Wafer cutting equipment and wafer cutting method

Abstract

The embodiment of the invention provides wafer cutting equipment and a wafer cutting method. The wafer cutting equipment comprises a porous chuck which comprises a first area and a second area surrounded by the first area; the first area comprises a plurality of thimbles, and the second area comprises a plurality of hole structures; wherein a distance is formed between the front surface of the wafer borne by the frame wafer and the second area through the lifting of the plurality of ejector pins, and the wafer is in a flat state through the blowing of the plurality of hole structures; the first visual system is used for positioning a cutting channel on the front surface of the wafer; and the cutting system is used for cutting the wafer in a flat state along the back surface of the wafer corresponding to the cutting channel in a hidden manner.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and relates to but is not limited to a wafer cutting device and a wafer cutting method. Background Art

[0002] The laser stealth dicing (Stealth Dicing) process requires transparent dicing on the back of the wafer when the front side of the wafer cannot accept the film lamination process. The front side of the wafer directly or indirectly contacts the chuck table, which may cause risks such as wafer particle residue and scratches. These risks need to be reduced or avoided. Summary of the invention

[0003] In view of this, an embodiment of the present application provides a wafer cutting device and a wafer cutting method.

[0004] In the first aspect, an embodiment of the present application provides a wafer cutting device, which includes: a multi-hole chuck, including a first area and a second area surrounded by the first area; the first area includes a plurality of ejector pins, and the second area includes a plurality of hole structures; wherein, by raising the plurality of ejector pins, a spacing is provided between the front side of the wafer supported by the frame wafer and the second area, and by blowing air through the plurality of hole structures, the wafer is placed in a flat state; a first visual system is used to locate the cutting path on the front side of the wafer; and a cutting system is used to implicitly cut the wafer in a flat state along the back side of the wafer corresponding to the cutting path.

[0005] In some embodiments, the second area is made of transparent material; the first vision system is located on the first side, and is used to locate the cutting line on the front side of the wafer through the second area; the cutting system is located on the second side; the first side and the second side are opposite sides of the porous chuck; or, the first vision system and the cutting system are located on the same side of the porous chuck; the first vision system is used to locate the cutting line on the front side of the wafer through the wafer.

[0006] In some embodiments, the wafer cutting equipment also includes a sealing structure located at the periphery of the frame wafer and the porous chuck; the sealing structure is used to form a cavity between the frame wafer and the porous chuck; wherein, air blowing through the multiple hole structures is used to create lift in the cavity, and the lift makes the wafer in a flat state.

[0007] In some embodiments, each hole structure includes a pressure regulating valve that independently controls the airflow; the different blowing states of the multiple hole structures are adjusted by multiple pressure regulating valves so that the wafer is in different flatnesses; the wafer cutting equipment also includes a ranging system; the ranging system is used to detect the flatness, and according to the flatness being less than a preset threshold, the adjustment of the multiple pressure regulating valves is stopped to fix the blowing states of the multiple hole structures so that the wafer is in a flat state.

[0008] In some embodiments, the frame wafer includes an annular frame and a wafer fixed in the annular frame by a cutting film; the back side of the wafer includes a substrate; the cutting film is attached to the substrate; and the cutting system is used to cut the wafer in a flat state through the cutting film and along the substrate corresponding to the cutting path.

[0009] In some embodiments, the wafer cutting equipment further includes a robot arm; the robot arm is used to carry the frame wafer and flip the carried frame wafer so that the front side of the wafer faces the porous chuck.

[0010] In some embodiments, each ejector pin is connected to a driving device; the driving device is used to control the raising / lowering of the ejector pin.

[0011] In some embodiments, the wafer cutting equipment also includes a second vision system; the second vision system and the cutting system are located on the same side of the multi-hole chuck; wherein, through the lowering of multiple pins, the back side of the wafer supported by the frame wafer is brought into contact with the second area, and through the suction of multiple hole structures, the wafer is placed in an attached state; the second vision system is used to locate the cutting path on the front side of the wafer; and the cutting system is used to implicitly cut the wafer in an attached state along the cutting path on the front side of the wafer.

