JP2021118301A - Substrate processing device and substrate processing method - Google Patents

Abstract

To provide a technique capable of improving measurement accuracy of thickness distribution of a substrate.SOLUTION: A substrate processing device includes a holding portion 2 including a holding surface 21 for holding a substrate W, a thickness detector that measures a thickness of the substrate, and a thickness measurement control unit 93 that controls the thickness detector and measures the thickness of the substrate at multiple points. The thickness measurement control unit executes the following (A) to (C). (A) In a state in which the holding surface is exposed, the position of the holding surface in an orthogonal direction of the holding surface is measured at a plurality of points. (B) In a state in which the substrate is held on the holding surface, the position of the surface of the substrate in the direction orthogonal to the holding surface is measured at a plurality of points. (C) The thickness of the substrate is calculated at a plurality of points from a difference between the position of the holding surface and the position of the surface of the substrate in the orthogonal direction of the holding surface.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a substrate processing apparatus and a substrate processing method.

The processing apparatus described in Patent Document 1 includes a height measuring unit that measures the height of the upper surface of the wafer and the height of the upper surface of the chuck. The height measuring unit has a first height gauge that measures the height of the upper surface of the wafer and a second height gauge that measures the height of the upper surface of the chuck. Since the height of the upper surface of the wafer and the height of the upper surface of the chuck are measured at the same time, they are measured at different points. The height difference between the height of the upper surface of the wafer and the height of the upper surface of the chuck is equal to the thickness of the wafer.

Japanese Unexamined Patent Publication No. 2019-214109

One aspect of the present disclosure provides a technique capable of improving the measurement accuracy of the thickness distribution of a substrate.

The substrate processing apparatus according to one aspect of the present disclosure controls a holding portion including a holding surface for holding the substrate, a thickness detector for measuring the thickness of the substrate, and the thickness detector to control the thickness of the substrate. It has a thickness measurement control unit that measures points. The thickness measurement control unit carries out the following (A) to (C). (A) With the holding surface exposed, the positions of the holding surface in the direction orthogonal to the holding surface are measured at the plurality of points. (B) With the substrate held on the holding surface, the position of the surface of the substrate in the direction orthogonal to the holding surface is measured at the plurality of points. (C) The thickness of the substrate is calculated at the plurality of points from the difference between the position of the holding surface and the position of the surface of the substrate in the direction orthogonal to the holding surface.

According to one aspect of the present disclosure, the measurement accuracy of the thickness distribution of the substrate can be improved.

FIG. 1 is a cross-sectional view showing a substrate processing apparatus according to an embodiment. FIG. 2 is a flowchart showing a substrate processing method according to an embodiment. FIG. 3A is a side view showing an example of measuring the height of the upper surface of the holding portion, and FIG. 3B is a side view showing an example of measuring the height of the upper surface of the substrate. FIG. 4A is a side view showing a modified example of the height measurement of the upper surface of the holding portion, and FIG. 4B is a side view showing a modified example of the height measurement of the upper surface of the substrate. FIG. 5 is a plan view showing an example of the arrangement of points for measuring the thickness. FIG. 6 is a plan view showing a modified example of the arrangement of the points for measuring the thickness.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding configurations may be designated by the same reference numerals and description thereof may be omitted. In the present specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. The X-axis direction and the Y-axis direction are the horizontal direction, and the Z-axis direction is the vertical direction.

As shown in FIG. 1, the substrate processing device 1 relatively moves the holding portion 2 that holds the substrate W, the thickness detector 3 that detects the thickness of the substrate W, and the holding portion 2 and the thickness detector 3. It has a moving unit 4 to be moved, a rotating unit 5 to rotate the holding unit 2, and a control unit 9 to control the thickness detector 3, the moving unit 4, and the rotating unit 5.

The substrate processing device 1 may have a function of measuring the thickness of the substrate W, and may have other functions. For example, the substrate processing device 1 may be a joining device for joining the substrate W and another substrate, a grinding device for grinding the substrate W, or the like. However, the substrate processing device 1 may be a dedicated device for measuring the thickness of the substrate W.

