JP6800763B2 - Alignment device - Google Patents

Description

The present invention relates to an alignment device that aligns the center of the wafer with the center of the chuck table.

In the semiconductor manufacturing process, a surface film such as a protective film or an insulating film is formed by uniformly applying a chemical solution on the upper surface of a semiconductor wafer or the like. As a method for forming the surface film, a method called spinner coating has been proposed in which a wafer is placed on the upper surface of a chuck table and a chemical solution is dropped on the center of the upper surface of the wafer while the chuck table is rotated (for example). See Patent Document 1). In the method described in Patent Document 1, the chemical solution dropped on the center of the upper surface of the wafer is spread to the outer peripheral side by receiving centrifugal force, so that the chemical solution is uniformly applied to the entire surface of the wafer.

Japanese Unexamined Patent Publication No. 2016-043293

By the way, when the chemical solution is applied to the upper surface of several wafers in a developed product or the like, the chemical solution is manually dropped on the wafer on the rotating chuck table. In this case, it is necessary for the operator to visually position the center of the wafer at the center of the chuck table, but it is difficult to accurately position the wafer on the chuck table by hand. By repositioning the wafer on the chuck table many times, it takes time to place the wafer and there is a risk that the wafer may be damaged. Further, the same problem has occurred not only when the chemical solution is applied but also when the wafer is manually placed on the chuck table as in the manual processing apparatus.

The present invention has been made in view of this point, and one of the objects of the present invention is to provide an alignment device capable of manually positioning the center of a wafer at the center of a chuck table and placing the wafer on the center of the chuck table.

The alignment device of one aspect of the present invention is an alignment device that aligns the center position of the wafer with the center of the chuck table, and is a chuck table that holds the wafer on the upper surface and a wafer held on the chuck table. An image projection means for projecting at least three pointer images at equal distances from the center of the chuck table is provided, and the tips of at least three pointer images projected from the image projection means are separated from each other to point to the outer peripheral edge of the wafer. The wafer can be placed on the chuck table by positioning the outer peripheral edge of the wafer at a position pointed to by the tip of the at least three pointer images.

According to this configuration, the center of the circle connecting the positions pointed to by the tips of at least three pointer images is the center of the chuck table, so that the alignment point of the wafer with respect to the chuck table is pointed by the tips of at least three pointer images. .. By placing the wafer on the chuck table while visually checking by the operator so that the tips of at least three pointer images point to the outer peripheral edge of the wafer, the wafer can be placed on the chuck table without having to reposition the wafer many times even by hand. The center position of the wafer can be positioned at the center of the chuck table. Further, since the pointer image is projected by the image projection means, the projection position, the brightness, and the like of the pointer image can be easily adjusted according to the type of the wafer.

According to the present invention, since the positioning position of the wafer with respect to the chuck table is pointed to by the tips of at least three pointer images, the center position of the wafer can be accurately positioned at the center of the chuck table even by manual operation.

It is a side schematic view of the chemical solution coating apparatus of this embodiment. It is explanatory drawing of the alignment of the wafer of this embodiment. It is explanatory drawing of the chemical solution supply to the wafer of this embodiment. It is a figure which shows an example of the chemical solution coating apparatus of a modification. It is a figure which shows an example of the application | coating operation of the chemical solution of this embodiment.

Hereinafter, the chemical solution coating apparatus of the present embodiment will be described with reference to the attached drawings. FIG. 1 is a schematic side view of the chemical solution coating device of the present embodiment. In the following description, an example in which the alignment device of the present embodiment is applied to a chemical solution coating device will be described, but the alignment device can also be applied to another manual type processing device for manually feeding a wafer. is there.

As shown in FIG. 1, the chemical solution coating device 1 is a device for spin coating used in the product development stage and the like, and the operator manually places the wafer W on the chuck table 20 and rotates it. It is configured to drip a chemical solution on the upper surface of the wafer W of the above. In spin coating, the chemical solution dripped on the wafer center O1 is spread over the entire upper surface of the wafer W by the centrifugal force generated by the rotation of the chuck table 20 to be applied. In this case, when the operator visually aligns the wafer W with the chuck table 20, the wafer center O1 is displaced with respect to the chuck table center O2, the chemical solution does not spread uniformly on the upper surface of the wafer W, and the chemical solution is unevenly applied. And must be reapplied.

