JPH08125004A - Wafer holder and wafer visual inspection device using it - Google Patents

Abstract

PURPOSE: To facilitate the visual inspection of the front and rear planes of a wafer by providing a wafer holder which holds and automatically drives the wafer in semiconductor manufacturing process with both front and rear planes of the wafer exposed. CONSTITUTION: A plurality of rollers 34 with a groove 35 which allows the outer circumference of a wafer W to fit are fit at a plurality of positions on the wafer outer circumference, respectively, so as to hold the wafer W. The wafer holder permits the autorotation of the holding wafer by rotating the rollers 34 under such a condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer holder capable of holding and rotating a wafer in a semiconductor manufacturing process in a state where both the front surface and the back surface are exposed, and a visual inspection of the front surface and the back surface using this wafer holder. The present invention relates to a wafer visual inspection device.

[0002]

Wafer in the background semiconductor manufacturing process of the Prior Art invention, in order to ensure high product quality, yield, etc., cleanliness of the surface of the semiconductor circuit is formed, of course be examined whether such a small flaw If it is defective, it is cleaned again or discarded. However, the back surface of the wafer has not been particularly inspected and has not been regarded as important. However, as the diameter of the wafer becomes larger and the circuit becomes finer, the cleanliness of the back surface and the presence or absence of scratches have become important for ensuring the quality of the product.

For example, in the exposure process for forming a resist pattern by photolithography,
Since the back surface of the wafer is adsorbed and the wafer is held on the stage for processing, if dust or the like adheres to the back surface of the wafer, even if it is minute, the dust will cause the front surface of the wafer to be localized. There is a problem that the swelling exposure process cannot be performed properly. There is also a problem that dust and the like attached to the back surface are carried into the next step.

Conventional wafer visual inspection apparatus In the conventional wafer visual inspection apparatus, however, a so-called adsorption stage (wafer stage) capable of performing operations such as rotation, elevation, tilting, etc. by adsorbing the back surface of the wafer is used as a wafer holding means (wafer holder). ), The wafer taken out from the carrier is conveyed and held on this suction stage installed at the inspection place and positioned in various postures, so that the inspector at the inspection place can see this with the naked eye or via a microscope. This is to inspect each part of the wafer surface on the suction stage from each direction in consideration of the light irradiation direction.

[0005]

Therefore, in the conventional wafer visual inspection apparatus, the back surface of the wafer cannot be inspected because it is covered by the suction stage, and the above-mentioned problems due to dust adhering to the back surface and the like have been described above. Since a defect cannot be prevented, there has been a problem that the yield or quality of the semiconductor manufacturing process is reduced as a result.

In view of this, the present invention provides a wafer holder capable of gripping and rotating the wafer in a semiconductor manufacturing process while the front surface and the back surface are exposed, and a wafer which enables visual inspection of the front surface and the back surface using the wafer holder. It is intended to provide a visual inspection device.

[0007]

In order to achieve the above object, a wafer holder according to a first aspect of the present invention comprises a plurality of rollers each having a groove formed on the outer periphery thereof into which a peripheral portion of a wafer is fitted in a semiconductor manufacturing process. A plurality of positions on the outer periphery of the wafer are provided with roller supporting means axially supported so as to be respectively fitted from the outside in the radial direction, and roller driving means for rotationally driving the roller. It is characterized in that the wafer is gripped by being fitted into each of the two, and the gripped wafer is rotated by rotating the roller by the roller driving means in this state.

According to a second aspect of the present invention, in the wafer holder, the roller supporting means includes a holder base portion and a pair of frames pivotally supported by the holder base portion and swingable so as to sandwich both outer peripheral sides of the wafer from outside in the radial direction. It is characterized in that it comprises a support member attached to the inside of each of these frames to support the roller so as to move forward and backward, and a biasing means for biasing this support member toward the forward side.

According to a third aspect of the present invention, in the wafer holder according to the third aspect, the roller supporting means has a holder base, a ring-shaped frame having a diameter larger than that of the wafer fixed to the holder base, and attached inside the frame. It is characterized by comprising a support member for axially supporting the roller so as to move forward and backward, a biasing means for biasing the support member toward the forward side, and a forward and backward drive means for driving forward and backward movement of the roller.

According to the fourth aspect of the present invention, the wafer visual inspection apparatus takes out the wafers in the carrier one by one so that an inspector at a fixed position in the semiconductor manufacturing process can visually inspect from various directions. 4. A wafer visual inspection apparatus for positioning the wafer in various postures, wherein the back surface of the wafer is sucked and moved by a suction pad to move the wafer into and out of the carrier. Has a wafer holder,
The wafer picked up by the wafer loading / unloading device is received by the wafer holder, moved to the inspection place, the wafer holder is positioned in various postures, and the grasped wafer is rotated by operating the roller driving means to perform the visual inspection. A wafer transfer positioning machine for positioning a wafer for inspection is provided.

