JP2008258368A - Device and method for joining substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate-joining device capable of continuing work for joining substrates even if lateral shift occurs between a pair of substrate-holding means when joining the substrates. <P>SOLUTION: The substrate-joining device comprises: a first substrate-holding means (101) for aligning and holding a first set of substrates; a second substrate-holding means (201) for aligning and holding a second set of substrates; an alignment-monitoring means (401) for monitoring the alignment of the first and second substrate-holding means within a permissive value; a moving means (205) for moving at least one of the first and second substrate-holding means; and a permissible value change means (403) for changing the permissive value of the alignment-monitoring means before force in the direction of a junction surface caused by joining the substrate operates. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate bonding apparatus and a substrate bonding method for aligning and bonding a plurality of substrates.

  In recent years, notebook computers and mobile phones that use semiconductor integrated circuits have become increasingly sophisticated. As a result, there is an increasing demand for higher density and higher functionality of semiconductor integrated circuits.

  One method for increasing the density and functionality of semiconductor integrated circuits is to bond substrates such as wafers and stack the substrates.

  In the case of bonding the substrates, for example, since it is necessary to bond the electrodes of the wafer, they need to be aligned and bonded to each other. In order to align and bond the substrates, a substrate bonding apparatus including a pair of substrate holding means is used. Here, the substrates to be bonded are first and second substrates. First, the first and second substrates are respectively positioned and held by a pair of substrate holding means. Next, with the pair of substrate holding means aligned, at least one of the pair of substrate holding means is moved to join the first and second substrates.

  Such a substrate bonding apparatus is described in Patent Document 1, for example.

JP 2005-302858 A

  However, in the substrate bonding apparatus as described above, when the first and second substrates are bonded in a state where the pair of substrate holding means are aligned, the pair of the first and second substrates are in contact with each other. Depending on the parallelism of the holding surface of the substrate holding apparatus and the flatness of the substrate, a force in an oblique direction with respect to the substrate surface may be generated. Such a force causes a lateral shift between the substrate and the pair of substrate holding means for holding the substrate. Even if a lateral shift occurs between the pair of substrate holding means, there is no problem as long as the substrate is aligned within a predetermined value range. However, if a lateral shift occurs between the pair of substrate holding means, it is determined that the alignment is abnormal, and the substrate bonding operation cannot be continued.

  Therefore, when the substrates are bonded, the substrate bonding operation can be continued even if a lateral shift occurs between the pair of substrate holding means due to the parallelism of the holding surfaces of the pair of substrate holding means or the flatness of the substrate. There is a need for a substrate bonding apparatus and a substrate bonding method that can be performed.

  A substrate bonding apparatus according to the present invention is a substrate bonding apparatus that aligns and bonds a first set of substrates and a second set of substrates. The substrate bonding apparatus according to the present invention includes a first substrate holding means for aligning and holding the first set of substrates, and a second substrate holding means for aligning and holding the second set of substrates. And an alignment monitoring means for monitoring that the first and second substrate holding means are aligned within an allowable value. The substrate bonding apparatus according to the present invention includes a moving unit that moves at least one of the first and second substrate holding units so as to bond the first group of substrates and the second group of substrates, And a tolerance changing means for changing the tolerance of the alignment monitoring means before a force in the joining surface direction due to joining of the first set of substrates and the second set of substrates is applied. It is characterized by that.

  According to the substrate bonding apparatus according to the present invention, the force in the bonding surface direction due to bonding of the first set of substrates and the second set of substrates acts to cause a gap between the first and second substrate holding means. Even if a lateral deviation occurs, the allowable value changing means changes the allowable value of the alignment monitoring means, so that the substrate bonding operation can be continued.

  The substrate bonding method according to the present invention is a substrate bonding method in which a first set of substrates and a second set of substrates are aligned and bonded. In the substrate bonding method according to the present invention, the first set of substrates and the second set of substrates are held by first and second substrate holding means, respectively, and the first set of substrates and the second set of substrates are held. The first substrate holding means and the second substrate holding means are aligned within an allowable value so as to align the pair of substrates. In the substrate bonding method according to the present invention, the first set of substrates and the second set of substrates are further bonded in a state where the first and second substrate holding means are aligned within the allowable value. As described above, before at least one of the first and second substrate holding means is moved and the first set of substrates and the second set of substrates are bonded, the force in the bonding surface direction acts. The allowable value is increased so as not to be affected by the force.

