed at the same height as the surface of the substrate 180 held by the substrate holder 190. Since the main stage 322 has a through hole penetrating in the thickness direction under the reference mark 321, the reference mark 321 can be observed from above and below the main stage 322. Note that the reference mark 321 may adopt any of the structures shown in FIGS.

The pair of microscope units 370 are arranged with the measurement unit 360 interposed therebetween. Each of the microscope units 370 includes a Y driving unit 372, a support column 374, and microscopes 376 and 378. The Y drive unit 372 moves the support column 374 in a direction intersecting with the extending direction of the guide unit 363 of the measurement unit 360. The support columns 374 support a pair of microscopes 376 and 378, respectively.

That is, the pair of microscopes 376 and 378 are fixed so as to face each other vertically inside the notch formed in the middle of the support column 374. The focal points F of the microscopes 376 and 378 are connected to a common point located in the middle of the microscopes 376 and 378.

On the other hand, the joint portion 380 includes an X drive portion 381, a Y drive portion 382, a θ drive portion 384, a Z drive portion 388, a pair of flat plates 389, and a pair of main stages, which are arranged in the stacking direction inside the frame 383. 312 and 322. Each of the main stages 312 and 322 carries a substrate holder 190 that holds a substrate 180.

The X drive unit 381 and the Y drive unit 382 drive the main stages 312 and 322 in the X direction or the Y direction indicated by arrows in the drawing. The Z drive unit 388 can move the main stage 312 in the Z-axis direction, and can also swing the main stage 322 by individually operating.

The bonding unit 380 is mounted on the main stage 312 by moving the substrate 180 mounted on the main stage 322 in an arbitrary direction by operating the X driving unit 381, the Y driving unit 382, and the θ driving unit 384. Alignment with respect to the substrate 180 is possible. Further, by operating the Z driving unit 388, the pair of substrates 180 aligned with each other can be brought into contact with each other and bonded.

FIG. 14 is a plan view of the alignment unit 300 shown in FIG. As illustrated, the alignment unit 300 further includes a robot arm 390 between the measurement unit 360 and the joint unit 380.

The robot arm 390 has a fork part 392 and an arm part 394. The fork unit 392 sucks and holds the substrate holder 190 that holds the substrate 180. The arm part 394 moves the fork part 392 holding the substrate holder 190 in an arbitrary direction. Thus, the robot arm 390 transports the substrate 180 and the substrate holder 190, which have been measured later in the measurement unit 360, from the main stages 312 and 322 of the measurement unit 360 to the main stages 312 and 322 of the joint unit 380. Can be transferred.

Depending on the layout of the multilayer substrate manufacturing system 100, a robot arm 172 that carries the substrate 180 and the substrate holder 190 into and out of the alignment unit 300 may be used. In this case, the robot arm 390 of the alignment unit 300 can be omitted.

15a, 15b, 15c, and 15d are diagrams for explaining the operation of the measurement unit 360 in the alignment unit 300 having the above-described structure. As shown in the figure, the alignment unit 300 is arranged on the side surfaces of the main stages 312 and 322 facing the interferometers 366 and 368 and the interferometers 366 and 368 which are hidden in the support column 361 in FIGS. It further includes a pair of reflecting mirrors 367 mounted. The operation of these interferometers 366 and 368 and the reflecting mirror 367 will be described later.

First, as shown in FIG. 15a, the X driving unit 362 is operated, and the main stages 312 and 322 are moved to positions close to different columns 361. Thereby, the lower surface of the main stage 312 and the upper surface of the main stage 322 are opened. In this state, a substrate holder 190 holding the substrate 180 is mounted on each of the main stages 312 and 322.

Next, as shown in FIG. 15B, under the control of the calibration control unit 122, the Z drive unit 364 of the lower main stage 322 is operated to raise the main stage 322. Thereby, the reference mark mounted on the main stage 322 becomes the same height as the focal point F of the microscopes 376 and 378.

Subsequently, the X drive unit 362 is operated to move the main stage 322 to a position where the reference mark 321 enters the field of view of the microscopes 376 and 378. In this state, by observing the common reference mark 321 with the pair of microscopes 376 and 378, the calibration control unit 122 can accurately detect the positions of the pair of microscopes 376 and 378.

Note that the microscopes 376 and 378 are fixed to the column 374, respectively, but their positions may change depending on environmental conditions such as temperature, inclination of the column 374 due to tolerance of the Y drive unit 372, and the like. However, as described above, the positional relationship between the microscopes 376 and 378 can be grasped by observing the common reference mark 321 prior to measuring the position of the alignment mark 184.

Next, as shown in FIG. 15 c, the X drive unit 362 is further operated to move the main stage 322, and the alignment mark 184 of the substrate 180 is placed in the field of view of the upper microscope 376. Since the reference mark 321 and the surface of the substrate 180 are located at the same height, the surface of the substrate 180 passes through the focal plane of the upper microscope 376.

