KR100675558B1 - Apparatus and method for measuring diameter of wafer - Google Patents

Abstract

The present invention relates to an apparatus and method capable of measuring and managing the diameter of a wafer. The disclosed invention has a support for mounting and supporting a wafer. The support is rotated by the drive. In addition, the present invention provides a first member and a light irradiated from the first member for irradiating light to one end of the wafer that is supported and rotated on the support and the other end of the wafer opposite the one end of the wafer It includes an optical unit provided with a second member for sensing. According to this, a wafer diameter can be measured by irradiating light to both edges of the wafer which rotates a wafer and makes the center of a wafer symmetrical. As a result of measuring the wafer diameter, it is possible to distinguish between good and bad about the wafer diameter, thereby preventing the defects in the process or wafer damage due to the error of the wafer diameter.

Semiconductors, Wafers, Rotary Chucks, Exposure Units (EEW)

Description

Apparatus and method for measuring the diameter of a wafer {APPARATUS AND METHOD FOR MEASURING DIAMETER OF WAFER}

1 is a cross-sectional view showing a wafer diameter measuring apparatus according to an embodiment of the present invention.

2 and 3 are cross-sectional views illustrating a wafer diameter measuring method using the wafer diameter measuring apparatus according to the embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

110; Support

120; Driving part

130; Optics

130a; Light emitting part

130b; Receiver

TECHNICAL FIELD The present invention relates to a semiconductor manufacturing apparatus, and more particularly, to an apparatus capable of measuring and managing an actual diameter of a wafer.

In manufacturing a semiconductor device, a variety of processes are required, and devices used in each of these processes are typically designed in consideration of the diameter of a wafer to be processed. If the diameter of the wafer is out of the design error range, there is a high risk of dropping or defective quality during wafer transfer or during the actual process. Therefore, it can be said that there is a need for an apparatus or method capable of measuring or managing the actual diameter of a wafer.

SUMMARY OF THE INVENTION The present invention has been made in view of the needs and needs of the prior art as described above, and an object of the present invention is to provide an apparatus and method capable of measuring and managing the actual diameter of a wafer.

Apparatus and method according to the present invention to achieve the above object is characterized by being able to measure and manage the actual diameter of the wafer depending on whether the light is received by irradiating light to the end of the wafer.

A wafer diameter measuring apparatus according to an embodiment of the present invention capable of implementing the above features includes a support unit for mounting and supporting a wafer, a driving unit for rotating the support unit, one end of a wafer supported and rotated on the support unit, and And an optical part including a first member for irradiating light to the other end of the wafer opposite to one end of the wafer and a second member for detecting light emitted from the first member.

In the apparatus of the embodiment of the present invention, the first member and the second member are spaced up and down relative to the wafer. The optical unit includes an image sensor. The distance between the central axis of the support and the light irradiated from the first member is a reference radius of the wafer.

A wafer diameter measuring apparatus according to a modified embodiment of the present invention capable of realizing the above characteristics includes: a chuck for mounting and supporting a wafer, a drive motor for structurally combining the chuck with the chuck, and a central axis of the chuck; The light emitting unit for irradiating light spaced apart by a distance corresponding to the reference radius of the light emitting unit and spaced apart from the upper and lower light receiving unit for detecting the light emitted from the light emitting unit.

According to an aspect of the present invention, there is provided a method of managing a wafer diameter, the method comprising: mounting a wafer on a rotatable support, irradiating light to one end of the wafer, and removing the light from the one end; Measuring a second distance, rotating the wafer by 180 °, and irradiating light to the other end opposite to the one end of the wafer by 180 ° to measure a second distance between the light and the other end. And the diameter of the wafer is good when the difference between the first distance and the second distance is zero when one of the one end and the other end of the wafer reaches the position of the light and the other does not reach the position of the light. Characterized in that it comprises the step of determining.

In the method of this embodiment, the distance between the central axis of the support and the light is the reference radius of the wafer.