The substrate W includes a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer, or a glass substrate. The substrate W may further include a device layer formed on the surface of the semiconductor substrate or the glass substrate. The device layer includes electronic circuits. Further, the substrate W may be a polymerized substrate in which a plurality of substrates are bonded.

The holding unit 2 holds, for example, the substrate W horizontally from below. The holding portion 2 has a holding surface 21 on the upper surface for holding the substrate W. The holding surface 21 is arranged horizontally, and the orthogonal direction of the holding surface 21 is the Z-axis direction. The holding portion 2 is, for example, a vacuum chuck, and a suction hole 22 for sucking the substrate W is formed on the holding surface 21.

The holding portion 2 is, for example, a pin chuck, and the holding surface 21 includes a rib 23 and a pin 24. The rib 23 is formed in an annular shape, for example, and divides the holding surface 21 into a plurality of regions in the radial direction. The degree of vacuum can be controlled independently in the plurality of regions, and the suction force can be controlled independently. A plurality of pins 24 are distributed and arranged in each of the plurality of regions.

The thickness detector 3 is, for example, a height sensor that measures the height of the upper surface of an object. The height sensor is a non-contact type in this embodiment, but may be a contact type. The number of thickness detectors 3 is one in this embodiment, but may be plural. The larger the number of thickness detectors 3, the shorter the time required for measurement.

The moving unit 4 is, for example, an XYZ stage, and moves the holding unit 2 in the X-axis direction, the Y-axis direction, and the Z-axis direction. Although the moving unit 4 of the present embodiment moves the holding unit 2, the thickness detector 3 may be moved, or both the thickness detector 3 and the holding unit 2 may be moved.

The rotating portion 5 rotates the holding portion 2 around a vertical rotation center line. The rotating unit 5 and the moving unit 4 form an XYZθ stage.

The control unit 9 is, for example, a computer, and includes a CPU (Central Processing Unit) 91 and a storage medium 92 such as a memory. The storage medium 92 stores programs that control various processes executed by the substrate processing device 1. The control unit 9 controls the operation of the substrate processing device 1 by causing the CPU 91 to execute the program stored in the storage medium 92.

As shown in FIG. 3, the control unit 9 includes, for example, a thickness measurement control unit 93 and a thickness storage unit 94. The thickness measurement control unit 93 controls the thickness detector 3 and measures the thickness H of the substrate W at a plurality of points P (see FIG. 5). The method for measuring the thickness H will be described later.

The thickness storage unit 94 stores the data measured by the thickness measurement control unit 93. For example, the thickness storage unit 94 stores the thickness H and the position of the point P for measuring the thickness H in association with each other. If data such as the thickness H is temporarily stored, the thickness H can be used at any time.

Next, the operation of the substrate processing apparatus 1 will be described with reference to FIG. Each step shown in FIG. 2 is carried out under the control of the control unit 9 of the substrate processing apparatus 1.

First, in S101 of FIG. 2, as shown in FIG. 3A, the thickness measurement control unit 93 positions the holding surface 21 in the Z-axis direction at a plurality of points P in a state where the holding surface 21 of the holding unit 2 is exposed. (See FIG. 5).

In this embodiment, the holding surface 21 is arranged horizontally, and the orthogonal direction of the holding surface 21 is the Z-axis direction. Hereinafter, the position in the Z-axis direction is also referred to as a height.

The thickness detector 3 is, for example, a laser displacement meter. The laser displacement meter can measure the distance from the laser displacement meter to the holding surface 21 in a non-contact manner by irradiating the holding surface 21 of the holding portion 2 with a laser beam and receiving the reflected light.

In FIG. 2, the height measurement (S101) of the holding surface 21 is performed before the loading (S102) of the substrate W, but may be performed after the loading (S105) of the substrate W. If the holding surface 21 is exposed, the height of the holding surface 21 can be measured (S101).