Also, while the main stage 322 moves, the amount of movement of the main stage 322 is accurately measured using the reflecting mirror 367 and one interferometer 368. Thereby, the position of the alignment mark 184 on the substrate 180 can be measured with reference to the position of the microscope 378 configured in the reference mark 321. The measured position information of the alignment mark 184 is stored in the alignment control unit 124.

Subsequently, as shown in FIG. 15d, the lower main stage 322 is returned to the original position while the upper main stage 312 is moved. That is, first, the Z driving unit 364 is operated to move the surface of the substrate 180 to the same height as the focal point F of the microscopes 376 and 378. Subsequently, the X driving unit 362 is operated to move the substrate 180 between the pair of microscopes 376 and 378.

At this time, the amount of movement of the main stage 312 can be accurately measured using the reflecting mirror 367 and the interferometer 366 provided on the upper main stage 312 side. Therefore, the position of the alignment mark 184 on the substrate 180 can be accurately detected by observing with the lower microscope 378. The measured position information of the alignment mark 184 is stored in the alignment control unit 124.

Thus, when the alignment control unit 124 acquires the position information of the alignment mark 184 for each of the pair of substrates 180, the substrate holder 190 that holds the substrate 180 is moved by the robot arm 390 to the main stages 312 and 322 of the bonding unit 380. Respectively. On the other hand, the alignment control unit 124 calculates an operation amount of the bonding unit 380 obtained when the substrate 180 is aligned based on the position information.

First, the bonding unit 380 in which the substrate holder 190 holding the substrate 180 is inserted operates the Z driving unit 388 individually to make the pair of substrates 180 parallel to each other. Subsequently, the X driving unit 381, the Y driving unit 382, and the θ driving unit 384 are operated based on an instruction from the alignment control unit 124, and the pair of substrates 180 are moved so that the positions of the corresponding alignment marks 184 coincide with each other. Align. Further, the Z driving unit 388 is operated simultaneously to bring the pair of substrates 180 into contact with each other, and by applying a higher pressure, the pair of substrates 180 is joined.

Note that the alignment unit 300 in this aspect includes a measurement unit 360 and a bonding unit 380, and individually performs the position measurement of the alignment mark 184 and the bonding of the substrate 180. With such a structure, in the measurement unit 360, the X drive unit 362 and the Z drive unit 364 can be downsized, and the movement range of the microscopes 376 and 378 can be expanded. In addition, in the bonding portion 380, it is possible to execute accurate alignment and bonding of the substrates 180 with high pressure using a large member having high strength. However, if the strength of the member can be ensured, it is possible to add the Y drive unit 382, the θ drive unit 384, and the like to the structure of the measurement unit 360 and execute the alignment and joining.

FIG. 16 is a plan view schematically showing the overall structure of another multilayer substrate manufacturing apparatus 600. FIG. The multilayer substrate manufacturing apparatus 600 includes a wafer stocker 610, a wafer pre-alignment apparatus 622, a wafer holder pre-alignment apparatus 624, a main controller 630, a wafer holder stocker 640, a pressure apparatus 650, a separation cooling apparatus 660, a wafer loader 672, and a wafer holder loader. 676 and an alignment device 700. Hereinafter, each element will be described individually.

The wafer stocker 610 includes wafer stockers 614 and 616 for accommodating a plurality of substrates 180 to be bonded, and a stacked substrate stocker 612 for storing a plurality of bonded substrates 180. Each of the multilayer substrate stocker 612 and the wafer stockers 614 and 616 is detachably mounted facing the outside of the multilayer substrate manufacturing apparatus 600. As a result, the substrate 180 can be loaded into the laminated substrate manufacturing apparatus 600 and the bonded substrates 180 can be collected. The wafer stockers 614 and 616 may be loaded with the same type of substrate 180 or may contain different types of substrates 180.

The wafer pre-alignment apparatus 622 performs quick pre-alignment on the substrate 180 taken out from the wafer stockers 614 and 616, although the accuracy is relatively low. Thereby, when the substrate 180 is loaded in the alignment apparatus 700 described later, the position of the substrate 180 can be avoided from being greatly shifted. Further, the work time in the alignment apparatus 700 can be shortened.

The wafer holder stocker 640 is arranged inside the multilayer substrate manufacturing apparatus 600 and accommodates a plurality of substrate holders 190. The substrate holder 190 sucks and supports the substrate 180. Further, the substrate holder 190 is repeatedly used inside the multilayer substrate manufacturing apparatus 600 except for a maintenance period that is carried out at a constant cycle. It should be noted that the substrate holder 190 may be used for all the substrates 180 with a single specification, or may have a different specification depending on the type of the substrate 180.

The wafer holder pre-alignment device 624 is disposed in the vicinity of the wafer holder stocker 640. The wafer holder pre-alignment apparatus 624 makes the mounting position of the substrate 180 relative to the substrate holder 190 substantially constant by placing the substrate holder 190 at a predetermined position. Thereby, the working time in the alignment apparatus 700 can be shortened.