According to the present invention, the wafer diameter can be measured according to whether the light receiving portion detects light emitted from the light emitting portion separated by the wafer radius distance from the center of the wafer. Even if the center of the wafer does not coincide with the center of the rotation chuck, the wafer diameter can be measured by irradiating light to both sides of the wafer by rotating the wafer so that the center of the wafer is symmetrical.

Hereinafter, a wafer diameter measuring apparatus and a management method according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Advantages of the present invention over prior art will become apparent from the detailed description and claims with reference to the accompanying drawings. In particular, the present invention is well pointed out and claimed in the claims. However, the present invention may be best understood by reference to the following detailed description in conjunction with the accompanying drawings.

(Example)

1 is a cross-sectional view showing an apparatus capable of measuring the actual diameter of a wafer according to an embodiment of the present invention.

Referring to FIG. 1, the wafer diameter measuring apparatus of the present embodiment includes a wafer support 110 on which a wafer W as an object is mounted, a driver 120 rotating the support 110, and an upper portion of the support 110. It is configured to include an optical unit 130 that can measure the diameter of the wafer (W) mounted on.

The optical unit 130 may include, for example, a first member 130a such as a light emitting unit that emits light to an edge portion of the wafer W, such as an image sensor, and a light receiving unit that senses light emitted from the first member 130a. The same second member 130b is comprised. It is preferable that any one of the first member 130a and the second member 130b has a function of obtaining an image of the wafer (W).

The first and second members 130a and 130b may be positioned symmetrically with respect to the edge of the wafer W to easily measure the diameter of the wafer W. FIG. In the present embodiment, the first member 130a is positioned above the second member 130b, but the arrangement positions thereof may be reversed. Preferably, the distance R between the light emitted from the first member 130a and the center of the wafer W is exactly the same as or substantially equal to the radius of the wafer W. On the other hand, the wafer W is gradually becoming larger in diameter. Therefore, it is preferable that the optical part 130 is movable left and right so that the distance R from the center of the wafer W to the optical part 130 can be changed.

The support 110 is mounted with a wafer W. The support 110 has a circular shape similar to the shape of the wafer W so that the optical unit 130 can irradiate and receive light at the edge of the wafer W. In addition, it is preferable to have a radius smaller than the radius of the wafer (W). The wafer W is preferably mounted on the support 110 such that the center of the support 110 and the center of the wafer W are on the same axis.

However, the wafer W may be mounted on the support 110 such that the center of the wafer W is shifted from the center of the support 110. When the wafer W is mounted on the support 110 so that the center of the wafer W is offset from the center of the support 110, the second member 130a is measured by measuring the diameter of the wafer W by the optical unit 130. ) May or may not detect light from the first member 130a. In this case, since the wafer having the correct diameter can actually be judged as a defective wafer having a diameter outside the tolerance, the diameter of the wafer W is measured by rotating the wafer W as described below with reference to FIGS. 2 and 3. do. Therefore, the support 110 is structurally combined with a drive unit 120, such as a motor, it is preferable that the support chuck is a rotary chuck that rotates as necessary.

2 and 3 are cross-sectional views for explaining the operation of the apparatus according to the embodiment of the present invention. At this time, the light emitted from the first member 130a is located at a distance from the center of the wafer W, that is, at a distance corresponding to the radius R of the wafer, when the wafer W is properly aligned. For example, assuming that the wafer to be measured and managed by the apparatus has a 300 mm diameter, the distance corresponding to the radius of the wafer is 150 mm.

Referring to FIG. 2, the center of the wafer W is shifted from the center of the support 110 so that either side A of the wafer W is mounted on the support 110 so that the radius of the wafer W is less than the radius of the wafer W. As shown in FIG. Assume the case. In this case, the portion A of the wafer W positioned toward the optical unit 130 is such that the second member 130b can detect the light emitted from the first member 130a. Here, one end (A) and light of a wafer (W) are spaced apart there is a predetermined distance (d _1), which means that it is enough as long as the wafer (W) a predetermined distance (d ₁₎ than the original radius. The distance d ₁ may be measured in the image obtained by obtaining an image of the wafer from the optical unit 130. Thereafter, the wafer W is rotated 180 degrees.

