JP3908054B2 - Aligner device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an aligner apparatus, and more particularly to an aligner apparatus capable of high-speed detection of wafer centering, orientation flat, and the like in a semiconductor manufacturing apparatus and a substrate inspection apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a semiconductor manufacturing apparatus and a substrate inspection apparatus, an aligner apparatus is used to accurately perform the angular direction and positioning during wafer transfer between processes. Conventionally, in the aligner apparatus, the back surface adsorption method has been adopted as a wafer holding method, but there is a tendency to be changed to the edge grip method according to the applicable standard. In the case of the edge grip method, when the direction of the wafer accommodated in the cassette is random, the wafer holding mechanism is given repeated accuracy, so that positioning is completed when the wafer is gripped. Further, in this state, the angle direction of the wafer is detected by a notch or orientation flat formed at the edge of the wafer. For this purpose, the aligner apparatus is provided with various sensors for notch search, and the speed of the notch search determines the tact time in the aligner apparatus.
[0003]
FIG. 7 is a side view showing an example of a conventional aligner device. In the aligner device 50 shown in the figure, the edge portion of the wafer 52 temporarily placed on the stationary frame 51 is held by the grip chuck arm 53 supported so as to be rotatable around the central rotation axis of the device, and the stationary device 51 is stationary. A state in which the frame 51 is retracted radially outward is shown. In this state, after the appropriate angle direction of the wafer is detected by the notch search, the wafer 52 positioned on the stationary frame 51 approaching again from the outer periphery to the gripping fixed position is placed again. At this time, a position detection sensor 55 is provided to detect the angle of the wafer 52 held by the grip chuck arm 53. As shown in an enlarged view in FIG. 8, the position detection sensor 55 is incorporated in a substantially U-shaped frame 56 projecting from the upper part of the aligner device main body 50. The position detection sensor 55 is a photoelectric sensor in which a light emitting portion 55A is provided in the upper frame portion 56a and a light receiving portion 55B is provided in the lower frame portion 56b. The optical axis L of the detection beam having a predetermined spot diameter emitted from the light emitting portion 55A. Position detection is performed across a notch (not shown) formed in the wafer edge 52b.
[0004]
[Problems to be solved by the invention]
By the way, in the conventional aligner shown in FIG. 7, there is a timing at which the optical axis of the sensor is blocked by the revolving grip chuck arm, and notch search is not possible at that position. Must be done. In addition, since only one position detection sensor is arranged in the circumferential direction, depending on the notch position when the wafer is first gripped, it is necessary to perform notch search by rotating the wafer close to one round at the maximum. It was.
[0005]
Further, when the wafer is held at the grip position of the grip chuck arm, the notch may overlap the grip position. In this case, the notch where the detection beam overlaps the grip position cannot be detected, and it is necessary to grip the wafer again, which increases the time required for the notch search and makes the tact time unstable.
[0006]
Further, in the stationary frame shown in FIG. 7, the wafer is first placed with the stationary frame close to the center, and the wafer is chucked (gripped) by the grip chuck arm in this state. When the grip chuck arm rotates for position detection, the stationary frame needs to be retracted outside in order to avoid interference within the turning radius of the wafer. Then, when the positioning is performed again, an operation of approaching the central direction to a position where the grip chuck arm does not overlap with the plane is taken. As described above, a complicated arm link mechanism that performs the extension operation of the arm in conjunction with the radial direction when the grip chuck arm turns is required.
