JP2020157438A - Substrate processing device - Google Patents

Abstract

To provide a substrate processing device which flattens a non-circular substrate in a desired thickness.SOLUTION: A substrate processing device 1 includes: a chuck table 21 which can suck and hold a substrate W; a rotation angle detection part 25 which can detect a rotation angle of the chuck table 21; a grinding stone 31 which processes the substrate W; an infeed mechanism 33 which moves the grinding stone 31 in a vertical direction; and a control device 4 which accelerates and decelerates a processing speed of processing the substrate W by the grinding stone 31 at every predetermined rotation angle of the chuck table 21 in response to a change of a contact area in which the substrate W contacts with the grinding stone 31.SELECTED DRAWING: Figure 1

Description

The present invention relates to a substrate processing apparatus for flatly processing a non-circular substrate.

In the field of semiconductor manufacturing, a substrate processing apparatus for flattening a semiconductor substrate such as a silicon wafer (hereinafter referred to as "substrate") into a thin and flat surface is known.

Patent Document 1 discloses a grinding device in which a rotating grindstone is brought into contact with the upper surface of a rectangular work held on a chuck table to grind the rectangular work to a predetermined thickness.

Japanese Patent No. 5230982

However, when grinding a rectangular workpiece while rotating the chuck table and the grindstone, the contact area between the grindstone and the rectangular workpiece expands or contracts according to the rotation angle of the chuck table. For example, a region having a relatively large contact area has a contact area. The amount of grinding of the rectangular workpiece tends to decrease as compared with the area where is relatively small. That is, when the grindstone is uniformly brought into contact with the rectangular work, there is a problem that the thickness of the rectangular work after processing varies according to the change in the contact area between the grindstone and the rectangular work.

Therefore, a technical problem to be solved in order to flatten the non-circular substrate to a desired thickness arises, and an object of the present invention is to solve this problem.

In order to achieve the above object, the substrate processing apparatus according to the present invention is a substrate processing apparatus for flatly processing a non-circular substrate, and rotates a chuck table capable of sucking and holding the substrate and the chuck table. A holding means including a chuck spindle and a rotation angle detection unit capable of detecting the rotation angle of the chuck table, a grindstone for processing the substrate, a spindle for rotating the grindstone, and the grindstone in the vertical direction. Processing in which the grindstone processes the substrate at a predetermined rotation angle of the chuck table in response to a change in the contact area between the substrate and the grindstone and a machining means including a moving in-feed mechanism. It is provided with a control means for accelerating or decelerating the speed.

According to this configuration, a non-circular shape is formed by accelerating or decelerating the processing speed at which the grindstone processes the substrate at each predetermined rotation angle of the chuck table according to the change in the contact area between the substrate and the grindstone due to the rotation of the chuck table. It is possible to suppress a local change in the processing amount of the substrate and reduce the variation in the thickness of the substrate after processing due to the shape of the substrate.

Further, in the substrate processing apparatus according to the present invention, when the control means has a large contact area as compared with a preset reference area, the processing speed of the grindstone is accelerated from the preset reference speed. Is preferable.

According to this configuration, it is possible to suppress a local decrease in the processing amount within the contact area of the substrate and the grindstone wider than the reference area.

Further, in the substrate processing apparatus according to the present invention, when the control means has a small contact area as compared with a preset reference area, the processing speed of the grindstone is reduced from the preset reference speed. Is preferable.

According to this configuration, it is possible to suppress a local increase in the processing amount within the contact area of the substrate and the grindstone narrower than the reference area.

The present invention has a non-circular shape by accelerating or decelerating the processing speed at which the grindstone processes the substrate at each predetermined rotation angle of the chuck table according to the change in the contact area between the substrate and the grindstone due to the rotation of the chuck table. It is possible to suppress local changes in the amount of processing of the substrate and reduce variations in the thickness of the substrate after processing due to the shape of the substrate.

The schematic diagram which shows the substrate processing apparatus which concerns on one Embodiment of this invention. The plan view which compared the contact area between a substrate and a grindstone at two places in a substrate. The figure which shows how the processing speed of a grindstone is changed.

An embodiment of the present invention will be described with reference to the drawings. In the following, when referring to the number, numerical value, quantity, range, etc. of components, it is limited to the specific number unless it is clearly stated or in principle it is clearly limited to the specific number. It is not a thing, and it may be more than or less than a specific number.

In addition, when referring to the shape and positional relationship of components, etc., unless otherwise specified or when it is considered that this is not the case in principle, those that are substantially similar to or similar to the shape, etc. shall be used. Including.

In addition, the drawings may be exaggerated by enlarging the characteristic parts in order to make the features easy to understand, and the dimensional ratios and the like of the components are not always the same as the actual ones.

