JP2020126924A - Substrate processing apparatus - Google Patents

Abstract

To provide a substrate processing apparatus capable of appropriately detecting foreign matter adhering to a chuck.SOLUTION: The substrate processing apparatus includes: a processing chamber with a chuck for attractively retaining a substrate; an imaging section for imaging the top face of the chuck; and a movement section for moving the imaging section between the inside and outside of processing chamber.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a substrate processing apparatus.

The bonding apparatus described in Patent Document 1 includes an upper chuck that chucks an upper substrate from above and a lower chuck that chucks a lower substrate from below, and bonds two substrates after facing each other. Specifically, the bonding apparatus first pushes down the central portion of the substrate adsorbed on the upper chuck to bring it into contact with the central portion of the substrate adsorbed on the lower chuck. As a result, the central portions of the two substrates are joined together by intermolecular force or the like. Next, the bonding apparatus spreads the bonded bonding region of the two substrates from the central portion to the outer peripheral portion.

JP, 2005-095579, A

The present disclosure provides a substrate processing apparatus that can appropriately detect foreign matter attached to a chuck.

A substrate processing apparatus according to an aspect of the present disclosure includes a processing chamber including a chuck that holds a substrate by suction, an imaging unit that captures an image of an upper surface of the chuck, and the imaging unit between the inside and outside of the processing chamber. And a moving unit that moves the.

According to the present disclosure, it is possible to appropriately detect a foreign substance attached to a chuck.

It is a top view which shows the joining system concerning one Embodiment. It is a side view which shows the joining system concerning one Embodiment. It is a side view which shows the state before joining of the 1st board|substrate and 2nd board concerning one Embodiment. It is a top view showing the joining device concerning one embodiment. It is a side view showing a joining device concerning one embodiment. FIG. 3 is a cross-sectional view showing an upper chuck and a lower chuck according to one embodiment, which is a cross-sectional view showing a state immediately before bonding of an upper wafer and a lower wafer. FIG. 7 is a cross-sectional view showing an operation of gradually bonding the upper wafer and the lower wafer according to one embodiment from the central portion toward the outer peripheral portion. It is a perspective view showing an imaging device concerning one embodiment. It is a flow chart which shows a part of processing which a joining system concerning one embodiment performs. FIG. 6 is an explanatory diagram showing an operation of horizontal alignment of an upper wafer and a lower wafer according to an embodiment. It is a schematic diagram (the 1) which shows the foreign material inspection method of a lower chuck. It is a schematic diagram (the 2) which shows the foreign material inspection method of a lower chuck. It is a flow chart which shows an example of the control method of the joining device concerning one embodiment. It is a figure (the 1) which shows the example of relative scanning of an imaging device and a lower chuck. It is a figure (the 2) which shows the example of relative scanning of an image pick-up device and a lower chuck.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each of the drawings, the same or corresponding constituents may be given the same or corresponding reference numerals and the description thereof may be omitted. In the following description, the X-axis direction, the Y-axis direction, and the Z-axis direction are mutually perpendicular directions, the X-axis direction and the Y-axis direction are horizontal directions, and the Z-axis direction is the vertical direction. The rotation direction with the vertical axis as the rotation center is also called the θ direction. In the present specification, the lower side means the vertically lower side, and the upper side means the vertically upper side.

<Joining system>
FIG. 1 is a plan view showing a joining system according to one embodiment. FIG. 2 is a side view showing the joining system according to the embodiment. FIG. 3 is a side view showing a state before joining the first substrate and the second substrate according to the embodiment. The bonding system 1 shown in FIG. 1 forms a superposed substrate T (see FIG. 7B) by bonding the first substrate W1 and the second substrate W2.

The first substrate W1 is a substrate in which a plurality of electronic circuits are formed on a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer. The second substrate W2 is, for example, a bare wafer on which no electronic circuit is formed. The first substrate W1 and the second substrate W2 have substantially the same diameter. An electronic circuit may be formed on the second substrate W2.

Hereinafter, the first substrate W1 may be referred to as an “upper wafer W1”, the second substrate W2 may be referred to as a “lower wafer W2”, and the overlapping substrate T may be referred to as an “overlapping wafer T”. Further, hereinafter, as shown in FIG. 3, among the plate surfaces of the upper wafer W1, the plate surface on the side to be bonded to the lower wafer W2 is referred to as “bonding surface W1j”, and the plate surface on the side opposite to the bonding surface W1j. The plate surface is described as "non-bonded surface W1n". Further, among the plate surfaces of the lower wafer W2, the plate surface on the side bonded to the upper wafer W1 is referred to as a “bond surface W2j”, and the plate surface opposite to the bonded surface W2j is referred to as a “non-bond surface W2n”. Enter.

As shown in FIG. 1, the joining system 1 includes a loading/unloading station 2 and a processing station 3. The loading/unloading station 2 and the processing station 3 are arranged side by side in the order of the loading/unloading station 2 and the processing station 3 along the X-axis positive direction. The loading/unloading station 2 and the processing station 3 are integrally connected.

