Wafer chuck for laser beam wafer dicing device

Abstract

To provide a chuck, a laser beam wafer dicing device, and a method for preventing a dicing tape for fixing a wafer from being hit by a laser beam outside the edge of a wafer and sticking to the surface of the wafer chuck during dicing with a laser beam.SOLUTION: A chuck 120 for a laser beam wafer dicing device 100 includes a wafer support plate 122 having an upper surface 122A for holding a wafer 140 placed on a dicing tape 160. The top surface has an annular groove 124 that overlaps a wafer edge 142 when the wafer placed on the dicing tape is placed on the top surface. The wafer support plate includes a ventilation channel 126 that ventilates the annular groove.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to the field of wafer handling, and more particularly to wafer chucks and methods for laser beam wafer dicing. [Background technology]

[0002] One particular process in wafer handling involves mounting a wafer on dicing tape and dividing the wafer into dies using a laser beam wafer dicing machine. More specifically, the wafer mounted on the dicing tape is placed on top of a wafer support plate of a wafer chuck, and a laser beam is used to cut the wafer into dies as it passes over the wafer.

[0003] The problem is that the dicing tape that holds the wafer during the cutting process (die separation) can stick to the wafer support plate of the wafer chuck in areas outside the wafer edge (i.e., the area where the laser beam directly hits the tape). This can cause chuck contamination due to tape residue sticking to the chuck's wafer support plate, and can also cause an additional difficulty: die-to-die knocking, where the already cut dies knock against each other when the tape is lifted with the cut wafer on it, or the tape sticks so strongly to the chuck that it cannot be lifted at all. The chuck contamination process is self-reinforcing, and in addition, the top surface of the chuck can be directly damaged by the laser beam in the overcut area.

[0004] Conventionally, chemical and high temperature cleaning of the chuck is used to remove tape residue from the support plate of the chuck, which is typically performed about once a day and is very expensive.

[0005] Another approach to circumventing this difficulty is to use a dicing tape that is specifically suited for laser dicing. This is extremely demanding, as subsequent processes must be precisely tailored to the new dicing tape. Therefore, if a different dicing tape were used, many subsequent processes would have to be changed.

[0006] A third possibility is to stop the laser beam before it reaches the wafer edge and perform wafer braking in the area of ​​the wafer edge in the back end (BE) where the dicing tape is being unrolled. However, this is also not feasible from a practical point of view, because braking the wafer edge in the BE would generate particle contamination that is unacceptable at that stage of the procedure (e.g., during the BE pick-and-place process). Summary of the Invention [Means for solving the problem]

[0007] According to one aspect of the present disclosure, a chuck for a laser beam wafer dicing apparatus includes a wafer support plate having an upper surface for holding a wafer disposed on a dicing tape, the upper surface including an annular groove that overlaps an edge of the wafer disposed on the dicing tape when the wafer is placed on the upper surface, and the wafer support plate includes a ventilation channel configured to ventilate the annular groove.

[0008] According to another aspect of the present disclosure, a laser beam wafer dicing machine includes a chuck as described above, the laser beam wafer dicing machine further including a laser unit for generating a laser beam configured to cut the wafer into dies as it passes over the wafer.

[0009] According to another aspect of the present disclosure, a method for dicing a wafer includes placing a wafer on an upper surface of a wafer support plate of a chuck. A dicing tape is disposed between the upper surface and the wafer. The upper surface includes an annular groove that overlaps the edge of the wafer. The annular groove is ventilated. The wafer is cut into dies by passing a laser beam over the wafer. The dicing tape is lifted off the upper surface along with the dies.

[0010] Elements in the drawings are not necessarily to scale relative to each other. Like reference numerals refer to corresponding like parts. Features of the various illustrated embodiments may be combined unless they are mutually exclusive and / or may be selectively omitted unless stated as necessary. Embodiments are illustrated in the drawings and illustratively described in the following description. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view of an example of a laser beam wafer dicing device. [Figure 2] 1 is a schematic cross-sectional partial view of an exemplary wafer support plate of a chuck, the wafer support plate having a non-ventilated annular groove near the wafer edge. [Figure 3] 1 is a schematic cross-sectional partial view of an exemplary wafer support plate of a chuck, the wafer support plate having a wide ventilated annular groove near the wafer edge. [Figure 4] 1 is a schematic cross-sectional partial view of an exemplary wafer support plate of a chuck, the wafer support plate having a ventilated annular groove of appropriate width near the wafer edge. [Figure 5] 1 is a schematic partial cross-sectional view of an exemplary wafer support plate of a chuck, the wafer support plate having a ventilated annular groove near the wafer edge, and a vacuum system including vacuum grooves and / or vacuum holes. [Figure 6]FIG. 1 is a partial cutaway perspective view of a wafer chuck having a base plate positioned below and spaced apart from a wafer support plate. [Figure 7] FIG. 1 is a top perspective view of an exemplary wafer support plate of a wafer chuck. [Figure 8] 1 is a flowchart illustrating an exemplary method for dicing a wafer. DETAILED DESCRIPTION OF THE INVENTION

