Substrate transfer apparatus

Abstract

Provided is a substrate transfer apparatus for stably delivering a semiconductor wafer (substrate) even to a mounting table that has a continuous surface. A substrate transfer device (10) is provided with: a body (11) that is positioned on the surface (12a) side of a substrate (12) on which a circuit pattern is formed; fixed locking parts (15) that are fixedly provided to the body (11) and that lock the edge of the substrate (12); and movable locking parts (16) that are movably provided to the body (11) and that detachably lock the edge of the substrate (12) at positions facing the fixed locking parts (15).

Description

Substrate transfer device

[0001] The present invention relates to a technique for detachably holding a substrate on which a circuit pattern is formed.

[0002] After a circuit pattern is formed on the surface of a semiconductor wafer (substrate), each of the multiple integrated circuits is inspected using an inspection device. During this inspection, the semiconductor wafer is repeatedly fed to the inspection device and then retrieved from a transport device. The methods for gripping the semiconductor wafer during substrate transport are classified into a method in which the wafer is gripped from the front side, on which the circuit pattern is formed, and a method in which the wafer is gripped from the back side (see, for example, Patent Documents 1 and 2).

[0003] JP 2015-103648 A JP 2006-128549 A

[0004] The method of gripping the semiconductor wafer from the front side uses air to attract it from the mounting table, but this method has the problem of lacking stability in transfer, as there is a risk that the semiconductor wafer will fall and be damaged if there is a loss of power or air.

[0005] In addition, in the method of gripping the semiconductor wafer from the backside, the semiconductor wafer is lifted from the mounting table by using lift pins that displace up and down to create an insertion space for the substrate gripper. However, there are cases where the semiconductor wafer mounting table in the inspection device is required to maintain a continuous surface. For this reason, there are circumstances where it is desirable to avoid introducing a mechanism such as the lift pins described above or creating an insertion space for the substrate gripper in advance on the mounting table.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a substrate transfer device that can stably transfer a semiconductor wafer (substrate) even to a mounting table having a continuous surface.

[0007] The substrate transfer device of the present invention comprises a main body portion located on the surface side of the substrate on which a circuit pattern is formed, a fixed locking portion fixedly provided on the main body portion and locking the edge of the substrate, and a movable locking portion movably provided on the main body portion and locking the edge of the substrate in a freely detachable manner at a position opposite the fixed locking portion.

[0008] The present invention provides a substrate transfer device that can stably transfer a semiconductor wafer (substrate) even to a mounting table having a continuous surface.

[0009] FIG. 1 is a plan view of a main body of a substrate transfer device according to an embodiment of the present invention, as viewed from above. FIG. 2 is a plan view of a main body of a substrate transfer device according to an embodiment of the present invention, as viewed from below. (A) A-A vertical cross-sectional view of a fixed locking portion applied to a substrate transfer device according to an embodiment, and (B) B-B vertical cross-sectional view of the movable locking portion of the same. FIG. 3 is a plan view of a mounting table of a substrate transfer device according to an embodiment of the present invention, as viewed from above. (A), (B), and (C) are CC vertical cross-sectional views of a substrate transfer device, explaining the operation of the embodiment.

[0010] First Embodiment An embodiment of the present invention will now be described with reference to the accompanying drawings. Fig. 1 is a plan view of a main body 11 of a substrate transfer device 10 according to an embodiment of the present invention, as viewed from above. Fig. 2 is a plan view of the main body 11, as viewed from below.

[0011] As such, the substrate transfer device 10 comprises a main body 11 located on the surface 12a side of the substrate 12 on which the circuit pattern is formed, a fixed locking portion 15 fixedly provided on the main body 11 and locking the edge of the substrate 12, and a movable locking portion 16 movably provided on the main body 11 at a position opposite the fixed locking portion 15 and locking the edge of the substrate 12 in a manner that allows it to be freely engaged and disengaged.

[0012] The substrate 12 is a thin, disk-shaped semiconductor wafer made of semiconductor crystals. Materials include, in addition to the typical silicon, compound semiconductors such as gallium arsenide, and minerals such as sapphire and diamond. The disk-shaped substrate 12 typically has a diameter of 50 mm to 300 mm and a thickness of 0.2 mm to 1.0 mm, which is the most common size at the time of filing.

[0013] Furthermore, the substrate transfer device 10 can handle substrates 12 with a diameter of 450 mm or more, which are being promoted for practical use in anticipation of future increases in diameter. The substrate transfer device 10 can also handle substrates 12 with and without a circuit pattern formed on the surface 12 a.

