KR20060076073A - Measurement system for distance of wafer edge exposure - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and in particular, when a photoresist is applied to an upper surface of a wafer loaded on a stage of an exposure apparatus, and a photoresist of a predetermined portion of the wafer edge is removed, the predetermined length region of the wafer edge portion is optically scanned. An optical scanner for collecting data; A scan data analyzer configured to receive scanning data measured by a scanning operation of an optical scanner and analyze a change in scanning data generated by a step between a stage and a wafer and a step between a wafer and a photo register; And a WEE distance measuring unit for calculating a distance between the wafer edge portion and the photoresist edge portion based on the data analyzed by the scan data analyzer, the EBR and WEE distance used in the existing photo process. It is possible to measure an area that could not be measured by an inaccurate person or a high magnification microscope, and the WEE distance can be adjusted precisely within 0.1 μm, thereby increasing the yield of the process and in real time during the process. Particles and defect inspection can be inspected, which contributes to overall yield improvement.

Laser Scanners, Steps, WEE

Description

JEE Distance Measuring Device {Measurement System for Distance of Wafer Edge Exposure}

1 is a cross-sectional view illustrating a process for explaining a general photoresist patterning process

2 is an exemplary view for explaining the operation of the WEE distance measuring device and the connection with the WEE module according to the present invention

3 is an exemplary view for explaining a measuring method of the WEE distance measuring device according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and in particular, between a wafer and a photoresist applied to a wafer in order to measure a WEE distance, which is one of important parameters in the case of exposure from a WEE (Wafer Edge Exposure) module to a WEE process in a lithography process. Since a step exists, it relates to a WEE distance measuring device for measuring the WEE distance through the scanning operation according to the contrast in the optical scanning method.

In general, the lithography process removes the photoresist at the wafer edge since the equipment used in the subsequent etching and deposition processes is a clamp structure or a structure close thereto.

In the semiconductor device manufacturing process, it is necessary to remove the photoresist of the wafer edge to prevent the contamination of the equipment, and also to form a die at the wafer edge in order to improve the uniformity of the subsequent planarization etching process.

In this case, two methods are commonly used to remove photoresist. The first method is to remove thinner by spraying thinner on the edge of a wafer that rotates at high speed during coating, and is commonly referred to as edge bead removal (EBR).

Another method is to install a slit having an exposure unit in the track equipment and expose the wafer edge using the same, which is commonly referred to as wafer edge exposure (WEE).

Therefore, in recent years, EBR (Edge Bid Remove) 2.0mm after coating in coating and developing system during lithography process and round type in Wafer Edge Exposure (WEE) module before developing after patterning operation in scanner ) Is exposed by 2.3mm or clamp type by 4mm WEE process.

FIG. 1 is a cross-sectional view illustrating a general photoresist patterning process. As shown in FIG. 1A, the wafer 1 is loaded into a semiconductor device. Thereafter, as shown in FIG. 1B, the photoresist 2 is applied onto the wafer 1, and the photoresist 2 of the edge portion of the wafer 1 is subjected to a cleaning process. Is removed (see reference numeral (c) of FIG. 1).

As shown by reference numeral (d) of FIG. 1, a UV (Ultraviolet) beam is irradiated onto the wafer 1 by using a first mask 3 that selectively exposes the wafer 1 in a scanner. The photoresist 2 is exposed, and as shown by reference numeral (e) of FIG. 1, the wafer (using a second mask 4 which exposes the edge of the wafer 1 in a wafer edge exposure (WEE) module) is used. 1) is irradiated with a UV (Ultraviolet) beam to expose the photoresist 2 at the edge of the wafer 1.

The photoresist 2 exposed through this process is developed to form a photoresist pattern 2a as referred to by reference numeral (f) of FIG. 1. In this case, the region referred to by reference number A in the photoresist pattern 2a is a portion patterned by an exposure process using the first exposure mask 3 through a scanner, and the region referred to by reference number B is a cleaning process. And a portion patterned by an exposure process using the second exposure mask 4 through a wafer edge exposure (WEE) module.

After developing the above-described conventional photoresist patterning process, the development is performed in the wafer edge area within 3mm in accordance with the round type within 3mm and the shape of the clamp of etching equipment. (Clamp) shape (area from which photoresist is removed) is formed about 12 (at 30 degree angle).

At this time, it is important to accurately measure the distance of the WEE (the distance from the wafer far edge to the far edge of the photoresist) in order to increase the yield of the semiconductor process. Until recently, semiconductor devices that can accurately measure the measurement have not been developed. Therefore, manual measurement is performed. In other words, the operator visually checks the 0.3mm against the SPEC.

The reason for the measurement through the visual inspection of the operator is that even if you want to use the microscope equipment, even in the microscope to measure the range from 0.1mm to 1mm, even the lens of the lowest magnification is impossible to measure. In addition, there was a problem that can not accurately measure the WEE distance between 0 degrees to 90 degrees, 90 degrees to 180 degrees, 180 degrees to 270 degrees, 270 degrees to 360 degrees.

Therefore, there is a strong need for equipment that can accurately measure the distance of WEE in order to increase the yield of semiconductor work and to create a reliable working condition.

An object of the present invention for solving the above problems relates to a semiconductor manufacturing apparatus, and in particular, to measure the WEE distance, which is one of the important parameters when exposed to a WEE process from a wafer edge exposure (WEE) module in the lithography process Since there is a step between the wafer and the photoresist applied to the wafer is to provide a WEE distance measuring device for measuring the WEE distance through the scanning operation according to the contrast in the optical scanning method.

