JPWO2009041421A1 - Substrate transfer device and observation device - Google Patents

Abstract

A substrate transfer apparatus for transferring a substrate (wafer (10)) between a substrate transfer position (32) and a predetermined position (observation unit (20)), wherein the substrate (10) is transferred to the substrate transfer position (32). And a rotatable rotary stage (33) that reciprocates between the predetermined position (20) and the rotary stage (33) while moving from the predetermined position (20) to the delivery position (32). And a positioning member (34) for positioning at a predetermined rotational position.

Description

  The present invention relates to a substrate transfer device for a substrate such as a semiconductor wafer and an observation device equipped with the substrate transfer device.

  In an observation apparatus for observing the surface of a substrate such as a semiconductor wafer with a microscope, a cassette containing the wafer is set in a substrate transfer unit, and the substrate transfer unit takes out the wafer from the cassette by an arm and places it on a turntable. After aligning the orientation flats formed on the wafer on the turntable, the wafer is transferred from the turntable to an observation unit equipped with a microscope, and after observation, the wafer is returned from the observation unit to the substrate transport unit. It is made to accommodate again inside (patent document 1).

At the time of observation, the wafer is placed on the rotary stage of the observation unit, the wafer is rotated by the rotary stage, and the surface of the wafer is observed with a microscope. For this reason, even if the orientation of the orientation flat of the wafer is aligned in the substrate transport section and the wafer is transferred to the observation section, the orientation of the orientation flat of the wafer often changes after observation. If the wafer is transferred from the observation unit to the substrate transfer unit and returned to the cassette in this state, the orientation flat directions of the wafer are scattered in the cassette. The wafer returned to the cassette is transported to other processing processes such as other inspection processes, resist coating process, exposure process, development process, etc., and subjected to inspection and various processes. The orientation flat orientation of the wafer in the cassette Since this is a disjointed state, it is first necessary to align the orientation flats of the wafer.
Japanese Patent No. 2659384

  For this reason, after the observation, when the wafer is transferred from the wafer observation section to the substrate transport section and returned to the cassette, it is desired to align the orientation flat of the wafer and then store it again in the cassette.

  However, after the observation, in order to align the orientation flat of the wafer in the transfer unit, the orientation flat is detected based on the detection result by detecting the orientation flat by rotating the wafer at least once by the turntable. It has been pointed out that it is necessary to further rotate the wafer by means of a turntable, and that it takes time to return the wafer to the cassette after observation, which hinders improvement in throughput.

  The present invention has been made in view of the above circumstances, and a substrate transfer apparatus capable of reducing the time required to align the substrate in a predetermined direction and returning the substrate to the substrate housing portion, thereby improving throughput, and the substrate An object of the present invention is to provide an observation apparatus equipped with a transport device.

  The substrate transfer apparatus according to claim 1 of the present invention that achieves the above object is a substrate transfer apparatus that transfers a substrate between a substrate transfer position and a predetermined position, wherein the substrate is transferred to the substrate transfer position and the predetermined position. A rotatable rotary stage that reciprocates between positions, and a positioning member that rotates and positions the rotary stage while moving from the predetermined position to the delivery position. It is characterized by that.

  The substrate transfer apparatus according to claim 2 of the present invention is characterized in that the positioning member positions the rotation stage at one rotation angle position among a plurality of rotation angle positions.

  In the substrate transfer apparatus according to a third aspect of the present invention, the positioning member has a cam disposed at one of the delivery position and the rotary stage, and a cam floor that moves following the cam on the other. It is characterized by.

  The substrate transfer apparatus according to claim 4 of the present invention further includes a transfer unit that transfers the substrate to the rotation stage, and the transfer unit detects rotation position range of the rotation stage. It has a detection part.

  The substrate transfer apparatus according to claim 5 of the present invention is characterized in that the rotational position information detection unit includes a photosensor.

  According to a sixth aspect of the present invention, there is provided a substrate transport apparatus, comprising: an alignment unit that detects a rotational position and adjusts a rotational position of the substrate before the transport; and a memory that stores a relative rotational position relationship between the rotary stage and the substrate. It further has a portion.