Next, in S102 of FIG. 2, a transport device (not shown) carries the substrate W into the substrate processing apparatus 1 and passes the substrate W to the holding unit 2. The holding portion 2 holds the substrate W horizontally from below.

Next, in S103 of FIG. 2, as shown in FIG. 3B, the thickness measurement control unit 93 holds the substrate W on the holding surface 21 of the holding unit 2, and the height of the surface Wa of the substrate W is high. Is measured at a plurality of points P. The front surface Wa of the substrate W is in the opposite direction (for example, upward) to the back surface in contact with the holding portion 2. The height of the substrate surface Wa and the height of the holding surface 21 are measured at the same plurality of points P.

The holding portion 2 is arranged at the same X-axis direction position, Y-axis direction position, and Z-axis direction position when the height of the substrate surface Wa is measured and when the height of the holding surface 21 is measured. In this case, the difference between the height of the substrate surface Wa and the height of the holding surface 21 is equal to the thickness H of the substrate W. However, instead of moving the holding portion 2, the thickness detector 3 may move, or both may move. Therefore, in a state where the relative positions (X-axis direction position, Y-axis direction position, and Z-axis direction position) of the holding portion 2 and the thickness detector 3 are the same, the height measurement of the holding surface 21 and the substrate surface Wa are measured. Height measurement may be performed. In this case, the difference between the height of the substrate surface Wa and the height of the holding surface 21 is equal to the thickness H of the substrate W.

Next, in S104 of FIG. 2, the thickness measurement control unit 93 calculates the difference between the height of the substrate surface Wa and the height of the holding surface 21 at a plurality of points P, and calculates the thickness H of the substrate W at the plurality of points P. .. The calculation of the thickness H of the substrate W (S104) may be performed after the unloading of the substrate W (S105).

According to this embodiment, the difference between the height of the substrate surface Wa and the height of the holding surface 21 is calculated at the same point P. Therefore, even when the thickness H of the substrate W varies, the thickness H can be measured accurately. The distribution of the thickness H of the substrate W can be measured more accurately than in the case of calculating the difference between the height of the substrate surface Wa and the height of the holding surface 21 at different points as in the conventional case.

The thickness storage unit 94 stores the thickness H measured by the thickness measurement control unit 93 in association with the position of the point P where the thickness H is measured. The position of the point P may be stored with reference to the position of the notch representing the crystal orientation of the substrate W.

It is sufficient that the holding portion 2 is controlled to the same X-axis direction position and Y-axis direction position when measuring the height of the substrate surface Wa and when measuring the height of the holding surface 21, and the holding portion 2 is Z. It may be displaced in the axial direction. In this case, the thickness H of the substrate W is calculated in consideration of the amount of displacement of the holding portion 2 in the Z-axis direction. However, instead of the holding unit 2 moving in the X-axis direction and the Y-axis direction, the thickness detector 3 may move in the X-axis direction and the Y-axis direction, or one of the holding unit 2 and the thickness detector 3 may move. It may move in the X-axis direction and the other may move in the Y-axis direction. Therefore, with the relative positions (X-axis direction position and Y-axis direction position) of the holding portion 2 and the thickness detector 3 in the Z-axis direction being the same, the height measurement of the holding surface 21 and the substrate surface Wa It suffices if the height measurement of is carried out.

Finally, in S105 of FIG. 2, the holding unit 2 releases the holding of the substrate W, the transfer device (not shown) receives the substrate W from the holding unit 2, and carries out the received substrate W to the outside of the substrate processing device 1. ..

The thickness detector 3 is not limited to the laser displacement meter. For example, as shown in FIGS. 4 (A) and 4 (B), the thickness detector 3 may include a camera.

In this case, the thickness measurement control unit 93 measures the thickness H of the substrate W by focusing the camera. Focusing of the camera is performed, for example, by moving the holding portion 2 in the Z-axis direction so that the edge strength of the object captured in the image captured by the camera is maximized. The edge strength is the magnitude of the difference in the amount of light received on both sides of the edge.