The alignment apparatus 700 aligns the pair of substrates 180 held by the substrate holder 190 with each other with high accuracy, and then bonds them together. The high accuracy referred to here is an accuracy that secures the performance required when the elements formed on the substrate 180 are stacked, and may be on the order of submicrons.

Further, the alignment here means that when a pair of substrates 180 are bonded together, an effective electrical connection is established between the connection terminal of the element formed on one substrate 180 and the connection terminal of the other substrate 180. This means that the positions of the two coincide with each other. The structure and operation of the alignment apparatus 700 will be described later with reference to FIG.

The pressing device 650 is disposed in the vicinity of the alignment device 700, pressurizes the substrate 180 that has been aligned and bonded by the alignment device 700, and permanently bonds the substrate 180 to form a laminated substrate. For this reason, the bonded substrate 180 may be pressurized while being heated.

The separation cooling device 660 is disposed adjacent to the pressurizing device 650. The separation cooling device 660 cools the substrate holder 190 and the bonded substrate 180 and removes the substrate holder 190 from the bonded substrate 180. The bonded substrate 180 is accommodated in a stacked substrate stocker 612 as a stacked substrate. The cooled substrate holder 190 is returned to the wafer holder stocker 640 and used for alignment and bonding of the next substrate 180.

The wafer loader 672 is an articulated robot and may have an arm having six degrees of freedom (X, Y, Z, θX, θY, θZ). Wafer loader 672 moves along rail 674 in the direction indicated by arrow X in the drawing.

The wafer loader 672 can be mounted and moved with the substrate 180 or the substrate 180 which is bonded to be a laminated substrate. However, the substrate holder 190 having a mass significantly larger than that of the substrate 180 or the laminated substrate cannot be transported. Accordingly, the wafer loader 672 transports the substrate 180 mainly between the wafer stocker 610 and the wafer pre-alignment apparatus 622.

The wafer holder loader 676 is also an articulated robot, and may have arms with six degrees of freedom (X, Y, Z, θX, θY, θZ). Wafer holder loader 676 moves along rail 678 in the direction indicated by arrow Y in the drawing.

The wafer holder loader 676 can withstand the transfer load of the substrate holder 190 and can also transfer the substrate 180 alone. Accordingly, the substrate holder 190 is transported between the wafer holder stocker 640 and the wafer holder pre-alignment device 624 or between the separation cooling device 660 and the wafer holder stocker 640. Further, between the wafer holder pre-alignment apparatus 624 and the alignment apparatus 700, between the alignment apparatus 700 and the pressurization apparatus 650, or between the pressurization apparatus 650 and the separation cooling apparatus 660, the substrate holder 190 and The substrate 180 is also transferred. Further, there is a case where the laminated wafer is transported in at least a partial section from the separation cooling device 660 to the laminated substrate stocker 612.

The main controller 630 controls the overall operation of the multilayer substrate manufacturing apparatus 600 as described above. That is, the main controller 630 provides signals to individual control devices such as the wafer loader 672, the wafer holder loader 676, the wafer pre-alignment device 622, and the wafer holder pre-alignment device 624 to cover the entire multilayer substrate manufacturing apparatus 600. Control. It also accepts external operations such as power on and off. Further, main controller 630 includes an alignment control unit that controls an alignment operation performed by alignment apparatus 700.

FIG. 17 is a perspective view showing the structure of the alignment apparatus 700. FIG. The alignment apparatus 700 includes a base 710, in- plane driving units 720 and 760, a tilt driving unit 730, a lower stage 740, an upper stage 750 and a frame 770, and a pair of microscope units 810 and 820.

The base 710 is fixed horizontally inside the multilayer substrate manufacturing apparatus 600. An in-plane driving unit 720, a tilt driving unit 730, and a lower stage 740 are sequentially stacked on the base 710.

The in-plane driving unit 720 includes a rotation driving unit 722, an X direction driving unit 724, and a Y direction driving unit 726 that are stacked on each other. Accordingly, the in-plane driving unit 720 can rotate the mounted tilt driving unit 730 in a horizontal plane parallel to the base 710 and move it two-dimensionally in the horizontal direction.

The tilt drive unit 730 includes a pair of flat plates 732 and 736 and three vertical actuators 734 sandwiched between the flat plates 732 and 736. Accordingly, the inclination of the upper flat plate 736 with respect to the horizontal plane is compensated on the in-plane driving unit 720.

The lower stage 740 has a horizontal actuator and a vertical actuator not shown. Accordingly, the lower stage 740 is displaced in the vertical direction (Z direction) with respect to the tilt driving unit 730 and is also advanced and retracted in the horizontal direction (X direction). The lower stage 740 holds the substrate 180 held by the substrate holder 190 on the upper surface. As a result, the lower stage 740 can put the mounted substrate 180 under the microscopes 818 and 828 described later.

