CN113140497A

CN113140497A - Workpiece holder, wafer chuck and method for manufacturing semiconductor package

Info

Publication number: CN113140497A
Application number: CN202110056762.3A
Authority: CN
Inventors: 翁正轩; 曹智强; 邱肇玮; 裴浩然; 陈威宇; 林修任; 谢静华; 郑佳申
Original assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
Current assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
Priority date: 2020-01-19
Filing date: 2021-01-15
Publication date: 2021-07-20

Abstract

A workpiece holder comprises a chuck body and a sealing ring. The chuck body includes a receiving surface configured to receive a workpiece and at least one vacuum port configured to apply a vacuum seal. The seal ring surrounds a side surface of the chuck body. The top surface of the seal ring is higher than the receiving surface of the chuck body and the workpiece abuts the seal ring when a vacuum seal is applied between the workpiece and the chuck body.

Description

Workpiece holder, wafer chuck and method for manufacturing semiconductor package

Technical Field

Embodiments of the present invention relate to a workpiece holder, a wafer chuck and a method of manufacturing a semiconductor package.

Background

Larger wafers accommodate more chips and may reduce the cost per chip. Therefore, wafers having a large size are commonly used in semiconductor manufacturing processes today. Although wafers having large sizes may be used to reduce manufacturing costs, larger wafers introduce new problems not previously considered in smaller wafers. One key issue is that wafer warpage (wafer warp) becomes more severe for larger wafers.

Wafer warpage causes many undesirable manufacturing defects. For example, a spin-on layer on a wafer may have a thickness at the center that is greater than the thickness at the outer edges. In an etching process, the problem of Critical Dimension (CD) uniformity from the center to the edge of the wafer arises at least in part from imperfect adsorption (chucking) of wafer warpage. Furthermore, in a photolithography process, the thickness uniformity of a Photoresist (PR) layer from the center to the outer edge of a wafer is critical. During exposure, focus drift (focus drift) caused by wafer warpage can have a devastating effect on CD uniformity. Furthermore, residual stresses in warped wafers have been observed to cause cracks (cracks) in the wafers.

Disclosure of Invention

Embodiments of the present invention are directed to a workpiece holder, a wafer chuck, and a method of fabricating a semiconductor package that provide adequate support and vacuum force for a warped workpiece and that increase the yield of subsequent processes performed on the workpiece.

According to some embodiments of the present disclosure, a workpiece holder includes a chuck body, a seal ring, and a support. The chuck body includes a receiving surface configured to receive a workpiece and at least one vacuum port configured to apply a vacuum seal. The seal ring surrounds an outermost surface of the chuck body. The top surface of the seal ring is higher than the receiving surface of the chuck body and the workpiece abuts the seal ring when a vacuum seal is applied between the workpiece and the chuck body. A support is disposed at the outermost surface and includes a groove, wherein at least a portion of the seal ring is disposed within the groove.

According to some embodiments of the present disclosure, a wafer chuck includes a chuck body and a seal ring. The chuck body includes a receiving surface configured to receive a wafer. A seal ring is disposed on an outermost surface of the chuck body and surrounds a periphery of the chuck body, wherein a top surface of the seal ring is higher than a receiving surface of the chuck body, and the seal ring is separated from an outer edge of the wafer from a top view.

According to some embodiments of the present disclosure, a wafer handling method includes the following steps. A semiconductor device is provided on a substrate. An encapsulation material is provided over the substrate to encapsulate the semiconductor device at least laterally and form a reconstituted wafer. The reconstituted wafer is attached to a tape carrier. Detaching the substrate from the reconstituted wafer. Providing the reconstituted wafer with the tape carrier onto a wafer chuck, wherein the wafer chuck comprises a chuck body and a sealing ring surrounding the periphery of the chuck body, and a top surface of the sealing ring is higher than a receiving surface of the chuck body. Fixing the tape carrier outside the chuck body, wherein the tape carrier abuts against the sealing ring, and a closed space is formed between the chuck body, the tape carrier and the sealing ring. A vacuum seal is formed by evacuating gas from the enclosed space to pull the periphery of the reconstituted wafer toward the chuck body. Processing the reconstituted wafer on the wafer chuck.

Drawings

Various aspects of the disclosure are best understood from the following detailed description when read with the accompanying figures. It should be noted that, in accordance with standard practice in the industry, the various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 illustrates a cross-sectional view of a workpiece holder, according to some exemplary embodiments of the present disclosure.

Fig. 2-8 illustrate cross-sectional views of intermediate stages in the manufacture of a semiconductor package according to some exemplary embodiments of the present disclosure.

Fig. 9 illustrates a top view of a workpiece holder, according to some exemplary embodiments of the present disclosure.