[0007]
Accordingly, the object of the present invention is to solve the above-mentioned problems of the prior art, perform a notch search regardless of the position of the notch at the time of wafer reception, realize a stable tact time, and easily position a positioned wafer. It is an object of the present invention to provide an aligner device that is placed on a stationary frame having an operation mechanism.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an apparatus main body, a stationary stage that is supported by a lifting column incorporated in the apparatus main body and places a wafer thereon, and chucks the wafer placed on the stationary stage. A wafer holding and swiveling means having a holding mechanism that operates each holding portion in synchronization with each other, a turning mechanism that turns the holding mechanism while holding the wafer, and the holding portion is a notch position of the wafer. A position detection sensor comprising a pair of light emitting portions and a light receiving portion forming the optical axis so that the optical axis of the detection light is transmitted through the gap formed between the notch and the gripping portion in a state where the optical axis is chucked. The light emitting unit and the light receiving unit are attached to a part of the outer peripheral edge of the stationary stage so that one of the light emitting unit and the light receiving unit is located on the radial center side with respect to the gripping unit. Department and The support means supported by the apparatus main body so that the other of the light parts is located radially outside the wafer gripping and turning means with respect to the outer peripheral edge where one of the light emitting part and the light receiving part is located. It is characterized in that it is attached to a part that can transmit and receive the detection light through a gap .
[0012]
In the position detection sensor, one of the light emitting unit and the light receiving unit is attached to a support member provided independently on an outer peripheral edge of the stationary stage on the radial center side of the gripping unit, and the light emitting unit It is preferable that the other of the light receiving portion and the light receiving portion is attached to an upper end of a support arm supported by the apparatus main body on the outer side in the radial direction of the wafer gripping and turning means.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an aligner device of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a plan view showing a planar configuration of an aligner apparatus 10 according to the present invention, and FIG. 2 is a cross-sectional view showing an internal configuration of the aligner apparatus 10. As shown in FIG. 1, a shape in which opposed portions of a disk having a diameter slightly smaller than the diameter of a wafer 1 placed on a substantially square device main body 11 in plan view are cut out by parallel strings. The stationary stage 12, the edge 1a of the wafer 1 placed on the stationary stage 12, and a grip chuck arm 20 for rotating the wafer 1 for detecting a predetermined position, and a notch formed on the wafer 1 are provided. The position detection sensor 30 to detect is comprised.
[0015]
The apparatus main body 11 is a drive source housing part covered with an aluminum casing, and is provided with a stationary stage elevating mechanism 15, a gripping mechanism 21 for a grip chuck arm 20, and a turning mechanism 22, which will be described later. It is designed to be fixed to the fixed surface. As described above, the stationary stage 12 has an arcuate shape of a flat plate portion obtained by cutting off a facing portion of the disk 12a having a diameter slightly smaller than the diameter of the wafer 1 to be placed with parallel chords. An edge 13 is formed. The vicinity of the wafer edge 1a is placed on the edge 13. The entire disk 12a is fixed on the lifting column 14 at the center position. The lifting column 14 is moved up and down at a predetermined timing in synchronism with the timing of chucking by the grip chuck arm 20 by a stationary stage lifting mechanism 15 installed in the apparatus main body 11 with a stroke of 5 mm in this embodiment. Can be made. As the stationary stage elevating mechanism 15, in this embodiment, the eccentric cam 16 is rotated by a stepping motor, and the linear movement amount converted in accordance with the cam eccentric amount becomes the elevating stroke.
[0016]
Further, a notch sensor 30 as a position detection sensor is attached to the center position in the circumferential direction of the arc-shaped edge 13 of the stationary stage 12. In the present embodiment, the light receiving portion 31B constituting the notch sensor 30 is mounted upward, and the light emitting portion 31A is located at the upper facing position as shown in FIGS. The light emitting portion 31A is incorporated in the end portion of the short upper end arm 32a of the support arm 32 having a substantially U shape. As schematically shown in FIG. 3, the wiring cables 33 of the light emitting part 31A and the light receiving part 31B are along grooves (not shown) formed along the support arm 32 or in the disc 12a of the stationary stage 12. And is led to the control unit 17 in the apparatus main body 11. At this time, the positional relationship between the light emitting unit 31A and the light receiving unit 31B may be reversed as long as light emission and light reception capable of forming an optical axis of a detection beam for performing a notch search described later are possible. Further, in this embodiment, two notch sensors 30 are provided at a position opposite to the edge 13 of the stationary stage 12 at 180 °. However, the notch sensors are increased by narrowing the interval between the circumferential arrangement angles. Thus, the tact time of the notch search can be shortened. In the present embodiment, the stationary stage 12 is shaped as an edge other than a part of the disk that is cut off by a parallel chord. However, the shape is not limited to this, and the wafer is supported. If the range of edges to be set can be set to an appropriate size according to the wafer diameter, various shapes can be obtained.