The frame 770 has a horizontal portion that is separated from the base 710. As a result, the frame 770 suspends the in-plane driving unit 760 and the upper stage 750 sequentially on the lower surface of the horizontal part. The in-plane drive unit 760 includes a rotation drive unit 762, an X direction drive unit 764, and a Y direction drive unit 766 that are sequentially suspended from each other. As a result, the in-plane driving unit 760 rotates and horizontally moves the upper stage 750 in a horizontal plane parallel to the base 710.

The upper stage 750 has a horizontal actuator and a vertical actuator not shown. The upper stage 750 advances and retreats in the vertical direction (Z direction) and the horizontal direction (X direction) with respect to the in-plane drive unit 760. The upper stage 750 holds the substrate 180 held by the substrate holder 190 on the lower surface. Accordingly, the upper stage 750 can put the mounted substrate 180 above the microscopes 816 and 826 described later.

The microscope unit 810 includes a linear drive unit 812, a support column 814, and a pair of microscopes 816 and 818. The linear drive unit 812 moves the support column 814 in the horizontal direction (Y direction) on the base 710 and moves it back and forth. Here, the advancing / retreating direction of the lower stage 740 and the upper stage 750 intersects the advancing / retreating direction of the support column 814. Accordingly, the support column 814 moves back and forth in the forward and backward direction with respect to the extended lower stage 740 and upper stage 750.

The support column 814 has a notch 811 in the middle of the height direction. The notch 811 has a rectangular shape, and a pair of microscopes 816 and 818 facing each other are fixed to the upper and lower surfaces on the inside. Accordingly, when the lower stage 740 or the upper stage 750 is extended, the substrate 180 mounted on the lower stage 740 or the upper stage 750 can be observed by one of the pair of microscopes 816 and 818.

Also, the alignment apparatus 700 includes a microscope unit 820 including another set of microscopes 826 and 828. The microscope unit 820 includes a linear drive unit 822, a support column 824, and a pair of microscopes 826 and 828. The linear drive unit 822 moves the support column 824 in the horizontal direction (Y direction) on the base 710 and moves it back and forth.

The advance / retreat direction of the microscope units 810, 820 intersects the advance / retreat direction of the lower stage 740 and the upper stage 750. As a result, the pair of microscopes 816 and 818 and the microscopes 826 and 828 are provided with an observation position where the alignment mark 184 of the substrate 180 put out by the lower stage 740 or the upper stage 750 enters the field of view, and the lower stage 740 or the upper stage 750. The alignment mark 184 of the substrate 180 thus moved moves between the retracted position where it is out of the field of view.

The support column 824 has a notch 821 in the middle of the height direction. The notch 821 has a rectangular shape, and a pair of microscopes 826 and 828 facing each other are fixed to an upper surface and a lower surface on the inside. Accordingly, when the lower stage 740 or the upper stage 750 is extended, the substrate 180 mounted on the lower stage 740 or the upper stage 750 can be observed by one of the pair of microscopes 816 and 818.

Note that the pair of microscopes 816, 818, 826, and 828 in each of the microscope units 810 and 820 are focused on a common position. Therefore, when observing the surface of the substrate 180 with the microscopes 816 and 818, the lower stage 740 or the upper stage 750 is displaced in the Z direction so that the surface of the substrate 180 is positioned at a common focal position.

Although not shown in the figure, the alignment apparatus 700 is additionally provided with a low-magnification microscope that observes the entire surface of the substrate 180 that is directed toward the microscope units 810 and 820. The resolution of the low-magnification microscope is less than the alignment accuracy of the substrate 180, but the approximate positions of the alignment mark 184 and the element region 186 on the substrate 180 can be recognized. By using such a low-magnification microscope together, when the alignment mark 184 to be observed deviates from the field of view of the microscopes 816, 818, 826, and 828, the position correction of the substrate 180 can be easily grasped.

Also, in each microscope unit 810, 820, a pair of opposed microscopes 816, 818 (microscopes 826, 828) measure and record the relative positional deviation in advance. Therefore, the relationship between the position of the object observed by the lower microscopes 816 and 826 and the position of the object observed by the upper microscopes 826 and 826 is based on the positional relationship of the microscopes 816, 818, 826, and 828. Know exactly.

FIG. 18 is a perspective view showing one operation of the alignment apparatus 700. FIG. As shown in the figure, the pair of microscope units 810 and 820 are driven by the linear drive units 812 and 822 and move symmetrically with each other. Thereby, the area | region observed with the microscopes 816, 818, 826, and 828 can be changed by changing the space | interval of the support | pillars 814 and 824. FIG.

FIG. 19 is a perspective view showing another operation of the alignment apparatus 700. FIG. As shown in the figure, by inserting the lower stage 740 from the in-plane driving unit 720 and the tilt driving unit 730 in the X direction, between the microscopes 816 and 818 in the microscope unit 810 and between the microscopes 826 and 828 in the microscope unit 820, The lower stage 740 can be presented. Thus, the substrate 180 held on the upper surface of the lower stage 740 via the substrate holder 190 can be observed by the microscopes 818 and 828 having a downward visual field in each of the microscope units 810 and 820.

