KR20060094146A - Wafer aligner and method for align - Google Patents

Abstract

The present invention relates to a wafer alignment apparatus and a wafer alignment method for wafer alignment, the wafer alignment apparatus comprising: a wafer chuck for loading and horizontally rotating a wafer; And a camera for storing the image of the notch portion of the wafer in advance and comparing the stored image with the notch image of the wafer rotating on the wafer chuck to center the wafer. According to the present invention, it is possible to reduce the time required for wafer alignment, and accurate wafer alignment is possible.

Wafer, align, CCD, camera, notch

Description

Wafer aligner and method for aligning

1 shows a conventional wafer alignment apparatus for aligning a wafer with a flat zone;

FIG. 2 is a diagram illustrating an alignment process of a wafer having a notch according to FIG. 1.

3 is a top view of a wafer with notches

4 illustrates a wafer alignment apparatus according to an embodiment of the present invention.

     * Description of the symbols for the main parts of the drawings *

    114: fixing base 111: wafer chuck

    112: motor 122: wafer

    130: camera

The present invention relates to a semiconductor manufacturing facility, and more particularly to a wafer alignment apparatus and an alignment method for wafer alignment.

Generally, a semiconductor device uses a deposition process for forming a film on a semiconductor substrate, a chemical mechanical polishing process for planarizing the film, a photolithography process for forming a photoresist pattern on the film, and the photoresist pattern. A series of unit processes such as an etching process for forming the film into a pattern having electrical characteristics, an ion implantation process for implanting specific ions into a predetermined region of the semiconductor substrate, and a cleaning process for removing impurities on the semiconductor substrate Formed by performing them.

These unit processes are performed with a predetermined semiconductor manufacturing facility, which is generally composed of a loader on which a cassette containing a wafer is placed, a load lock chamber, a buffer chamber, an alignment chamber and a process chamber. During the semiconductor process, an alignment process for adjusting a flat zone or notch of a wafer to a certain direction should be performed.

A cassette loaded with a wafer is loaded into the loader, a process is performed, and a wafer is loaded into the load lock chamber. The wafer in the load lock chamber is transferred into the buffer chamber by a transfer device and sent to the alignment chamber to perform an alignment process of the wafer. After the alignment process is completed, the wafer is sent to the process chamber through a buffer chamber to perform a manufacturing process.

Such semiconductor manufacturing equipment has a long process time in the main process or a single process chamber, but the process speed of the alignment chamber is sufficient so that the overall process speed is not affected. In the case of a multi process chamber, an alignment process time is insufficient, and thus a process progression is determined according to the alignment process time.

1 is a view showing an alignment apparatus for alignment in a 200 mm wafer having a conventional flat zone.

As shown in FIG. 1, the conventional alignment apparatus includes a light emitting unit 16 provided in the prealigner 14, a light receiving unit 18, etc. provided in the receiving unit 20.

Hereinafter, a method for aligning a center point of a wafer by a conventional alignment device will be described.

The wafer 10 is loaded onto the wafer chuck and the wafer chuck is rotated horizontally. When the wafer chuck is rotated, the wafer 10 loaded on the wafer chuck is also fixed.

In the light emitting unit 16 fixed to the support 14, a predetermined light beam 13 is scanned upwardly of the wafer 10. At this time, when the flat zone 12 of the wafer 10 passes between the light emitting portion 16 and the light receiving portion 18 by the rotation of the wafer 10, the light rays 13 emitted from the light emitting portion 16 It is sensed by the light receiving unit 18. The light receiver 18 receiving light beams applies an electric signal according to light beam reception to a controller (not shown). According to this process, light is irradiated to the edge portion of the wafer 10 as the wafer rotates, and the flat zone portion 12 is sensed by the difference in the amount of light generated by the irradiated light being blocked by the wafer 10. do.

The position of the center point of the wafer is calculated by the position of the flat zone 12.

FIG. 2 is a view for aligning a 300 mm wafer by the alignment device of FIG. 1. FIG.

As shown in FIG. 2, the wafer is provided with notches, and the alignment is performed as in the case of the wafer having a flat zone. In the case of the 200 mm wafer, the flat zone portion of the wafer is clearly separated, so it is easy to detect. In the case of the 300 mm wafer 22, the flat zone is not a flat zone but a notch 24, which causes a problem.

As described in FIG. 1, when the alignment process is performed, the time for alignment takes about 2 seconds for the 200mm wafer, but the time for the 300mm wafer takes about 6 to 7 seconds. This is because in the case of 200mm wafers, the flat zone is clearly separated and is easy to detect, but in the case of 300mm wafers, this is notched. Therefore, in the case of a wafer having a notch, there is a need for measures to reduce the alignment time.

Accordingly, an object of the present invention is to provide a wafer alignment apparatus and an alignment method which can overcome the above-mentioned conventional problems.