[0012] In a second aspect, an embodiment of the present application provides a wafer cutting method, which includes: providing a frame wafer; raising a plurality of ejector pins in a porous chuck so that the top surfaces of the plurality of ejector pins are higher than the top surfaces of a plurality of hole structures in the porous chuck; wherein the porous chuck includes a first area and a second area surrounded by the first area; the first area includes a plurality of ejector pins, and the second area includes a plurality of hole structures; placing the frame wafer on the plurality of ejector pins so that there is a spacing between the front side of the wafer carried by the frame wafer and the second area; and blowing air toward the wafer through the plurality of hole structures so that the wafer is in a flat state; using a first visual system to locate the cutting path on the front side of the wafer; and using a cutting system to implicitly cut the wafer in a flat state along the back side of the wafer corresponding to the cutting path.

[0013] In some embodiments, a first vision system is used to locate the cutting path on the front side of the wafer, including: using the first vision system located on the first side to locate the cutting path on the front side of the wafer through the second area; wherein the second area is a transparent material; the cutting system is located on the second side; the first side and the second side are opposite sides of a porous chuck; or, using the first vision system located on the same side of the porous chuck as the cutting system to locate the cutting path on the front side of the wafer through the wafer.

[0014] In some embodiments, a frame wafer is provided, including: providing a wafer; the back side of the wafer includes a substrate; the front side of the wafer includes a cutting path; sticking a cutting film on the back side of the wafer, and fixing the wafer in a ring frame through the cutting film to obtain a frame wafer; placing the frame wafer on multiple ejector pins, including: a robot carries the frame wafer, flips the frame wafer, and the front side of the wafer faces multiple hole structures; using a cutting system to implicitly cut the wafer in a flat state along the back side of the wafer corresponding to the cutting path, including: the cutting system penetrates the cutting film and implicitly cuts the wafer in a flat state along the substrate corresponding to the cutting path.

[0015] On the third aspect, an embodiment of the present application provides another wafer cutting method, which includes: providing a frame wafer; lowering a plurality of ejector pins in a porous chuck so that the top surfaces of the plurality of ejector pins are not higher than the top surfaces of a plurality of hole structures in the porous chuck; wherein the porous chuck includes a first area and a second area surrounded by the first area; the first area includes a plurality of ejector pins, and the second area includes a plurality of hole structures; placing the frame wafer on the plurality of hole structures so that the back side of the wafer carried by the frame wafer is in contact with the second area; and, vacuuming the wafer through the plurality of hole structures so that the wafer is in an attached state; using a second vision system to locate the cutting path on the front side of the wafer; using a cutting system to implicitly cut the wafer in an attached state along the cutting path on the front side of the wafer; the second vision system and the cutting system are located on the same side of the porous chuck.

[0016] In some embodiments, a frame wafer is provided, including: providing a wafer; the back side of the wafer includes a substrate; the front side of the wafer includes a cutting line; sticking a cutting film on the back side of the wafer, and fixing the wafer in a ring frame through the cutting film to obtain a frame wafer; placing the frame wafer on multiple hole structures, including: a robot carries the frame wafer and places it on the multiple hole structures, with the back side of the wafer facing the multiple hole structures.