FIG. 10 illustrates a perspective view of a workpiece holder, according to some exemplary embodiments of the present disclosure.

Fig. 11A and 11B illustrate cross-sectional views of seal rings according to some exemplary embodiments of the present disclosure.

FIG. 12 illustrates a partial cross-sectional view of a workpiece holder, according to some exemplary embodiments of the present disclosure.

[ description of symbols ]

100: workpiece holder/wafer chuck

110: chuck body

112: receiving surface

114: vacuum port

116: outermost surface

120: sealing ring

122: top surface

130: support piece

132: fastening assembly

134: groove/step groove

140: clamping assembly

200: workpiece

201: encapsulated semiconductor device

210: workpiece body/wafer/reconstituted wafer

211. 211 a: semiconductor device with a plurality of transistors

212: back surface

212 a: encapsulation material

213: through hole

214: heavy wiring structure

217: insulating layer

220: carrier/tape carrier

222: adhesive tape portion

224: frame part

280: electrical connector

2112: electrical contact

AL: adhesive layer

D1, Y, Y1, Z: vertical distance

F1: vacuum force/vacuum seal

S1: closed space

ST: substrate

X, X1: horizontal distance

θ: angle of rotation

Detailed Description

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are set forth below to simplify the present disclosure. Of course, these are merely examples and are not intended to be limiting. For example, forming a first feature "over" or "on" a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. Such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Furthermore, for ease of description, spatially relative terms such as "below", "lower", "above", "upper", and the like may be used herein to describe one element or feature's relationship to another element or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may have other orientations (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly as such.

In addition, for ease of description, terms such as "first", "second", "third", "fourth", and the like may be used herein to describe one or more similar or different components or features shown in the figures, and the terms may be used interchangeably depending on the order of presentation or context of description.

FIG. 1 illustrates a cross-sectional view of a workpiece holder, according to some exemplary embodiments of the present disclosure. Fig. 2-8 illustrate cross-sectional views of intermediate stages in the manufacture of a semiconductor package according to some exemplary embodiments of the present disclosure. It should be understood that only the major components of the workpiece holder (workbench) 100 are shown. In order not to obscure the drawing, nuts, bolts, screws, fittings, etc. required for assembling the workpiece holder 100 are not shown in detail in the drawing. Referring to fig. 1 and 8, in some embodiments, the workpiece holder 100 is configured to hold the workpiece 200 and hold the workpiece 200 in a fixed position for subsequent processing. In some embodiments, the workpiece 200 may include a carrier 220 and a workpiece body 210 disposed on the carrier 220.

In semiconductor device fabrication, to produce the final product of Integrated Circuit (IC) chips, the wafer must be processed through many processing steps (e.g., up to several hundred). In various chemical or physical processes for performing fabrication steps, a wafer must be securely held to a wafer carrier device (e.g., a wafer chuck) in a processing chamber so that an active surface of the wafer can be processed. According to some embodiments of the present disclosure, workpiece body 210 may be a wafer, and carrier 220 may be a tape carrier. In such an embodiment, workpiece holder 100 may be referred to as a wafer chuck 100 configured to hold wafer 210 and hold wafer 210 in a fixed position for uniform processing of wafer 210 in semiconductor wafer processing processes such as Chemical Mechanical Polishing (CMP), laser drilling, solder paste printing, die sawing, and the like. The present disclosure is not limited thereto. Different processes may be applied to form wafers 210 having different patterns and feature sizes. For example, to fabricate a pattern, photolithography (lithography), x-ray lithography (x-ray lithography), imprint lithography (imprint lithography), photolithography (photolithography), and the like may be used.

In some embodiments, wafer 210 may represent a reconstituted wafer, a reconstituted panel, a reconstituted substrate, or the like. For example, in a plan view perspective, the wafer 210 may have a circular shape, a rectangular shape, or the like. The plurality of semiconductor devices may be arranged in an array in a reconstituted wafer, reconstituted panel or reconstituted substrate. For example, the manufacturing process of the reconstituted wafer 210 may include the following steps. Referring to fig. 2, at least one semiconductor device 211a (one semiconductor device 211a is shown, but an array of semiconductor devices is contemplated) is provided on a substrate ST. An adhesive layer AL may be provided on the substrate ST. In some embodiments, the substrate ST may be a glass carrier, a ceramic carrier, or the like. The adhesion layer AL may be a light to heat conversion release coating (LTHC) or the like. In some embodiments, an insulating layer 217 may optionally be provided on the substrate ST or on the adhesive layer AL (if present).