[0014] The substrate 12 (semiconductor wafer) has a notch or orientation flat (OF) cut into it as a reference for its crystal orientation. A notch is a V-shaped groove formed in the wafer, while an orientation flat is a linear cutout formed in the wafer. At the time of filing, both the terms "notch" and "OF" were used interchangeably for wafers up to 8 inches, but for 12-inch (300 mm diameter) wafers, the term "notch" has become the standard. These references (notch or OF) are used to align multiple substrates 12 in a certain direction when processing them in semiconductor manufacturing, and when loading them into manufacturing and inspection equipment.

[0015] The main body 11 is positioned along the surface 12a, on which a circuit pattern is formed and where contact is avoided. The main body 11 secures the edge of the thin substrate 12 with the fixed locking portion 15 and the movable locking portion 16, and grips it to prevent damage. The main body 11 is also attached to the tip of the robot arm 25 and functions as its end effector.

[0016] Fig. 3(A) is a vertical cross-sectional view taken along line A-A of the fixed locking unit 15 applied to the substrate transfer device 10 according to the embodiment. Fig. 3(B) is a vertical cross-sectional view taken along line B-B of the movable locking unit 16. In Fig. 3(B), the solid lines indicate a setting for locking the substrate 12 in the main body 11 (locking setting), and the dashed lines indicate a setting for releasing the locking of the substrate 12 in the main body 11 (releasing setting).

[0017] The fixed locking portion 15 is fixedly provided on the main body 11 and locks the edge of the substrate 12. The movable locking portion 16 is movably provided on the main body 11 and detachably locks the edge of the substrate 12 at a position opposite the fixed locking portion 15 across the substrate 12 (alternately repeating locking and unlocking settings).

[0018] 3, the fixed locking portion 15 and the movable locking portion 16 each have a protrusion 17 (17a, 17b) at the lower end thereof that extends toward the center of the substrate 12. Furthermore, in each of the movable locking portion 16 and the fixed locking portion 15, a stroke portion 18 (18a, 18b) is formed from the upper end that contacts the main body portion 11 to the protrusion 17 (17a, 17b).

[0019] When the movable locking portion 16 is in the locked position (solid line), the distance between the tips of the protrusions 17 (17a, 17b) is set to be smaller than the diameter of the substrate 12, and the distance between the stroke portions 18 (18a, 18b) is set to be larger than the diameter of the substrate 12. As a result, the substrate 12 is held by the main body portion 11 at the protrusions 17, while the stroke portions 18 (18a, 18b) have a width that allows free movement in the vertical direction. When the movable locking portion 16 is in the released position (dashed line), the distance between the tips of the protrusions 17 (17a, 17b) is set to be larger than the diameter of the substrate 12, and the substrate 12 is released from the main body portion 11.

[0020] The movable locking portion 16 is locked (solid line) and unlocked (dashed line) by driving and moving a position-controllable actuator (e.g., a stepping motor, a servo motor, or a linear motor, etc.), but there is no particular limitation.

[0021] 4 is a plan view of the mounting table 20 of the substrate transfer device 10 according to an embodiment of the present invention. The substrate 12 is placed on the mounting table 20 with its back surface 12b in contact with the mounting table 20. The mounting table 20 is provided with a regulating structure 21 that regulates the position of the substrate 12 in the planar and rotational directions. The mounting table 20 is also provided with a notch 22 that avoids interference with the fixed locking portion 15 and the movable locking portion 16.

[0022] The defining structure 21 is erected on the outer periphery of the mounting table 20, and the edge of the substrate 12 slides against it to define the planar position of the substrate 12. Furthermore, the defining structure 21 also defines the rotational position of the substrate 12 in cooperation with a notch or orientation flat that indicates the crystal orientation of the substrate 12 in a known manner. The notch 22 provides a space that accommodates at least a portion of the fixed locking portion 15 and the movable locking portion 16 when the main body 11 is gripping the substrate 12 placed on the mounting table 20.

[0023] In addition to being fixedly installed on the foundation of a building, the mounting table 20 may also be provided on a displacement mechanism (e.g., an X-Y-Z-θ stage) that displaces the substrate 12 in at least one of the planar, vertical, and rotational directions.