FIG. 1 is a front view showing a basic configuration of the substrate processing apparatus 1. The substrate processing apparatus 1 grinds the wafer. The substrate processing apparatus 1 includes a holding means 2 and a processing means 3.

The holding means 2 includes a chuck table 21 and a chuck spindle 22.

The chuck table 21 includes an adsorbent 23 made of a porous material such as alumina on the upper surface thereof, and a compact body 24 in which the adsorbent 23 is embedded substantially in the center. The chuck table 21 includes a pipeline (not shown) that extends through the interior to the surface. The pipeline is connected to a vacuum source, compressed air source or water supply source via a rotary joint (not shown). When the vacuum source is activated, the substrate W placed on the adsorbent 23 is adsorbed and held by the adsorbent 23. Further, when the compressed air source or the water supply source is activated, the adsorption between the substrate W and the adsorbent 23 is released.

The adsorbent 23 is formed in a shape corresponding to the substrate W when viewed from a plane. Further, the compact body 24 is formed in a substantially circular shape when viewed from a plane, but the shape of the compact body 24 is not limited to this.

The chuck spindle 22 is configured to rotationally drive the chuck table 21 around the rotation shaft 2a. As the drive source of the chuck spindle 22, for example, a servomotor or the like can be considered.

The holding means 2 further includes a rotation angle detecting unit 25. The rotation angle detection unit 25 detects the rotation angle of the chuck table 21 and sends a detection signal to the control device 4 described later each time the chuck table 21 rotates by a predetermined angle. For example, when the chuck spindle 22 is rotationally driven by a servomotor, the rotation angle detection unit 25 corresponds to the rotation angle of the chuck table 21 and the rotation angle of the servomotor. Therefore, the rotation angle detection unit 25 reads the rotation angle of the servomotor to chuck the chuck. The rotation angle of the table 21 can be detected.

The processing means 3 includes a grindstone 31, a grindstone spindle 32, and an in-feed mechanism 33.

The grindstone 31 is, for example, a cup-type grindstone, and is attached to the lower end of the grindstone spindle 32.

The grindstone spindle 32 is rotatable around the rotation shaft 3a, and the grindstone 31 and the grindstone spindle 32 are integrally rotatable so as to be rotatable.

The in-feed mechanism 33 raises and lowers the grindstone spindle 32 in the vertical direction. The in-feed mechanism 33 has a known configuration, and is composed of, for example, a plurality of linear guides for guiding the moving direction of the grindstone spindle 32 and a ball screw slider mechanism for raising and lowering the grindstone spindle 32. The in-feed mechanism 33 is interposed between the grindstone spindle 32 and the column 34.

The operation of the substrate processing device 1 is controlled by the control device 4. The control device 4 controls each of the components constituting the substrate processing device 1. The control device 4 is composed of, for example, a CPU, a memory, and the like. The function of the control device 4 may be realized by controlling using software, or may be realized by operating using hardware.

Next, when the machined surface of the grindstone 31 is brought into contact with the machined surface of the non-circular board W in parallel to flatten the board W, the machined amount (grinding amount) of the board W is stable in the plane. Explain the reason for not doing so. FIG. 2 is a plan view comparing the contact areas between the substrate W and the grindstone 31 at two points in the substrate W. In the following description, a square substrate W in a plan view will be described as an example, but the shape of the substrate W is not limited to this.

As shown in FIG. 2, the contact area S1 between the substrate W and the grindstone 31 set so that the machined surface of the grindstone 31 passes through the corner of the substrate W and the rotation center O of the chuck table 21, and the machined surface of the grindstone 31 Comparing the contact area S2 between the grindstone 31 and the substrate W set to pass through the center of the side of the substrate W and the center of rotation O, it can be seen that the contact area S1 is about twice as large as the contact area S2.

When the grindstone 31 is uniformly contacted with the substrate W over the entire surface, the processing amount of the substrate W decreases as the contact area between the substrate W and the grindstone 31 increases, and the processed substrate W becomes It gets thicker. Therefore, when the contact areas S1 and S2 shown in FIG. 2 are compared, it is predicted that the contact area S1 will locally thicken the substrate W after processing.

Therefore, in the substrate processing apparatus 1, the in-feed mechanism 33 is driven to move the grindstone 31 up and down in response to a change in the contact area between the substrate W and the grindstone 31 due to the rotation of the chuck table 21, and the grindstone 31 is used as the substrate W. The pressure of pressing the substrate W is adjusted to accelerate or decelerate the processing speed at which the grindstone 31 processes the substrate W.

Hereinafter, the procedure for accelerating / decelerating the processing speed of the grindstone 31 will be specifically described. FIG. 3 is a schematic view showing how the processing speed of the grindstone 31 changes according to the rotation angle of the chuck table 21. Note that A in FIG. 3 indicates the rotation angle of the chuck table 21 corresponding to the case where the grindstone 31 in FIG. 2 comes into contact with each other so as to pass through the angle of the substrate W and the rotation center O (rotation angle = Θ), and is shown in FIG. B in the chuck table 21 corresponds to the case where the substrate W and the grindstone 31 come into contact with each other (rotation angle = Θ-45 degrees) so that the grindstone 31 in FIG. 2 passes through the center of the side of the substrate W and the rotation center O. Indicates the rotation angle of.

