Patent Application
20080047651
The embodiments will be described in detail with reference to the following drawings, in which like reference numerals refer to like elements, and wherein:
The first chamber 110 is provided with a first surface plate 111 upon which the first substrate S1 is held. The first surface plate 111 is provided with a first chuck 113 for holding the first substrate S1. The first chuck may be an electrostatic chuck which is capable of holding a substrate via the application of an electric charge which creates an electrostatic holding force. Installed between the first surface plate 111 and the first chuck 113 is a first chuck plate 115 for mounting the first chuck 113 to the first surface plate 111.
The second chamber 130 is provided with a second surface plate 131 upon which the second substrate S2 is held. The second surface plate 131 is provided with a second chuck 133 for holding the second substrate S2. Installed between the second surface plate 131 and the second chuck 133 is a second chuck plate 135 for mounting the second chuck 133 to the second surface plate 131.
Either or both of the first and second surface plates 111 and 131 is provided with one or more spacing sensors 117 for measuring a spacing between the first surface plate 111 and the second surface plate 131. Preferably, multiple spacing sensors 117 are installed at different locations on one or both of the surface plates. For example, a spacing sensor 117 may be installed at each of the four corners of the first surface plate 111 such that each sensor 117 is directed at a corresponding corner of the second surface plate 131. The spacing sensors 117 may employ a non-contact sensor such as a laser sensor or an ultrasonic sensor.
The first and second chucks 113 and 133 may be electrostatic chucks (ESCs) which can hold the first and second substrates S1 and S2 using an electrostatic force. The electrostatic chucks are configured in such a way that one or more electrodes are disposed inside of an insulator body. Electric power is applied to these electrodes to generate an electrostatic force. That is, the substrate surface exhibits an artificial polarity due to a dielectric polarization, thereby generating the electrostatic holding force.
Installed at the upper side of the first chamber 110 are one or more cameras 171 for viewing alignment marks (not shown) formed on the first and second substrates S1 and S2 (hereinafter, referred to as “two substrates”). At the lower side of the second chamber 130, one or more corresponding illuminator devices 173 may be provided for illuminating the alignment marks so that the cameras 171 can obtain a clear image of the alignment marks. In addition, imaging holes 171a are formed so that they pass through the first chamber 110 and the first chuck 113, and illumination holes 173a may be formed so that they pass through the second chamber 130 and the second chuck 113.
The first chamber 110 is installed so as to be supported by a lift driver unit 190. The lift driver unit 190 operates such that when two substrates S1 and S2 are to be bonded to one another, the first chamber 110 descends into the processing space 1a. After the two substrates S1 and S2 are bonded together, the first chamber 110 ascends to open the processing space 1a, and thus facilitate transportation of the two substrates S1 and S2 into and out of the apparatus.
Although not illustrated, the first chamber 110 and the second chamber 130 may be provided with one or more exhaust pumps (not shown) and gas supply pumps (not shown). Once the first and second chambers have been brought together, the exhaust pump is used to evacuate the processing space 1a to generate a vacuum state while bonding the two substrates S1 and S2 together.
Typically, once the processing space has been evacuated, the first and substrates are brought together. Then, the gas supply pump is used to supplying a processing gas into the processing space 1a. The pressure of the processing gas pushes the two substrates S1 and S2 against each other to facilitate bonding.
In addition, the first and second chambers 110 and 130 may be provided with a lift pin (not shown) and a lift driver unit (not shown) for guiding the two substrates S1 and S2 as they are introduced into the processing space 1a, and are attached to the first chuck 113 and the second chuck 133.
A first surface plate alignment unit 150a is provided between the first chamber 110 and the first surface plate 111. A second surface plate alignment unit 150b is provided between the second chamber 130 and the second surface plate 131. The first surface plate alignment unit 150a and the second surface plate alignment unit 150b are configured so as to be capable of a six-degrees-of-freedom alignment procedure. Although the embodiment shown in
Hereafter, for the purposes of convenience of explanation and understanding, an explanation will be provided with respect to the second surface plate alignment unit 150b. It should be noted, however, that the first surface alignment unit 150a is basically identical to the second surface plate alignment unit 150b and would operate in the same general manner.
The actuators may be coupled to the connector plate 151 and the support plate 152 respectively by means of universal joints, or simple pivot joints. In addition, in alternate embodiments, the support plate and/or the connector plate could be eliminated, and the actuators could be attached directly to the second chamber 130 and the second surface plate 131.
A first actuator 153a and a second actuator 153b are disposed and installed in a pair so as to form a “V”-shape. In addition, a third actuator 153c and a fourth actuator 153d are disposed in a pair to form a “V”-shape. Furthermore, a fifth actuator 153e and a sixth actuator 153f are disposed in a pair in the form of “V”. As a result of this arrangement, the second surface plate alignment unit 150b is capable of a six-degrees-of-freedom alignment, i.e., X, Y, Z-axis direction, and roll, pitch and yaw aligning operations.