The loading/unloading station 2 includes a mounting table 10 and a transfer area 20. The mounting table 10 includes a plurality of mounting plates 11. On each mounting plate 11, cassettes C1, C2, C3 for accommodating a plurality of (for example, 25) substrates in a horizontal state are mounted, respectively. For example, the cassette C1 is a cassette that houses the upper wafer W1, the cassette C2 is a cassette that houses the lower wafer W2, and the cassette C3 is a cassette that houses the overlapped wafer T.

The transport area 20 is arranged adjacent to the X-axis positive direction side of the mounting table 10. In the transport area 20, a transport path 21 extending in the Y-axis direction and a transport device 22 movable along the transport path 21 are provided. The transfer device 22 is movable not only in the Y-axis direction but also in the X-axis direction and is rotatable around the Z-axis, and is provided with cassettes C1 to C3 mounted on the mounting plate 11 and a processing station 3 described later. The upper wafer W1, the lower wafer W2, and the overlapped wafer T are transferred to and from the third processing block G3.

The number of cassettes C1 to C3 mounted on the mounting plate 11 is not limited to that shown in the figure. In addition to the cassettes C1, C2, and C3, a cassette or the like for collecting the defective substrate may be mounted on the mounting plate 11.

The processing station 3 is provided with a plurality of processing blocks including various devices, for example, three processing blocks G1, G2, G3. For example, a first processing block G1 is provided on the front side of the processing station 3 (Y-axis negative direction side of FIG. 1), and a second processing block G1 is provided on the back side of the processing station 3 (Y-axis positive direction side of FIG. 1). A processing block G2 is provided. A third processing block G3 is provided on the loading/unloading station 2 side of the processing station 3 (on the negative side of the X-axis in FIG. 1).

In the first processing block G1, a surface reforming device 30 that reforms the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 is arranged. The surface modification device 30 cuts the bond of SiO _{2 on} the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 to form a single bond of SiO, so that the bonding surface W1j is easily hydrophilized thereafter. , W2j are modified.

In the surface reforming apparatus 30, for example, oxygen gas or nitrogen gas, which is a processing gas, is excited to be plasmaized and ionized in a reduced pressure atmosphere. Then, the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 are irradiated with such oxygen ions or nitrogen ions, so that the bonding surfaces W1j and W2j are plasma-treated and modified.

A surface hydrophilization device 40 and a joining device 41 are arranged in the second processing block G2. The surface hydrophilization device 40 hydrophilizes the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 with pure water, for example, and cleans the bonding surfaces W1j and W2j. The surface hydrophilization apparatus 40 supplies pure water onto the upper wafer W1 or the lower wafer W2 while rotating the upper wafer W1 or the lower wafer W2 held by, for example, a spin chuck. As a result, the pure water supplied onto the upper wafer W1 or the lower wafer W2 diffuses on the bonding surfaces W1j, W2j of the upper wafer W1 or the lower wafer W2, and the bonding surfaces W1j, W2j are made hydrophilic.

The bonding apparatus 41 bonds the hydrophilized upper wafer W1 and lower wafer W2 by intermolecular force. The configuration of the joining device 41 will be described later.

In the third processing block G3, as shown in FIG. 2, transition (TRS) devices 50 and 51 for the upper wafer W1, the lower wafer W2 and the overlapped wafer T are provided in two stages in order from the bottom.

Further, as shown in FIG. 1, a transport region 60 is formed in a region surrounded by the first processing block G1, the second processing block G2, and the third processing block G3. A transport device 61 is arranged in the transport area 60. The transfer device 61 has a transfer fork 62 that is movable in, for example, the vertical direction, the horizontal direction, and the vertical axis. The transfer device 61 moves in the transfer region 60, and the upper wafer W1 and the lower wafer W2 are moved to predetermined devices in the first processing block G1, the second processing block G2, and the third processing block G3 adjacent to the transfer region 60. And the superposed wafer T is transported. The transport device 61 includes an image pickup device 63 and a sensor arm 64 that moves the image pickup device 63 in the Y-axis direction. The sensor arm 64 moves the imaging device 63 between the inside and outside of the processing container 100 (see FIGS. 4 and 5) of the joining device 41. The sensor arm 64 is an example of a moving unit.

Further, as shown in FIG. 1, the joining system 1 includes a control device 70. The control device 70 controls the operation of the joining system 1. The control device 70 is configured by a computer, for example, and has a CPU (Central Processing Unit) 71, a storage medium 72 such as a memory, an input interface 73, and an output interface 74. The control device 70 performs various controls by causing the CPU 71 to execute the programs stored in the storage medium 72. Further, in the control device 70, the input interface 73 receives a signal from the outside, and the output interface 74 transmits the signal to the outside.