[0017]
Next, the configuration of the grip chuck arm 20 will be described with reference to the drawings. As shown in FIGS. 1, 2, and 5, the grip chuck arm 20 includes two substantially U-shaped arm bodies 23 whose ends are open at an obtuse angle in plan view, and these arm bodies. 23 holding parts 24 are held by a holding mechanism 21 including a link that realizes a linear movement in the radial direction toward the central axis of the apparatus main body 11 by an operation from the turning mechanism 22 using one drive motor 25 as a driving source. Has been. The gripping mechanism 21 is supported by a hollow rotating shaft 26 in the apparatus main body, and the gripping mechanism 21 and the arm main body 23 as a whole are driven by a belt that is transmitted from a drive motor 25 while the wafer 1 is gripped by the gripping portion 24 at the tip of the arm. Thus, it is possible to turn while controlling the predetermined direction and rotation angle with high accuracy.
[0018]
2 and 3, the grip chuck arm 20 includes a grip portion 24 erected so as to be L-shaped from the arm tip 23 b of the arm body 23 when viewed from the side. In the present embodiment, since the grip portion 24 directly chucks the wafer edge 1a, the PEEK resin member is connected to the tip of the aluminum arm. FIG. 4 is an enlarged view showing the grip portion in a state where the wafer 1 is chucked. As shown in the figure, the V-shaped groove 24a formed on the inner surface of the gripping portion 24 is set to a depth of about 0.5 mm, and the wafer 1 is held to the extent that it is slightly locked to the chucked wafer edge 1a. I can support it. At this time, the optical axis L of the detection beam of the notch sensor 30 described above is set to a spot diameter that passes through the notch 1b formed in the wafer edge 1a. Therefore, the notch search of the wafer edge 1a can be performed by the optical axis L of the detection beam even when the grip chuck arm 20 is turned. Needless to say, the depth of the V-shaped groove 24a can be appropriately set depending on the size (thickness) of the wafer.
[0019]
Next, the chucking operation of the grip chuck arm 20 will be described with reference to FIGS. FIG. 5 shows that the arm main body 23 constituting the grip chuck arm 20 and the four gripping portions 24 formed on the two arm main bodies 23 are completely synchronized with each other toward or away from the center of the wafer 1. A gripping mechanism 21 as a link mechanism to be moved to is shown. As shown in the figure, the two arm main bodies 23 face each other across the center axis of the apparatus, and a slider 27 for linearly moving the arm main body 23 in the direction of arrow X is fixed to the arm central portion 23a of the arm main body 23. Yes. Further, a link arm 29 is provided between slider blocks 28 arranged in a direction (Y direction) orthogonal to the moving direction of the slider 27. The slider block 28 moves linearly in a direction perpendicular to the slider 27, and this linear movement causes the slider 27 to move linearly via the link arm 29. The linear motion of the slider block 28 is realized by a reciprocating motion along a rod 28 a incorporated in the slider block 28. The reciprocating motion of the slider block 28 along the rod 28a is realized by the movement operation of the rod 41 attached to the solenoid 40 in the longitudinal direction. At this time, the movement amount δ related to the center direction of the gripping portion 24 is set in advance so that when the corresponding wafer 1 is chucked, an appropriate holding force is obtained according to the wafer diameter so that the wafer 1 is not distorted. Specified by the teaching process.