  The observation apparatus according to claim 7 of the present invention is an apparatus for observing the surface of the substrate, and includes a substrate accommodating portion that accommodates the substrate, an observation portion that observes the surface of the substrate, and the substrate accommodating portion. The board | substrate conveyance apparatus as described in any one of Claims 1 thru | or 6 which conveys the said board | substrate between the said observation parts, It is characterized by the above-mentioned.

  According to the present invention, it is possible to improve the throughput by shortening the time for aligning the substrate in a predetermined direction and returning the substrate to the substrate housing portion.

It is the top view shown partially omitted which shows one Embodiment of the observation apparatus equipped with the board | substrate conveyance apparatus of this invention. FIG. 2 is an enlarged plan view showing a part of a rotation stage 33, a positioning member 34, and a rotation information detection unit 35 of the substrate transfer apparatus 30 of FIG. FIGS. 3A and 3B are diagrams illustrating a part of the rotary stage 33 in FIG. 2, in which FIG. 3A is a partially omitted side view, and FIG. FIG. 3 is a side view showing a part of the rotary stage 33, positioning member 34, and rotation information detection unit 35 in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wafer 11 Cassette 20 Observation part 21 Microscope 23 Slide member 24,25 Guide board 30 Substrate conveyance apparatus 32 Delivery position 33 Rotation stage 34 Positioning member 35 Rotation information detection part 36 Transfer part 37 Rotation shaft 38 Stage 39 Bearing 40 Light shielding plate 41 Cam 42, 43 Photo sensor 45 Memory 46 Arm 47 Alignment unit 48, 49 Replacement arm 50 Arithmetic processing unit

  Hereinafter, an embodiment of a substrate transfer apparatus of the present invention and an observation apparatus equipped with the substrate transfer apparatus will be described with reference to FIGS.

  The substrate transfer apparatus of the present invention is an apparatus for transferring a substrate between a substrate transfer position and a predetermined position, and FIG. 1 is a plan view showing a main part showing an embodiment of an observation apparatus equipped with the substrate transfer apparatus. is there.

  As shown in FIG. 1, the observation apparatus according to the present embodiment includes a cassette 11 that constitutes a substrate housing portion that houses a semiconductor wafer (hereinafter referred to as a wafer) 10 as a substrate, and a microscope 21 that micro-observes the surface of the wafer 10. And a substrate transfer device 30 that transfers the wafer 10 between the cassette 11 and the observation unit 20.

  The cassette 11 accommodates the wafers 10 in a plurality of shelves (not shown) arranged at predetermined intervals in the vertical direction, and includes an elevator 31 arranged on the substrate transfer device 30. The elevator 31 conveys the wafer 10 accommodated in the cassette 11 up and down, and is configured to move the cassette 11 in the vertical direction by a pitch corresponding to the wafer accommodation interval in the vertical direction (interval of wafer storage shelves). Has been. For example, when the wafer 10 on the lowermost shelf in the cassette 11 is taken out or returned to the lowermost shelf after observation, the lowermost shelf in the cassette 11 is taken up by the elevator 31 at the height position where the wafer is taken out. Then, the cassette 11 is moved up and down so as to reach the storage height position.

  As shown in FIGS. 1, 2, and 4, the substrate transfer device 30 includes a rotatable rotary stage 33 on which the wafer 10 is placed and reciprocated between a delivery position 32 and a position facing the microscope 21. And a positioning member 34 for positioning the rotary stage 33 moving from the position facing the microscope 21 to the delivery position 32 at a predetermined rotational position.

  The delivery position 32 is located on the transfer path of the wafer 10 between the cassette 11 and the observation unit 20. At the transfer position 32, a transfer unit 36 is provided. In the transfer unit 36, the wafer 10 taken out from the cassette 11 is transferred onto the rotary stage 33, and the wafer 10 after being observed from the rotary stage 33. It returns to the delivery position 32. The transfer unit 36 includes a rotation position information detection unit 35 that detects rotation position information of the rotation stage 33.

  The rotary stage 33 is rotated on the slide member 23 that is arranged on the XY stage 22 constituting the observation table of the microscope 21 and can move in the direction of arrow A in FIG. The end portion on the 36th side) is located. The rotary stage 33 is transported to a position (under the objective lens of the microscope 21) where the wafer 10 faces directly below the microscope 21 in a state where the wafer 10 is placed in accordance with the slide movement of the slide member 23. Then, after performing a predetermined observation while rotating the wafer 10 at this position, a transfer operation opposite to the above is performed, and the wafer 10 is transferred to the transfer unit 36.