[0012] As used herein, layers or elements illustrated as adjacent layers or elements are not necessarily in direct contact with each other, i.e., there may be intervening elements or layers between such layers or elements. However, in accordance with the present disclosure, elements or layers illustrated as adjacent layers or elements may specifically be in direct contact with each other, i.e., there may be no intervening elements or layers between them, respectively.

[0013] The terms "above" or "below" with respect to a portion, element, or layer of material formed or located or arranged or disposed or located "above" or "below" a surface can be used herein to mean that the portion, element, or layer of material is located (e.g., located, formed, located, arranged, disposed, etc.) "directly on" or "directly below," e.g., in direct contact with, the implied surface. However, the terms "above" or "below" when used with respect to a portion, element, or layer of material formed or located or arranged or disposed "above" or "below" a surface can also be used to mean that the portion, element, or layer of material is located (e.g., located, formed, arranged, disposed, etc.) "indirectly on" or "indirectly below" the implied surface, with one or more additional portions, elements, or layers disposed between the implied surface and the portion, element, or layer of material.

[0014] Referring to FIG. 1, a laser beam wafer dicing apparatus 100 , hereinafter referred to as wafer dicing apparatus 100 , can include a chuck 120 and a laser unit 180 for generating a laser beam 182 .

[0015] As known in the art, a chuck 120 is a device configured to support a wafer during various stages of wafer processing. Typically, a chuck is designed according to the wafer processing that will be performed on the wafer while the wafer is held by the chuck. In the following, a chuck 120 designed to support a wafer during laser beam wafer dicing will be considered. Such a chuck 120 is also referred to in the art as a "dicing chuck."

[0016] 1 shows portions of such a wafer dicing apparatus 100, namely, a chuck 120 and a laser unit 180. Wafer dicing apparatus 100 may further include a mechanism (not shown) for carrying chuck 120 and a mechanism (not shown) to which laser unit 180 is attached. These mechanisms allow laser unit 180 to be moved relative to chuck 120 in lateral directions (X and / or Y directions) and Z directions (i.e., directions perpendicular to the plane defined by the X and Y directions, except that the Y direction is perpendicular to the plane of the paper).

[0017] The chuck 120 includes a wafer support plate 122 having an upper surface 122A and a lower surface 122B opposite the upper surface 122A. Typically, the chuck 120 includes an additional plate (e.g., a chuck base plate and / or a chuck vacuum plate and / or a chuck receiver) disposed below the wafer support plate 122. Such plates, which provide mechanical stability and / or vacuum functionality to the chuck 120, are not shown in FIG. 1 . In other words, FIG. 1 shows only the upper plate of the chuck 120, i.e., the wafer support plate 122.

[0018] For example, the wafer support plate 122 can include or consist of glass, such as fused silica, or another material, such as a metallic material (eg, stainless steel) or polycarbonate.

[0019] During operation of the wafer dicing apparatus 100, the wafer 140 is placed on and held by the upper surface 122A of the wafer support plate 122. The wafer 140 is mounted on the dicing tape 160. That is, the dicing tape 160 has a lower surface that can be in direct contact with the upper surface 122A of the wafer support plate 122, and an upper surface that can be in direct contact with and adhere to the lower surface of the wafer 140. That is, the dicing tape 160 is disposed between the upper surface 122A of the wafer support plate 122 and the wafer 140.

[0020] The dicing tape 160 can be attached to a dicing frame 170. The dicing frame 170 is used as a tool for transporting and mounting the dicing tape 160 together with the mounted wafer 140. During the process of dicing the wafer 140, the dicing frame 170 can be fixed to the chuck 120 by a detachable connection means, such as a clamp connection, a screw connection, or a vacuum cup (not shown). That is, the wafer support plate 122 and the dicing tape 160 are in a fixed positional relationship during operation of the wafer dicing apparatus 100.