As shown in FIG. 4A, the thickness measurement control unit 93 focuses the camera on the holding surface 21 in a state where the holding surface 21 of the holding unit 2 is exposed. The camera is focused on each of the plurality of points P in order. This focusing is performed before the loading of the substrate W (S102). This focusing may be performed after the substrate W is carried out (S105). The thickness measurement control unit 93 stores the position of the holding unit 2 in the Z-axis direction at the time of focusing.

Further, as shown in FIG. 4B, the thickness measurement control unit 93 focuses the camera on the surface Wa of the substrate W while holding the substrate W on the holding surface 21 of the holding unit 2. The thickness measurement control unit 93 stores the position of the holding unit 2 in the Z-axis direction at the time of focusing.

The thickness measurement control unit 93 positions the position of the holding unit 2 in the Z-axis direction when the camera is focused on the surface Wa of the substrate W and when the camera is focused on the holding surface 21 of the holding unit 2. The shift amount is calculated at a plurality of points P. The shift amount is equal to the thickness H of the substrate W. Therefore, the thickness H can be calculated by a plurality of points P.

The focusing of the camera may include moving the thickness detector 3 in the Z-axis direction instead of moving the holding portion 2 in the Z-axis direction.

FIG. 5 shows the arrangement of the points P for measuring the thickness H of the substrate W. The plurality of points P are arranged on the holding surface 21 at positions avoiding the suction holes 22. The height of the holding surface 21 can be measured by arranging the plurality of points P at positions avoiding the suction holes 22.

The holding portion 2 has a rib 23 forming a flat surface on the holding surface 21. A plurality of points P are arranged on the flat surface of the rib 23. By measuring the height of the flat surface of the rib 23, the height of the holding surface 21 can be accurately measured.

A part of the flat surface of the rib 23 is formed in a straight line. The linear ribs 23 can be arranged in the radial direction of the substrate W, the height of the holding surface 21 can be measured at a plurality of points in the radial direction of the substrate W, and the thickness H can be measured at a plurality of points in the radial direction of the substrate W.

A part of the flat surface of the rib 23 may be formed in a straight line and may be formed so as to pass through the center of the holding surface 21. The height of the holding surface 21 can be measured at the radial center point of the substrate W, and the thickness H can be measured at the radial center point of the substrate W.

The other part of the flat surface of the rib 23 is formed in an annular shape. The annular ribs 23 can be arranged in the circumferential direction of the substrate W, the height of the holding surface 21 can be measured at a plurality of points in the circumferential direction of the substrate W, and the thickness H can be measured at a plurality of points in the circumferential direction of the substrate W.

A plurality of annular ribs 23 having different diameters may be arranged concentrically. The height of the holding surface 21 can be measured at a plurality of points in the radial direction of the substrate W, and the thickness H can be measured at a plurality of points in the radial direction of the substrate W.

Further, the circular rib 23 may be arranged at the center of the annular rib 23. The height of the holding surface 21 can be measured at the radial center point of the substrate W, and the thickness H can be measured at the radial center point of the substrate W.

When the holding portion 2 has an annular rib 23, if the substrate processing device 1 has a rotating portion 5 for rotating the holding surface 21, the position of the point P for measuring the height of the holding surface 21 is the circumference of the substrate W. Can be displaced in the direction.

As shown in FIG. 6, the flat surface of the rib 23 may have an annular portion having the same diameter as the substrate W, and may have only a linear portion inside the portion. Further, although not shown, the flat surface of the rib 23 may have only a plurality of annular portions having different diameters concentrically.

Further, the plurality of points P may be arranged on the holding surface 21 at a position avoiding the suction hole 22, and may be arranged on the tip surface of the pin 24 instead of the tip surface of the rib 23. Further, the plurality of points P may be separately arranged on both the tip surface of the rib 23 and the tip surface of the pin 24.

The holding portion 2 is not limited to the pin chuck and may be a porous chuck. The porous chuck contains a porous body. Since the porous body contains a large number of suction holes, the plurality of points P are arranged at positions avoiding the porous body. A plurality of points P are arranged on the tip surface of the rib that divides the porous body into a plurality of regions.