In some embodiments, a plurality of through holes (conductive pillars) 213 are provided on the substrate ST, and the through holes 213 surround a device mounting region where the semiconductor device 211a is provided. In some embodiments, the semiconductor device 211a may be a logic chip including a logic circuit therein. In some exemplary embodiments, the number of the semiconductor devices 211a may be plural and may be device dies designed for mobile applications (mobile applications), and may include, for example, Power Management Integrated Circuit (PMIC) dies and Transceiver (TRX) dies.

In some embodiments, the substrate ST may include a plurality of device mounting regions arranged in, for example, an array. Accordingly, the through-holes 213 may be formed to surround each of the regions, and a plurality of semiconductor devices 211a may be respectively disposed on the device mounting regions, and thus the through-holes 213 may surround each of the semiconductor devices 211 a. With this arrangement, a plurality of semiconductor packages can be formed simultaneously. For simplicity and clarity, the fabrication process of one of the semiconductor packages is shown in fig. 2-8.

Then, referring to fig. 3, the semiconductor device 211a and the via hole 213 on the substrate ST are encapsulated by the encapsulation material 212 a. In other words, the encapsulation material 212a is provided over the substrate ST to encapsulate the via hole 213 and the semiconductor device 211a at least in a lateral direction. In some embodiments, the encapsulation material 212a may include a molding compound, an epoxy or resin, or the like. In some embodiments, the encapsulation material 212a may cover the top of the via 213 and the top surface of the semiconductor device 211 a.

Then, referring to fig. 3 and 4, a thinning process, which may be a grinding process, is performed to thin encapsulation material 212a until the top of vias 213 and electrical contacts 2112 of semiconductor device 211a are revealed. The resulting structure is shown in fig. 4. As a result of the thinning process, as shown in fig. 4, the top of via 213 is substantially flush with the top surface of electrical contact 2112, and substantially flush with the top surface of encapsulation material 212. Throughout the description, the resulting structure including semiconductor device 211, vias 213, and encapsulating material 212 as shown in fig. 4 is referred to as an encapsulated semiconductor device 201, which may have a wafer form in the process.

Any desired processes may then be sequentially performed on the encapsulated semiconductor device 201 to form a reconstituted wafer. For example, referring to fig. 5, a redistribution structure (redistribution structure)214 may be formed over the encapsulated semiconductor device 201. The rewiring structure 214 is electrically connected to the semiconductor device 211 of the encapsulated semiconductor device 201 and the via hole 213. The redistribution structure 214 may be formed by, for example, depositing a conductive layer, patterning the conductive layer to form redistribution traces (redistribution circuits), partially covering the redistribution traces, filling gaps between the redistribution traces with a dielectric layer, and so forth. The redistribution trace material may comprise a metal or metal alloy (including aluminum, copper, tungsten, and/or alloys thereof). The dielectric layer may be formed of a dielectric material such as an oxide, nitride, carbide, carbonitride, combinations thereof, and/or multilayers thereof. The redistribution lines are formed in the dielectric layer and electrically connected to the semiconductor device 211 and the via hole 213. In addition, an Under Bump Metallurgy (UBM) layer may be formed on the redistribution structure 214 by sputtering, evaporation, electroless plating, or the like. In some embodiments, at least one electrical connection 280 and/or at least one Integrated Passive Device (IPD) may be disposed over the rerouting structure 214, according to some example embodiments. Formation of electrical connections 280 may include placing solder balls on rerouting structures 214 and then reflowing the solder balls. In an alternative embodiment, the formation of electrical connection 280 may include performing a plating process to form a solder region on rerouting structure 214, and then reflowing the solder region. Electrical connections 280 may also include conductive posts that may also be formed by plating or conductive posts with solder caps (solder caps). At this time, the reconstituted wafer 210 may be formed on the substrate ST. It should be noted that the process required to form the reconstituted wafer and the detailed structure of the reconstituted wafer are not limited in this disclosure. For purposes of clarity and brevity, the reconstituted wafer 210 in the following figures will be shown in abstract form as a layer for convenience.

Referring now to fig. 6 and 7, in subsequent processes, the reconstituted wafer 210 may be attached to the tape carrier 220, and then the reconstituted wafer 210 is detached (detached) from the (glass) substrate ST. For example, the substrate ST may be detached by projecting light onto the adhesive layer AL of the substrate ST, and the light (e.g., a laser beam) penetrates the transparent substrate ST. The adhesive layer AL is thus decomposed and the reconstituted wafer 210 is released from the substrate ST. In general, after the lift-off process, the reconstituted wafer 210 may suffer from significant warpage problems, which may result in non-uniform distribution of the vacuum force F1 and the supporting force from the wafer chuck 100(wafer chuck), and poor yield (yield rate) of subsequent processes to be performed on the wafer chuck 100. In some example embodiments, subsequent processes may be performed on the reconstituted wafer 210 on the wafer chuck 100, and may include, for example, patterning (laser drilling) processes performed on the insulating layer 217 of the reconstituted wafer 210, solder paste printing, singulation (die sawing) processes, and the like. However, the present disclosure is not limited thereto.