Therefore, in the chemical solution coating device 1 of the present embodiment, the pointer image projected from the image projection means 30 toward the wafer W points to the alignment portion of the wafer W with respect to the chuck table 20. By manually aligning the pointer image on the wafer W with the tip of the pointer image as a mark, the wafer center O1 can be accurately positioned at the chuck table center O2 even by manual operation. As the chemical solution, a surface film such as a protective film or an insulating film may be formed on the upper surface of the wafer W, and a liquid resin such as PVA (Polyvinyl Alcohol) is used.

A chuck table 20 for holding the wafer W is rotatably housed inside the cover portion 10 of the chemical solution coating device 1. A holding surface 21 is formed on the upper surface of the chuck table 20 by a porous ceramic material, and the wafer W is suction-held by the negative pressure generated on the holding surface 21. A motor (not shown) is connected to the lower part of the chuck table 20, and the chuck table 20 is rotationally driven by the motor. Further, the chuck table 20 is formed to have a smaller diameter than the wafer W so that the chemical solution that has reached the outer peripheral edge Wa of the wafer does not adhere to the chuck table 20 when the chemical solution is applied to the wafer W.

An image projection means 30 is provided above the chuck table 20 to indicate the alignment portion of the outer peripheral edge Wa of the wafer by pattern projection. The image projection means 30 projects pointer images S1 and S2 (see FIGS. 2A and 3A) described later toward the wafer W held on the chuck table 20. The image projection means 30 is composed of, for example, a DLP (Digital Light Processing) projector, collects light from a light source with a condenser lens, and reflects it with a large number of DMD (Digital Micromirror Device) elements 31 to produce projected light. ing.

The image projection means 30 is provided with a controller 32 that controls the drive of a large number of DMD elements 31, and the drive of the DMD element 31 is controlled according to the image data input to the controller 32. When the image data is read into the controller 32, pointer images S1 and S2 (see FIGS. 2A and 3A) corresponding to the image data are formed by a large number of DMD elements 31. In this case, the pointer image is projected by partially changing the ON / OFF switching speed of the DMD element to create the shade of the projected light. It is also possible to change the brightness (light intensity) by adjusting the switching speed of the DMD element 31.

Further, the image projection means 30 is provided with a slot 33 for an external storage medium such as a USB memory. An external storage medium is mounted in the slot 33 of the image projection means 30, and the image data in the external storage medium is read into the controller 32 to control the DMD element 31. The image data is not limited to the configuration of being read from the external storage medium, and may be prepared in the internal memory of the controller 32, or may be input from an external device by wireless communication or wired communication. It is also possible to project a colored pointer image by transmitting the color wheel through the light from the light source of the image projection means 30.

Projection lenses 34 are provided at three locations (only two locations are shown) on the lower surface of the image projection means 30, and pointer images S1 and S2 (see FIGS. 2A and 3A) are projected from each projection lens 34 toward the wafer W. Will be done. At the time of aligning the wafer W, at least three pointer images S1 are projected equidistantly from the chuck table center O2 toward the wafer W on the chuck table 20 from each projection lens 34 of the image projection means 30. At the time of supplying the chemical solution, the image data is switched, and the pointer image S2 is projected from the projection lens 34 of the image projection means 30 toward the wafer W on the chuck table 20 near the center O2 of the chuck table.

Each pointer image S1 (see FIG. 2A) at the time of aligning the wafer W is projected in a wedge shape pointing to one point, and the alignment points of the outer peripheral edge Wa of the wafer are aligned on the chuck table 20 by the tips of at least three pointer images S1. Pointed to. The pointer image S2 (see FIG. 3A) at the time of supplying the chemical solution to the wafer W is projected in a wedge shape pointing to one point, and the tip of the pointer image S2 points to the point where the chemical solution is supplied to the wafer W. Further, the image projection means 30 is prepared with a plurality of types of image data so that the projection position of the pointer image and the shape of the pointer image can be changed according to the outer diameter of the wafer W, the type of the wafer W, and the like. You may.

Above the chuck table 20, a container 40 containing a chemical solution is positioned by an operator. By tilting the container 40 above the wafer W, the chemical solution is supplied from the container 40 to the upper surface of the wafer W. In the chemical solution coating device 1 configured in this way, the outer peripheral edge Wa of the wafer is positioned at the three points indicated by the tip of each pointer image S1 (see FIG. 2A) projected by the image projection means 30, and the chuck table 20 is used. The wafer W is placed on it. Then, the chuck table 20 is rotated to supply the chemical solution to one point indicated by the tip of the pointer image S2 (see FIG. 3A) projected by the image projection means 30, and the chemical solution is applied to the entire surface of the wafer W.