[0021] The dicing tape 160 is required to support each die after die separation (i.e., after cutting the wafer 140 into multiple dies by passing a laser beam 182 over the wafer 140). After die separation, the dicing tape 160 is lifted together with the dies from the upper surface 122A of the wafer support plate 122. Lifting the dicing tape 160 together with the dies from the upper surface 122A can be performed by a mechanism (not shown) that provides relative movement between the wafer support plate 122 and the dicing frame 170 in the Z direction.

[0022] The laser unit 180 may be of any type suitable for laser dicing. In particular, a UV (ultraviolet) laser, a green laser (e.g., 532 nm wavelength), or an IR (infrared) laser, which are effective for dividing the wafer 140, which requires high energy for laser dicing, may be used. Furthermore, a pulsed laser may be used for dividing.

[0023] The wafer 140 can be made of any semiconductor material, such as SiC, Si, GaN, etc. The wafer 140 can have a thickness of 20 μm or more, or 50 μm or more, or 100 μm or more. Depending on the semiconductor material and the thickness of the wafer, the laser energy and / or pulse length should be appropriately selected.

[0024] For example, SiC is a mechanically very durable and electrically efficient material. Its mechanical properties are comparable to those of diamond. Furthermore, in back-end (BE) processes, the SiC die is very sensitive, and this must be taken into account already at the wafer separation stage.

[0025] To achieve high yields, the dicing process must be tailored to the wafer thickness, and the dicing process must ensure complete separation and overcut at the wafer edge to ensure complete separation of the wafer. In this overcut area OA (see FIG. 1), all of the laser energy of the semiconductor dicing process is introduced into the dicing tape 160.

[0026] As a result, the dicing tape 160 may be altered or damaged by localized melting on the top surface, back surface, and inside the tape (e.g., intermediate layer, if provided) of the dicing tape 160.

[0027] A further consequence of the laser beam 182 going beyond the wafer edge 142 is that the top surface 122A of the wafer support plate 122 may be locally damaged (chip-out) and / or locally melted dicing tape 160 may stick to the top surface 122A of the wafer support plate 122. The latter effect causes contamination of the dicing chuck 120. Both effects on the top surface 122A of the wafer support plate 122, i.e., damage and contamination, are self-reinforcing, i.e., already damaged and / or already contaminated surface areas are more susceptible to further damage or contamination than undamaged surface areas.

[0028] As a result, automated wafer lifting from the wafer support plate 122 may become more difficult or fail after processing a relatively small number of wafers 140. Contamination and damage (e.g., cut lines) on the upper surface 122A of the wafer support plate 122 increases with each wafer. Finally, the stuck wafer 140 must be manually removed from the chuck 120, which may result in wafer scrap. In a worst-case scenario from a product reliability perspective, even if wafer lifting (so-called dechucking) is still possible, locally stuck dicing tape 160 may cause bending of the dicing tape 160. As a result, die knocking may occur, which may induce cracks and chips in the die.

[0029] For example, when cutting a SiC wafer having a thickness of 100 μm or more, the above-mentioned problem becomes serious.

[0030] To avoid the above and other problems, the upper surface 122A of the wafer support plate 122 includes an annular groove 124 that overlaps with the wafer edge 142 when the wafer 140, disposed on the dicing tape 160, is placed on the upper surface 122A.

[0031] The annular groove 124 partially or completely overlaps the wafer edge 142 when the wafer 140 mounted on the dicing tape 160 is placed on the top surface 122A. For example, the entire wafer edge 142 can extend radially beyond the inner edge 124I of the annular groove 124, but cannot extend radially beyond the outer edge 124O of the annular groove 124.

[0032] The annular groove 124 can be shaped as a ring. The inner edge 124I and / or the outer edge 124O can be, for example, circular or part-circular (see, eg, FIG. 7).

[0033] The annular groove 124 can ensure that any contact between the top surface 122A and the dicing tape 160 is avoided near the wafer edge 142 (ie, within the overcut area OA).

[0034] In other words, an overcut of the wafer edge is applied when sawing the wafer 140 into dies. The overcut area length OAL is the radial dimension of the overcut area OA (see FIG. 1). The outer edge 124O of the annular groove 124 extends radially beyond the wafer edge 142 by at least the maximum overcut area length OAL.