In some embodiments, the workpiece holder (wafer chuck) 100 includes a chuck body 110 and a seal ring 120. In some embodiments, chuck body 110 includes a receiving surface 112 and at least one vacuum port (e.g., without limitation, four vacuum ports 114 shown in fig. 4). In some embodiments, the receiving surface 112 is configured to receive the workpiece 200, and the vacuum port 114 may be configured to form a vacuum seal by applying the vacuum seal F1. In some embodiments, a vacuum port 114 may be disposed on the receiving surface 112, while a vacuum device (not shown) may be coupled to the chuck body 110 and in fluid communication with the vacuum port 114. For example, the vacuum device may include a vacuum pump or the like. In such embodiments, the vacuum device is configured to apply a vacuum force F1 to the backside of the workpiece 200 to hold the workpiece 200 in place, e.g., to hold the workpiece 200 to the receiving surface 112. In some embodiments, the vacuum port 114 may also be used to offset (neutralize) the vacuum to "desorb" the workpiece 200 after the process to be performed is complete. Accordingly, a vacuum system and/or an air compressor may be in fluid communication with the vacuum port 114 to provide a vacuum for holding the wafer 210 and/or for providing pressurized air in the vacuum port 114. The present disclosure is not limited thereto.

When the various components are assembled together, they form a circular chuck body 110 that is substantially flat, for example, on both a top surface and a bottom surface. In some embodiments, the chuck body 110 may be a rigid circular plate for attaching to the base (or lower portion) of the workpiece holder (wafer chuck) 100. In some embodiments, the underside of the chuck body 110 can be coupled to a spindle (also known as a spindle or spindle) that supports the workpiece holder (wafer chuck) 100 in place. Openings or holes through the chuck body 110 enable fastening tools (screws, bolts, etc.) to be used to mount the chuck body 110 to a shaft. In some embodiments, there is also an opening for the passage of a fluid (e.g., air or an inert gas) or for providing a vacuum (e.g., vacuum port 114).

In some embodiments, wafer chuck 100 can further include a rotation mechanism configured to rotate/spin chuck body 110 about an axis of the shaft extending in a direction perpendicular to the center of receiving surface 112. The shaft may be coupled to a rotation mechanism such as a spindle motor. Thus, the chuck body 110 and the shaft are rotated by the rotating mechanism. In some embodiments, the shaft is hollow, allowing a fluid, such as air, to pass through the vacuum port 114 to create a vacuum state between the wafer chuck 100 and the workpiece 200 through the vacuum port 114. In some embodiments, the vacuum port 114 may be connected to the vacuum device by a plurality of vacuum lines or channels arranged along the axis of the shaft and converging at, for example, the center of the shaft. In some embodiments, the wafer chuck 100 may further include gas valves disposed within the spindle to control the vacuum performance (e.g., on and off, strong or weak, etc.) of the vacuum device. The purpose of the vacuum device is to provide a secure arrangement for wafer 210 in addition to chuck body 110.

According to some embodiments of the present disclosure, the seal ring 120 may surround the outermost surface 116 of the chuck body 110. In other words, the seal ring 120 may be considered an O-ring for encircling the circumference of the chuck body 110. In other words, the seal ring 120 may be a continuous annular ring for surrounding the outermost surface 116 of the chuck body 110. However, in other embodiments, the packing ring 120 may take any shape suitable for a particular application. In some exemplary embodiments, the outer edge of the wafer 210 may extend to the outer edge (or rim) of the chuck body 110, but not beyond the outermost surface 116 where the seal ring 120 is disposed. In other words, the seal ring 120 may be spaced from the outer edge of the wafer 210 from a top view. In some embodiments, the top surface 122 of the seal ring 120 is higher than the receiving surface 112 of the chuck body 110. In such a configuration, when the vacuum force F1 is applied to form a vacuum seal between the workpiece 200 and the chuck body 110, the workpiece 200 will abut the seal ring 120. In some exemplary embodiments, the perpendicular distance D1 between the top surface 122 of the seal ring 120 and the receiving surface 112 ranges substantially from 1.5mm to 3.5 mm. In one embodiment, the range of perpendicular distance D1 may be generally between 2mm to 3mm, although the disclosure is not so limited. In detail, the carrier (tape carrier) 220 is configured to abut against the seal ring 120 while the workpiece body (wafer) 210 is disposed on the carrier (tape carrier) 220. Accordingly, when the wafer 210 is placed on the receiving surface 112 along with the tape carrier 220, the tip of the sealing ring 120 is in physical contact with the tape carrier 220 so that the tape carrier 220 can reside thereon and a sealed state is formed between the chuck body 110 and the tape carrier 220 when a vacuum is applied.