  According to the substrate bonding apparatus according to the present invention, the force in the bonding surface direction due to bonding of the first set of substrates and the second set of substrates acts to cause a gap between the first and second substrate holding means. Even if a lateral deviation occurs, the allowable value for alignment of the first and second substrate holding means is changed, so that the substrate bonding operation can be continued.

  According to the present invention, when the substrates are bonded, even if a lateral shift occurs between the pair of substrate holding means due to the parallelism of the holding surfaces of the pair of substrate holding means or the flatness of the substrate, the substrate bonding operation is performed. A substrate bonding apparatus and a substrate bonding method that can be continued are obtained.

  FIG. 1 is a diagram illustrating a configuration of a substrate bonding apparatus according to an embodiment of the present invention.

  The substrate bonding apparatus according to the present embodiment includes an upper frame 301 and a lower frame 303. Further, the substrate bonding apparatus includes a first stage 105 installed on the upper frame 301, a first intermediate plate 103 installed on the first stage 105, and a first stage installed on the first intermediate plate 103. Substrate holder 101. The first substrate holder 101 holds the first substrate W1. Further, the substrate bonding apparatus includes a second stage 205 installed on the lower frame 303, a second intermediate plate 203 installed on the second stage 205 via a load cell 207, and a second intermediate plate 203. And a second substrate holder 201 installed on the substrate. The second substrate holder 201 holds the second substrate W2.

  The first substrate holder 101 and the second substrate holder 201 may be configured to hold the substrate by an electrostatic chuck or a vacuum chuck.

  Here, the substrate surface is the XY plane, and the direction perpendicular to the substrate surface is the Z-axis direction. The first stage 105 is configured to be movable in the X and Y axis directions and to be rotatable around the Z axis for position adjustment. The second stage 205 can be moved in the X and Y axis directions for position adjustment, can be rotated about the Z axis, and can be tilted. The second stage 205 is further configured to be movable in the Z-axis direction. The operations of the first stage 105 and the second stage 205 are controlled by the control device 405.

  In the present embodiment, both the first and second stages are configured to be movable for position adjustment, but only one of them may be configured to be movable for position adjustment. In the present embodiment, only the second stage is configured to be movable in the Z-axis direction, but only the first stage or both the first and second stages are configured to be movable in the Z-axis direction. May be.

  Laser distance meters 4011A and 4012A are installed on the upper frame 301. Between the reflector 4011B installed on the first substrate holder 101 and the reflector 4012B installed on the second substrate holder 201, respectively. Measure the distance. The distances measured by the laser distance meters 4011A and 4012A are monitored by the alignment monitoring device 401. The laser distance meter may be installed in two directions of the X and Y axes. When the distance between the upper frame 301 and the first substrate holder 101 and the second substrate holder 201 deviates from the aligned state, the alignment monitoring device 401 determines that the position is displaced. The positions of the first and second substrate holders (first and second stages) may be measured by other sensors such as a linear encoder.

  On the lower frame 303, a support column 305A for supporting the alignment microscope 307A and a support column 305B for supporting the alignment microscope 307B are installed.

  FIG. 2 is a flowchart illustrating a substrate bonding method according to an embodiment of the present invention.

  In step S2010 of FIG. 2, the first substrate W1 and the second substrate W2 are used as the first substrate holder 101 (first substrate holding means) and the second substrate holder 201 (second substrate holding means). Hold. Here, each of the first substrate W1 and the second substrate W2 may be a set of a plurality of substrates already bonded. As shown in FIG. 1, the first substrate holder 101 and the second substrate holder 201 are provided with a holder fiducial mark FM for alignment. Using this holder fiducial mark FM and a substrate fiducial mark (not shown) attached to the substrate, the substrate holder and the substrate may be aligned in advance.

  In step S2020 of FIG. 2, the first substrate holder 101 and the second substrate holder 201 are aligned so that the first and second substrates are aligned. When the substrate holder and the substrate are aligned in advance, the first substrate holder 101 and the second substrate holder 201 are observed by observing the holder fiducial mark FM with the alignment microscopes 307A and 307B. May be aligned. When the substrate holder and the substrate are not aligned in advance, the alignment microscopes 307A and 307B use the alignment microscopes 307A and 307B to hold the first and second substrate holders 201 and 201, the fiducial marks FM, and the first and The first substrate holder 101 and the second substrate holder 201 may be aligned so as to align the first and second substrates by observing the fiducial marks on the second substrate. .