Although the substrate processing apparatus and the substrate processing method according to the present disclosure have been described above, the present disclosure is not limited to the above-described embodiment and the like. Within the scope of the claims, various changes, modifications, replacements, additions, deletions, and combinations are possible. Of course, they also belong to the technical scope of the present disclosure.

1 Substrate processing device 2 Holding unit 21 Holding surface 22 Suction hole 93 Thickness measurement control unit W Substrate Wa surface

Claims (15)

A holding portion including a holding surface for holding the substrate,
A thickness detector that measures the thickness of the substrate, and
It has a thickness measurement control unit that controls the thickness detector and measures the thickness of the substrate at a plurality of points.
The thickness measurement control unit
With the holding surface exposed, the position of the holding surface in the direction orthogonal to the holding surface is measured at the plurality of points.
With the substrate held on the holding surface, the position of the surface of the substrate in the direction orthogonal to the holding surface is measured at the plurality of points.
A substrate processing apparatus for calculating the thickness of the substrate at a plurality of points from the difference between the position of the holding surface and the position of the surface of the substrate in the direction orthogonal to the holding surface. In a state where the relative positions of the holding portion and the thickness detector in the orthogonal direction view of the holding surface are the same, the position measurement of the holding surface in the orthogonal direction of the holding surface and the said in the direction orthogonal to the holding surface. The substrate processing apparatus according to claim 1, wherein the position measurement of the surface of the substrate is performed. A suction hole for sucking the substrate is formed on the holding surface.
The substrate processing apparatus according to claim 1 or 2, wherein the plurality of points are arranged at positions on the holding surface so as to avoid the suction holes. The holding portion has ribs that form a linear flat surface on the holding surface.
The substrate processing apparatus according to claim 3, wherein the plurality of points are arranged on the flat surface of the rib. The substrate processing apparatus according to claim 4, wherein at least a part of the flat surface of the rib is formed in a straight line or an annular shape. At least a part of the flat surface of the rib is formed in an annular shape.
The substrate processing apparatus according to claim 5, further comprising a rotating portion that rotates the holding surface. The substrate processing apparatus according to any one of claims 1 to 6, wherein the thickness detector includes a laser displacement meter. The thickness detector includes a camera.
The substrate processing apparatus according to any one of claims 1 to 6, wherein the thickness measurement control unit measures the thickness of the substrate by focusing the camera. A substrate processing method in which a substrate is held by a holding surface of a holding portion and the thickness of the substrate is measured at a plurality of points by a thickness detector.
With the holding surface exposed, the position of the holding surface in the direction orthogonal to the holding surface is measured at the plurality of points.
With the substrate held on the holding surface, the position of the surface of the substrate in the direction orthogonal to the holding surface is measured at the plurality of points.
A substrate processing method comprising calculating the thickness of the substrate at a plurality of points from the difference between the position of the holding surface and the position of the surface of the substrate in the direction orthogonal to the holding surface. In a state where the relative positions of the holding portion and the thickness detector in the orthogonal direction view of the holding surface are the same, the position measurement of the holding surface in the orthogonal direction of the holding surface and the said in the orthogonal direction of the holding surface. The substrate processing method according to claim 9, wherein the position measurement of the surface of the substrate is carried out. A suction hole for sucking the substrate is formed on the holding surface.
The substrate processing method according to claim 9 or 10, wherein the plurality of points are arranged on the holding surface at positions avoiding the suction holes. A rib forming a linear flat surface is provided on the holding surface.
The substrate processing method according to claim 11, wherein the plurality of points are arranged on the flat surface of the rib. The substrate processing method according to claim 12, wherein at least a part of the flat surface of the rib is formed in a straight line or an annular shape. At least a part of the flat surface of the rib is formed in an annular shape.
The substrate processing method according to claim 13, further comprising rotating the holding surface in order to displace the point at which the thickness of the substrate is measured. The substrate processing method according to any one of claims 9 to 14, wherein the thickness of the substrate is measured by focusing the camera.

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