[0017] In each embodiment of the present application, the porous chuck of the wafer cutting equipment includes a plurality of ejector pins located at the periphery (first area) and a plurality of hole structures located at the interior (second area); the plurality of ejector pins are raised to support the frame part (non-wafer part, such as a ring frame) located at the periphery of the frame wafer, so that there is a spacing between the front side of the wafer carried by the frame wafer and the porous chuck, and air is blown through the plurality of hole structures to make the wafer in a flat state for hidden cutting; the wafer cutting equipment allows a spacing between the front side of the wafer carried by the frame wafer and the porous chuck used to carry the frame wafer. Since the wafer directly or indirectly contacts the porous chuck carrying the frame wafer, the risk of wafer particle residue and scratches can be reduced or avoided during the hidden cutting process of the wafer; at the same time, there is no need to use a porous protective film on the porous chuck to reduce cost consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a schematic diagram of the through-film hidden cutting process in the related art;

[0019] Figure 2A A three-dimensional perspective schematic diagram of a frame wafer provided in an embodiment of the present application; Figure 2B for Figure 2A A schematic top view of a frame wafer;

[0020] Figure 3A A three-dimensional perspective schematic diagram of a porous chuck provided in an embodiment of the present application; Figure 3B for Figure 3A A top plan view of a porous chuck;

[0021] Figure 4A One of the three-dimensional perspective schematic diagrams of the wafer cutting equipment provided in the embodiment of the present application; Figure 4B for Figure 4A A schematic top view of a wafer cutting device; Figure 4C for Figure 4A A cross-sectional schematic diagram of a wafer cutting device;

[0022] Figure 4D A cross-sectional schematic diagram of another wafer cutting device provided in an embodiment of the present application;

[0023] Figure 5A A three-dimensional perspective schematic diagram of a sealing structure provided in an embodiment of the present application; Figure 5B for Figure 5A A top plan view of a sealing structure;

[0024] Fig. 6A The second three-dimensional perspective schematic diagram of the wafer cutting equipment provided in the embodiment of the present application; Figure 6B for Fig. 6A A schematic top view of a wafer cutting device; Figure 6C for Fig. 6A A cross-sectional schematic diagram of a wafer cutting device;

[0025] Fig.6D A cross-sectional schematic diagram of another wafer cutting device provided in an embodiment of the present application;

[0026] Fig. 7A One of the three-dimensional perspective schematic diagrams of a robot for loading wafers provided in an embodiment of the present application; Figure 7B for Fig. 7A A schematic top view of a loaded wafer;

[0027] Fig. 8A The second three-dimensional perspective schematic diagram of a robot for loading wafers provided in an embodiment of the present application; Figure 8B for Fig. 8A A schematic top view of a loaded wafer;

[0028] Fig. 9 A three-dimensional perspective schematic diagram of an ejector pin and a driving device thereof provided in an embodiment of the present application;

[0029] Fig.10 A cross-sectional schematic diagram of another wafer cutting device provided in an embodiment of the present application;

[0030] Fig.11 A schematic flow chart of a wafer cutting method is provided for an embodiment of the present application;

[0031] Fig.12 A flow chart of another wafer cutting method is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0032] The following will combine the implementation methods and drawings of this application to clearly and completely describe the technical solutions in the implementation methods of this application. The described implementation methods are only part of the implementation methods of this application, not all of the implementation methods. Based on the implementation methods in this application, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] In the drawings, the sizes of layers, regions, elements and their relative sizes may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0034] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0035] In wafer laser stealth cutting technology, for example, in the process of stealth dicing after grinding (SDAG), the laser needs to be incident from top to bottom. Since it cannot penetrate the metal layer on the front side of the wafer, it is often necessary to focus from the back side of the wafer, so a dicing film (for example, UV film (Ultraviolet Rays film)) needs to be attached to the front side of the wafer. However, for processes where the film cannot be attached to the front side of the wafer, for example, the circuit layer on the front side of the wafer has a ball implant or high bump structure, and the dicing line (also called scribe line (SL)) is narrow, the laser cannot be incident from the front side, or the circuit on the front side of the wafer is sensitive to residual glue (film cannot be attached to the front side), the film can only be attached to the back side of the wafer. At this time, the wafer needs to be placed with the front side facing down and the back side facing up to achieve laser stealth cutting through the dicing film (referred to as stealth dicing through tape (SDTT)).