The program of the control device 70 is stored in the information storage medium and installed from the information storage medium. Examples of the information storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical desk (MO), and a memory card. The program may be downloaded from a server via the Internet and installed.

<Joining device>
FIG. 4 is a plan view showing the joining device according to the embodiment. FIG. 5: is a side view which shows the joining apparatus concerning one Embodiment.

As shown in FIG. 4, the joining device 41 has a processing container 100 capable of sealing the inside. A loading/unloading port 101 for the upper wafer W1, the lower wafer W2, and the overlapped wafer T is formed on the side surface of the processing container 100 on the transfer region 60 side, and the loading/unloading port 101 is provided with an opening/closing shutter 102. The processing container 100 is an example of a processing chamber.

Inside the processing container 100, an upper chuck 140 for adsorbing and holding the upper surface (non-bonding surface W1n) of the upper wafer W1 and a lower surface (non-bonding surface W2n) for mounting the lower wafer W2 are placed. A lower chuck 141 that holds by suction from below is provided. The lower chuck 141 is provided below the upper chuck 140 and is arranged so as to face the upper chuck 140. The upper chuck 140 and the lower chuck 141 are arranged separately in the vertical direction.

As shown in FIG. 5, the upper chuck 140 is held by the upper chuck holding portion 150 provided above the upper chuck 140. The upper chuck holding unit 150 is provided on the ceiling surface of the processing container 100. The upper chuck 140 is fixed to the processing container 100 via the upper chuck holding unit 150.

The upper chuck holding unit 150 is provided with an upper imaging unit 151 that images the upper surface (bonding surface W2j) of the lower wafer W2 held by the lower chuck 141. For the upper imaging unit 151, for example, a CCD camera is used.

The lower chuck 141 is supported by a first lower chuck moving unit 160 provided below the lower chuck 141. The first lower chuck moving unit 160 moves the lower chuck 141 in the horizontal direction (X-axis direction) as described later. Further, the first lower chuck moving unit 160 is configured to be able to move the lower chuck 141 in the vertical direction and to rotate about the vertical axis.

The first lower chuck moving unit 160 is provided with a lower imaging unit 161 that images the lower surface (bonding surface W1j) of the upper wafer W1 held by the upper chuck 140 (see FIG. 5). A CCD camera, for example, is used for the lower imaging unit 161.

The first lower chuck moving unit 160 is provided on the lower surface side of the first lower chuck moving unit 160, and is attached to a pair of rails 162, 162 extending in the horizontal direction (X-axis direction). The first lower chuck moving unit 160 is configured to be movable along the rail 162.

The pair of rails 162, 162 are arranged on the second lower chuck moving portion 163. The second lower chuck moving unit 163 is provided on the lower surface side of the second lower chuck moving unit 163, and is attached to a pair of rails 164 and 164 extending in the horizontal direction (Y-axis direction). The second lower chuck moving unit 163 is configured to be movable in the horizontal direction (Y-axis direction) along the rail 164. The pair of rails 164 and 164 are arranged on a mounting table 165 provided on the bottom surface of the processing container 100.

The first lower chuck moving unit 160, the second lower chuck moving unit 163, and the like form a positioning unit 166. The alignment unit 166 moves the lower chuck 141 in the X-axis direction, the Y-axis direction, and the θ direction, and thereby the upper wafer W1 held by the upper chuck 140 and the lower wafer W2 held by the lower chuck 141. Horizontal alignment with. The alignment unit 166 also moves the lower chuck 141 in the Z-axis direction to vertically position the upper wafer W1 held by the upper chuck 140 and the lower wafer W2 held by the lower chuck 141. Make a match.

The alignment unit 166 of the present embodiment performs horizontal alignment of the upper wafer W1 and the lower wafer W2 by moving the lower chuck 141 in the X-axis direction, the Y-axis direction, and the θ direction. The disclosure is not limited to this. The alignment unit 166 only needs to be able to move the upper chuck 140 and the lower chuck 141 relatively in the X-axis direction, the Y-axis direction, and the θ direction. For example, the alignment unit 166 moves the lower chuck 141 in the X-axis direction and the Y-axis direction and moves the upper chuck 140 in the θ direction to align the upper wafer W1 and the lower wafer W2 in the horizontal direction. You can go.

Further, the alignment unit 166 of the present embodiment performs vertical alignment between the upper wafer W1 and the lower wafer W2 by moving the lower chuck 141 in the Z-axis direction, but the present disclosure is not limited to this. The alignment unit 166 only needs to be able to move the upper chuck 140 and the lower chuck 141 relatively in the Z-axis direction. For example, the alignment unit 166 may align the upper wafer W1 and the lower wafer W2 in the vertical direction by moving the upper chuck 140 in the Z-axis direction.