The alignment of the wafer and the supply of the chemical solution to the wafer will be described with reference to FIGS. 2 and 3. FIG. 2 is an explanatory diagram of wafer alignment according to the present embodiment. FIG. 3 is an explanatory diagram of supplying a chemical solution to the wafer of the present embodiment. Note that FIG. 2A shows a perspective view at the time of wafer alignment, and FIG. 2B shows a side view at the time of wafer alignment. Further, FIG. 3A shows a perspective view when the chemical solution is supplied to the wafer, and FIG. 3B shows a side view when the chemical solution is supplied to the wafer.

As shown in FIGS. 2A and 2B, when the wafer W is aligned, the image projection means 30 selects image data indicating the outer peripheral edge of the wafer Wa, and a pointer image S1 is generated based on the image data. The pointer image S1 is projected from the image projection means 30 toward the wafer W, and three wedge-shaped pointer images S1 are projected on the upper surface of the wafer W. At this time, the pointer image S1 from the image projection means 30 so that the center of the circle connecting the three alignment points pointed to by the tip of each pointer image S1 is the chuck table center (rotation center) O2 of the chuck table 20. The projection position of is adjusted.

Further, in the image projection means 30, the amount of projected light is adjusted according to the projection distance so that the outline of each pointer image S1 becomes clear. The tips of the three pointer images S1 projected on the image projection means 30 point to the separated wafer outer peripheral edges Wa, and the wafer outer peripheral edges Wa are positioned at the positions pointed to by the tips of the three pointer images S1. That is, while the operator visually confirms the three points pointed to by the tips of the three pointer images S1, the chuck table 20 is provided so that the outer peripheral edge Wa of the wafer coincides with all three points indicated by the tips of the pointer image S1. The wafer W is aligned.

In this case, since the chuck table 20 is formed to have a diameter smaller than that of the wafer W, the tip of the pointer image S1 indicating the alignment portion of the outer peripheral edge Wa of the wafer is operated by the operator until the wafer W is placed on the chuck table 20. Cannot be confirmed. Therefore, the wafer W is temporarily placed on the chuck table 20, and the position of the wafer W is finely adjusted by using the tip of the pointer image S1 projected on the upper surface of the wafer W as a clue. In this way, the wafer center O1 is accurately positioned at the chuck table center O2 even manually, and the wafer W is placed on the chuck table 20.

As shown in FIGS. 3A and 3B, when the chemical solution is supplied to the wafer W, the image projection means 30 selects image data indicating the wafer center O1, and the pointer image S2 is generated based on the image data. Further, the pointer image S2 is projected from the image projection means 30 toward the wafer W, and one wedge-shaped pointer image S2 is projected on the upper surface of the wafer W. At this time, the projection position of the pointer image S2 is adjusted so that the tip of the pointer image S2 points to the wafer center O1. Further, since the projected light is emitted from a position deviating from directly above the wafer center O1, the chemical solution L can be supplied to the wafer center O1 while avoiding the projected light.

Further, also when the pointer image S2 is projected, the amount of projected light is adjusted according to the projection distance so that the outline of the pointer image S2 becomes clear by the image projection means 30 as in the case of projecting each pointer image S1. Has been done. The tip of the pointer image S2 projected on the image projection means 30 indicates the wafer center O1, and the chemical solution L is supplied to the position pointed to by the tip of the pointer image S2. That is, while the operator visually confirms one point pointed by the tip of the pointer image S2, the chemical solution L is dripped from the container 40 aiming at the one point indicated by the tip of the pointer image S2, and the chemical solution L is dropped on the upper surface of the wafer W. It is applied.

In this case, since the wafer center O1 coincides with the chuck table center O2, the wafer W is rotated without being eccentric with respect to the chuck table 20. By dripping the chemical solution L from the container 40 aiming at the tip of the pointer image S2 projected on the upper surface of the wafer W, the chemical solution L is uniformly spread from the wafer center O1 toward the outer peripheral edge Wa of the wafer by centrifugal force. In this way, the chemical solution L is accurately supplied to the wafer center O1 even manually, and the chemical solution L is applied to the entire upper surface of the wafer W with a uniform thickness so that coating unevenness does not occur.

