JPH0341718A - Periphery aligner - Google Patents

Abstract

PURPOSE:To perform exposure at the uniform amount of light by providing a filter at a light projecting part, and providing a transmittance at which the difference between the amounts of the projected light caused by the speeds of exposure is offset. CONSTITUTION:In a light projecting part 30, light for exposure from a light source is guided through a lightguide 15 and passes through a filter 16. The light is projected on a peripheral part 50 of a circular peripheral semiconductor wafer 2. A periphery aligner rotates the semiconductor wafer 2 with a rotary mechanism 8. The end surface of the semiconductor wafer is detected with an edge face detecting means 9. Under this state, the position of the light projecting part 30 is controlled. The light is projected on a resist film on the wafer along the periperal part of the semiconductor wafer. A gradient is provided in the transmittance of the filter 16 that is provided in the light projecting part 30. When the peripheral part of the circular semiconductor wafer 2 is illuminated with the light projecting part 30, the magnitudes of the amounts of the projected light caused by the difference between the mvoing speeds at an inner part 60 and an outer part 70 are offset. Thus the uniform amount of the projected light is obtained.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a peripheral exposure device.

[Prior Art and Problems to be Solved by the Invention] In general, the phosphorography process, which is one of the manufacturing processes of semiconductor devices, is mainly divided into five steps: surface treatment, resist coating, exposure, development, and etching. The projection exposure equipment, etching, and other vacuum equipment used in these processes employ a mechanical method of clamping the periphery of the wafer as a method of transporting the semiconductor wafer and fixing it to the processing table.

However, if the post-treatment in the previous resist coating step is insufficient, resist and the like may remain on the peripheral edge of the semiconductor wafer. In such a case, when the semiconductor wafer is transported, resist peeling occurs and foreign matter is likely to be generated.

In order to prevent the generation of foreign matter due to such resist peeling, a method has been adopted in which the resist layer at the peripheral edge of the semiconductor wafer is exposed to light in an annular manner and is removed by development.

As such an exposure device (Japanese Unexamined Patent Publication No. 58-159535
No., JP-A-59-158520, patent application No. 62-21.
No. 6009).

As shown in FIG. 4, this peripheral exposure device rotates a semiconductor wafer 2 positioned on a mounting table 1 and attracted thereto, and directs light sent through an optical fiber 4 to the front side by a light irradiation unit 3 whose position can be controlled. The peripheral edge portion including the orientation flat portion is selectively exposed.

By the way, in such a conventional peripheral exposure device,
As shown in FIG. 5, as the mounting table 1 rotates, the circular semiconductor wafer 2 rotates and is exposed.
The moving distance is different in the outer peripheral part 7, and when the light intensity distribution of the light source is uniform, the light irradiated from the light irradiation part 3 to the peripheral part 5 of the semiconductor wafer 2 is different in the outer peripheral part 7 compared to the inner peripheral part 6. The amount of light irradiated will be reduced. Therefore, high-intensity irradiation cannot be performed, and as shown in FIG. 6, the cross section of the resist layer R after exposure and development is not removed in the desired shape and perpendicular to the semiconductor wafer 2, as shown by the dotted line. So-called film sag development occurs.6 Therefore, the remaining resist layer cannot be completely removed, and there is a drawback that the yield of ICs is lowered.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a peripheral exposure device that can effectively expose a desired resist layer without film sagging.

[Means for Solving the Problems] In order to achieve the above object, the peripheral exposure apparatus of the present invention moves a light irradiation section relatively along the peripheral edge of the object to be processed, thereby exposing the peripheral edge of the object to be processed. In a peripheral exposure device that exposes a portion, a filter having a low transmittance at an inner peripheral portion and a high transmittance at an outer peripheral portion of the peripheral portion is provided in the optical path of the light irradiation portion.

[Operation] By creating a gradient in the transmittance of the filter provided in the light irradiation section from the inner periphery toward the outer periphery, when the light irradiation section irradiates the periphery of a circular object, the inner periphery Since the magnitude of the amount of irradiated light caused by the difference in moving speed between the outer circumferential portion and the outer peripheral portion can be canceled out, the amount of irradiated light is uniform over the entire irradiated portion.

Therefore, since a strong irradiation light can be used, the boundary between the exposed area and the non-exposed area becomes sharp, and the resist film after development can be completely removed in a desired shape without film sagging.