Referring to fig. 2 and 3, according to some exemplary embodiments, to hold a workpiece body (wafer) 210 by a workpiece holder (wafer chuck) 100, the workpiece body (wafer) 210 may first be attached to a carrier (tape carrier) 220. In some exemplary embodiments, the wafer 210 may warp on its surface, wherein the warp is a result of previous processing (pre-processing) applied to the wafer 210. For example, a thin layer of material (not shown) formed on the top surface of the wafer 210 typically warps the wafer 210 in a concave (smiling shape) or convex (crying shape) manner. In some embodiments, wafer 210 is in a concave warp (i.e., the warp of wafer 210 is negative) manner if residual stresses in wafer 210 cause the outer edge to warp upward. In this case, the periphery of the wafer 210 may extend away from the wafer chuck 100, and the central region of the wafer 210 may be in contact with the wafer chuck 100 (via the tape carrier 220). In some embodiments, wafer 210 may be placed on chuck body 110 in a recessed fashion, with tape carrier 220 attached to wafer 210 covering back surface 212 of wafer 210 in a conformal (compliant) manner. In some embodiments, the tape carrier 220 extends beyond the periphery of the chuck body 110 and abuts the sealing ring 120 as shown in fig. 7.

In some exemplary embodiments, the carrier (tape carrier) 220 may include a tape portion 222 and a frame portion 224 disposed at a periphery of the tape portion 222. In some embodiments, tape portion 222 and frame portion 224 are capable of temporarily fixing the position of wafer 210 during any suitable tape-based process, such as Chemical Mechanical Polishing (CMP), laser drilling, solder paste printing, die sawing, and the like. After the tape-based process, the frame portion 224 may be reusable and the tape portion 222 may be removable from the frame portion 224, although the disclosure is not so limited.

Fig. 9 illustrates a top view of a workpiece holder, according to some exemplary embodiments of the present disclosure. Referring to fig. 7 and 9, then, in some exemplary embodiments, a workpiece body (wafer) 210 is disposed on the workpiece holder (wafer chuck) 100 along with a carrier (tape carrier) 220. As shown in fig. 9, the top surface of the seal ring 120 does not overlap the receiving surface 112 of the chuck body 110 from a top view. In some embodiments, wafer 210 is disposed on wafer chuck 100 in a concave warped manner, and tape portion 222 of tape carrier 220 that is attached to wafer 210 conformally covers back surface 212 of wafer 210. In some embodiments, the workpiece holder (wafer chuck) 100 may further include at least one clamping assembly 140 disposed on one side of the chuck body 110, and the tape carrier 220 abuts against the sealing ring 120 when the tape carrier 220 is secured (clamped) by the clamping assembly 140 disposed outside the chuck body 110. In some exemplary embodiments, the clamping assembly 140 may be a mechanical clamp or the like. In some exemplary embodiments, abutting the sealing ring 120 is a tape portion 222 when the frame portion 224 is clamped by the clamping assembly 140.

In the present embodiment, a plurality of vacuum ports 114 are provided on the chuck body 110. The use of multiple vacuum ports 114 distributed at different locations on the chuck body 110 reduces the presence of local low pressure regions between the chuck body 110, wafer 210 and tape carrier 220 because they share the pressure at which each vacuum port 114 is operable to achieve a uniform vacuum pressure. In other words, by operating a greater number of vacuum ports 114, a uniform vacuum pressure can be achieved between the chuck body 110 and the workpiece 200. Thus, the use of multiple vacuum ports 114 allows for the creation of a low pressure vacuum between the chuck body 110 and the workpiece 200 without creating a local low pressure region that would otherwise be caused by the high vacuum required to attach the larger wafer 210 to the chuck body 110.

It should be understood that the shape of the vacuum port 114 may vary in different embodiments without significantly reducing the uniformity of the vacuum formed between the chuck body 110 and the tape carrier 220. For example, in the present embodiment, the vacuum port 114 includes a vacuum hole of a circular shape. In other embodiments, the vacuum ports 114 may include vacuum holes of triangular, square, and/or polygonal shapes. In some embodiments, the shape of each of the vacuum ports 114 may be different from the shape of another of the vacuum ports 114.

According to some embodiments of the present disclosure, as shown in fig. 9, a workpiece holder (wafer chuck) 100 may include a plurality of clamping assemblies 140. In some embodiments, four clamping assemblies 140 are shown herein, and the clamping assemblies 140 are disposed at four sides (e.g., front, back, right, and left) of the chuck body 110. Of course, the embodiments are for illustration only, and the present disclosure does not limit the number and location of the clamping assemblies 140. In some exemplary embodiments, the vacuum ports 114 may be evenly distributed across the receiving surface 112 to create a vacuum zone (or low pressure zone) on the chuck body 110. In some embodiments, the seal ring 120 may define a vacuum region of the chuck body 110 surrounded by the seal ring 120. The vacuum region is in fluid communication with a vacuum device (not shown) via a vacuum port 114.