Further, the lower stage 740 is supported by the in-plane drive unit 720 via the tilt drive unit 730. Accordingly, the lower stage 740 can be rotated or horizontally moved while observing the substrate 180 with the microscopes 818 and 828.

FIG. 20 is a perspective view showing still another operation of the alignment apparatus 700. As illustrated, the lower stage 740 is retracted above the tilt drive unit 730 and the upper stage 750 is extended from the in-plane drive unit 760 in the X direction. Accordingly, the upper stage 750 is provided between the microscopes 816 and 818 in the microscope unit 810 and between the microscopes 826 and 828 in the microscope unit 820. Accordingly, the substrate 180 held on the lower surface of the upper stage 750 via the substrate holder 190 can be observed by the microscopes 816 and 826 having an upward visual field in each of the microscope units 810 and 820.

The upper stage 750 is supported by an in-plane drive unit 760 suspended from the frame 770. Thereby, the upper stage can be rotated or horizontally moved while observing the substrate 180 with the microscopes 816 and 826.

FIG. 21 is a flowchart showing a procedure for aligning the substrate 180 in the alignment apparatus 700. The substrate 180 held by the substrate holder 190 in the wafer holder pre-alignment apparatus 624 is first loaded on the upper stage 750 in the alignment apparatus 700 (step S201). The substrate 180 held by the substrate holder 190 next in the wafer holder pre-alignment apparatus 624 is loaded on the lower stage 740 in the alignment apparatus 700 (step S202).

The substrate 180 is held by the substrate holder 190 by, for example, electrostatic adsorption. Further, the substrate holder 190 is held by the upper stage 750 and the lower stage 740 by, for example, vacuum suction. However, the present invention is not limited to these methods, and the substrate 180, the substrate holder 190, and the upper stage 750 or the lower stage 740 are integrated with each other, and can be fixed by any method that does not cause misalignment in the following alignment operation.

Next, using the tilt driving unit 730, the substrate 180 held on the upper stage 750 and the substrate 180 held on the lower stage are made parallel to each other (step S203). Accordingly, the alignment of the pair of substrates 180 can be limited to the horizontal plane by the in- plane driving units 720 and 760 below.

Subsequently, the microscope units 810 and 820 are fixed (step S204). At this time, the distance between the support columns 814 and 824 is adjusted by the linear drive unit 812, and the microscope units 810 and 820 are fixed at positions where three or more alignment marks 184 can be observed for each of the substrates 180. Thereafter, the microscope units 810 and 820 are fixed and are not moved until the bonding of the pair of substrates 180 is completed.

Next, as shown in FIG. 19, the lower stage 740 is inserted between the microscopes 816 and 818 and between the microscopes 826 and 828, and the substrate 180 mounted on the lower stage 740 is placed by the downward microscopes 818 and 828. The alignment mark 184 is observed (step S205). At this time, a specific alignment mark 184 to be observed can be easily selected from a plurality of alignment marks 184 formed on the substrate 180 by referring to the image of the substrate 180 obtained by the low-power microscope described above.

22 to 27 are diagrams schematically showing a state in which the alignment mark 184 is observed with the microscopes 818 and 828. FIG. As shown in FIG. 22, if the positions of the microscope units 810 and 820 are appropriate, the alignment mark 184 is observed by the microscopes 818 and 828 when the lower stage 740 is extended in the X direction. Thereby, the position of the alignment mark 184 with respect to the fixed microscopes 818 and 828 is determined. Accordingly, relative position information of the alignment mark 184 with respect to the microscopes 818 and 828 is calculated and recorded from the driving amount of the in-plane driving unit 720 at this time (step S106).

The driving amount of the in-plane driving unit 720 can be known based on the operation amount of the in-plane driving unit 720 itself. The same drive amount can also be measured with reference to a linear encoder or the like provided for the purpose of controlling the operation of the in-plane drive unit 720. Further, the amount of movement of the lower stage 740 may be measured by an interferometer or the like provided independently of the in-plane drive unit 720.

Next, as shown in FIG. 23, the lower stage 740 is moved to a position where the other alignment mark 184 of the substrate 180 can be observed by the microscopes 818 and 828, and the microscope 818, The relative position information of the next alignment mark 184 with respect to 828 is recorded.

Further, as shown in FIG. 24, the substrate 180 may be rotated at a rotation angle α in the plane including the substrate 180. In such a case, as shown in FIG. 25, the lower stage 740 is rotated (−α) by the in-plane driving unit 720 so that the set of alignment marks 184 can be observed with the microscopes 818 and 828. Also in this case, the rotation angle α of the substrate 180 can be recorded based on the driving amount of the in-plane driving unit 720.

Further, as shown in FIGS. 26 and 27, by observing three or more alignment marks 184 using one microscope 818, relative to the substrate 180 held by the lower stage 740 with reference to the position of the microscope 818. Location information is recorded.