[0035] The overcut area OA begins at the wafer edge 142. The radial length OAL of the overcut area OA is defined by parameters such as die size, wafer positional tolerance, etc. Thus, different OALs can be used for different wafers. The annular groove 124 can be sized to completely overlap the overcut area OA for all OALs (and thus, for example, for all die sizes intended to be manufactured on the chuck 120), thereby ensuring that the dicing tape 160 extends freely across the annular groove 124, i.e., is completely unsupported, no matter where the (focused) laser beam 182 strikes the dicing tape 160.

[0036] The overcut area length OAL can be set to 1.5 mm or less. For example, the OAL may be greater than or less than 0.3 mm, 0.6 mm, 0.9 mm, 1.2 mm, or 1.5 mm.

[0037] By avoiding contact between the dicing tape 160 and the upper surface 122A of the wafer support plate 122 at the wafer edge 142 and radially beyond the wafer edge 142 (e.g., at least in the overcut area OA), chuck contamination is significantly reduced, thereby allowing the interval between chuck cleaning times to be significantly extended.

[0038] Additionally, the wafer support plate 122 includes ventilation channels 126 configured to ventilate the annular groove 124 .

[0039] FIG. 2 shows downward deformation of the dicing tape 160 when a vacuum is applied to the annular groove 124. In this case, the annular groove 124 may result in wafer edge delamination (ED) from the dicing tape 160. Furthermore, after wafer dicing, die spatter may be generated in the area where the wafer 140 extends over the inner edge 124I of the annular groove 124. To avoid downward deformation of the dicing tape at the wafer edge 142 and thus edge delamination (ED), a ventilation channel 126 is used ( FIG. 3 ). The ventilation channel 126 is in communication with the annular groove 124 and ensures that the annular groove 124 is vented to ambient pressure, e.g., atmospheric pressure. In this way, downward deformation of the dicing tape 160, which occurs when the annular groove 124 is not ventilated and / or is connected to a vacuum system, can be avoided. As a result, peeling of the dicing tape 160 prior to the laser dicing process can be avoided.

[0040] 3 illustrates another problem that can arise even when a ventilated annular groove 124 is present. The process exhaust PE generated by the laser beam 182 can lift the dicing tape 160 from the wafer support plate 122. This lifting of the dicing tape 160 can also be critical because the wafer 140 can no longer stabilize the dicing tape 160 at the wafer edge 142 when cutting the wafer edge 142. As a result, this effect can also cause die knocking or die splashing and is therefore unacceptable during wafer dicing.

[0041] It has been found that to avoid the effects of the upward deformation of the dicing tape 160 shown in Figure 3, the area of ​​the tape not supported by the vacuum should be as small as possible, and therefore the width of the annular groove 124 can be limited.

[0042] Additionally, deformation of the dicing tape 160 as shown in Figure 2 or 3 can move the wafer edge 142 out of focus of the laser beam 182. This can result in areas of the wafer edge that are not split or not split completely due to the out-of-focus laser beam 182. For this reason, too, the two effects (Figures 2 and 3) need to be controlled.

[0043] It should be noted that the adverse effects caused by downward tape deformation (FIG. 2) and upward tape deformation (FIG. 3) only occur during laser dicing, i.e., when the wafer edge 142 is diced, which can cause the individual dies to become disjointed and come into contact with each other.

[0044] FIG. 4 illustrates a laser dicing operation in which a ventilated annular groove 124 is used, with the width WG of the annular groove set to prevent the area of ​​the dicing tape 160 not supported by the vacuum from becoming too large. Preferably, the annular groove 124 has a width WG between 1 mm and 8 mm, particularly between 5 mm and 7 mm. More specifically, the width WG of the annular groove may be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, or 7 mm, or more or less. The smaller the width WG of the annular groove 124, the smaller the area of ​​the tape not supported by the vacuum.

[0045] The annular groove 124 may have a depth of, for example, between 0.1 mm and 5 mm. In particular, the depth may be greater than or less than 0.5 mm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, or 5.0 mm.

[0046] The area of ​​the tape not supported by vacuum is equal to the width W of the annular groove plus the distance from the inner edge 124I and outer edge 124O of the annular groove 124 to the next vacuum groove or hole, respectively (see FIGS. 5 and 6). These distances are preferably equal to or less than 4 mm, 3 mm, 2 mm, or 1 mm. Furthermore, the upper surface 122A of the wafer support plate 122 can have low roughness and / or high flatness, at least near the annular groove 124, to improve mechanical contact between the wafer support plate 122 and the dicing tape 160 near the inner edge 124I and outer edge 124O of the annular groove 124.