[0036] Figure 1 It is a schematic diagram of the through-film hidden cutting process in the related art.

[0037] refer to Figure 1 In the through-film hidden cutting process, in order to maintain the flatness of the wafer 106, a cutting film 108 (for example, a UV film) is attached to the back side S2 of the wafer, and the wafer 106 is fixed in the annular frame 110 by the cutting film 108. The front side S1 of the wafer needs to contact the chuck table of the chuck 102. Since the wafer directly or indirectly contacts the chuck table of the equipment, there is a risk of causing, for example, wafer particle residue and scratches. The chuck table of the current through-film hidden cutting equipment will be attached with a porous protective film 104 to prevent the wafer 106 from directly contacting the chuck 102, but this still cannot completely avoid the problem of particle residue and scratches; the porous protective film attached to the chuck table is also a consumable material, which increases the production cost. In other cases, because the front side S1 of the wafer faces downward, the through-film hidden cutting process needs to use, for example, an infrared vision system 112 to locate the cutting path located on the front side S1 of the wafer from the back side S2 of the wafer. After the infrared vision system 112 is positioned, the cutting system 114 (for example, an infrared laser) is used to perform hidden cutting on the wafer 106. Compared with the machine vision system, the infrared vision system is more expensive.

[0038] In view of this, an embodiment of the present application provides a wafer cutting device and a wafer cutting method.

[0039] Figure 2A A three-dimensional perspective schematic diagram of a frame wafer provided in an embodiment of the present application; Figure 2B for Figure 2A Schematic diagram of a top view of a frame wafer. Figure 3A A three-dimensional perspective schematic diagram of a porous chuck provided in an embodiment of the present application; Figure 3B for Figure 3A Schematic top plan view of a porous chuck. Figure 4A One of the three-dimensional perspective schematic diagrams of the wafer cutting equipment provided in the embodiment of the present application; Figure 4B for Figure 4A A schematic top view of a wafer cutting device; Figure 4C for Figure 4A Schematic cross-sectional view of wafer cutting equipment.

[0040] It should be noted that some components / devices / systems in the cross-sectional schematic diagram are not shown in the three-dimensional perspective schematic diagram and the top plan schematic diagram, for example, Figure 4C The first visual system 211, the cutting system 214, and the distance measuring system 215 are shown in Figure 4A and Figure 4B Some components / devices / systems in the three-dimensional perspective schematic diagram and the top plan schematic diagram are shown in perspective form (specifically using dashed boxes), for example Figure 2A The wafer 206 is shown in Figure 2B It is shown with a dotted line ring. Figure 4D for Figure 4C A modified example of the wafer dicing equipment is shown.

[0041] In a first aspect, the present application provides a wafer cutting device, referring to Figures 2A to 4C The wafer cutting device 200 includes: a multi-hole chuck 202, including a first area 2021 and a second area 2022 surrounded by the first area; the first area 2021 includes a plurality of ejector pins 2023, and the second area 2022 includes a plurality of hole structures 2024; wherein, by raising the plurality of ejector pins 2023, a spacing CA1 is provided between the front side S1 of the wafer 206 carried by the frame wafer 201 and the second area 2022, and, by blowing the plurality of hole structures 2024, the wafer 206 is placed in a flat state; a first visual system 211 is used to locate the cutting path of the front side S1 of the wafer; and a cutting system 214 is used to implicitly cut the wafer 206 in a flat state along the back side S2 of the wafer corresponding to the cutting path.

[0042] For the convenience of describing the embodiments of the present application, the first direction and the second direction are represented as two intersecting directions parallel to the top / bottom surface of the porous chuck, for example, the first direction and the second direction are orthogonal; the third direction is a direction perpendicular to the top / bottom surface of the porous chuck, or the third direction is the direction in which the porous chuck and the wafer are stacked. For example, the first direction can be represented as the X direction in the accompanying drawings; the second direction can be represented as the Y direction in the accompanying drawings; and the third direction can be represented as the Z direction in the accompanying drawings.