[Preparation process]
First, the contact area between the substrate W and the grindstone 31 is calculated for each predetermined rotation angle of the chuck table 21 (for each orientation of the substrate W) and stored in the control device 4. The interval of the rotation angle of the chuck table 21 for calculating the contact area can be arbitrarily changed.

Further, the control device 4 determines the contact area (reference area) of the substrate W and the grindstone 31 which is a reference stored in advance in the control device 4 and the contact area of the substrate W and the grindstone 31 for each rotation angle of the chuck table 21. For comparison, the machining speed of the grindstone 31 at the time of flat surface machining is calculated and stored for each rotation angle of the chuck table 21.

Specifically, when the contact area between the substrate W and the grindstone 31 is larger than the reference area, the machining speed of the grindstone 31 is accelerated from a preset reference speed to locally increase the machining amount of the substrate W. .. The reference speed means a processing speed at which the substrate W can be processed to a desired thickness when the reference area is processed. As a result, it is possible to prevent the amount of processing in the contact area between the substrate W and the grindstone 31, which is wider than the reference area, from being locally reduced.

When the contact area between the substrate W and the grindstone 31 is smaller than the reference area, the machining speed of the grindstone 31 is reduced from the reference speed to locally reduce the machining amount of the substrate W. As a result, it is possible to prevent the amount of processing in the contact area between the substrate W and the grindstone 31, which is narrower than the reference area, from increasing locally.

The amount of change in the processing speed of the grindstone 31 may be calculated so as to increase or decrease the processing speed of the grindstone 31 in proportion to the reference speed, for example, according to the ratio of the contact area between the substrate W and the grindstone 31 to the reference area. I do not care. For example, when the contact area S2 shown in FIG. 2 is set as the reference area and the reference speed (machining speed within the contact area S2) is set to 0.25 μm / s, the contact is about twice as much as the contact area S2. It is conceivable to set the processing speed in the area S1 to 0.5 μm / s.

[Plane processing process]
First, the rotation angle detection unit 25 detects the rotation angle of the chuck table 21 during machining and sends the rotation angle of the chuck table 21 to the control device 4.

The control device 4 calls the machining speed of the grindstone 31 for each rotation angle of the chuck table 21 stored in advance based on the rotation angle of the chuck table 21 detected by the rotation angle detection unit 25 so as to match this machining speed. The in-feed mechanism 33 is controlled to accelerate or decelerate the processing speed at which the grindstone 31 processes the substrate W.

In this way, the substrate processing apparatus 1 according to the present embodiment adds a processing speed at which the grindstone 31 processes the substrate W for each rotation angle of the chuck table 21 according to a change in the contact area between the substrate W and the grindstone 31. By decelerating, it is possible to suppress a local change in the processing amount of the non-circular substrate W and reduce the thickness variation of the processed substrate W due to the shape of the substrate W.

Further, the present invention can be modified in various ways other than the above as long as the spirit of the present invention is not deviated, and it is natural that the present invention extends to the modified ones. Moreover, the above-described embodiment and each modification may be combined with each other.

1 ... Substrate processing device 2 ... Holding means 21 ... Chuck table 22 ... Chuck spindle 23 ... Adsorbent 24 ... Dense body 25 ... Rotation angle detector 3 ... Machining Means 31 ... Grindstone 32 ... Grindstone Spindle 33 ... Infeed mechanism 34 ... Column 4 ... Control device (control means)
O ・ ・ ・ Center of rotation (of chuck table) W ・ ・ ・ Substrate

Claims (3)

A substrate processing device that flat-processes a non-circular substrate.
A holding means including a chuck table capable of sucking and holding the substrate, a chuck spindle for rotating the chuck table, and a rotation angle detecting unit capable of detecting the rotation angle of the chuck table.
A processing means including a grindstone for processing the substrate, a spindle for rotating the grindstone, and an in-feed mechanism for moving the grindstone in the vertical direction.
A control means for accelerating or decelerating the processing speed at which the grindstone processes the substrate at a predetermined rotation angle of the chuck table according to a change in the contact area between the substrate and the grindstone.
A substrate processing apparatus characterized by being equipped with. The substrate according to claim 1, wherein the control means accelerates the processing speed of the grindstone from a preset reference speed when the contact area is larger than a preset reference area. Processing equipment. The control means according to claim 1 or 2, wherein when the contact area is smaller than a preset reference area, the processing speed of the grindstone is reduced from a preset reference speed. Substrate processing equipment.