[0047] 5, the wafer support plate 122 includes a vacuum system configured to hold the dicing tape 160 by suction to the upper surface 122A of the wafer support plate 122. More specifically, the vacuum system may include a first pressure region P1 located radially inward of the annular groove 124, a second pressure region P2 including the annular groove 124 and the ventilation channel 126, and a third pressure region P3 located radially outward of the annular groove 124.

[0048] A vacuum is applied to the first pressure region P1 to suck the wafer, a second pressure region P2 is vented (e.g., at atmospheric pressure), and a vacuum is applied to the third pressure region P3 to suck the dicing tape.

[0049] The pressure in the first pressure zone P1 and the pressure in the third pressure zone P3 may be different or equal. For example, the pressure zones P1 and P3 may be connected to each other by a pressure connection 510. The pressure connection 510 bridges the annular groove 124. The pressure connection 510 may be formed as a channel or duct extending into the interior of the wafer support plate 122.

[0050] 6 shows a partial cutaway view of wafer chuck 120. Wafer chuck 120 includes a base plate 620 and a wafer support plate 122. Base plate 620 is disposed below and spaced apart from wafer support plate 122.

[0051] In the above example and all other examples, the upper surface 122A of the wafer support plate 122 may be provided with thin vacuum grooves 628 located radially inward and radially outward of the annular groove 124. Alternatively or additionally, vacuum holes (not shown) may be formed in the upper surface 122A of the wafer support plate 122. The vacuum grooves 628 and / or the vacuum holes (not shown) form part of pressure zones P1 and P3, respectively.

[0052] For this purpose, the wafer support plate 122 may be provided with a vacuum duct 624 extending horizontally, for example radially. The vacuum duct 624 corresponds to the pressure connection 510 shown in Figure 5. The vacuum duct 624 may connect a vacuum suction groove 628 provided radially inside the annular groove 124 with a vacuum suction groove 628 provided radially outside the annular groove 124.

[0053] The chuck 120 may further include an annular sealing 630 disposed between the base plate 620 and the wafer support plate 122. The annular sealing 630 may be, for example, an O-ring or any other sealing means. The annular sealing 630 may seal the inner vacuum region between the base plate 620 and the wafer support plate 122 from the outer ventilation region between the base plate 620 and the wafer support plate 122. The ventilation air flow is indicated by the arrows with reference numeral 640, and the internal vacuum gas flow (suction flow) is indicated by the hatched arrows.

[0054] The inner vacuum zone may be part of pressure zones P1 and P3, and the outer ventilation zone may be part of pressure zone P2.

[0055] More specifically, the vacuum supply for the pressure region P3 outside the annular groove 124 can be implemented by a horizontal pressure connection 510 (e.g., vacuum duct 624) that traverses below the annular groove 124 to the inner vacuum region. The connection between the inner vacuum region (between the base plate 620 and the wafer support plate 122) and the horizontal pressure connection 510 can be formed by one or more connection holes 626. The ventilation channels 126 in the wafer support plate 122 can penetrate the wafer support plate 122 and communicate with the outer ventilation region. Here and in all examples disclosed herein, the ventilation channels 126 can have a diameter of, for example, 2 mm, 3 mm, or 4 mm or more or less.

[0056] The design of the vacuum grooves 628 should be adapted to accommodate the exhaust adjustment described in connection with FIG. 3 . More specifically, the vacuum grooves 628 adjacent to the annular groove 124 should be located as close as possible to the inner edge 124I and outer edge 124O of the annular groove 124. For example, the distance between the inner edge 124I of the annular groove 124 and the adjacent vacuum groove 628 may be 4 mm, 3 mm, 2 mm, or 1 mm or less. The same positional relationship can be established for the distance between the outer edge 124O of the annular groove 124 and the adjacent vacuum groove 628. The vacuum grooves 628 may be circular and concentric with the annular groove 124.

[0057] 7 shows an example of a wafer support plate 122. The wafer support plate 122 can include radial vacuum grooves 728. The radial vacuum grooves 728 can connect the circular vacuum grooves 628. The radial vacuum grooves 728 are not connected to the annular groove 124.