Next, the lower stage 740 is removed from the field of view of the microscopes 818 and 828 and retracted to above the tilt drive unit 730, and as shown in FIG. 20, the upper stage is placed between the microscopes 816 and 818 and between the microscopes 826 and 828. The stage 750 is inserted, and the alignment marks 184 of the substrate 180 held on the lower surface of the upper stage 750 are observed with the upward microscopes 816 and 826 (step S107). Subsequently, as in the case of the substrate 180 held on the lower stage 740, relative position information is recorded for the plurality of alignment marks 184 (step S108).

In this way, using the position of the fixed microscope 818 as a reference, the relative position information of the substrate 180 mounted on the lower stage 740 and the relative position information of the substrate 180 held on the upper stage 750 are each three or more. The alignment mark 184 is recorded. Based on the relative position information, alignment information that means a deviation to be compensated when the pair of substrates 180 are aligned is calculated (step S109).

That is, as already described, the substrate 180 used for bonding is formed with elements and the like through a lot of processing and processing. For this reason, various distortions are generated in the substrate 180. Further, the strain distribution on one substrate 180 is not uniform. For this reason, when aligning the substrate 180, even if the positions of the specific alignment marks 184 corresponding to the pair of substrates 180 are matched, the positional deviation may be increased in a part of the substrate 180.

However, by performing the following processing on the relative position information of each of the three or more alignment marks 184 corresponding to each other between the pair of substrates 180, the positional deviation of the alignment marks 184 generated in the entire substrate 180 is minimized. You can stay.

Thus, when aligning the pair of substrates 180, relative position information regarding the position in the plane of the substrate 180 and the rotation in the same plane for each of the three or more alignment marks 184 with reference to the position of one microscope unit 810. Then, from the relative position information, alignment information that minimizes the positional deviation of the corresponding alignment marks 184 between the substrates 180 as a whole is calculated. By aligning the lower stage 740 and the upper stage 750 according to the alignment information, the pair of substrates 180 can be aligned with high accuracy.

By aligning one of the lower stage 740 and the upper stage 750 with respect to the other based on the alignment information calculated as described above, the displacement of the alignment marks 184 corresponding to each other on the pair of substrates 180 is minimized as a whole. Can be aligned. Therefore, in a state where the substrate 180 is aligned, for example, the lower stage 740 is raised toward the upper stage 750 to bond the pair of substrates 180 (step S610).

Further, for the purpose of maintaining the aligned state of the substrate 180, the substrate holder 190 is coupled by the fastener 192 as shown in FIG. 2d (step S111). Since the substrate holder 190 and the substrate 180 in which the aligned state is ensured can be easily transported while maintaining the state, they are unloaded from the aligning device 700 and transported to the pressurizing device (step S612). As described above, the effective alignment accuracy of the substrate 180 to be stacked can be improved.

Note that when the pair of substrates 180 are facing each other, the alignment mark 184 formed on the surface of the substrate 180 may not be observed. Therefore, in the substrate holder 190, the lower stage 740, the upper stage 750, or the like that moves integrally with the substrate 180, a reference mark is provided in an area that can be easily observed even when the substrate 180 is facing, while observing the reference mark. By operating the lower stage 740 or the upper stage 750, it is possible to maintain the same accuracy as when operating while observing the alignment mark 184. In this case, it is required to measure in advance the relative positions of the alignment mark 184 and the reference mark.

16 to 27, the lower stage 740 and the upper stage 750 move in two directions XY, but the moving method is not limited to this. As another example, when the alignment mark 184 is arranged on a straight line along the radial direction of the substrate 180, the lower stage 740 and the upper stage 750 may be moved linearly along the alignment mark 184. . In particular, by arranging the substrate 180 on the lower stage 740 and the upper stage 750 so that the alignment direction of the alignment marks 184 is the same as the moving direction of the lower stage 740 and the upper stage 750 toward the microscope, The alignment mark 184 can be detected simultaneously with the movement of the lower stage 740 and the upper stage 750.

In the above description, the laminated substrate manufacturing apparatus 600 is exemplified. However, the alignment apparatus 700 and the method of the present invention are used in an exposure apparatus used for photolithography in the process of manufacturing a semiconductor device, such as a substrate to be exposed and a reticle. It can also be used for positioning the pattern forming substrate.

In the embodiment shown in FIG. 1 to FIG. 27, a microscope for observing the substrate 180 held on the upper stage unit 310 or the like is disposed on the lower stage unit 320 or the like facing the substrate 180 and the substrate 180 held on the lower stage unit 320 or the like. The microscope to be observed is disposed on the upper stage unit 310 or the like facing the microscope. However, the arrangement of the microscope is not limited to this. A microscope for observing the substrate 180 held on the upper stage unit 310 or the like is arranged on the same upper stage unit 310 or the like, and a microscope for observing the substrate 180 held on the lower stage unit 320 or the like is arranged on the same lower stage unit 320 or the like May be. In this case, the microscope lens arranged on the upper stage unit 310 is arranged to face upward, and the microscope lens arranged on the lower stage unit 320 is arranged to face downward.