Referring to FIG. 3, when the wafer W is rotated 180 °, the opposite side B of the wafer W may exceed the radius of the actual wafer W. In this case, light emitted from the first member 130a may not be detected by the second member 130b. Here, the opposite end portion B of the wafer W is located on the left side rather than light by a predetermined distance d ₂ , which means that the wafer W is over a predetermined distance d ₂ above the original radius of the wafer W. do. The spacing d ₂ here may also be measured in the image obtained by obtaining the image of the wafer from the optical unit 130.

Rotation of the wafer W yields distances d ₁ and d ₂ of light for each of the one end A and the opposite chisel B of the wafer W and these distances d ₁ and d ₂ . If the difference is zero, it is confirmed that the wafer W here is actually a 300 mm wafer. If the difference between these distances d ₁ and d ₂ has a predetermined value α rather than zero, it is confirmed that the actual diameter of the wafer W is (300 + α) mm. When the reference wafer diameter is 300 mm, it is determined as good if the actual diameter (300 + α) mm is within the tolerance range with respect to the wafer diameter, and when it is outside the tolerance range, it is determined as bad.

On the other hand, even when the wafer W is rotated, if the second member 130b does not continuously receive the light transmitted from the first member 130a, it means that the wafer here has a diameter larger than the reference wafer diameter. At this time, the actual diameter of the wafer can be known by measuring by moving the optical unit 130. Here again, the good and badness regarding the wafer diameter is determined by comparing the actual wafer diameter value with the reference value to determine whether it is within the tolerance range.

On the contrary, if the second member 130b continues to receive light from the first member 130a even when the wafer W is rotated, it means that the wafer here has a smaller diameter than the reference wafer diameter. At this time, of course, the actual wafer diameter can be known by moving the optical unit 130. The wafer diameter can be determined by comparing the actual wafer diameter value with the reference value to determine whether the wafer diameter is within the tolerance range.

The apparatus configured as described above can be applied to a so-called semiconductor exposure apparatus (EEW) for etching wafer edges. When applied to a semiconductor exposure equipment (EEW), the device of the present invention can proceed in situ with the etching process on the wafer edge after actually measuring the wafer diameter. If it is determined that the wafer diameter is determined to be good, the etching process is performed on the edge of the wafer. If the wafer diameter is determined to be defective, a series of measures are taken to alert the operator, such as generating an alarm without performing the etching process.

The foregoing detailed description illustrates the present invention. In addition, the foregoing description merely shows and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. And, it is possible to change or modify within the scope of the concept of the invention disclosed in this specification, the scope equivalent to the written description, and / or the skill or knowledge in the art. The above-described embodiments are for explaining the best state in carrying out the present invention, the use of other inventions such as the present invention in other state known in the art, and the specific fields of application and uses of the present invention. Various changes are also possible. Accordingly, the detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Also, the appended claims should be construed to include other embodiments.

As described above in detail, according to the present invention, the wafer diameter can be measured according to whether the light receiving portion detects light emitted from the light emitting portion separated by the wafer radius distance from the center of the wafer. Even if the center of the wafer does not coincide with the center of the rotation chuck, the wafer diameter can be measured by irradiating light to both sides of the wafer by rotating the wafer so that the center of the wafer is symmetrical. As a result of measuring the wafer diameter, it is possible to distinguish between good and bad about the wafer diameter, thereby preventing the defects in the process or wafer damage due to the error of the wafer diameter.

Claims (7)

delete delete delete delete delete Mounting the wafer on a rotatable support; Irradiating light on one end of the wafer to measure a first distance between the light and the one end; Rotating the wafer 180 °; Measuring a second distance between the light and the other end by irradiating light to the other end opposite the one end of the wafer by 180 °; Determining that the diameter of the wafer is good when the difference between the first distance and the second distance is zero when one of the one end and the other end reaches the position of the light and the other is less than the other; Wafer diameter measurement method comprising a. The method of claim 6, Wafer diameter measuring method, characterized in that the distance between the central axis of the support and the light is a reference radius of the wafer.

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