[0058] The wafer support plate 122 can be used, for example, for a wafer chuck 120 supporting a 6-inch wafer. A 6-inch wafer can have a diameter ranging from 149.75 mm to 150.25 mm. The wafer support plate 122 can have a diameter of 220 mm and / or a thickness of 10 mm. The groove width WG can be, for example, 6±0.02 mm. The groove depth can be, for example, 2 mm. The diameter of the inner edge 124I of the annular groove 124 can be, for example, 148±0.1 mm. The wafer support plate 122 can include multiple ventilation channels 126, six ventilation channels 126 in this example. The wafer support plate 122 is made of, for example, quartz glass. All of these features and dimensions of the specific example shown in FIG. 7 can be selectively used for any of the examples disclosed herein.

[0059] The inner edge 124I and / or the outer edge 124O of the annular groove 124 can have a linear section 124L. In this case, the linear section 124L has a shape similar to or matching (e.g., matching) the wafer edge 142, which in some cases also has a linear section. For example, the linear length of the wafer edge 142 of a 6-inch wafer 140 can be in the range of, for example, between 46 mm and 49 mm.

[0060] Other suitable wafer sizes that can be supported by the wafer support plate 122 of the wafer chuck 120 are 6-inch wafers, 8-inch wafers, 12-inch wafers, and wafers greater than 12 inches.

[0061] The annular groove 124 may have a constant width along the entire circular extension of the annular groove 124, for example, even between linear sections 124L of the edges 124I, 124O of the annular groove.

[0062] 8, the process of dicing a wafer can include, in S1, placing a wafer on an upper surface of a wafer support plate of a chuck, with a dicing tape disposed between the upper surface and the wafer. The upper surface includes an annular groove that overlaps the edge of the wafer. The annular groove makes it possible to avoid contact between the upper surface of the wafer support plate and the dicing tape in a small area radially outward of the edge of the wafer.

[0063] At S2, the annular groove is ventilated.

[0064] In S3, the wafer is cut into dies by passing a laser beam over the wafer. The energy of the laser beam must be set according to the laser dicing parameters, including, among other things, the wafer material, the wafer thickness, and (optionally) the thickness of the dicing tape. The dicing tape can be relatively thin (compared to dicing tape that must otherwise be used to avoid surface damage or contamination), for example, having a thickness of 200 μm or less, or 150 μm or 100 μm or less.

[0065] In S4, the dicing tape is lifted from the top surface of the wafer support plate of the chuck. Lifting the dicing tape 160 can be accomplished by moving the dicing frame 170 away from the chuck 120 (see FIG. 1). As mentioned above, the lifting procedure is greatly facilitated by providing the annular groove 124 in the wafer support plate 122.

[0066] Example The following examples relate to further aspects of the present disclosure:

[0067] In Example 1, a chuck for a laser beam wafer dicing apparatus includes a wafer support plate having an upper surface for holding a wafer disposed on a dicing tape. The upper surface includes an annular groove, and the annular groove overlaps an edge of the wafer disposed on the dicing tape when the wafer is placed on the upper surface. The wafer support plate includes a ventilation channel configured to ventilate the annular groove.

[0068] In Example 2, the subject matter of Example 1 can optionally include that the entire wafer edge protrudes radially beyond the inner edge of the annular groove.

[0069] In Example 3, the subject matter of Example 1 or 2 can optionally include that the annular groove has a width between 1 mm and 8 mm, particularly between 5 mm and 7 mm.

[0070] In Example 4, the subject matter of any preceding Example can optionally include: the annular groove having a depth of 0.1 mm or greater.

[0071] In Example 5, the subject matter of any preceding example can optionally include that the wafer support plate includes a vacuum system configured to hold the dicing tape on the upper surface by suction.

[0072] In Example 6, the subject matter of Example 5 can optionally include that the vacuum system includes vacuum suction grooves and / or vacuum suction holes formed in the upper surface, and the vacuum suction grooves and / or vacuum suction holes are provided radially inside and radially outside the annular groove.

[0073] In Example 7, the subject matter of Examples 5 or 6 can optionally further include a base plate disposed below the wafer support plate and spaced apart from the wafer support plate, and an annular sealing disposed between the base plate and the wafer support plate, wherein the annular sealing defines an inner vacuum region and an outer ventilation region between the base plate and the wafer support plate.

[0074] In Example 8, the subject matter of Example 7 can optionally include that the vacuum system of the wafer support plate is in communication with the inner vacuum region and the ventilation channels of the wafer support plate are in communication with the outer ventilation region.