[0043] In some embodiments, the second area 2022 is made of transparent material; the first vision system 211 is located on the first side, and is used to locate the cutting path on the front side S1 of the wafer through the second area 2022; the cutting system 214 is located on the second side; the first side and the second side are opposite sides of the porous chuck 202; or, the first vision system 211 and the cutting system 214 are located on the same side of the porous chuck 202; the first vision system 211 is used to locate the cutting path on the front side of the wafer through the wafer.

[0044] It should be noted that the second side can be understood as the side of the porous chuck used for placing the wafer (which can be referred to as the front side of the porous chuck), and the first side can be understood as the side of the porous chuck not used for placing the wafer (which can be referred to as the back side of the porous chuck).

[0045] In some embodiments, the material of the first region 2021 of the porous chuck 202 is different from the material of the second region 2022. In some embodiments, the second region 2022 is a transparent material having a plurality of pore structures (which may be referred to as the inner disk of the porous chuck 202). Figure 1 The infrared vision system 112 shown in the figure, the first vision system 211 located on the first side can be a machine vision system, which can locate the cutting path of the wafer front side S1 through the second area 2022 made of transparent material (refer to Figure 4C ), which has a greater cost advantage. In other embodiments, the first vision system 211 may be an infrared vision system, located on the second side, and may locate the cutting path of the wafer front side S1 through the wafer (refer to Figure 4D or Fig.6D ).

[0046] In some embodiments, the first region 2021 and the second region 2022 are in sealed contact or can be used as a whole, that is, the outer disk of the porous chuck 202 is in sealed contact with the inner disk of the porous chuck 202. The plurality of ejector pins 2023 are in sealed contact with other components of the first region (which can be referred to as the outer disk of the porous chuck 202) in contact with them, and the plurality of ejector pins 2023 can penetrate the outer disk of the porous chuck 202, and the plurality of ejector pins 2023 are in sealed contact with the outer disk of the porous chuck 202. In the embodiments of the present application, the term "sealed contact" can be understood as airtightness.

[0047] refer to Figure 2A and Figure 2B In some embodiments, the frame wafer 201 includes an annular frame 210 and a wafer 206 fixed in the annular frame by a cutting film 208; the back side S2 of the wafer includes a substrate; the cutting film 208 is attached to the substrate; and the cutting system 214 is used to cut the wafer 206 in a flat state through the cutting film 208 and along the substrate corresponding to the cutting path.

[0048] It should be noted that the ring frame 210 and the wafer 206 are fixed by the cutting film 208. When the ring frame 210 is placed on the plurality of ejector pins 2023, while the ring frame 210 ensures good flatness, due to the lack of rigidity of the cutting film 208 (compared to the lack of rigidity of the ring frame 210 or the wafer 206), the wafer 206 is tilted downward by gravity. At this time, the wafer 206 cannot be guaranteed to have the same flatness as the ring frame 210. It is necessary to readjust the flatness of the wafer 206 to adapt to the hidden cutting process. In the following description, reference is made to Figure 3A and Figure 3B The hole structures 2024 at multiple different positions provide lift forces at multiple different positions, which can be used to finely adjust the flatness of the wafer 206 .

[0049] The annular frame 210 has an annular opening ( Figure 2A and Figure 2B The wafer 206 is a wafer having a plurality of wafers and a plurality of wafers. ... The memory chip may be a volatile memory chip, such as a dynamic random access memory (DRAM) chip and a static random access memory (SRAM) chip, or may be a non-volatile memory chip, such as a resistive random access memory (RRAM) chip. In some embodiments, the wafer 206 includes a functional circuit ( Figure 2A and Figure 2B (not shown). Functional circuits may be formed on one side of the substrate of wafer 206 (front side of the substrate). Functional circuits may include a variety of active and passive devices (e.g., capacitors, resistors, inductors, and the like) that meet the desired structural and functional requirements of the design. Functional circuits may include NMOS devices or PMOS devices. The material of the insulating layer includes, but is not limited to, silicon oxide, silicon nitride, silicon oxynitride, or any combination thereof. The material of the interconnect layer includes, but is not limited to, tungsten, cobalt, nickel, copper, aluminum, polysilicon, doped silicon, silicide, nitride, or any combination thereof.