  As shown in FIGS. 3A and 3B, the rotary stage 33 is fixed to the rotary shaft 37 rotatably attached to the slide member 23 (not shown in FIG. 3) and the upper end of the rotary shaft 37. And a disk-shaped stage 38 that rotates together with the rotation shaft 37. Further, four bearings 39 as cam floors constituting the positioning member 34 are arranged on the back surface of the stage 38 at intervals of 90 ° along the circumferential direction on the same circumference. Further, four light shielding plates 40 are arranged on the back surface of the stage 38 so as to protrude from the peripheral edge portion as shown in the figure (in particular, see FIG. 3B). These light shielding plates 40 are detected by a rotation information detector 35 as will be described later, whereby the rotational position information of the rotary stage 33 is detected. The slide member 23 is manually slid in the direction of the arrow A in FIG. 2 by grasping a handle 23a provided protruding from the lower surface.

  The positioning member 34 is an upper surface of one guide plate 24 of the pair of guide plates 24 and 25 that guides the bearing 39 as the cam floor and the slide member 23 from both sides and guides in the direction of arrow A in FIG. And a cam 41 disposed on the surface.

  The cam 41 has a cam surface 41a as shown in the figure, and any one of the cam floors in the process in which the rotary stage 33 is moved from the position facing directly below the microscope 21 to the transfer unit 36 by the slide member 23. The bearing 39 (the bearing 39 closest to the cam 41) is configured to contact the cam 41. For this reason, when the bearing 39 comes into contact with the cam surface 41a, the bearing 39 rolls on the surface while contacting the cam surface 41a and moves along the cam surface 41a. As a result, the rotary stage 33 is centered on the rotary shaft 37. Rotate on the slide member 23. Here, since the bearings 39 are provided at 90 ° intervals on the same circumference, when the slide member 23 on which the rotary stage 33 is arranged moves to the position closest to the transfer portion 36 (position shown in FIG. 2), The rotary stage 33 is positioned at any rotation angle position of 0 °, 90 °, 180 °, and 270 ° with respect to the reference position.

  The rotation information detection unit 35 detects rotation position information (0 °, 90 °, 180 °, 270 °) of the rotary stage 33 positioned by the positioning member 34. The rotation information detection unit 35 has a transfer unit 36 as shown in FIG. A set of photosensors 42 and 43 is provided.

  The photosensors 42 and 43 are configured by a combination of a light emitting diode and a photodiode that detects light from the light emitting diode. When the light shielding plate 40 fixed to the back surface of the stage 38 as shown in FIG. 3B is located between the light emitting diode and the photodiode and blocks light from the light emitting diode (see FIG. 4), the photo sensor 42 and 43 detect the light shielding plate 40.

  The outputs of the photosensors 42 and 43 are sent to the memory 45 and stored therein. The rotational position information (0 °, 90 °, 180 °, 270 °) of the rotary stage 33 is known from the outputs of the photosensors 42, 43. For example, the rotary stage 33 is at a rotation position of 0 ° when the outputs of the photosensors 42 and 43 are both on (both in a light shielding state), and the output of the photosensor 42 is on (in the light shielding state). When the sensor is off, it is at a rotational position of 180 °. When the output of the photosensor 42 is off, when the output of the photosensor 43 is on, it is at a rotational position of 90 °. In the rotational position of °.

  In addition to the rotation information detection unit 35 described above, the transfer unit 36 takes out the wafer 10 from the cassette 11 as shown in FIG. 1, and accommodates the arm 46 accommodated in the cassette 11 and the unillustrated wafer 10 taken out. An alignment unit 47 that detects the orientation flat orientation and adjusts the rotational position of the wafer 10 to align the orientation flat, and conveys the wafer 10 from the alignment unit 47 to the rotary stage 33. The wafer 10 is also transferred from the rotary stage 33. Replacement arms 48 and 49 that return to the alignment unit 47 are arranged.