[0024] The operation of this embodiment will be described with reference to the CC longitudinal cross-sectional views of the substrate transfer device 10 shown in Figures 5(A), (B), and (C). First, as shown by the solid arrow in Figure 5(A), the substrate 12 is transferred to the upper part of the mounting table 20 while being locked by the fixed locking portion 15 and the movable locking portion 16 and held by the main body portion 11.

[0025] 5(B), the main body 11 is lowered to bring the substrate 12 into contact with the mounting table 20. After the substrate 12 has contacted the mounting table 20, the main body 11 is further lowered slightly. At this time, the substrate 12 remains stationary relative to the mounting table 20 within the range allowed by the free movement width of the stroke portions 18 (18a, 18b) of the fixed locking portion 15 and the movable locking portion 16.

[0026] Next, as shown by the dashed arrow in Fig. 5(B), when the main body 11 is stopped, the substrate 12 is released from the engagement of the movable locking portion 16, thereby releasing the substrate 12. In the state shown in Fig. 5(B), the fixed locking portion 15 and the movable locking portion 16 are both housed in the notch 22, and therefore do not interfere with the mounting table 20.

[0027] Next, as shown by the dashed arrow in Fig. 5(C), with the substrate 12 released, the main body 11 is shifted in the horizontal direction to eliminate interference between the fixed locking portion 15 and the substrate 12 in the vertical direction. Furthermore, as shown by the solid arrow in Fig. 5(C), the main body 11 is raised to maintain the state in which the substrate 12 is placed on the mounting table 20.

[0028] 5A, 5B, and 5C, the process of supplying the substrate 12 to the mounting table 20 by the substrate transfer device 10 has been described. In contrast, the process of retrieving the substrate 12 from the mounting table 20 for transfer to another mounting table (not shown) can also be described based on the movement of the main body 11 in the reverse order.

[0029] According to at least one of the embodiments of the substrate transfer device described above, by positioning the main body on the surface side on which the circuit pattern is formed and gripping the substrate (semiconductor wafer), it is possible to stably transfer the substrate even to a mounting table with a continuous surface.

[0030] 10...substrate transfer device, 11...main body, 12...substrate, 12a...surface of substrate, 12b...back surface of substrate, 15...fixed locking portion, 16...movable locking portion, 17...protrusion portion, 18...stroke portion, 20...mounting table, 21...regulating structure, 22...notch portion, 25...robot arm

Claims

1. a main body portion located on the front surface side of the substrate on which a circuit pattern is to be formed; a fixed engaging portion fixedly provided on the main body portion and configured to engage an edge of the substrate; a movable locking portion movably provided on the main body portion and configured to detachably lock an edge of the substrate at a position opposite the fixed locking portion; a protrusion provided at a lower end of each of the fixed locking portion and the movable locking portion toward the center of the substrate; a stroke portion formed in each of the movable locking portion and the fixed locking portion from an upper end contacting the main body portion to the protrusion; a mounting table on which the substrate is placed with its back surface in contact; a regulating structure provided on the outer periphery of the mounting table, regulating the position of the substrate in a planar direction and regulating the rotation direction so that a reference indicating a crystal orientation is aligned in a certain direction; a notch provided on the mounting table to avoid interference with the fixed locking portion and the movable locking portion, The main body portion is configured to place the substrate on the mounting table. a step of transporting the substrate, which is held by the fixed locking portion and the movable locking portion, to an upper portion of the mounting table; a step of lowering the substrate so that the substrate contacts the stage; a step of lowering the substrate in contact with the mounting table within a range permitted by a free movement width of the stroke section while maintaining the substrate in a stationary state; a step of stopping the fixed locking portion and the movable locking portion in a state where they are both accommodated in the notch without interfering with the mounting base; a step of releasing the substrate by releasing the engagement by the movable engagement portion; a step of shifting the substrate in a planar direction, and then lifting the substrate after eliminating interference between the fixed engaging portion and the substrate in a vertical direction.

2. 2. The substrate transfer device of claim 1, To recover the substrate from the mounting table, The substrate transfer device in which the main body operates by performing the above steps in reverse order.

3. 3. The substrate transfer device according to claim 1, The mounting table is The substrate transfer device is provided with a displacement mechanism that displaces the substrate in at least one of a planar direction, a vertical direction, and a rotational direction.

4. 3. The substrate transfer device according to claim 1, The movable locking portion is movable by driving a position-controllable actuator.

5. 3. The substrate transfer device according to claim 1, The main body of the substrate transfer device constitutes an end effector attached to the tip of a robot arm.