Then, in some embodiments, a vacuum force F1 (see fig. 7) is applied on the receiving surface 112 through the vacuum port 114. Thus, a vacuum seal is formed/applied between the tape carrier 220 and the chuck body 110. At this time, when the vacuum seal is applied between the tape carrier 220 and the chuck body 110, the tape portion 222 of the tape carrier 220 abuts against the sealing ring 120. In other words, when the vacuum force F1 is applied, the sealing ring 120 is in physical contact with the tape carrier 220, such that the tape carrier 220, the sealing ring 120, and the chuck body 110 together form the enclosed space S1, and a vacuum seal is formed by evacuating gas from the enclosed space. With the configuration in which the sealing ring 120 protrudes from the receiving surface 112, the sealing ring 120 can abut against the tape carrier 220 and seal the space between the tape carrier 220 and the chuck body 110.

Accordingly, when the vacuum force F1 is applied through the vacuum port 114, the wafer 210 is pulled toward the chuck body 110 by the vacuum force F1 as shown in fig. 8, and thus the warp profile of the wafer 210 can be well improved (adjusted). In addition, the vacuum force F1 and the supporting force from the wafer chuck 100 may be more evenly distributed. That is, the seal ring 120 may first contact the tape carrier 220 attached to the wafer 210 having a concave warpage to form an initial sealed state between the tape carrier 220 (or the workpiece 200 as a whole) and the chuck body 110. When vacuum (or low pressure) is applied in the initial sealing state, the periphery of the warped wafer 210 is pulled toward the chuck body 110, so warpage of the wafer 210 can be improved (reduced), and the sealing ring 120 can be slightly deformed accordingly.

With this configuration, when the warped wafer 210 is disposed on the wafer chuck 100 along with the tape carrier 220, the sealing ring 120 abuts against the tape carrier 220, thereby further enhancing the vacuum (or low pressure) state between the workpiece 200 and the wafer chuck 100. In other words, due to the configuration of the sealing ring 120 being higher than the receiving surface 112 of the carrier wafer 210, the sealing ring 120 may be in physical contact with the tape carrier 220 when a vacuum (or low pressure) is applied. Accordingly, an initial sealing state may be formed, and the periphery of the warped wafer 210 may be pulled toward the chuck body 110 to reduce the warpage of the wafer 210. Accordingly, the wafer chuck 100 may provide sufficient support and vacuum force to the warped wafer 210, and may improve the yield of subsequent processes to be performed on the wafer 210. In addition, because wafer chuck 100 provides sufficient and uniform support and vacuum force to warped wafer 210, wafer chuck 100 is able to handle wafers 210 that tend to exhibit more significant warpage, such as larger sized wafers 210. In one of the implementations, the wafer chuck 100 is capable of handling wafers 210 having significant warpage of up to about 5000 μm, although the disclosure is not so limited.

FIG. 10 illustrates a perspective view of a workpiece holder, according to some exemplary embodiments of the present disclosure. Referring to fig. 1 and 10, in some embodiments, the wafer chuck (workpiece holder)100 may further include a support 130, the support 130 being disposed at the outermost surface 116 and including a groove 134 for receiving the seal ring 120. According to some embodiments of the present disclosure, a stepped recess 134 may be present for receiving the seal ring 120. More specifically, the bottom surface of the stepped recess 134 meets (extends to) the side surface of the support 130 (i.e., the surface immediately adjacent to the chuck body 110). Accordingly, at least a portion of the packing ring 120 is disposed within the groove 134 such that the support 130 is configured to hold and position the packing ring 120. In some embodiments, the support 130 can be the same shape as the chuck body 110 (e.g., a circular shape) for encircling the outermost surface 116 of the chuck body 110. The support 130 may further include a plurality of fastening assemblies 132 to lock the support 130 to the chuck body 110. In some exemplary embodiments, the fastening assembly 132 may include a plurality of screws that respectively extend through the support 130 to secure the support 130 in place. The packing ring 120 may be placed in the groove 134 to maintain the position of the packing ring 120 in a manner such that the top surface of the packing ring 120 is higher than the receiving surface 112.