[0011]

In the wafer holder of the present invention, the plurality of rollers, each having the groove on the outer periphery of which the outer peripheral portion of the wafer fits, are fitted to the plurality of positions on the outer periphery of the wafer by the roller supporting means to grip the wafer. The gripped wafer is rotated by rotating the roller by the driving means. Therefore, the wafer can be held and rotated while the front and back surfaces are exposed.

Further, in the wafer visual inspection apparatus of the present invention, the wafer taken out by the wafer loading / unloading machine is received by the wafer transfer positioning machine having the wafer holder and moved to the inspection place to position the wafer holder in various postures. Visual inspection can be performed by operating the roller driving means of the wafer holder to rotate the held wafer. Therefore, it is possible to visually inspect the wafer on both the front surface and the back surface.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Configuration of Embodiments One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the wafer visual inspection apparatus of the present embodiment receives a wafer loading / unloading device 10 for loading / unloading a wafer W into / from a carrier 1, and a wafer W taken out by the wafer loading / unloading device 10 to receive a visual inspection location 2 Alternatively, it is provided with a wafer transfer positioner 20 that moves the microscope inspection location 3 and positions the wafer for visual inspection.

In this case, the wafer loading / unloading machine 10 is a so-called horizontal articulated robot provided with, for example, a base 11, a first arm 12, a second arm 13, and a wrist portion 14 which are sequentially rotatably connected from the base 11 in a horizontal direction. And wrist 14
Thin suction pad 1 that sticks the backside of wafer W to the tip of
5 is attached. The wafer loading / unloading machine 10 inserts a suction pad 15 between a plurality of horizontally loaded wafers in the carrier 1, sucks the back surface of a wafer W to be inspected, and then removes the suction pad 15. The wafer W is taken out by the first arm 1 as shown by the chain line in FIG.
2 and the wafer W attracted by rotating the second arm 13 and the like
Is moved to a position where it can be delivered to the wafer transfer positioner 20.

The operation of the wafer loading / unloading machine 10 may be controlled by, for example, a so-called teaching playback system by a controller (not shown), or may be manually operated by an inspector. In the case where the carrier 1 is of a type in which the wafer W is taken out from the upper surface opening, the wafer loading / unloading machine 10 is provided with a function of raising and lowering the first arm 12, the second arm 13 and the like, and the suction pad 15 is pulled out from the upper surface. And it is sufficient.

In this case, the wafer transfer positioner 20 is provided with a base 21, an arm 22 horizontally rotatably connected to the base 21, and a wrist portion 23 attached to the tip of the arm 22 so as to be twisted and rotatable. In the robot, a wafer holder 30 is attached to the tip of the wrist 23 to hold the wafer W and rotate it. The wafer transfer positioner 20 is operated by a controller (not shown), for example, according to a program taught in advance. The wafer W taken out by the wafer in / out machine 10 is received by the wafer holder 30 and the macroscopic inspection place 2 or the microscope is operated as described later. The wafer holder 30 is moved to the inspection place 3, the wafer holder 30 is positioned in various postures, and the wafer holder 30 described later is used.
By rotating the roller 34 and rotating the gripped wafer, the wafer is positioned for visual inspection.

The wafer holder 30, as shown in FIG.
A holder base 31, a pair of frames 32, 33 attached to the holder base 31 and swingable so as to sandwich both outer peripheral sides of the wafer W from the outside in the radial direction, and a holder base 31 is attached to the insides of the frames 32, 33 so as to be movable back and forth. A plurality of rollers 3 that can be fitted into the outer periphery of the wafer W, respectively,
4 and.

Each of the frames 32 and 33 has a wafer W.
For example, an arcuate shape having a diameter larger than that of the base end 31 is rotatably supported by the base portion 31 and is rotatably driven by a motor (not shown) so as to open as shown by a chain line in FIG. 2 or close as shown by a solid line. . As shown in FIG. 3, the roller 34 has a groove 35 having a V-shaped cross section into which the outer peripheral portion of the wafer W fits, and in this case, two rollers are provided on each of the frames 32 and 33.
They are attached one by one, and are arranged on the same plane so as to fit into four equally divided positions on the outer periphery of the wafer W.