Another object of the present invention is to provide a wafer alignment apparatus and an alignment method which can reduce the alignment time in the case of a wafer having a notch.

It is still another object of the present invention to provide a wafer alignment apparatus and an alignment method capable of performing accurate wafer alignment.

According to an aspect of the present invention for achieving some of the above technical problems, a wafer aligning apparatus according to the present invention comprises: a wafer chuck for loading and horizontally rotating a wafer; And a camera for storing the image of the notch portion of the wafer in advance and comparing the stored image with the notch image of the wafer rotating on the wafer chuck to center the wafer.

The camera may be a CCD camera, and the wafer may be a wafer having a notch.

According to an aspect of the present invention for achieving some of the above technical problems, the wafer alignment method according to the present invention comprises the steps of: storing a notch image of the wafer, horizontally rotating the wafer chuck on which the wafer is placed; Sensing an image of the edge portion of the horizontally rotating wafer; comparing the image of the sensed wafer edge portion with a stored notch image; Generating a phosphorus signal, and centering the wafer in response to the alignment signal.

The wafer may be a wafer having a notch.

According to the above configuration, the time required for wafer alignment can be reduced, and accurate alignment is possible.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, without any other intention than to provide a thorough understanding of the present invention to those skilled in the art.

3 illustrates a waiter to which a wafer alignment apparatus according to an embodiment of the present invention is applied.

As shown in FIG. 3, the wafer 122 has a notch 124 instead of a flat zone, unlike conventional wafers (eg 200 mm wafers). Typically, notches are provided on 300mm wafers.

4 is a schematic diagram of a wafer alignment apparatus according to an embodiment of the present invention.

As shown in FIG. 4, the wafer alignment apparatus according to the exemplary embodiment of the present invention includes a camera 130 unlike the conventional art.

As shown in FIG. 3, a wafer chuck 111 for loading a wafer 122 is provided. The wafer chuck is formed smaller than the size of the wafer 122 to be placed. A motor 112 is connected to the wafer chuck and horizontally rotates the wafer chuck.

The edge of the wafer 122 that rotates as the wafer chuck 111 rotates by the motor 112 while the camera 130 previously stores an image of the notch portion 124 of the wafer 122. Shoot the image.

When the image photographed according to the rotation of the wafer 122 is the same as the pre-stored notch image, alignment of the wafer is performed.

The camera 130 may be a charge coupled device (CCD) camera. The camera 130 may have a function of checking a lot ID of a wafer and thus may have a structure capable of checking a lot ID image with a camera when loading a wafer.

The camera 130 may be fixedly installed by the holder 114 at an appropriate position so that the edge portion of the upper surface of the wafer 122 may be photographed.

The wafer alignment apparatus according to an embodiment of the present invention may be applied to wafers having notches or flat zones as well as wafers having notches.

An operation for aligning the wafer 122 is as follows.

First, the notch image 124 of the wafer 122 is stored in advance. Next, the wafer chuck 111 on which the wafer 122 is placed is horizontally rotated by the motor 112. Then, an image of the edge portion of the horizontally rotating wafer 122 is sensed or photographed. When the image of the sensed wafer edge and the image of the sensed notch are the same, when the stored notch image and the image of the sensed wafer edge are the same, an alignment signal is generated according to the same and the center of the wafer is responded to in response to the alignment signal. Alignment is performed through a series of processes, such as matching.

As described above, in the wafer alignment apparatus according to the exemplary embodiment of the present invention, the time required for the wafer alignment may be reduced by performing the alignment of the wafer by a camera unlike the conventional art, and accurate alignment may be performed. have.

The description of the above embodiments is merely given by way of example with reference to the drawings for a more thorough understanding of the present invention, and should not be construed as limiting the present invention. In addition, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the basic principles of the present invention.

As described above, according to the present invention, unlike the wafer alignment, which is performed by attaching the conventional light emitting sensor and the light receiving sensor, the time required for the wafer alignment can be reduced by performing the wafer alignment by the camera. Phosphorus can be performed.

Claims (5)

In the wafer alignment device: A wafer chuck that loads the wafer and rotates horizontally; And And a camera for storing the image of the notch portion of the wafer in advance and comparing the stored image with the notch image of the rotating wafer on the wafer chuck to center the wafer. The method of claim 1, Wafer alignment device, characterized in that the camera is a CCD camera. The method of claim 2, Wafer alignment apparatus, characterized in that the wafer having a notch. In the wafer alignment method: Storing a notch image of the wafer; Horizontally rotating the wafer chuck on which the wafer is placed; Sensing an image of an edge portion of the horizontally rotating wafer; Comparing the image of the sensed wafer edge with the stored notch image to generate an alignment signal when the stored notch image and the image of the sensed wafer edge are the same; And And centering the wafer in response to the alignment signal. The method of claim 4, wherein Wafer alignment method, characterized in that the wafer having a notch.

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