Fig. 11A and 11B illustrate cross-sectional views of seal rings according to some exemplary embodiments of the present disclosure. Referring to fig. 10-11B, a seal ring 120 in the form of an elastomer may be placed along the outer periphery of the chuck body 110, according to some embodiments of the present disclosure. In one of the embodiments, the sealing ring 120 may be a rubber O-ring that fits tightly around the chuck body 110. In some embodiments, the sealing ring 120 may be made of an elastomeric material, such as rubber, silicone rubber, Polyurethane (PU), or any other suitable elastomeric or flexible material, and may be stretched to wrap around the outer edge (i.e., the outermost surface) of the chuck body 110. The material of the packing ring 120 should include sufficient hardness characteristics to maintain the packing ring 120 in stretched orientation around the outer edge of the chuck body 110. On the other hand, the material of the seal ring 120 should also be flexible enough to allow slight deformation to form a better seal with the workpiece 200. In some embodiments, the cross-section of the seal ring 120 may be, for example, circular, rectangular, or square in shape, although the disclosure is not so limited.

FIG. 12 illustrates a partial cross-sectional view of a workpiece holder, according to some exemplary embodiments of the present disclosure. Referring to fig. 7, in some embodiments, the vertical distance Y from the outer edge of the workpiece body (wafer) 210 to the receiving surface 112 is the vertical distance Y from the outer edge of the receiving surface 112 to the carrier (tape carrier) 220₁1.5 to 5 times as long. In some embodiments, the vertical distance Y may actually be considered as the amount of warpage of the wafer (workpiece body) 210. Therefore, by measuring the warpage amount of the wafer (workpiece body) 210, the vertical distance Y representing the shortest distance between the tape carrier (carrier) 220 and the outer edge of the chuck body 110 can be obtained₁. Thus, the location and size of the packing ring 120 may be obtained.

In some exemplary embodiments, the metrology device is configured to measure the amount of warpage of the wafer (workpiece body) 210 in situ in a tool performing the fabrication process. For example, the metrology device may have a scanning laser configured to measure the distance between the laser and the top surface of the wafer (workpiece body) 210 to detect the height profile of the top surface wafer (workpiece body) 210. In some exemplary embodiments, data indicative of an amount of warpage of the wafer 210 is measured. In some embodiments, measuring includes measuring the height of a plurality of points on the top surface of wafer 210. For example, the measuring may include scanning a height of a top surface of the wafer 210 with a laser. In some embodiments, the laser of the metrology device is scanned back and forth across the surface of the wafer 210. In other embodiments, the laser beam is stationary (stationary) and the chuck body 110 holding the wafer 210 can be reciprocated back and forth in, for example, the X and Y directions to scan the stationary beam over the surface of the wafer 210. The present disclosure is not limited thereto.

Vertical distance Y and vertical distance Y₁The proportional relationship therebetween may be satisfied in many different configurations to enable the sealing ring 120 to abut against the carrier (tape carrier) 220 and form an initial sealing state. In one of the exemplary embodiments, the vertical distance Y is the same as the vertical distance Y₁The proportional relationship between them can be determined by the equation Eq. (1) listed below:

thus, the vertical distance Y₁Can be determined by the equation Eq. (2) listed below:

where θ is expressed as an angle between the tape carrier and a reference horizontal line extending from a base point (base point) of the clamping assembly 140; z is represented as the vertical distance between the receiving surface 112 to a reference horizontal line; x₁Quilt watchShown as the horizontal distance between the chuck body 110 and the base point of the clamping assembly 140; and X is represented as the horizontal distance between the outer edge of the wafer (workpiece body) 210 and the base point of the clamping assembly 140. In some embodiments, the base point is where the clamping assembly 140 clamps the frame portion 224 of the tape carrier 220, but the disclosure is not so limited. Therefore, the vertical distance Y is obtained by solving Eq. (2)₁The position and dimensions of the sealing ring 120 may be obtained such that the sealing ring 120 may be configured in a manner capable of abutting against and forming an initial sealing state with the carrier (tape carrier) 220.

In view of the foregoing, when the workpiece body (wafer) 210 is disposed on the workpiece holder (wafer chuck) 100 along with the carrier (tape carrier), the sealing ring 120 abuts against the tape carrier 220, thereby further enhancing the vacuum (or low pressure) condition between the workpiece 200 and the workpiece holder (wafer chuck) 100. In other words, due to the configuration of the sealing ring 120 being higher than the receiving surface 112 of the chuck body 110, the sealing ring 120 may be in physical contact with the tape carrier 220 when a vacuum (or low pressure) is applied. Accordingly, an initial sealing state may be formed, and the periphery of the warped wafer 210 may be pulled toward the chuck body 110 to reduce the warpage of the wafer 210. Accordingly, the wafer chuck 100 may provide sufficient support and vacuum force to the warped wafer 210, and may improve the yield of subsequent processes to be performed on the wafer 210. In addition, because wafer chuck 100 provides sufficient and uniform support and vacuum force to warped wafer 210, wafer chuck 100 is able to handle wafers 210 that tend to exhibit more significant warpage, such as larger sized wafers 210. In one of the implementations, the wafer chuck 100 is capable of handling wafers 210 having significant warpage of up to about 5000 μm, although the disclosure is not so limited.