  The alignment unit 47 detects the orientation flat orientation and adjusts the rotational position of the wafer 10 as described above. At this time, the rotational position of the wafer 10 is also detected. The rotation position information of the wafer 10 is sent to the memory 45 and stored as the rotation position information of the wafer 10 before being transferred to the observation unit 20.

  The rotational position information of the rotary stage 33 stored in the memory 45 and the rotational position information of the wafer 10 before being transferred to the observation unit 20 are sent to the arithmetic processing unit 50, respectively.

  The arithmetic processing unit 50 aligns the orientation flat orientation from the rotational position information of the wafer 10 before being transferred to the observation unit 20 and the rotational position information of the rotary stage 33 that is the rotational position information of the wafer 10 after the observation is finished. Then, the amount of rotation of how many times the wafer 10 returned by the alignment unit 47 is rotated in order to accommodate the wafer 10 in the cassette 11 again is calculated.

  When the observed wafer 10 returns to the alignment unit 47, the alignment unit 47 rotates based on the calculation result in the calculation processing unit 50 to align the orientation flat orientation of the wafer 10.

  According to the above embodiment, when the wafer 10 is macro-inspected with the microscope 21, the first wafer 10 is taken out from the cassette 11 by the arm 46 and placed on the alignment unit 47 so that the orientation flat orientation of the wafer 10 is changed. For example, the rotation position of the wafer 10 is adjusted by being rotated by the alignment unit 47 so that the orientation flat is directed to the observer side during observation with the microscope 21. The rotational position of the wafer 10 at this time is stored in the memory 45.

  Next, the wafer 10 is transported to the transfer unit 36 by any one of the replacement arms 48 and 49, and the wafer 10 is mounted on the rotary stage 33 that has been waiting on the transfer unit 36 side. Put.

  Next, the rotary stage 33 on which the wafer 10 is placed by the slide member 23 is transferred to a position almost directly below the objective lens of the microscope 21, the rotary stage 33 is rotated at the same position, and the wafer 21 on the rotary stage 33 is rotated by the microscope 21. Observe the surface.

  After the observation is finished, the rotary stage 33 is transferred to the transfer unit 36 by the slide member 23. When the rotary stage 33 approaches the transfer portion 36 side, one of the four bearings 39 arranged on the rear surface of the stage 38 comes into contact with the cam 41, and the bearing is moved along with the movement of the slide member 23. 39 rolls on the cam 41 and moves following the cam 41, and as a result, the rotary stage 33 rotates relative to the slide member 23. When one end side of the slide member 23 moves to the transfer portion 36, the rotary stage 33 is positioned at any one of four rotation angle positions of 0 °, 90 °, 180 °, and 270 °. Even if the rotary stage 33 is rotated many times at a position almost directly below the objective lens of the microscope 21, the rotary stage 33 is positioned at any one of these four rotational angular positions. The rotation position of the rotation stage 33 (the rotation position of the wafer 10) is detected by the photosensors 42 and 43 and sent to the memory 45.

  The memory 45 stores the rotational position of the first wafer 10 before being transferred to the observation unit 20 and the rotational position of the wafer 10 after observation by the observation unit 20. The arithmetic processing unit 50 stores these rotational positions. Is input from the memory 45, and the rotation amount of the wafer 10 for storing the wafer 10 in the cassette 11 with the orientation flat aligned is calculated.

  The first wafer 10 observed by the transfer unit 36 is transferred from the rotary stage 33 to, for example, a replacement arm 49. At this time, the second wafer 10 is taken out from the cassette 11 by the arm 46, and the rotation position of the wafer 10 is adjusted by the alignment unit 47 so that the orientation flat is in a predetermined direction. For example, 10 is transferred onto another replacement arm 48.

  The first wafer 10 after the observation is transferred to the alignment unit 47 by the replacement arm 49, and the second wafer 10 before the observation is transferred to the rotary stage 33 waiting on the transfer unit 36 side by the replacement arm 48. Be transported.

  In the first wafer 10, the alignment unit 47 rotates the alignment unit 47 to the rotation amount calculated by the arithmetic processing unit 50, thereby adjusting the rotation position and aligning the orientation flat in a predetermined direction. In this embodiment, in order to align the orientation flat orientation of the wafer 10, it is necessary to detect the orientation flat by rotating the wafer 10 once and further rotate it by one rotation or less (from 360 ° to 720 °). There is no need to rotate it 180 degrees at the maximum. Next, the wafer 10 is returned from the alignment unit 47 into the cassette 11 by the arm 46.