FIG. 6 is a cross-sectional view showing the upper chuck and the lower chuck according to the embodiment, and is a cross-sectional view showing a state immediately before joining the upper wafer and the lower wafer. FIG. 7A is a cross-sectional view showing a state in which the upper wafer and the lower wafer according to the embodiment are being joined. FIG. 7B is a cross-sectional view showing a state at the time when joining of the upper wafer and the lower wafer according to the embodiment is completed. In FIG. 6, FIG. 7A, and FIG. 7B, the arrow shown by the solid line indicates the suction direction of air by the vacuum pump.

The upper chuck 140 and the lower chuck 141 are, for example, vacuum chucks. In the present embodiment, the upper chuck 140 corresponds to the first holding unit described in the claims, and the lower chuck 141 corresponds to the second holding unit described in the claims. The upper chuck 140 has a suction surface 140a for sucking the upper wafer W1 on the surface (lower surface) facing the lower chuck 141. On the other hand, the lower chuck 141 has a suction surface 141a for sucking the lower wafer W2 on the surface (upper surface) facing the upper chuck 140.

The upper chuck 140 has a chuck base 170. The chuck base 170 has the same diameter as the upper wafer W1 or a diameter larger than the upper wafer W1. The chuck base 170 is supported by the support member 180. The support member 180 is provided so as to cover at least the chuck base 170 in a plan view, and is fixed to the chuck base 170 by, for example, screwing. The support member 180 is supported by a plurality of support columns 181 (see FIG. 5) provided on the ceiling surface of the processing container 100. The support member 180 and the plurality of support columns 181 configure the upper chuck holding unit 150.

Through holes 176 are formed in the support member 180 and the chuck base 170 so as to vertically penetrate the support member 180 and the chuck base 170. The position of the through hole 176 corresponds to the central portion of the upper wafer W1 that is suction-held by the upper chuck 140. The push pin 191 of the striker 190 is inserted into the through hole 176.

The striker 190 is arranged on the upper surface of the support member 180, and includes a pressing pin 191, an actuator portion 192, and a linear motion mechanism 193. The pressing pin 191 is a columnar member extending along the vertical direction, and is supported by the actuator portion 192.

The actuator unit 192 generates a constant pressure in a constant direction (here, vertically downward) by air supplied from an electropneumatic regulator (not shown), for example. The actuator section 192 can contact the central portion of the upper wafer W1 and control the pressing load applied to the central portion of the upper wafer W1 by the air supplied from the electropneumatic regulator. Further, the tip end of the actuator portion 192 is vertically movable by the air from the electropneumatic regulator through the through hole 176.

The actuator section 192 is supported by the linear motion mechanism 193. The linear motion mechanism 193 moves the actuator unit 192 in the vertical direction by, for example, a drive unit having a built-in motor.

The striker 190 is configured as described above, the movement of the actuator portion 192 is controlled by the linear motion mechanism 193, and the pressing load of the upper wafer W1 by the pressing pin 191 is controlled by the actuator portion 192.

The striker 190 presses the upper wafer W1 suction-held by the upper chuck 140 and the lower wafer W2 suction-held by the lower chuck 141 together. Specifically, the striker 190 deforms the upper wafer W1 sucked and held by the upper chuck 140 to press it against the lower wafer W2. The striker 190 corresponds to the pressing portion described in the claims.

A plurality of pins 171 that come into contact with the non-bonding surface W1n of the upper wafer W1 are provided on the lower surface of the chuck base 170. The chuck base 170, the plurality of pins 171, and the like constitute the upper chuck 140. The suction surface 140a that suction-holds the upper wafer W1 of the upper chuck 140 is radially divided into a plurality of regions, and the suction force is generated and the suction force is released in each of the divided regions.

The lower chuck 141 may be configured similarly to the upper chuck 140. The lower chuck 141 has a plurality of pins that contact the non-bonded surface W2n of the lower wafer W2. The suction surface 141a for suction-holding the lower wafer W2 of the lower chuck 141 is radially divided into a plurality of regions, and the suction force is generated and the suction force is released in each of the divided regions.

<Imaging device>
FIG. 8A and FIG. 8B are perspective views showing the imaging device 63 according to the embodiment.

The imaging device 63 has a base 81 connected to the sensor arm 64. A support portion 82 extending in the X-axis direction is provided on the lower surface of the base portion 81, and a line sensor 83 extending in the X-axis direction is provided at the lower end of the support portion 82. Further, an illumination section 84 is provided from the vicinity of the lower end of the line sensor 83 to both ends of the base section 81 in the Y-axis direction. The lighting unit 84 includes, for example, a light emitting diode (LED). Further, two projection units 85 and a camera 86 for projecting a pattern are provided so as to penetrate the illumination unit 84.

The length of the imaging range of the line sensor 83 in the X-axis direction is preferably larger than the diameter of the lower chuck 141. Although the details will be described later, it is possible to image the entire lower chuck 141 with one scan. The length of the imaging range of the line sensor 83 in the X-axis direction may be smaller than the diameter of the lower chuck 141 on the assumption that scanning is performed a plurality of times.