[0050] In some embodiments, the first visual system 211 may be a machine vision system. The machine vision system converts the captured target (e.g., the cutting path on the front side of the wafer S1) into an image signal through, for example, an image capture device (CMOS (Complementary Metal Oxide Semiconductor) image sensor and CCD (Charge Coupled Device)), and transmits it to a dedicated image processing system to obtain the morphological information of the captured target, and converts it into a digital signal based on pixel distribution, brightness, color and other information. The image system performs various operations on these signals to extract the characteristics of the target, and then controls the on-site equipment action (e.g., locates the cutting path on the front side of the wafer S1) based on the results of the determination of the characteristics of the target. In other embodiments, the first visual system 211 may also be an infrared vision system. The infrared vision system converts the infrared radiation signal incident from the captured target (e.g., the cutting path on the front side of the wafer S1) into an electrical signal output through, for example, an infrared detector, and performs various operations on these signals to extract the characteristics of the target (e.g., the cutting path on the front side of the wafer S1), and then controls the operation of the equipment on site (e.g., locating the cutting path on the front side of the wafer S1) based on the results of the determination of the characteristics of the target.

[0051] In some embodiments, the cutting system 214 is used to implicitly cut the wafer 206 in a flat state along the back side S2 of the wafer corresponding to the cutting path, including: causing a modified layer of a certain depth inside the wafer 206; after the modified layer is formed, separating the wafer 206 into multiple chips (dies) through a film expansion device, or separating the wafer 206 into multiple chips through a splitting device and a film expansion device. The cutting system 214 focuses a uniformly emitted laser beam (such as an infrared laser) from the back side S2 of the wafer to the inside of the wafer 206 through a lens. When the laser beam is focused inside the wafer 206, the energy absorbed by the multi-photons will not be converted into heat energy in large quantities, and a modified layer of a certain depth will be caused inside the wafer 206. After the modified layer is formed, the wafer 206 is separated into multiple chips through a film expansion device, or the wafer 206 is separated into multiple chips through a splitting device and a film expansion device. For example, some wafer materials (such as gallium arsenide (GaAs) materials whose cleavage ability is not as good as silicon (Si)) cannot be directly expanded after the modified layer is formed by implicit cutting, and a slicing device is required to apply longitudinal pressure through a slicing knife to assist in cleaving the wafer; then, a film expansion device is required to stretch the cutting film 208 to generate a radial tension that expands in all directions. The cutting film 208 applies a tension that expands in all directions to the wafer 206, so that the wafer 206 is split into multiple chips.

[0052] Figure 5A A three-dimensional perspective schematic diagram of a sealing structure provided in an embodiment of the present application; Figure 5B for Figure 5A A top plan view of a sealing structure. Fig. 6A The second three-dimensional perspective schematic diagram of the wafer cutting equipment provided in the embodiment of the present application; Figure 6B for Fig. 6A A schematic top view of a wafer cutting device; Figure 6C for Fig. 6A Schematic cross-sectional view of wafer cutting equipment. Fig.6D for Figure 6C A modified example of the wafer dicing equipment is shown.

[0053] refer to FIG. 5A to FIG. 6C In some embodiments, the wafer cutting device 200 also includes a sealing structure 216 located at the periphery of the frame wafer and the porous chuck; the sealing structure 216 is used to form a cavity CA2 between the frame wafer 201 and the porous chuck 202; wherein, air is blown through the multiple hole structures 2024 to create lift in the cavity CA2, and the lift makes the wafer 206 in a flat state.