A feature of the WEE distance measuring device according to the present invention for achieving the above object is that, after the photoresist is applied to the upper surface of the wafer loaded on the stage of the exposure equipment and the photoresist of the predetermined portion of the wafer edge is removed, the wafer edge An optical scanner for optically scanning a predetermined predetermined length region of the negative to collect the data; A scan data analyzer configured to receive scanning data measured by a scanning operation of an optical scanner and analyze a change in scanning data generated by a step between a stage and a wafer and a step between a wafer and a photo register; And a WEE distance calculator configured to calculate a distance between the wafer edge and the photo resistor edge based on the data analyzed by the scan data analyzer.

As an additional feature of the WEE distance measuring device according to the present invention for achieving the above object, the optical scanner is the data of the wafer edge area about 360 degrees with respect to the center of the wafer as the stage of the exposure equipment is rotated Is in acquiring.

The above object and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Briefly, the technical idea applied to the present invention is

Typically, the wafer is placed on a work stage of the exposure apparatus, and a photoresist having a predetermined thickness is coated on the wafer. That is, since the wafer also has a predetermined thickness, one step is formed in the work stage and the wafer edge part, and another step is formed in the photoresist edge part applied to the wafer surface.

At this time, since the WEE distance is the distance between the wafer edge portion and the photo resistor edge portion, if the contrast is detected by using an optical scanner and the distance is calculated based on this, the accurate distance is measured. It was conceived that this would be possible.

2 is an exemplary view for explaining the operation of the WEE distance measuring apparatus and the connection with the WEE module according to the present invention, Figure 3 is a view for explaining a measuring method of the WEE distance measuring apparatus according to the present invention It is an illustration.

Referring to FIG. 2, the operation of the WEE distance measuring device and the connection with the WEE module are described. For the exposure, the wafer W is loaded on an exposure apparatus and placed on the stage 100A. Thereafter, the photoresist PR is applied onto the wafer W, and a predetermined portion of the photoresist PR of the edge portion of the wafer W is removed by a cleaning process.

At this time, the optical scanner 200 located at the outer periphery of the stage 100A moves to measure the WEE distance and scans the area of the wafer W edge.

As the optical scanner 200 optically scans the wafer W edge portion, a change in contrast occurs due to a terminal between the stage 100A, the wafer W, and the photoresist PR.

That is, since the photoresist PR having a predetermined thickness is coated on the wafer W, one step area exists, and the wafer W also has a predetermined thickness, so the stage 100A and the wafer W are used. Since one step region exists again at the edge part, the above-described two step regions are detected as optical images or signals by the scanning operation of the optical scanner 200.

At this time, the optical scanner 200 has a scan area for measuring the WEE distance is sufficient type and fixed or fixed at the time of WEE distance measurement or moving type to measure the WEE distance while moving by a separate transfer device, but preferably Fixed type is preferable.

The reason is that the stage 100A is rotatable about an axis of rotation referred to by reference numeral 100B, and the WEE distance measurement must be measured in all directions 360 degrees from the center of the wafer W.

The scanning data measured by the scanning operation of the optical scanner 200 is input to the scan data analyzer 210, and the scan data analyzer 210 shows peak values in the stepped region as shown in FIG. Scan data will be analyzed.

Accordingly, based on the data analyzed by the scan data analyzer 210, the WEE distance calculator 220 uses the actual WEE distance, that is, the wafer, based on the distance between signals showing peak values in the stepped region as shown in FIG. 3. The distance between the edge portion and the photo register edge portion is calculated in all directions 360 degrees from the center of the wafer W.

Since the calculated WEE distance is provided to the WEE module control unit 300 that controls the WEE module 310, accordingly, the WEE module control unit 300 adjusts the position in the WEE module 310.

The reference point for such a process may be easily applied because the wafer loaded on the stage 100A is loaded by a specific reference point.

Such a WEE distance measuring device may be formed as a single device or a separate system module in connection with the WEE module.

While the invention has been shown and described in connection with specific embodiments thereof, it is well known in the art that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the claims. Anyone who owns it can easily find out.

By providing the WEE distance measuring apparatus according to the present invention as described above, it is possible to measure the area EBR, WEE distance used in the conventional photo process, the inaccurate or high magnification microscope could not be measured, 0.1 Because the WEE distance can be adjusted precisely within um, the yield of the process can be increased, and the particles or defect inspection of the WEE region can be inspected in real time during the process, thereby increasing the overall yield. Contributions are expected.

Claims (2)

An optical scanner for applying photoresist to the upper surface of the wafer loaded on the stage of the exposure apparatus and optically scanning a predetermined length region of the wafer edge portion to collect the data when the photoresist of the predetermined portion of the wafer edge is removed; A scan data analyzer configured to receive scanning data measured by the scanning operation of the optical scanner and analyze a change in scanning data generated by the step between the stage and the wafer and the step between the wafer and the photoresist; And And a WEE distance calculator configured to calculate a distance between the wafer edge and the photoresist edge based on the data analyzed by the scan data analyzer. In claim 1,        And the optical scanner acquires data of a wafer edge region about 360 degrees with respect to the center of the wafer as the stage of the exposure apparatus rotates.

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