<Joining method>
FIG. 9 is a flowchart showing a part of the processing executed by the joining system according to the embodiment. The various processes shown in FIG. 9 are executed under the control of the control device 70.

First, the cassette C1 accommodating a plurality of upper wafers W1, the cassette C2 accommodating a plurality of lower wafers W2, and an empty cassette C3 are mounted on a predetermined mounting plate 11 of the loading/unloading station 2. After that, the upper wafer W1 in the cassette C1 is taken out by the transfer device 22 and transferred to the transition device 50 of the third processing block G3 of the processing station 3.

Next, the upper wafer W1 is transferred by the transfer device 61 to the surface reforming device 30 of the first processing block G1. In the surface modification device 30, oxygen gas, which is a processing gas, is excited to be plasma and ionized under a predetermined reduced pressure atmosphere. The bonding surface W1j of the upper wafer W1 is irradiated with the oxygen ions, and the bonding surface W1j is plasma-processed. As a result, the bonding surface W1j of the upper wafer W1 is modified (step S101).

Next, the upper wafer W1 is transferred to the surface hydrophilization device 40 of the second processing block G2 by the transfer device 61. The surface hydrophilization apparatus 40 supplies pure water onto the upper wafer W1 while rotating the upper wafer W1 held by the spin chuck. Then, the supplied pure water diffuses on the bonding surface W1j of the upper wafer W1, and a hydroxyl group (silanol group) is attached to the bonding surface W1j of the upper wafer W1 modified in the surface reforming device 30 to cause the bonding surface. W1j is made hydrophilic (step S102). Further, the bonding surface W1j of the upper wafer W1 is washed with pure water used to make the bonding surface W1j hydrophilic.

Next, the upper wafer W1 is transferred to the bonding device 41 of the second processing block G2 by the transfer device 61 (step S103). At this time, the upper wafer W1 is conveyed with its front and back surfaces reversed. That is, the bonding surface W1j of the upper wafer W1 is directed downward.

After that, the transport fork 62 moves below the upper chuck 140 in the joining device 41. Then, the upper wafer W1 is transferred from the transfer fork 62 to the upper chuck 140. The upper wafer W1 is attracted and held by the upper chuck 140 in a direction in which the non-bonding surface W1n is in contact with the upper chuck 140 (step S104).

While the processing of steps S101 to S104 described above is performed on the upper wafer W1, the processing of the lower wafer W2 is performed. First, the lower wafer W2 in the cassette C2 is taken out by the transfer device 22 and transferred to the transition device 50 of the processing station 3.

Next, the lower wafer W2 is transferred to the surface modification device 30 by the transfer device 61, and the bonding surface W2j of the lower wafer W2 is modified (step S105). The modification of the bonding surface W2j of the lower wafer W2 in step S105 is the same as in step S101 described above.

After that, the lower wafer W2 is transferred to the surface hydrophilization device 40 by the transfer device 61, and the bonding surface W2j of the lower wafer W2 is hydrophilized (step S106). Further, the joint surface W2j is washed with pure water used for making the joint surface W2j hydrophilic. The hydrophilicity of the bonding surface W2j of the lower wafer W2 in step S106 is the same as the hydrophilicity of the bonding surface W1j of the upper wafer W1 in step S102.

After that, the lower wafer W2 is transferred to the bonding device 41 by the transfer device 61 (step S107).

After that, the transport fork 62 moves above the lower chuck 141 in the joining device 41. Then, the lower wafer W2 is transferred from the transfer fork 62 to the lower chuck 141. The lower wafer W2 is suction-held on the lower chuck 141 in a direction in which the non-bonding surface W2n contacts the lower chuck 141 (step S108).

Next, horizontal position adjustment of the upper wafer W1 held by the upper chuck 140 and the lower wafer W2 held by the lower chuck 141 is performed (step S109). For this alignment, the alignment marks W1a, W1b, W1c (see FIG. 10) previously formed on the bonding surface W1j of the upper wafer W1 and the alignment marks W2a, W2b, W2c previously formed on the bonding surface W2j of the lower wafer W2 are used. (See FIG. 10) is used.

The horizontal alignment operation of the upper wafer W1 and the lower wafer W2 will be described with reference to FIG. FIG. 10A is a diagram illustrating an alignment operation between the upper imaging unit and the lower imaging unit according to the embodiment. FIG. 10B is a diagram illustrating an imaging operation of the lower wafer by the upper imaging unit and an imaging operation of the upper wafer by the lower imaging unit according to the embodiment. FIG. 10C is a diagram for explaining the alignment operation of the upper wafer and the lower wafer according to the embodiment.