In the second surface plate alignment unit 150b, the X-axis direction aligning operation is carried out by varying the amount of extension/retraction of the various actuators 153. In order to move the connector plate in the positive X axis direction, the sixth actuator 153f is minimally extended, and the first and fifth actuators 153a and 153e are extended greater than the sixth actuator 153f. The second and fourth actuators 153b and 153d are extended greater than the first and fifth actuators 153a and 153e, and the third actuator 153c is maximally extended. In this way, the second surface plate 131 moves along the positive X-axis direction, while still maintaining a parallel alignment between the second surface plate and the first surface plate. Conversely, if the multiple actuators 153 are moved in opposite ways to those described above (retracted), the second surface plate 131 is moved in the negative X-axis direction.
The roll alignment, i.e., the rotation about the X-axis, is performed in such a way that, with the third and sixth actuators 153c and 153f fixed, the first and second actuators 153a and 153b are extended, and the fourth and fifth actuators 153d and 153e are contracted, or vice versa.
The Y-axis direction aligning operation is carried out as follows. The fourth actuator 153d is minimally extended, and then the third and fifth actuators 153c and 153e are extended greater than the fourth actuator 153d. The second and sixth actuators 153b and 153f are extended greater than the third and fifth actuators 153c and 153e, and the first actuator 153a is maximally extended. In this way, the second surface plate 131 moves along the positive Y-axis direction in the figure while maintaining a parallel alignment between the first and second surface plates. If the multiple actuators 153 are extended in opposite ways to those described above (retracted), the second surface plate 131 would move in the negative Y-axis direction.
The pitch alignment, i.e., rotation about the Y-axis, is performed in such a way that, with the first and fourth actuators 153a and 153d fixed, the fifth and sixth actuators 153e and 153f are extended and the second and third actuators 153b and 153c are contracted, or vice versa.
The Z-axis direction aligning, which is an operation of causing the second surface plate 131 to ascend or descend, is performed by extending or shrinking all of the plurality of actuators 153. The yaw alignment, rotation about the Z axis, is obtained in a way that the actuators 153 are extended or shrank all together with a predetermined magnitude.
Using the above six-degrees-of-freedom alignment, for the purposes of accomplishing a more accurate alignment of the second surface plate 131, two or more directions of alignment can be carried out simultaneously and interlockingly. In this way, more rapid and accurate alignment between the first and second surface plates 111 and 131 can be achieved in an efficient manner.
Hereafter, a method of aligning the substrates will be explained with reference to
Once the spacing between the first and second surface plates 111 and 131 is measured, in step S200, a control unit (not shown) in the bonding apparatus 100 compares the values detected by the different spacing sensors 117. If the spacing sensors indicate that all portions of the first and second surface plates are the same distance apart, the control unit (not shown) determines that the first and second surface plates 111 and 131 are aligned.
If the control unit determines that the spacing between the various portions of the first and second surface plates is not the same, in step S300 the control unit (not shown) operates the alignment unit 150 until all the distance values measured from all the spacing sensors 117 are the same.
In an alternate embodiment, a predetermined spacing value between the plates may be input. Then, the first and second surface plate alignment units 150a and 150b are operated until all the spacing sensors detect the desired input spacing value. In this way, the first and second surface plates 111 and 131, which are installed in the first and second chambers 110 and 130 respectively, can be adjusted so that the first and second surface plates are parallel.
In addition to using the input from the spacing sensors, the control unit may use input from one or more cameras 171 to ensure that the two substrates S1 and S2 mounted on the first and second surface plates are properly aligned in the X and Y axis directions. That is, aligning marks formed on the two substrates S1 and S2 can be used to carry out an alignment of the substrates in the X- and/or Y-axis directions.
In the embodiment shown in
In order to align the first and second substrates, an image of alignment marks on the first and second substrates would by captured by the camera. Such alignment marks are typically in the form of a cross or X. If the marks on both substrates are perfectly aligned, the image would only show one cross or X. In that instance, there would be no need to adjust the position of either substrate.
On the other hand, if the alignment marks of both substrates were visible in the image captured by one of the cameras, this would indicate that the two substrates are not properly aligned. In this instance, one or both of the substrates would be moved in the X aixs and/or Y axis directions by one or more of the aligning units until the alignment marks do coincide, and it appears as thought there is only one alignment mark.
Of course, in alternate embodiments, the alignment marks could take different forms which also indicate how the substrates must be moved with respect to each other to achieve proper alignment.
In still other embodiments, when no aligning marks are visible to the cameras 171, the cameras 171 could still be used to align the first and second spacing plates in the X and Y axis directions by simply measuring the amount of light received at the cameras 171 from the illumination devices 173. That is, in case where the first and second surface plates 111 and 131 are not properly aligned in the X- and Y-axis directions, different cameras 171 will receive different intensities of light. For example, some cameras 171 may receive a relatively large amount of light since the illumination holes 173a and corresponding photographing holes 171a are only slightly misaligned. Other cameras 171 would receive a relatively small amount of light since the illumination holes 173a and corresponding photographing holes 171a are more greatly misaligned. In this case, the light intensities detected by the respective cameras can be compared, and the actuators 153 can be controlled until the light received by all the cameras comes to within a critical value. As a result, the first and second surface plates will be properly aligned in the X and Y axis directions.