  The positioning of the first substrate holder 101 and the second substrate holder 201 is performed by moving one or both of the first stage 105 and the second stage 205 in the X and Y axis directions by the control device 405, or Z Do this by rotating around an axis.

  In a state where the first substrate holder 101 and the second substrate holder 201 are aligned, the alignment monitoring device 401 uses the laser distance meters 4011A and 4012A to perform the upper frame 301, the first substrate holder 101, and the second substrate. The distance from the holder 201 is measured and stored.

  In step S2030 of FIG. 2, the first substrate holder 101 and the second substrate holder 201 are brought close to each other with the first substrate holder 101 and the second substrate holder 201 being aligned. Specifically, the first substrate holder 101 and the second substrate holder 201 are moved closer to each other by moving the second stage 205 upward in the Z-axis by the control device 405. While moving the second stage 205 upward in the Z-axis, the alignment monitoring device 401 uses the laser distance meters 4011A and 4012A to move the upper frame 301, the first substrate holder 101, and the second substrate holder. The distance to 201 is measured. If the difference between the measured distance and the stored distance in the aligned state is within an allowable value, the first holder and the second holder are aligned with an accuracy within the allowable value. To be judged. If the difference exceeds the allowable value, it is determined that the first holder and the second holder are displaced. In this case, since the state is abnormal, the process is interrupted.

  In step S2040 in FIG. 2, the tolerance value changing unit 403 in FIG. 1 determines whether or not the tolerance value for the alignment should be increased. Whether or not the allowable value should be increased may be determined based on the position of the second stage 205 in the Z-axis direction, for example. Since the thickness of the substrate and the dimensions of each part are known, the distance between the substrate can be known if the position of the second stage 205 in the Z-axis direction is known. Therefore, the position of the second stage 205 in the Z-axis direction is measured by a measuring device such as a linear scale, and the above-described alignment tolerance is increased when the distance between the substrates becomes a predetermined value or less. You may judge that you should. Alternatively, the distance between the holders is measured by installing a distance measuring capacitance sensor or eddy current sensor (both not shown) in the first holder 101 and the second holder 201 and measuring the distance between the holders. It may be determined that the allowable value for the above alignment should be increased when becomes less than a predetermined value. Here, the sensor may be another sensor for distance measurement. The sensor may be installed on an intermediate plate, a stage, or a frame as long as the distance between the substrate and the substrate can be estimated based on the thickness of the substrate and the dimensions of each part. Furthermore, when the force generated by the contact between the substrate and the substrate is detected by the load cell 207, it may be determined that the allowable value of the alignment should be increased.

  If the above alignment tolerance value should not be increased, the process proceeds to step S2050, waits for a predetermined time, and returns to step S2040. If the allowable value for the alignment should be increased, the process proceeds to step S2060.

  In step S2060 of FIG. 2, the allowable value changing unit 403 sends an instruction to the alignment monitoring device 401 to increase the above alignment allowable value. Here, in the present specification and claims, increasing the allowable value includes setting the allowable value to infinity, that is, not checking the allowable value.

  In step S2070 in FIG. 2, the second stage 205 is further moved upward in the Z-axis to join the first substrate and the second substrate. When the first and second substrates are in contact with each other, an oblique force is generated with respect to the substrate surface due to the parallelism of the holding surfaces of the first substrate holder 101 and the second substrate holder 201, the flatness of the substrate, and the like. Even if a lateral deviation occurs between the first substrate holder 101 and the second substrate holder 201, the tolerance for the above-mentioned alignment is increased. Therefore, the joining operation can be continued.

  In the case where the substrate is a wafer and bonding is performed by inserting a resin between the wafers, the bonded wafer may be taken out. When the substrate is a wafer and no resin is used for bonding, the first substrate holder 101 and the second substrate holder 201 may be fixed with a magnet or the like and taken out.

  As described above, according to the present invention, when the substrates are bonded, the first and second substrate holding means are arranged depending on the parallelism of the holding surfaces of the first and second substrate holding means and the flatness of the substrate. Even if a lateral shift occurs, a substrate bonding apparatus and a substrate bonding method capable of continuing the substrate bonding operation are obtained.