A shaft 36 of the roller 34 is rotatably attached to a support member 37, and a shaft portion 38 on the base end side of the support member 37 is slidably inserted into each of the frames 32 and 33. Toward the inside (towards the center of the wafer)
It is free to go back and forth. A retaining ring 39 is attached to the end of the shaft portion 38 of each supporting member 37, and each supporting member 3
The forward movement of 7 is restricted to prevent falling off,
As shown in FIG. 3, a compression coil spring 40 (biasing means) is mounted between each frame 32, 33 and each support member 37 to bias each support member 37 inward. Further, the support member 37 has a shaft 36 of the roller 34 as shown in FIG.
A motor 41 (roller driving means) that is directly connected to the motor 41 and rotates the gripped wafer W by rotating the roller 34 is attached.

At least the surfaces of the rollers 34, the frames 32, 33 and the like are made of a material having no dust generation such as Teflon or prepropylene. Also,
The motor 41 does not have to be provided for all of the rollers 34, and may be provided at least at two positions in consideration of the presence of the orientation flat W1 (shown in FIG. 2) of the wafer W. Further, in the case of this embodiment, the holder base 31, the frame 32,
33, each support member 37, the compression coil spring 40, etc. constitute the roller support means of the present invention.

Operation of Embodiment Next, the operation of the above-described wafer visual inspection apparatus will be described. In the above configuration, when the carrier 1 is transferred, the wafer loading / unloading machine 10 is activated to adsorb the wafers W in the carrier 1, pick up the wafers one by one, and deliver them to the wafer transfer positioning machine 20. In this transfer, the wafer transfer / positioning machine 20 moves the wafer W to the movable position of the wafer transfer / positioning machine 20 and stops the wafer transfer / positioning machine 20 while the wafer transfer / positioning machine 10 moves the arm as shown by the chain line in FIG. The wafer holder 30 holds the attracted wafer W from both sides.
The wafer loading / unloading machine 10 releases the suction state and retracts, so that interference is not caused. At this time, in the wafer holder 30, each roller 34 elastically fits into the outer periphery of the wafer W by the forward / backward movement of the support member 37 and the urging force of the compression coil spring 40, and the outer peripheral portion of the wafer W forms the respective rollers 3.
The wafer W is held in the groove 35 of No. 4 so as to be held flexibly and stably.

Then, the wafer transfer positioner 20 that has received the wafer W in this way first turns the wrist 23 in the macroscopic inspection location 2 by rotating the wrist 23 to position the wafer holder 30 in various postures and activates the motor 41. The front surface and the back surface of the wafer W are positioned in various postures and rotation angles by rotating the rollers 34 of the wafer holder 30 and rotating the held wafer W on its own axis. As a result, an inspector near the naked eye inspection place 2 can inspect each part of the front surface and the back surface of the wafer W with naked eyes from various directions with respect to the light irradiation direction while staying at a fixed position.

Then, the wafer transfer positioner 20 transfers the wafer W to the microscope inspection place 3 and the microscope inspection place 3
Each part of the wafer W is positioned with respect to the microscope installed in the. At this time, the wafer transfer positioner 20 moves the wrist 2 with the wafer holder 30 retracted to a position where it does not interfere.
The front surface and the back surface of the wafer W are alternately positioned by rotating the wafer 3 by twisting and rotating. As a result, an inspector near the microscope inspection place 3 can inspect each part of the front surface and the back surface of the wafer W with a microscope while staying at a fixed position.

When a series of inspections of the wafer W is completed in this way, the wafer W is handed over from the wafer transfer positioning machine 20 to the wafer loading / unloading machine 10, and the wafer W after the inspection is carried by the wafer loading / unloading machine 10. Back to 1,
After that, the next wafer W is taken out again, and the above operation is repeated for all the wafers W in the carrier 1.

As described above, according to the above-mentioned wafer visual inspection apparatus, each part of the front surface and the back surface of the wafer W can be sufficiently and easily inspected by naked eyes and a microscope. Therefore, it is possible to improve yield and quality while maintaining high productivity in the semiconductor manufacturing process.

Other Embodiments The present invention is not limited to the above-mentioned embodiments, but may have various modes. First, as shown in FIG. 4, the roller supporting means has a ring-shaped frame 52 having a diameter larger than that of the wafer W fixed to the holder base 51, and is mounted inside the frame 52 so as to be movable back and forth. The roller 3 by the support member 37
4 may be provided, and the advancing / retreating drive means 53 for driving the advancing / retreating movement of the support member 37 may be provided. Even in this case, the wafer W is positioned inside each of the rollers 34 in a state where the roller 34 is retracted by the advancing / retreating driving means 53, and then the roller 34 is advanced to elastically move the roller 34 to the outer periphery of the wafer W. The wafer W can be fitted and held in a flexible and stable manner. The advancing / retreating drive means 53 in this case can be configured by, for example, a pneumatic cylinder or the like in which an output rod is connected to the shaft portion 38 of the support member 37, but not necessarily provided for all the rollers 34.