First, as shown in FIG. 10A, the horizontal positions of the upper imaging unit 151 and the lower imaging unit 161 are adjusted. Specifically, the lower chuck 141 is moved horizontally by the alignment unit 166 so that the lower imaging unit 161 is located substantially below the upper imaging unit 151. Then, the common target 149 is confirmed by the upper imaging unit 151 and the lower imaging unit 161, and the horizontal position of the lower imaging unit 161 is adjusted so that the horizontal positions of the upper imaging unit 151 and the lower imaging unit 161 match. Adjusted.

Next, as shown in FIG. 10B, the lower chuck 141 is moved vertically upward by the alignment section 166. After that, while the lower chuck 141 is moved in the horizontal direction by the alignment unit 166, the upper imaging unit 151 is used to sequentially image the alignment marks W2c, W2b, W2a on the bonding surface W2j of the lower wafer W2. At the same time, while moving the lower chuck 141 in the horizontal direction, the lower imaging unit 161 is used to sequentially image the alignment marks W1a, W1b, W1c on the bonding surface W1j of the upper wafer W1. Note that FIG. 10B shows how the upper imaging unit 151 images the alignment mark W2c of the lower wafer W2 and the lower imaging unit 161 images the alignment mark W1a of the upper wafer W1.

The captured image data is output to the control device 70. The control device 70 causes the alignment unit 166 to adjust the horizontal position of the lower chuck 141 based on the image data captured by the upper imaging unit 151 and the image data captured by the lower imaging unit 161. This horizontal alignment is performed so that the alignment marks W1a, W1b, W1c of the upper wafer W1 and the alignment marks W2a, W2b, W2c of the lower wafer W2 overlap each other when viewed in the vertical direction. Thus, the horizontal positions of the upper chuck 140 and the lower chuck 141 are adjusted, and the horizontal positions of the upper wafer W1 and the lower wafer W2 (including, for example, the X-axis direction position, the Y-axis direction position, and the θ-direction position) are adjusted. It

Next, as shown by the solid line in FIG. 10C, the vertical positions of the upper wafer W1 held by the upper chuck 140 and the lower wafer W2 held by the lower chuck 141 are adjusted (step S110). Specifically, the alignment unit 166 moves the lower chuck 141 vertically upward to bring the lower wafer W2 closer to the upper wafer W1. As a result, as shown in FIG. 6, the gap WS1 between the bonding surface W2j of the lower wafer W2 and the bonding surface W1j of the upper wafer W1 is adjusted to a predetermined distance, for example, 50 μm to 200 μm.

Next, after the suction holding of the central portion of the upper wafer W1 by the upper chuck 140 is released (step S111), the pressing pin 191 of the striker 190 is lowered as shown in FIG. The central part of is pushed down (step S112). When the center of the upper wafer W1 contacts the center of the lower wafer W2 and the center of the upper wafer W1 and the center of the lower wafer W2 are pressed with a predetermined force, the center of the pressed upper wafer W1 is pressed. Bonding is started between and the central portion of the lower wafer W2. Then, a bonding wave for gradually joining the upper wafer W1 and the lower wafer W2 from the central portion toward the outer peripheral portion is generated.

Here, since the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are modified in steps S101 and S105, respectively, first, the Van der Waals force (intermolecular force) is generated between the bonding surfaces W1j and W2j. Occurs, and the joint surfaces W1j and W2j are joined together. Further, since the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are hydrophilized in steps S102 and S106, respectively, the hydrophilic group between the bonding surfaces W1j and W2j is hydrogen-bonded, and the bonding surfaces W1j and W2j are bonded. The two are firmly joined together.

After that, while the pressing pin 191 presses the central portion of the upper wafer W1 and the central portion of the lower wafer W2, the suction holding of the entire upper wafer W1 by the upper chuck 140 is released (step S113). As a result, as shown in FIG. 7B, the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 are entirely in contact with each other, and the upper wafer W1 and the lower wafer W2 are bonded. After that, the pressing pin 191 is raised to the upper chuck 140, and the suction holding of the lower wafer W2 by the lower chuck 141 is released.

Then, the overlapped wafer T is transferred by the transfer device 61 to the transition device 51 of the third processing block G3, and then transferred by the transfer device 22 of the loading/unloading station 2 to the cassette C3. In this way, a series of joining processes is completed.

<Foreign matter inspection of lower chuck>
The series of bonding processes shown in steps S101 to S113 shown in FIG. 9 are repeatedly performed to repeatedly manufacture the overlapped wafer T. Meanwhile, as shown in FIG. 6, in a process in which the upper wafer W1 and the lower wafer W2 are close to each other and bonded, the lower wafer W2 may be adsorbed and held by the lower chuck 141 in a state where foreign matter is attached to the non-bonded surface W2n. .. When such foreign matter is present, the lower wafer W2 is distorted, so that a void may occur between the lower wafer W2 and the upper wafer W1. Furthermore, if the foreign matter remains on the lower chuck 141, voids may continue to be generated unless the foreign matter is removed.