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 execution order 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”. It should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for the sake of convenience, it means that it is essential to carry out in this order. is not.

100 laminated substrate manufacturing system, 101 housing, 102 room temperature section, 111, 112, 113 substrate cassette, 120 control panel, 122 calibration control section, 124 alignment control section, 130 pre-aligner, 142, 210 heat insulation wall, 144, 222, 224 shutter, 160 substrate holder rack, 171, 172, 230, 390 robot arm, 180 substrate, 182 notch, 184 alignment mark, 186 element area, 190 substrate holder, 191 groove, 192 fastener, 202 high temperature part, 220 air lock , 240 Pressurization part, 300 Alignment part, 301 Frame, 302 Top plate, 303 Bottom plate, 304, 374 Column, 306 Bottom plate, 310 Upper stage part, 311 Spacer, 312, 322 Main stay 314, 324 Substage, 316, 326, 367 Reflector, 318, 328, 376, 378 Microscope, 320 Lower stage part, 321 Reference mark, 323 Through hole, 329 Vertical actuator, 330 Measuring part, 332, 334, 366 368 interferometer, 340, 350 drive unit, 341, 351, 362, 381 X drive unit, 342, 352, 372, 382 Y drive unit, 344, 384 θ drive unit, 346 φ drive unit, 348, 364, 388 Z drive unit, 360 measurement unit, 361 support column, 363 guide unit, 370 microscope unit, 380 joint unit, 383 frame, 389 flat plate, 392 fork unit, 394 arm unit, 421 support frame, 422 transparent substrate, 423 opaque thin film, 425 Opaque substrate, 427 Knife edge, 600 Laminated substrate manufacturing device, 610 Wafer stocker, 614 Wafer stocker, 616 Wafer stocker, 612 Laminated substrate stocker, 622 Wafer pre-alignment device, 624 Wafer holder pre-alignment device, 630 Main controller, 640 Wafer holder stocker, 650 pressure device, 660 separation cooling device, 672 wafer loader, 674 rail, 678 rail, 676 wafer holder loader, 700 alignment device, 710 base, 720 in-plane drive unit, 760 in-plane drive unit, 722 rotation drive unit, 762 Rotation drive unit, 724 X direction drive unit, 764 X direction drive unit, 726 Y direction drive unit, 766 Y direction drive unit, 730 tilt drive unit, 732, 736 flat plate, 734 vertical actuator , 740 lower stage, 750 upper stage, 770 frame, 810 microscope unit, 820 microscope unit, 811 notch, 821 notch, 812 linear drive, 822 linear drive, 814 support, 824 support, 816 microscope, 818 Microscope, 826 microscope, 828 microscope

Claims (25)