Further, the number of rollers is not necessarily limited to four, and may be two if the wafer W can be held.
Further, even when the rollers are attached to the pair of frames that are opened and closed as in the above-described embodiment, some of the plurality of rollers can be fixedly supported by the holder base. Further, in the above-described embodiment, the wafer W is positioned with respect to the microscope by the wafer transfer positioner 20 having a wafer holder, but a suction stage for positioning the wafer with respect to the microscope (moving up and down, etc.) is provided at the microscope inspection place. At the time of microscopic inspection, the wafer transfer positioner 20 may set the wafer W on the suction stage and retract it. Even in this case, if the wafer transfer / positioning machine 20 performs the front / back conversion of the wafer, the back surface can be easily inspected.

The roller driving means is not limited to a mode in which it is constituted by a motor directly connected to the shaft of the roller. For example, when a part of the roller is fixedly supported by the holder base, the roller driving means is constituted by the motor provided in the holder base. The roller may be driven. Further, the wafer transfer positioner 20
In the above embodiment, the robot is configured by a robot having one arm. However, the robot can be configured by a multi-joint robot to increase the degree of freedom and further facilitate the positioning and transfer of the wafer W.

[0029]

According to the wafer holder of the present invention, the wafer can be gripped and rotated while the front surface and the back surface of the wafer are exposed, and the wafer visual inspection apparatus of the present invention using the wafer holder can easily perform the operation. Visual inspection of the front and back surfaces of the wafer is possible. Therefore, it is possible to prevent defects due to contamination and scratches on the wafer surface without increasing the number of laborious steps, and it is possible to improve yield and quality while maintaining high productivity in the semiconductor manufacturing process.

[Brief description of drawings]

FIG. 1 is a plan view showing the overall configuration of a wafer visual inspection apparatus that is an embodiment of the present invention.

FIG. 2 is an enlarged plan view showing a wafer holder in the embodiment of the present invention.

FIG. 3 is a sectional view taken along line III in FIG.

FIG. 4 is an enlarged plan view showing a wafer holder which is another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer carrier 2 Visual inspection place 3 Microscope inspection place 10 Wafer loading / unloading machine 20 Wafer transfer positioning machine 30 Wafer holder 31 Holder base 32, 33 Frame 34 Roller 35 Groove 37 Supporting member 40 Biasing member (compression coil spring) 41 Roller driving means (motor) ) 51 holder base 52 frame 53 forward / backward drive means

Claims (4)

[Claims] 1. In a semiconductor manufacturing process, a plurality of rollers each having a groove formed on the outer periphery thereof into which the outer peripheral portion of the wafer is fitted, and these rollers are axially supported so as to be respectively fitted to a plurality of positions on the outer peripheral portion of the wafer from the outside in the radial direction. Roller support means,
A roller driving unit that rotationally drives the roller, and holds the wafer by fitting the roller into a plurality of positions on the outer periphery of the wafer by the roller supporting unit, and rotating the roller by the roller driving unit in this state. A wafer holder characterized in that the wafer gripped in step 1 is rotated. 2. The roller supporting means comprises a holder base,
A pair of frames pivotally supported by the holder base and swingable so as to sandwich both outer peripheral sides of the wafer from the outside in the radial direction,
2. The wafer holder according to claim 1, further comprising: a supporting member attached to the inside of each of the frames to rotatably and axially support the roller, and an urging means for urging the supporting member toward the advancing side. 3. The roller supporting means comprises a holder base,
A ring-shaped frame having a diameter larger than that of the wafer, which is fixed to the holder base, a support member attached to the inside of the frame to support the roller so that the roller can move back and forth, and the support member is urged toward the forward side. 2. The wafer holder according to claim 1, further comprising a biasing means for driving the roller, and a forward / backward driving means for driving the forward / backward movement of the roller. 4. A wafer visual inspection apparatus for picking up wafers one by one in a carrier and positioning them at various inspection positions in various postures so that an inspector at a fixed position in each semiconductor manufacturing process can visually inspect from various directions. A wafer loading / unloading machine for loading / unloading a wafer to / from a carrier by suctioning and moving a back surface of the wafer with a suction pad, and the wafer loading / unloading machine having the wafer holder according to claim 1. A wafer for the visual inspection by receiving the taken-out wafer by the wafer holder, moving it to the inspection place, positioning the wafer holder in various postures, and operating the roller driving means to rotate the gripped wafer. And a wafer transfer positioning machine for positioning the wafer.査 apparatus.