Based on the above discussion, it can be seen that the present disclosure provides a number of advantages. However, it is to be understood that not necessarily all advantages may be discussed herein, and that other embodiments may provide different advantages, and that no particular advantage is required for all embodiments.

According to some embodiments of the present disclosure, a workpiece holder includes a chuck body, a seal ring, and a support. The chuck body includes a receiving surface configured to receive a workpiece and at least one vacuum port configured to apply a vacuum seal. A seal ring surrounds an outermost surface of the chuck body, wherein a top surface of the seal ring is higher than the receiving surface of the chuck body, and the workpiece abuts the seal ring when the vacuum seal is applied between the workpiece and the chuck body. A support is disposed at the outermost surface and includes a groove, wherein at least a portion of the seal ring is disposed within the groove.

According to some embodiments of the present disclosure, a vertical distance between the top surface of the seal ring and the receiving surface ranges from 1.5mm to 3.5 mm.

According to some embodiments of the present disclosure, the workpiece includes a carrier extending beyond a periphery of the chuck body and a workpiece body disposed on the carrier, and the sealing ring protrudes from the receiving surface and contacts the carrier when the vacuum seal is applied between the workpiece and the chuck body.

According to some embodiments of the present disclosure, the workpiece body comprises a semiconductor device and an encapsulation material encapsulating the semiconductor device at least in a lateral direction.

According to some embodiments of the disclosure, a vertical distance from an outer edge of the workpiece body to the receiving surface is 1.5 to 5 times as long as a vertical distance from an outer edge of the receiving surface to the carrier.

According to some embodiments of the present disclosure, the workpiece holder further comprises a clamping assembly disposed on a side of the chuck body, wherein the workpiece abuts the seal ring when the workpiece is clamped by the clamping assembly.

According to some embodiments of the present disclosure, the support further comprises a plurality of fastening assemblies to secure the support to the chuck body.

According to some embodiments of the present disclosure, the workpiece, the seal ring, and the chuck body together form an enclosed space for the vacuum seal to be applied thereto.

According to some embodiments of the present disclosure, a wafer chuck includes a chuck body and a seal ring. The chuck body includes a receiving surface configured to receive a wafer. A seal ring is disposed on an outermost surface of the chuck body and surrounds a periphery of the chuck body, wherein a top surface of the seal ring is higher than the receiving surface of the chuck body, and the seal ring is separated from an outer edge of the wafer from a top view.

According to some embodiments of the disclosure, the top surface of the seal ring does not overlap the receiving surface of the chuck body from a top view.

According to some embodiments of the present disclosure, the wafer is bonded to a tape carrier that extends beyond the periphery of the chuck body and against the sealing ring.

According to some embodiments of the disclosure, the seal ring has a circular shape or a rectangular shape in cross-section.

According to some embodiments of the disclosure, the seal ring is a continuous annular ring surrounding the outermost surface of the chuck body.

According to some embodiments of the present disclosure, the wafer chuck further comprises a clamping assembly disposed at one side of the chuck body, wherein the tape carrier abuts the sealing ring when the tape carrier is clamped by the clamping assembly.

According to some embodiments of the present disclosure, the tape carrier includes a tape portion and a frame portion disposed around the tape portion, and the tape portion abuts against the sealing ring when the frame portion is clamped by the clamping assembly.

According to some embodiments of the present disclosure, the wafer chuck further comprises a support disposed at the outermost surface and the support comprises a stepped recess for receiving the seal ring.

According to some embodiments of the present disclosure, the vacuum seal is applied through a vacuum port on the receiving surface after the tape carrier is secured outside the chuck body.

According to some embodiments of the present disclosure, fixing the tape carrier to the outside of the chuck body includes clamping the tape carrier by a clamping assembly provided at one side of the chuck body.

According to some embodiments of the present disclosure, securing the tape carrier includes clamping a frame portion of the tape carrier while a tape portion of the tape carrier abuts the sealing ring.

The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the various aspects of the disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

Claims

1. A workpiece holder, comprising:

a chuck body comprising a receiving surface configured to receive a workpiece and at least one vacuum port configured to apply a vacuum seal; and

a seal ring surrounding an outermost surface of the chuck body, wherein a top surface of the seal ring is higher than the receiving surface of the chuck body and the workpiece abuts the seal ring when the vacuum seal is applied between the workpiece and the chuck body; and

a support disposed at the outermost surface and comprising a groove, wherein at least a portion of the seal ring is disposed within the groove.