[0075] In Example 9, the subject matter of any one of the preceding Examples can optionally include that the wafer support plate is made of quartz glass.

[0076] Example 10 is a laser beam wafer dicing apparatus including a chuck as described in any one of the preceding examples and a laser unit for generating a laser beam configured to cut the wafer into dies as it passes over the wafer.

[0077] In Example 11, the subject matter of Example 10 can optionally include wherein the laser unit includes a pulsed laser.

[0078] In Example 12, the subject matter of Examples 10 or 11 can optionally include that the laser unit includes a UV laser, a green laser, or an IR laser.

[0079] Example 13 is a method for dicing a wafer, the method including: placing a wafer on an upper surface of a wafer support plate of a chuck, with a dicing tape disposed between the upper surface and the wafer, the upper surface including an annular groove that overlaps the edge of the wafer; ventilating the annular groove; cutting the wafer into dies by passing a laser beam over the wafer; and lifting the dicing tape together with the dies from the upper surface.

[0080] In Example 14, the subject matter of Example 13 can optionally further include applying an overcut of the wafer edge when cutting the wafer into dies, the wafer edge overcut length being dependent on the size of the dies to be manufactured, and the outer edge of the annular groove extending radially beyond the wafer edge by at least the maximum overcut length.

[0081] In Example 15, the subject matter of Examples 13 or 14 can optionally include that the wafer is a SiC wafer.

[0082] In Example 16, the subject matter of any one of Examples 13 to 15 can optionally include that the wafer has a thickness of 100 μm or more.

Claims

1. 1. A chuck for a laser beam wafer dicing apparatus, comprising: the chuck includes a wafer support plate having an upper surface for holding a wafer disposed on a dicing tape; the upper surface includes an annular groove; the annular groove overlaps with an edge of the wafer when the wafer placed on the dicing tape is placed on the upper surface; the wafer support plate includes a ventilation channel configured to ventilate the annular groove. Zipper.

2. the entire wafer edge protruding radially beyond the inner edge of the annular groove; The chuck of claim 1.

3. The annular groove has a width between 1 mm and 8 mm, in particular between 5 mm and 7 mm; The chuck of claim 1.

4. The annular groove has a depth of 0.1 mm or more. The chuck of claim 1.

5. the wafer support plate includes a vacuum system configured to hold the dicing tape on the upper surface by suction; The chuck of claim 1.

6. the vacuum system includes vacuum suction grooves and / or vacuum suction holes formed in the upper surface; The vacuum suction groove and / or the vacuum suction hole are provided on the radially inner side and the radially outer side of the annular groove.

6. The chuck of claim 5.

7. The chuck is a base plate disposed below the wafer support plate and spaced apart from the wafer support plate; an annular sealing disposed between the base plate and the wafer support plate; further comprising the annular sealing defines an inner vacuum region and an outer ventilation region between the base plate and the wafer support plate; 6. The chuck of claim 5.

8. the vacuum system of the wafer support plate is in communication with the inner vacuum region; the ventilation channel of the wafer support plate communicates with the outer ventilation region; 8. The chuck of claim 7.

9. The wafer support plate is made of quartz glass. The chuck of claim 1.

10. A laser beam type wafer dicing apparatus, comprising: A chuck according to any one of claims 1 to 9; a laser unit for generating a laser beam configured to cut the wafer into dies as it passes over the wafer; A laser beam wafer dicing device comprising:

11. The laser unit includes a pulsed laser.

11. The laser beam wafer dicing device according to claim 10.

12. The laser unit includes a UV laser, a green laser, or an IR laser.

11. The laser beam wafer dicing device according to claim 10.

13. 1. A method of dicing a wafer, the method comprising: placing a wafer on an upper surface of a wafer support plate of a chuck; a dicing tape disposed between the upper surface and the wafer; the upper surface including an annular groove that overlaps the edge of the wafer; ventilating the annular groove; cutting the wafer into dies by passing a laser beam over the wafer; Lifting the dicing tape together with the die from the top surface; A method comprising:

14. The method further includes applying a wafer edge overcut when cutting the wafer into dies; the wafer edge overcut length is dependent on the size of the die to be manufactured; an outer edge of the annular groove extending radially beyond the wafer edge by at least a maximum overcut length; 14. The method of claim 13.

15. The wafer is a SiC wafer.

14. The method of claim 13.

16. The wafer has a thickness of 100 μm or more.

14. The method of claim 13.

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