1. A first stage that moves in the surface direction of the substrate while holding one of the pair of substrates facing each other;
   A second stage for holding the other of the pair of substrates;
   A first microscope for observing an alignment mark of the substrate held on the second stage;
   A second microscope for observing an alignment mark of the substrate held on the first stage;
   A calibration marker commonly observed from the first microscope and the second microscope;
   1st position information which shows the position of the alignment mark observed with the relative position of the 1st microscope and the 2nd microscope acquired by observing the calibration mark with the 1st microscope and the 2nd microscope, and the 2nd microscope And an alignment control unit that aligns the pair of substrates based on second position information indicating the position of the alignment mark observed with the first microscope.
2. A calibration control unit that calibrates the relative positions of the first microscope and the second microscope by observing the calibration mark with the first microscope and the second microscope;
   The calibration result by the calibration control unit, the first position information indicating the position of the alignment mark observed by the alignment control unit with the second microscope, and the second indicating the position of the alignment mark observed with the first microscope. The substrate alignment apparatus according to claim 1, wherein the pair of substrates is aligned based on a difference in position information.
3. The calibration marker moves with the first stage;
   The calibration control unit calibrates the relative positions of the first microscope and the second microscope by observing the calibration mark with the first microscope and the second microscope in a state where the first stage is stopped. Item 3. The substrate alignment apparatus according to Item 2.
4. The substrate alignment apparatus according to claim 3, wherein the first microscope moves together with the first stage.
5. The alignment control unit moves the first stage holding one of the pair of substrates to align the substrate with the other of the pair of substrates held by the second stage. 5. The substrate alignment apparatus according to 4.
6. 6. The substrate alignment apparatus according to claim 2, wherein the calibration control unit calibrates the relative position after any of the first microscope and the second microscope moves.
7. 7. The substrate alignment apparatus according to claim 2, wherein the calibration control unit calibrates the relative position after any of the first microscope and the second microscope changes a moving direction.
8. 8. The substrate alignment apparatus according to claim 1, wherein the calibration mark includes a transparent substrate and an opaque thin film attached to the transparent substrate.
9. 9. The calibration mark according to claim 1, wherein the calibration mark is formed at a line of intersection of a pair of surfaces that intersect each line connecting the first microscope and the second microscope and have different inclinations. 10. Substrate alignment device.
10. 10. The substrate alignment apparatus according to claim 1, further comprising an interferometer that detects positions of the first stage and the second stage.
11. 2. The apparatus according to claim 1, further comprising a vertical drive unit that moves either the first stage or the second stage in a direction in which a pair of substrates held on the first stage and the second stage are brought into contact with or separated from each other. The substrate alignment apparatus according to any one of 10.
12. The substrate alignment apparatus according to any one of claims 1 to 11, wherein the first microscope and the second microscope are fixed to each other.
13. The alignment control unit replaces one of the pair of substrates from the first stage to the third stage, and after replacing the other of the pair of substrates from the second stage to the fourth stage, The substrate alignment apparatus according to claim 1, wherein either the third stage or the fourth stage is moved to align the pair of substrates.
14. The first microscope and the second microscope each observe three or more alignment marks on each of a pair of substrates held on the first stage and the second stage. Substrate alignment device.
15. A detection unit for detecting a plurality of alignment marks formed on the two substrates aligned with each other;
    A pair of stages holding each of the two substrates;
    A drive unit for moving each of the two stages;
    A control unit for controlling the driving of the driving unit, the position of the alignment mark corresponding between the two substrates based on the position of the alignment mark of the two substrates detected by the detection unit; A controller that drives the drive unit to align the two substrates so that the displacement is minimized as a whole,
    The control unit drives the driving unit to move the pair of stages so that the detection unit detects the positions of three or more alignment marks of the two substrates held on the pair of stages. Substrate alignment device.
16. The detection unit has a pair of microscopes whose relative positions are fixed in a state of facing each other,
    The pair of stages individually hold a pair of substrates facing each other, and individually move in the surface direction of the held substrate while inserting the substrate into any field of view of the pair of microscopes. Substrate alignment device.
17. The controller is
    Three or more alignments formed on the one substrate by moving one of the pair of stages and observing one of the pair of substrates positioned between the pair of microscopes with one of the pair of microscopes Measure the relative position of the mark to the one microscope,
    Three or more alignments formed on the other substrate by moving the other of the pair of stages and observing the other of the pair of substrates positioned between the pair of microscopes with the other of the pair of microscopes Measure the relative position of the mark to the other microscope,
    Based on the relative position of each alignment mark of the pair of substrates with respect to the pair of microscopes, the pair of stages is moved so that the positional deviation of the corresponding alignment mark between the pair of substrates is minimized as a whole. The substrate alignment apparatus according to claim 16.
18. The substrate alignment apparatus according to claim 16 or 17, comprising two or more pairs of the pair of microscopes.
19. The pair of microscopes are:
    An observation position where the alignment mark of the substrate presented by the pair of stages enters a visual field; and
    The substrate alignment apparatus according to any one of claims 16 to 18, wherein the alignment mark of the substrate extended by the pair of stages moves between a retraction position where the alignment mark deviates from the field of view.
20. Each of the pair of stages causes any one of the pair of microscopes fixed in position to observe three or more of the alignment marks formed on any of the pair of substrates held on the stage. The substrate alignment apparatus according to any one of claims 16 to 18, which moves as described above.
21. The control unit moves each of the pair of stages while observing a reference mark that moves integrally with one of the pair of substrates held on the pair of stages. Substrate alignment device.
22. The substrate alignment apparatus according to any one of claims 16 to 21, wherein the pair of stages rotate in a plane including the substrate held on the stage.
23. A substrate alignment apparatus according to any one of claims 1 to 22,
    And a bonding apparatus that pressurizes and bonds the pair of substrates aligned in the substrate alignment apparatus.
24. A first holding step of holding one of a pair of substrates facing each other on a first stage that moves in the surface direction of the substrate;
    A second holding stage for holding the other of the pair of substrates on a second stage;
    A calibration step of observing with a first microscope and a second microscope to detect a relative position of the first microscope and the second microscope;
    A first detection step of observing an alignment mark of the substrate held on the first stage with the second microscope and detecting first position information indicating a position of the alignment mark;
    A second detection step of observing an alignment mark of the substrate held on the second stage with the first microscope and detecting second position information indicating a position of the alignment mark;
    And a positioning step of aligning the pair of substrates according to a difference between the first position information and the second position information.
25. By moving one of the pair of stages on which each of the pair of substrates is supported, inserting the substrate held on the stage between the pair of microscopes, and observing the substrate on one of the pair of microscopes Measuring a relative position of the three or more alignment marks formed on the substrate with respect to the one microscope;
    3 formed on the substrate by moving the other of the pair of stages, inserting the substrate held on the stage between the pair of microscopes, and observing the substrate with the other of the pair of microscopes. A second measurement stage for measuring the relative position of the alignment mark with respect to the other microscope;
    An alignment step of moving the pair of stages based on the relative position of the alignment mark with respect to the pair of microscopes so that the positional deviation of the corresponding alignment mark between the pair of substrates is minimized as a whole; A substrate alignment method comprising:

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