JPH01217916A - Wafer periphery exposure mechanism - Google Patents

Abstract

PURPOSE:To expose the orientation flat part of a wafer in a predetermined width by detecting the exposure amount of the end of the wafer or the end itself, and moving a radiation lens in response to the detected result in the normal direction of the wafer. CONSTITUTION:A wafer 1 fixed to a wafer base 2 by suction is rotated by a rotating device 3, and exposed with an ultraviolet light from a lens 5. In this case, the irradiated light is received by a light quantity sensor 6. A drive amplifier and a linear motion source 8 are so set that, when the detected quantity of light is more than a preset light quantity, the lens 5 is moved toward the center of the wafer, while when it is, on the contrary, less than that, the lens 5 is moved toward the outer periphery of the wafer.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to wafer periphery exposure for exposing and developing photoresist on the outer periphery of the wafer to remove the photoresist around the wafer in a semiconductor manufacturing photo process. Regarding the mechanism.

[Prior Art] Conventional exposure equipment for removing photoresist from the edge of a wafer rotates the wafer while irradiating the outer periphery of the wafer with ultraviolet light condensed to a diameter of several m/m, and the outer periphery of the wafer is exposed to a diameter of 3 to 6 Il.
Exposure was carried out at a width of l/ffi, and in the development process, the photoresist was removed from the exposed area on the wafer's outer periphery. In this exposure step, the orientation flat portion of the wafer must also be exposed with a constant width from the outer periphery of the wafer. For this reason, in the past, the orientation flat was exposed by first stopping the rotation to E and moving the exposure mechanism in parallel along the orientation flat, and then rotating the wafer again and exposing the wafer along the circular outer periphery of the wafer. was doing.

[Problems to be Solved by the Invention] In the conventional exposure apparatus, the orientation flat of the wafer must be aligned with the parallel movement direction of the exposure mechanism, and an alignment mechanism for this purpose is required. This eliminates the disadvantage that the mechanism becomes complicated and the cost increases because a parallel movement means is required.

[Object of the Invention] The present invention has been made in view of the drawbacks of the prior art described above, and it is possible to expose the peripheral area of sea urchins, including the orientation flat part, with a simple structure without using a positioning mechanism for the orientation flat part. The purpose of this invention is to provide a mechanism for exposing the periphery of sea urchins, which makes it possible to reduce costs.

[Embodiment] FIG. 1 shows an embodiment of the present invention, in which a wafer 1 having an orientation flat (not shown) is mounted on a wafer stand 2 and fixed by vacuum suction. The wafer table 2 is a rotating device 3
Rotates due to The ultraviolet light is guided from a light source (not shown) through an optical fiber 4 and irradiates the outer circumference of the wafer 1 via a lens 5 . At this time, the amount of irradiated light is detected by a light amount sensor 6, and the linear motion source 8 is driven through a drive amplifier 7 according to the detected amount of light. This light amount sensor 6 detects the amount of light that is outside the wafer 1 out of the light that exposes the periphery of the sea urchin 8 through the lens 5. A linear motion bearing 9 is connected to the linear motion source 8 . A support 10 is provided on this linear motion bearing 9, and the lens 5 is provided on this support 10. The linear motion bearing 9 moves the lens 5 linearly along the rotation radius direction (normal direction) of the wafer table.

The wafer 1 suctioned and fixed on the wafer table 2 is rotated by a rotating device 3 and exposed to ultraviolet light from a lens 5. At this time, the irradiated light is received by the light amount sensor 6.

The drive amplifier 7 and the linear motion source 8 are set so that if the detected light amount is greater than a preset light amount, the lens 5 is moved toward the wafer center, and conversely, when it is less, the lens 5 is moved toward the wafer outer circumference. put.

FIG. 2 shows another embodiment of the present invention, in which the lens, which is the exposure means, is moved by mechanical means rather than electrical means. That is, the light amount sensor 6, drive amplifier 7, and linear motion source 8 in FIG. 1 are replaced with a guide roller 11 and a tension spring 1 as shown in FIG.
It is equipped with 2.

The guide roller 11 is a support 10 provided on the linear motion bearing 9.
The wafer 1 can be moved along the radial direction of the wafer 1 on the wafer table 2 together with the lens 5 while maintaining a predetermined position relative to the lens 5. The linear motion bearing 9 is always urged toward the center of rotation of the wafer table 2 by a tension spring 12 .

When the wafer 1 rotates, the guide roller 11 comes into contact with the outer peripheral side surface of the wafer 1 by the tension spring 12, and as the wafer 1 rotates, a certain dimension area is always irradiated from the outer periphery of the wafer 1. Therefore, the orientation is flat while the wafer is rotating. It becomes possible to expose the area. Further, when the wafer 1 is attracted to the wafer stand 2, high accuracy is not required for centering the wafer 1 and the wafer stand 2.

[Effects of the Invention] As explained above, in the periphery exposure mechanism according to the present invention, the exposure amount at the edge of the wafer or the edge itself is detected, and the irradiation lens is aligned with the normal to the wafer according to the detection result. By moving the wafer in the direction, it becomes possible to expose the orientation flat part of the wafer at a constant width without the need for a special orientation flat alignment mechanism, which simplifies the mechanism and reduces the planar dimensions of the equipment, making the equipment more compact. In addition, exposure control can be easily performed, and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of another embodiment of the present invention. 1: Wafer, 2: Wafer stand, 3: Rotating device, 4: Optical fiber, 5: Lens, 6: Light intensity sensor, 8: Linear motion source, 9: Linear motion bearing, 11 Ni guide roller, 12: Extension spring. Patent applicant Canon Co., Ltd.

Claims (4)

[Claims] (1) A wafer stand for mounting and fixing a wafer having an orientation flat, a rotation device for rotating the wafer stand, an exposure means for irradiating light onto the outer circumference of the wafer, and linear movement means for linearly moving the exposure means along the rotation radius direction of the wafer table; and exposure control means for driving the linear movement means in accordance with the amount of light irradiated onto the wafer by the exposure means. A wafer peripheral exposure mechanism characterized by comprising: (2) The exposure means comprises a lens connected to a light source via an optical fiber and a support supporting the lens above the outer peripheral edge of the wafer, and the support is fixed to the linear motion means. A wafer peripheral exposure mechanism according to claim 1. (3) The exposure control means includes a light amount sensor for detecting the amount of light that is off the wafer among the light that exposes the outer peripheral portion of the wafer through the lens, and the linear movement means according to the output of the light amount sensor. 3. The wafer periphery exposure mechanism according to claim 2, comprising an electric circuit for driving the wafer periphery exposure mechanism. (4) The exposure control means includes a guide roller that comes into contact with the outer peripheral side of the wafer mounted on the wafer table, and a spring means that always biases the linear movement means toward the rotation center of the wafer table. 3. The wafer periphery exposure mechanism according to claim 2, wherein said guide roller is fixed relative to said linear movement means.