  In one embodiment of the present invention, the distance between the first and second substrate holding means is detected, and the first set of substrates and the second set of substrates are determined according to the result of comparison between the distance and a predetermined value. Before the force in the joining surface direction due to joining is applied, the allowable value is increased so as not to be affected by the force.

  According to this embodiment, the force in the bonding surface direction due to the bonding of the first set of substrates and the second set of substrates by detecting the distance between the first and second substrate holding means. The tolerance can be increased without fail before the action.

  Another embodiment of the present invention is characterized in that the distance between the first and second substrate holding means is detected by a sensor attached to at least one of the first and second substrate holding means.

  According to this embodiment, the distance between the first and second substrate holding means can be easily and reliably detected by the sensor attached to at least one of the first and second substrate holding means.

  Another embodiment of the present invention is characterized in that the distance between the first and second substrate holding means is detected by detecting the position of at least one of the first and second substrate holding means. .

  According to this embodiment, it is possible to easily and reliably detect the distance between the first and second substrate holding means by detecting the position of at least one of the first and second substrate holding means. it can.

  In another embodiment of the present invention, a force acting between the first and second substrate holding means is detected, and the first set of substrates and the second substrate are detected based on a result of comparison between the force and a predetermined value. Before the force in the bonding surface direction due to bonding of a pair of substrates is applied, the allowable value is increased so as not to be affected by the force.

  According to the present embodiment, the distance between the first and second substrate holding means can be easily and reliably detected by detecting the force acting between the first and second substrate holding means. Can do.

It is a figure which shows the structure of the board | substrate bonding apparatus by one Embodiment of this invention. 3 is a flowchart illustrating a substrate bonding method according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... 1st board | substrate holder, 103 ... 1st intermediate | middle plate, 105 ... 1st stage, 201 ... 2nd board | substrate holder, 203 ... 2nd intermediate | middle plate, 205 ... 2nd stage

Claims (8)

A substrate bonding apparatus for aligning and bonding a first set of substrates and a second set of substrates,
First substrate holding means for aligning and holding the first set of substrates;
Second substrate holding means for aligning and holding the second set of substrates;
Alignment monitoring means for monitoring that the first and second substrate holding means are aligned within an allowable value;
Moving means for moving at least one of the first and second substrate holding means to join the first set of substrates and the second set of substrates;
And a tolerance changing means for changing the tolerance of the alignment monitoring means.   The allowable value changing unit detects a distance between the first and second substrate holding units and compares the distance with a predetermined value to determine the first group of substrates and the second group. 2. The substrate bonding apparatus according to claim 1, wherein before the force in the bonding surface direction due to bonding of the substrates is applied, the allowable value is increased so as not to be affected by the force.   3. The tolerance changing means detects a distance between the first and second substrate holding means by a sensor attached to at least one of the first and second substrate holding means. A substrate bonding apparatus according to claim 1.   The tolerance value changing means detects a distance between the first and second substrate holding means by detecting a position of at least one of the first and second substrate holding means. Item 3. The substrate bonding apparatus according to Item 2.   The permissible value changing unit detects a force acting between the first and second substrate holding units, and compares the force with a predetermined value to determine a first set of substrates and a second set. 2. The substrate bonding apparatus according to claim 1, wherein before the force in the bonding surface direction due to bonding of the substrates is applied, the allowable value is increased so as not to be affected by the force. A substrate bonding method for aligning and bonding a first set of substrates and a second set of substrates,
Holding the first set of substrates and the second set of substrates in first and second substrate holding means, respectively;
Aligning the first substrate holding means and the second substrate holding means within an allowable value so as to align the first set of substrates and the second set of substrates;
The first and second substrates are bonded so that the first set of substrates and the second set of substrates are joined in a state where the first and second substrate holding means are aligned within the allowable value. Move at least one of the holding means,
A substrate bonding method for increasing the allowable value so as not to be affected by the force before the force in the bonding surface direction caused by bonding the first and second sets is applied.   The substrate bonding method according to claim 6, wherein a distance between the first and second substrate holding means is detected, and the allowable value is increased according to a result of comparison between the distance and a predetermined value.   7. The substrate bonding according to claim 6, wherein a force acting between the first and second substrate holding means is detected, and the allowable value is increased according to a result of comparison between the force and a predetermined value. Method.

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