Therefore, in the present embodiment, a foreign matter inspection using the imaging device 63 is performed after the superposed wafer T is unloaded and before the next lower wafer W2 is transferred. 11 to 12 are schematic views showing a method of inspecting a lower chuck for foreign matter.

When the adsorption and holding of the lower wafer W2 by the lower chuck 141 is released, as shown in FIG. 11A, the three support pins 91 penetrating the lower chuck 141 ascend and the overlapped wafer T is removed from the lower chuck 141. Be separated.

Next, the opening/closing shutter 102 is opened, and the transfer fork 62 moves into the processing container 100 through the loading/unloading port 101 and receives the overlapped wafer T on the support pin 91, as shown in FIG. Then, the transfer fork 62 collects the overlapped wafer T from the processing container 100.

After that, as shown in FIG. 11C, the support pin 91 descends.

Subsequently, as shown in FIG. 11D, the sensor arm 64 having the imaging device 63 fixed to the tip thereof moves into the processing container 100 through the loading/unloading port 101, and stops above the lower chuck 141. Then, while the first lower chuck moving unit 160 and the second lower chuck moving unit 163 move in the X-axis direction and the Y-axis direction, the foreign matter inspection of the upper surface of the lower chuck 141 is performed.

Next, as shown in FIG. 12A, the sensor arm 64 moves to the outside of the processing container 100.

After that, as shown in FIG. 12B, the support pins 91 are raised to prepare for receiving the next lower wafer W2.

Subsequently, as shown in FIG. 12C, the transfer fork 62 on which the lower wafer W2 is placed moves into the processing container 100.

Thereafter, as shown in FIG. 12D, the lower wafer W2 is delivered to the support pins 91, and the transfer fork 62 moves to the outside of the processing container 100. Further, the support pins 91 are lowered, and the lower chuck 141 sucks and holds the lower wafer W2.

According to such an embodiment, it is possible to appropriately perform a foreign matter inspection on the upper surface of the lower chuck 141. Therefore, even if foreign matter is attached to the non-bonding surface W2n of the lower wafer W2 and brought into the bonding apparatus 41, and the foreign matter remains on the upper surface of the lower chuck 141, the foreign matter can be properly detected. Further, since the image pickup device 63 is taken out of the processing container 100 after the foreign matter inspection, it is not necessary to provide a space for fixing the image pickup device 63 in the processing container 100. Furthermore, when the imaging device 63 is fixed in the processing container 100, the heat generated by the illumination unit 84 may affect the bonding between the lower wafer W2 and the upper wafer W1, but such an effect can be suppressed. ..

Here, an example of a control method of the bonding apparatus 41 using the result of the foreign matter inspection will be described. FIG. 13 is a flowchart showing an example of a control method of the welding device 41 according to the embodiment.

In this example, when the foreign matter inspection is started, the line sensor 83 captures an image while the upper surface of the lower chuck 141 is irradiated with light from the illumination unit 84 (step S201).

If no foreign matter is detected by the line sensor 83 (step S202), the foreign matter inspection is ended as it is. On the other hand, when a foreign substance is detected by the line sensor 83 (step S202), the foreign substance is photographed by the pattern projection method using the two projection units 85 and the camera 86 (step S203). According to the pattern projection method, the three-dimensional size of a foreign substance can be specified.

If the size of the foreign matter is smaller than the preset threshold value (step S204), the foreign matter inspection is terminated because it is possible to continue the process. For example, if the maximum diameter of the foreign substance in the planar shape is less than 50 μm, the foreign substance inspection is terminated even if the foreign substance is present. On the other hand, if the size of the foreign matter is equal to or larger than the threshold value, if the processing is continued as it is, the bonding processing is stopped because it is highly likely that voids will occur in the next overlapped wafer T. In this case, for example, a lamp, a sound, or both are used to notify the operator that the joining process has been stopped. If there is a host computer that manages the joining system 1, the host computer may be notified.

The imaging data acquired using the line sensor 83 (step S201) and the imaging data acquired by the pattern projection method (step S203) may be discarded each time, but in the bonding system 1 or the host computer. May be stored in.

Further, instead of the size determination in step S204, artificial intelligence (AI) is used to extract a characteristic portion from a captured image of a foreign substance obtained by the pattern projection method, and the characteristic portion causes a void. Based on the possibility, it may be determined whether to continue or stop the process.

Further, an automatic cleaning device such as a cleaning pad of the lower chuck 141 is built in the bonding device 41, and instead of stopping the process of step S205, the automatic cleaning device is operated to remove foreign matters on the upper surface of the lower chuck 141. You may do so.

The frequency of the foreign matter inspection using the imaging device 63 is not particularly limited. For example, it may be performed each time the lower wafer W2 is loaded, may be performed each time a certain number of overlapping wafers T are processed, or may be performed before the first lower wafer W2 is loaded for each lot. Alternatively, the process may be performed every time a certain number of overlapping wafers T are processed, and may be performed before the first lower wafer W2 is loaded for each lot.