The cameras 171 may employ a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) image sensor. In the CCD and CMOS image sensors, the light intensity can be measured by computing the number of turned-on pixels. In other embodiments, the cameras may be replaced with simple light sensors capable of detecting the relative amount of light being received by the sensors.
Other embodiments will now be explained with reference to the accompanying drawings. In the description that follows, components in the other embodiments that are similar to those in the first embodiment are denoted by the same terminologies, and details thereof will not be repeated.
The multiple spacing sensors 217, which are installed on the first surface plates 211 (or the second surface plates 231), measure and compare the spacing values between the first and second surface plates. According to the measurement and comparison results, the first surface plate alignment units 250a and the second surface plate alignment units 250b perform the six-degrees-of-freedom alignment with respect to the first and second surface plates 211 and 231, to thereby adjust the plates so that they are parallel, and have a desired spacing therebetween.
The multiple spacing sensors 317, which are installed ot the first surface plate 311 (or the second surface plate 331), measure and compare the spacing values between the first and second surface plates. According to the measurement and comparison results, the alignment unit 350 performs the six-degrees-of-freedom alignment procedure to ensure that the first and second surface plates are parallel and have a required spacing therebetween. In this embodiment, the lift driver unit 390 may be omitted. Instead, the second chamber 330 may be made to ascend or descend by means of the alignment unit 350, thereby sealing or opening the processing space 1c.
The multiple spacing sensors 417, which are installed on the first surface plate 411 (or the second surface plate 431), measure and compare the spacing values between the first and second surface plates. According to the measurement and comparison results, the alignment unit 450 performs the six-degrees-of-freedom alignment procedure to ensure that the first and second surface plates are parallel and have a desired spacing therebetween.
In the fourth embodiment, the lift driver unit 490 may be omitted. Instead, the first chamber 410 may be made to ascend or descend by means of the alignment unit 450, thereby sealing or opening the processing space 1d.
The multiple spacing sensors 517, which are installed on the first surface plate 511 (or the second surface plate 531), measure and compare the spacing values between the first and second surface plates. According to the measurement and comparison results, the alignment unit 550 performs the six-degrees-of-freedom alignment procedure to ensure that the first and second surface plates are parallel and have a desired spacing therebetween.
The substrate bonding apparatus 500 of fifth embodiment is provided with a bellows 539 for sealing the multiple actuators 553 and the through-opening 539a of the second chamber 530, thereby maintaining air-tightness of the processing space 1e during the process for bonding two substrates S1 and S2. The bellows 539 is configured so as to expand or contract during the up and down movements that would occur during the six-degrees-of-freedom alignment process, and as the second chamber ascends and descends relative to the first chamber.
The multiple spacing sensors 617, which are installed on the first surface plate 611 (or the second surface plate 631), measure and compare the spacing values between the first and second surface plates. According to the measurement and comparison results, the alignment unit 650 performs the six-degrees-of-freedom alignment with respect to the first surface plate 611, thereby ensuring that the first and second surface plates are parallel, and that a desired spacing is maintained therebetween.
The substrate bonding apparatus 600 of sixth embodiment is provided with a bellows 619 for sealing the multiple actuators 653 and the through-opening 619a of the first chamber 610, thereby maintaining air-tightness of the processing space 1f during the process for bonding two substrates S1 and S2. The bellows 619 is configured so as to expand or contract during the up and down movements that occur during the six-degrees-of-freedom alignment process, and as the first chamber ascends and descends.
Hereafter, for the purposes of convenient explanation and understanding, the second chuck plate alignment unit 750b will be explained. It should be understood that the first chuck plate alignment unit 750a is basically identical to the second chuck plate alignment unit, and would operate in the same fashion.
The second surface plate 731 is a single plate. The second chuck plate 735 may be divided into plural second chuck plates, as shown in
Multiple spacing sensors 717 may be installed at any one of the first and second chucks 713 and 733, or on the chuck plates 715 and 735. The multiple spacing sensors 717, measure and compare the spacing values. According to the measurement and comparison results, the second chuck plate alignment units 750b perform the six-degrees-of-freedom alignment with respect to each of the second chuck plates 735, thereby ensuring that the first and second chucks are parallel and have a desired spacing therebetween.
As described above, a substrate bonding apparatus using an alignment unit capable of a six-degrees-of-freedom alignment, enables the apparatus to efficiently achieve a quick and precise alignment of two substrates. The alignment unit may be modified in part and installed in different ways. In addition, the individual actuators of the alignment unit may be driven pneumatically, hydraulically, through an electromagnetic operation by electromagnetic force, or through a mechanical operation using a ball screw and motor, or by other means.
Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.
Although a number of illustrative embodiments have been described, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements which would fall within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0081141 | Aug 2006 | KR | national |