[0020]
The operation of the aligner apparatus 10 having the above configuration will be briefly described. First, the wafer 1 accommodated in a cassette (not shown) is temporarily placed on a stationary stage 12 with a precision that the center of the apparatus main body 11 and the center of the wafer 1 approximately coincide with each other on a stationary stage 12. In this state, the grip chuck arm 20 is moved toward the center of the apparatus, and the wafer 1 is chucked by the grip portion 24 at the tip of the arm. At this time, since the chuck position of the grip portion 24 of the grip chuck arm 20 is positioned by teaching, positioning is completed by this chuck operation. When the wafer 1 is chucked, the stationary stage 12 is lowered. The grip chuck arm 20 is pivoted for notch search with the wafer 1 being chucked. When the notch position is detected, the grip chuck arm 20 turns and stops so that the notch 1b comes to the specified position. In this state, the stationary stage 12 is lifted so as to support the wafer 1 from below. At the same time, the chucking of the wafer 1 by the grip portion 24 is released, and the wafer 1 is placed at a fixed position on the stationary stage 12. At this time, the grip portion 24 of the grip chuck arm 20 returns to a fixed position, and the wafer 1 can be transferred to the next process.
[0021]
【The invention's effect】
As described above, according to the present invention, the notch search can be performed regardless of the position of the notch at the time of wafer reception, a stable tact time can be realized, and the wafer is positioned on a stationary stage having a simple operation mechanism. By placing the wafer, the notch search time can be further shortened.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of an aligner device according to the present invention.
2 is a cross-sectional view taken along the line II-II of the aligner device of FIG.
3 is an enlarged view of the position detection sensor shown in FIG. 2. FIG.
FIG. 4 is a partially enlarged view showing an enlarged gripping portion of a grip chuck arm.
FIG. 5 is a plan view showing a configuration of a grip chuck arm (initial position state).
FIG. 6 is a plan view showing a configuration of a grip chuck arm (wafer gripping state).
FIG. 7 is a side view showing the overall configuration of a conventional aligner device.
8 is an enlarged view of the position detection sensor shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wafer 10 Aligner apparatus 11 Apparatus main body 12 Stationary stage 13 Edge 20 Grip chuck arm 21 Wafer gripping mechanism 22 Turning mechanism 23 Arm main body 24 Grip part 30 Position detection sensor (notch sensor)
31A Light emitting unit 31B Light receiving unit 32 Support arm

Claims (2)

An apparatus main body, and a stationary stage on which a wafer is supported by a lifting column incorporated in the apparatus main body ,
Wafer gripping swivel having a gripping mechanism section that operates each gripping section that chucks the wafer placed on the stationary stage in synchronization, and a swiveling mechanism that pivots the gripping mechanism section while gripping the wafer. Means,
A pair of light emitting units forming the optical axis so that the optical axis of the detection light is transmitted through a gap formed between the notch and the gripping part in a state where the gripping part chucks the notch position of the wafer. And an aligner device comprising a position detection sensor comprising a light receiving unit,
It is attached to a part of the outer peripheral edge of the stationary stage so that one of the light emitting part and the light receiving part is located closer to the center side in the radial direction than the grip part,
The outer peripheral edge portion where one of the light emitting portion and the light receiving portion of the support means is supported by the apparatus main body so that the other of the light emitting portion and the light receiving portion is located radially outside the wafer gripping and turning means. The aligner device is attached to a portion that can transmit and receive the detection light through the gap . In the position detection sensor, one of the light emitting unit and the light receiving unit is attached to a support member provided on the outer peripheral edge of the stationary stage on the radial center side of the gripping unit, and the light emitting unit 2. The aligner apparatus according to claim 1, wherein the other of the first and second light receiving sections is attached to an upper end of a support arm supported by the apparatus main body on the outer side in the radial direction of the wafer gripping and turning means .

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