[Embodiment 1] Hereinafter, an embodiment in which the peripheral exposure apparatus of the present invention is applied to a peripheral exposure apparatus in a semiconductor manufacturing process will be described with reference to the drawings.

The peripheral exposure apparatus shown in FIG. 1 consists of a mounting table 10 which attracts and holds a semiconductor wafer 2 coated with resist, which is a circular object to be processed. Rotation mechanism 8 for rotationally driving the mounting table 10. An end face detection means 9 for detecting the peripheral end face of the semiconductor wafer 2 , a light irradiation unit 30 for exposing the peripheral part 50 of the semiconductor wafer 2 , and a control unit 11 for driving and controlling the rotation mechanism 8 and the like based on signals from the end face detection means 9 The end face detection means 9 includes a light source 1
2 and a light sensor 14 that detects light from a light source 12 through a lens 13. The light irradiation unit 30 includes an opening mechanism (not shown), and this drive mechanism moves the light irradiation unit 30 in response to a signal from the optical sensor 14, thereby exposing the semiconductor wafer 2 along its periphery, including the orientation flat portion 50a. It is configured so that it can be done.

Here, the light irradiation section 30 is the main point of the present invention.

Exposure light from a light source (not shown), for example, light guided by a light conduit 15 such as an optical fiber or liquid fiber for guiding UV light is transmitted through a filter 16 and irradiated onto the peripheral edge 50 of the circular semiconductor wafer 2. .

The irradiation loop 7 of the filter 6 may be rectangular as shown in FIG. 2, or may be circular, elliptical, etc. It is designed to have a transmittance such that the amount of transmitted light to the outer circumferential portion 70 is small. To change the transmittance of the filter 16 by using a characteristic of a desired wavelength, as shown in FIG. It is possible to adopt a method such as making the filter 16 thinner in the transmission region or making the film thickness of the filter 16 thicker in the irradiated light transmitting part of the inner peripheral part 60 and thinner in the irradiated light transmitting part of the outer peripheral part 70.

The peripheral exposure device configured as above includes a rotating mechanism 8
While rotating the semiconductor wafer 2 and detecting the end face of the semiconductor wafer by the end face detection means 9, the light irradiation unit 3
The resist film on the wafer is irradiated with light along the peripheral edge of the semiconductor wafer by controlling the position of 0. However, by creating a gradient in the transmittance of the filter 16 provided in the light irradiation section 30, When the light irradiation unit 30 irradiates the peripheral edge of the circular semiconductor wafer 2, the amount of irradiated light caused by the difference in moving speed between the inner peripheral portion 60 and the outer peripheral portion 70 is canceled out, and a uniform amount of irradiated light is achieved.

For this reason, the irradiated light can be of high intensity,
The boundary between the exposed area and the non-exposed area becomes sharp, and the resist film after development can be completely removed into a desired shape without film sagging.

Although the above description has been made regarding a peripheral exposure apparatus for semiconductor manufacturing, the present invention is not limited thereto, and can be applied to any apparatus as long as it relates to circular irradiation.

[Effects of the Invention] As is clear from the above description, according to the peripheral exposure apparatus of the present invention, a filter is provided in the light irradiation section.

Since it has a transmittance that cancels out the difference in the amount of irradiated light caused by the exposure speed, it is possible to perform exposure with a uniform amount of light. Therefore, intense irradiation can be performed, sharp removal of the residual resist film without film sagging can be achieved, and a clean semiconductor can be formed.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a peripheral exposure device for a semiconductor device to which the peripheral exposure device of the present invention is applied, and FIGS. 2 and 3 show essential parts of the embodiment shown in the construction drawing. Explanatory diagram, 4th
5 and 5 show a conventional peripheral exposure device, and FIG. 6 is a cross-sectional view of a resist film manufactured by the conventional device. 2... Object to be processed 10... Mounting table 16... Filter 50... Peripheral part 60... Inner peripheral part 70... Outer peripheral part (semiconductor wafer)

Claims (1)

[Claims] In a peripheral exposure device that exposes the peripheral edge of the object to be processed by moving a light irradiation part relatively along the peripheral edge of the object, the inner peripheral area of the peripheral area has low transmittance, and the outer peripheral area has low transmittance. A peripheral exposure device characterized in that a filter with high transmittance is provided in the optical path of the light irradiation section.