  Similarly to the first wafer 10, the second wafer 10 is transferred to the position just below the objective lens of the microscope 21 and observed by the rotary stage 33, and the orientation flat of the first wafer 10 is oriented after observation. Are returned to the cassette 11 in the same direction.

  The above operation is repeated for all the wafers 10 accommodated in the cassette 11. The wafer 10 that has been observed is accommodated in the cassette 11 in a state in which the orientation flats are aligned.

  Therefore, the orientation flat orientation of the wafer 10 in the cassette 11 is aligned when it is transported to various processing steps such as another inspection step or resist coating step, exposure step, and development step and subjected to inspection and various types of processing. Again, it is not necessary to align the orientation flat orientation of the wafer 10.

  Further, in order to align the orientation flat, it is only necessary to rotate the wafer 10 up to a maximum of 180 °, and the throughput can be greatly improved.

  The present invention is not limited to that shown in the above embodiment. For example, although the case where the positioning member 34 is configured by the bearing 39 and the cam 41 as the cam floor is shown, the present invention is not limited to this.

  When the bearing 39 and the cam 41 are used as in the above embodiment, the structure of the device is very simple. Further, by setting the number of bearings 39 to 6, for example, the rotary stage 33 can be positioned at any one of 0 °, 120 °, 180 °, 240 °, and 300 °.

  Moreover, although the case where the rotation information detection unit 35 is configured by a pair of photosensors 42 and 43 and the light shielding plate 40 is shown, the present invention is not limited to this, and the rotation position of the rotation stage 33 is detected by an encoder. It may be.

  In addition, instead of using the positioning member 34 constituted by the bearing 39 and the cam 41 as the cam floor, an encoder for detecting the rotational position of the rotary stage 33 may be provided instead. In this case, when the wafer 10 is transferred to the transfer unit 36 after microscopic observation, the rotational position information of the wafer 10 detected by the encoder is sent to the arithmetic processing unit 50 by an electrical communication means or the like, and the arithmetic processing unit 50 calculates the amount of rotation of the wafer 10 based on this rotational position information.

  Further, after the microscopic observation, the rotation position of each wafer 10 is stored in association with the cassette 11 and the wafer 10 in which the wafer 10 is stored, and returned to the corresponding cassette 11 without aligning the rotation position of the wafer 10. The associated rotational position information may be transmitted to the next process, and the pre-alignment of the next process may be performed based on the transmitted information.

Claims (7)

A substrate transfer device for transferring a substrate between a substrate delivery position and a predetermined position,
A rotatable rotation stage that reciprocates the substrate between the substrate delivery position and the predetermined position;
A positioning member that rotates the rotary stage to position the rotary stage while moving from the predetermined position to the delivery position;
A substrate transfer apparatus comprising: The substrate transfer apparatus according to claim 1,
The positioning member positions the rotary stage at one rotation angle position among a plurality of rotation angle positions. The substrate transfer apparatus according to claim 2,
The substrate conveying apparatus, wherein the positioning member includes a cam disposed at one of the delivery position and the rotary stage, and a cam floor that moves following the cam on the other. In the board | substrate conveyance apparatus as described in any one of Claims 1 thru | or 3,
A transfer unit for transferring the substrate to the rotary stage;
The substrate transfer apparatus, wherein the transfer unit includes a rotation position information detection unit that detects a rotation position range of the rotation stage. The substrate transfer apparatus according to claim 4,
The rotation position information detection unit includes a photo sensor. In the board | substrate conveyance apparatus as described in any one of Claims 1 thru | or 5,
An alignment unit that performs rotation position detection and rotation position adjustment of the substrate before the conveyance;
The substrate transfer apparatus further comprising a storage unit that stores a relative rotational positional relationship between the rotation stage and the substrate. An apparatus for observing the surface of a substrate,
A substrate housing portion for housing the substrate;
An observation unit for observing the surface of the substrate;
The substrate transfer apparatus according to any one of claims 1 to 6, wherein the substrate is transferred between the substrate container and the observation unit,
An observation apparatus comprising:

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