When it is determined that the processing is stopped by a certain foreign matter inspection, the overlapped wafer T produced between the latest foreign matter inspection and the foreign matter inspection is soft-marked as the foreign matter may be attached, and the overlapped wafer T The information may be stored in a host computer that manages the characteristics of.

In the above-described embodiment, as shown in FIG. 14A, the lower chuck 141 is moved in the bonding device 41 with the position of the imaging device 63 fixed, thereby scanning the entire upper surface of the lower chuck 141. However, the form of scanning is not limited to this. For example, as shown in FIG. 14B, the imaging device 63 may be moved while the position of the lower chuck 141 is fixed, and the entire upper surface of the lower chuck 141 may be scanned. In this case, the scanning can be performed continuously after the operation of moving the imaging device 63 into the bonding device 41 after the transfer of the overlapped wafer T.

Further, as shown in FIG. 15A, one end of the image pickup device 63 is fixed to the sensor arm 64 at a position separated from the lower chuck 141, and the image pickup device 63 is used as a wiper of an automobile with this fixed point as a rotation axis. Alternatively, the entire upper surface of the lower chuck 141 may be scanned by swinging. Further, as shown in FIG. 15B, one end of the image pickup device 63 is fixed to the sensor arm 64 above the center of the lower chuck 141, and the image pickup device 63 is rotated at 360° C. with this fixed point as a rotation axis. The entire upper surface of the lower chuck 141 may be scanned. In this case, the length of the image pickup device 63 can be reduced to about half of that in the above-described embodiment.

When the image pickup device 63 is moved, vibration may occur in the image pickup device 63 and the sensor arm 64 depending on the rigidity. Considering this vibration, it is preferable that the position of the image pickup device 63 is fixed and the lower chuck 141 is moved, as shown in FIG.

The form of the imaging device 63 is not particularly limited. For example, the illumination unit 84 may include a rotating mechanism and may rotate so as to reciprocate within a certain range. In this case, the rotational movement of the illumination unit 84 may be controlled by using a motor. By changing the inclination angle of the light emitted from the illumination unit 84 using the rotating mechanism, the detection accuracy of the foreign matter can be adjusted. Further, the illumination unit 84 may be provided on the sensor arm 64 instead of the imaging device 63. Further, the entire upper surface of the lower chuck 141 may be scanned in one reciprocation, and the inclination angle of light may be different between the forward path and the return path.

Alternatively, the camera 86 may not be provided in the image pickup device 63, and the upper image pickup unit 151 (for example, a microscope camera) may be used to perform pattern photographing.

Although the preferred embodiments and the like have been described in detail above, the present invention is not limited to the above-described embodiments and the like, and various embodiments and the like described above are possible without departing from the scope described in the claims. Modifications and substitutions can be added.

1 Bonding System 41 Bonding Device 70 Control Device 141 Lower Chuck 61 Transport Device 62 Transport Fork 63 Imaging Device 64 Sensor Arm 83 Line Sensor 84 Illumination Unit 85 Projection Unit 86 Camera

Claims (9)

A processing chamber having a chuck for sucking and holding a substrate;
An imaging unit for imaging the upper surface of the chuck,
A moving unit that moves the imaging unit between the inside and the outside of the processing chamber;
A substrate processing apparatus having: A transfer device having a transfer fork for transferring the substrate to and from the chuck,
The substrate processing apparatus according to claim 1, wherein the moving unit is provided in the transfer device. The substrate processing apparatus according to claim 1, wherein the imaging unit includes a line sensor capable of imaging a range larger than a diameter of the chuck. The moving unit moves the imaging unit into the processing chamber, and while the position in the processing chamber is fixed, the chuck is moved horizontally below the line sensor, so that the chuck is moved by the line sensor. The substrate processing apparatus according to claim 3, wherein the upper surface of the substrate is scanned. The moving unit moves the imaging unit into the processing chamber, and horizontally moves the line sensor above the chuck with one end of the line sensor located at a position displaced from above the chuck as a rotation axis. 4. The substrate processing apparatus according to claim 3, wherein the line sensor scans the upper surface of the chuck. The substrate processing apparatus according to claim 1, wherein the imaging unit includes a line sensor capable of imaging a range larger than a radius of the chuck. The moving unit moves the imaging unit into the processing chamber, and one end of the line sensor at the center position of the chuck is used as a rotation axis to move the line sensor in the horizontal direction above the chuck. The substrate processing apparatus according to claim 6, wherein an upper surface of the chuck is scanned by a line sensor. The substrate processing apparatus according to claim 1, wherein the imaging unit includes a projection unit that projects a pattern on an upper surface of the chuck. The substrate processing apparatus according to claim 1, wherein when the image acquired by the imaging unit satisfies a predetermined condition, loading of the substrate into the processing chamber is stopped.

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