In the present embodiment, the image projection means 30 is configured to irradiate diffused light, but the image projection means 30 may be configured to irradiate parallel light. For example, as shown in FIG. 4, a collimating lens may be used as the projection lens 36 of the image projection means 30 to produce parallel light. As a result, the tip of the pointer image S2 is projected more clearly on the upper surface of the wafer W, and the wafer center O1 is more accurately pointed to. Further, since the light is parallel light, the contour of the pointer image S2 is not ambiguous even if the projection distance from the projection lens 36 to the upper surface of the wafer W changes.

Subsequently, the application work of the chemical solution using the chemical solution application device will be described with reference to FIG. FIG. 5 is a diagram showing an example of the application operation of the chemical solution of the present embodiment. 5A and 5B are diagrams showing an example of a wafer mounting step, and FIG. 5C is a diagram showing an example of a chemical solution application step. Further, FIGS. 5A and 5B show an example in which diffused light is emitted from the image projection means, and FIG. 5C shows an example in which parallel light is emitted from the image projection means.

As shown in FIG. 5A, in the wafer mounting step, the image data for alignment is selected by the image projection means 30, and the pointer image S1 corresponding to the image data is projected on the outer peripheral side of the chuck table 20 at three locations. .. However, since the tip of each pointer image S1 is detached from the chuck table 20, the operator may visually check the alignment point pointed to by the pointer image S1 until the wafer W is accurately placed on the chuck table 20. Can not. Therefore, the wafer W is temporarily placed on the chuck table 20 so as to slide on the holding surface 21 of the chuck table 20.

Next, as shown in FIG. 5B, when the wafer W is temporarily placed on the chuck table 20, the tip of the pointer image S1 is projected on the upper surface of the wafer W. At this time, since the tip of the pointer image S1 points to the alignment points of the three points on the outer peripheral edge of the wafer Wa, all three points are positioned by the tips of the pointer images S1 until the wafer center O1 coincides with the chuck table center O2. The mating point is not projected on the outer peripheral edge Wa of the wafer. By finely adjusting the position of the wafer W with respect to the chuck table 20, the three points pointed to by the tip of each pointer image S1 on the upper surface of the wafer W are placed so as to be the outer peripheral edge Wa of the wafer.

In this way, the operator manually positions the wafer center O1 with respect to the chuck table center O2 while visually observing the tip of the pointer image S1 on the upper surface of the wafer W. Therefore, the wafer W can be easily aligned with the chuck table 20, the alignment time can be shortened, and the wafer W is not frequently replaced and the wafer W is not damaged. Further, since the wafer center O1 is positioned at the chuck table center O2, the wafer W placed on the chuck table 20 does not rotate eccentrically.

Next, as shown in FIG. 5C, a chemical solution application step is performed after the wafer mounting step. In the chemical solution application step, the chuck table 20 is rotated, and the image projection means 30 switches from the image data for alignment to the image data for supplying the chemical solution. As a result, the pointer image S2 corresponding to the image data after switching is projected in the vicinity of the wafer center O1 rotated together with the chuck table 20. Since the tip of the pointer image S2 points to the wafer center O1, the chemical solution L is dripped from the container 40 aiming at one point pointed to by the tip of the pointer image S1.

Since the wafer center O1 coincides with the chuck table center O2 and the chemical solution L continues to drip on the wafer center O1, the chemical solution L is uniformly spread over the entire surface of the wafer W from the wafer center O1. In this way, the operator can manually supply the chemical solution L to the wafer center O1 while visually observing the tip of the pointer image S1 on the upper surface of the wafer W. Since the chemical solution L can be easily supplied to the wafer W, it is not necessary to reapply the chemical solution L, and waste of the chemical solution L can be eliminated. In this way, the surface film is formed by the chemical solution L uniformly supplied over the entire upper surface of the wafer W.

As described above, according to the chemical solution coating device 1 of the present embodiment, the center of the circle connecting the positions pointed to by the tips of the three pointer images S1 is the chuck table center O2, so that the wafer W with respect to the chuck table 20 The alignment point is pointed to by the tips of the three pointer images S1. By placing the wafer W on the chuck table 20 while visually checking by the operator so that the tips of the three pointer images S1 point to the outer peripheral edge Wa of the wafer, the wafer W can be placed many times even by hand. The wafer center O1 can be positioned at the chuck table center O2 without modification. Further, since the pointer image S1 is projected by the image projection means 30, the projection position, the brightness, and the like of the pointer image S1 can be easily adjusted according to the type of the wafer W.

In the present embodiment, the image projection means may automatically switch the image data according to the type of the wafer to project a pointer image suitable for the outer diameter and the surface state of the wafer. For example, the projection position of the pointer image, the shape of the pointer image, and the color of the pointer image may be automatically changed according to the type of wafer. As a result, even when another wafer is placed on the chuck table, the wafer can be easily aligned with the chuck table.

Further, in the present embodiment, the configuration in which the alignment device is applied to the chemical solution application device has been described, but the configuration is not limited to this configuration. The alignment device of the present invention may be applied to a processing device that manually aligns a wafer with respect to a chuck table. For example, it may be used for aligning a wafer with respect to a chuck table of a manual dicer, aligning a wafer with respect to a chuck table of a manual grinder, and aligning a wafer with respect to a chuck table of a tape mounter. Further, if it is a manual feed processing device, it can be applied to the alignment of the wafer with respect to the chuck table of another processing device such as a polishing device, a laser processing device, an etching device, a trimming device, and a braking device.

Further, in the present embodiment, as the wafer, for example, various workpieces such as a semiconductor device wafer, an optical device wafer, a package substrate, a semiconductor substrate, an inorganic material substrate, an oxide wafer, a raw ceramic substrate, and a piezoelectric substrate may be used. Good. As the semiconductor device wafer, a silicon wafer or a compound semiconductor wafer in which a device such as an IC is formed may be used. As the optical device wafer, a sapphire wafer or a silicon carbide wafer in which an optical device such as an LED is formed may be used. Further, a CSP (Chip Size Package) substrate may be used as the package substrate, silicon, gallium arsenide or the like may be used as the semiconductor substrate, and sapphire, ceramics, glass or the like may be used as the inorganic material substrate. Further, as the oxide wafer, lithium tantalate or lithium niobate may be used.

Further, in the present embodiment, the image projection means projects the three pointer images toward the wafer at the time of aligning the wafers, but the configuration is not limited to this. At the time of aligning the wafers, the image projection means may be configured to project at least three pointer images toward the wafer, and for example, four or more pointer images may be projected toward the wafer.

Further, in the present embodiment, the image projection means is provided with three projection lenses, and one pointer image is projected from each projection lens, but the present invention is not limited to this configuration. One projection lens may be provided in the image projection means, and a plurality of pointer images may be projected from one projection lens.

Further, in the present embodiment, a wedge-shaped pointer image is projected, but the present embodiment is not limited to this configuration. The shape of the pointer image is not particularly limited, and any shape may be used as long as it points to the outer peripheral edge of the wafer.

Further, in the present embodiment, the chuck table is not limited to the suction chuck type table, and may be an electrostatic chuck type table.

Further, in the present embodiment, the DLP projector has been described as an example as the image projection means, but the present invention is not limited to this configuration. The image projection means may be configured as long as it can project at least three pointer images, and may be configured by, for example, an LCD (Liquid Crystal Display) projector.

Moreover, although the present embodiment and the modified example have been described, as another embodiment of the present invention, the above-described embodiment and the modified example may be combined in whole or in part.

Further, the embodiment of the present invention is not limited to the above-described embodiment, and may be variously modified, replaced, or modified without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by the advancement of technology or another technology derived from it, it may be carried out by using that method. Therefore, the scope of claims covers all embodiments that may be included within the scope of the technical idea of the present invention.

Further, in the present embodiment, the configuration in which the present invention is applied to the chemical solution supply device has been described, but it is also possible to apply the present invention to other devices that need to point to the alignment point of the outer peripheral edge of the wafer.

As described above, the present invention has an effect that the center of the wafer can be manually positioned and placed on the center of the chuck table with high accuracy. In particular, a protective film such as PVA is provided on the upper surface of the wafer. It is useful for the chemical solution coating device to be formed.

1 Chemical coating device 20 Chuck table 30 Image projection means O1 Wafer center O2 Chuck table center S1, S2 Pointer image W Wafer Wa Wafer outer peripheral edge

Claims (1)

An alignment device that aligns the center position of the wafer with the center of the chuck table.
A chuck table that holds the wafer on the upper surface and an image projection means that projects at least three pointer images equidistant from the center of the chuck table toward the wafer held on the chuck table are provided.
The tips of at least three pointer images projected from the image projection means are separated from each other and point to the outer peripheral edge of the wafer, and the outer edges of the wafer are positioned at the positions pointed to by the tips of the at least three pointer images on the chuck table. An alignment device characterized in that a wafer can be placed on the surface.

Images