[0054] Compared with the frame wafer 201 and the porous chuck 202, no relatively independent cavity is formed (refer to FIG. 4A to FIG. 4C The wafer cutting equipment 200 shown in FIG. Fig. 6A , Figure 6B and Figure 6C The wafer cutting equipment 200 shown can form a cavity CA2, which can be an independent space for providing lift, thereby preventing the blowing of multiple hole structures 2024 from being affected by the external gas disturbance of the cavity CA2, and ensuring the provision of stable lift; at the same time, the cavity CA2 can be filled with the blowing of multiple hole structures 2024 more quickly and easily to form a stable airflow, thereby providing lift more quickly and easily.

[0055] The cavity CA2 can be understood as a relatively sealed environment, and the gas pressure therein is mainly affected by the blowing or exhausting of the multiple hole structures 2024. It should be noted that the cavity CA2 can be an absolutely closed space, and the gas can only be blown in or exhausted from the multiple hole structures 2024. The cavity CA2 can also be a closed space relative to the equipment cavity where the wafer cutting equipment 200 is located. For example, the gas can be blown in from the multiple hole structures 2024, or it can overflow from other weak parts (for example, between the sealing structure 216 and the frame wafer 201, or between the sealing structure 216 and the porous chuck). When lift is provided, a balance is formed between the blowing in and the overflowing of the gas. For another example, the gas can be exhausted from the multiple hole structures 2024, or it can enter from other weak parts (between the sealing structure 216 and the frame wafer 201, or between the sealing structure 216 and the porous chuck). When pressure (or suction) is provided, a balance is formed between the extraction and entry of the gas (in this case Fig. 6A and Figure 6B not shown).

[0056] For example, blowing air into the cavity CA2 may cause the wafer 206 to be subjected to an upward lift force, so that a distance CA1 is formed between the wafer 206 and the second region 2022. For another example, evacuating the cavity CA2 may cause the wafer 206 to be subjected to a downward pressure, so that the distance CA1 formed between the wafer 206 and the second region 2022 is reduced or the wafer 206 is attached to the surface of the second region 2022 (in this case, Fig. 6A and Figure 6B not shown).

[0057] refer to Figure 3A and Figure 3B In some embodiments, each hole structure 2024 includes a pressure regulating valve ( Figure 3A and Figure 3BThe wafer 206 is flattened by adjusting the different blowing states of the multiple hole structures through multiple pressure regulating valves; the wafer cutting device 200 further includes a distance measuring system 215; the distance measuring system 215 is used to detect the flatness, and according to the flatness being less than a preset threshold, the multiple pressure regulating valves are stopped to fix the blowing states of the multiple hole structures, so that the wafer 206 is flattened. In some embodiments, the distance measuring system 215 and the cutting system 214 are located on the same side of the multi-hole chuck 202.

[0058] The blowing aperture and blowing pressure of the pressure regulating valve can characterize the lift provided in the blowing state. Each hole structure 2024 can provide independently controlled lift. Hole structures 2024 at multiple different positions provide lift at multiple different positions, which can finely adjust the flatness of the wafer 206.

[0059] Fig. 7A One of the three-dimensional perspective schematic diagrams of a robot for loading wafers provided in an embodiment of the present application; Figure 7B for Fig. 7A Schematic diagram of a top view of a loaded wafer. Fig. 8A The second three-dimensional perspective schematic diagram of a robot for loading wafers provided in an embodiment of the present application; Figure 8B for Fig. 8A Schematic diagram of a top view of a loaded wafer.

[0060] refer to 7A to 8B In some embodiments, the wafer cutting device further includes a robot 218; the robot 218 is used to carry the frame wafer 201, flip the carried frame wafer 201, so that the front side of the wafer 206 faces the porous chuck (refer to Figure 4A ).

[0061] refer to Fig. 7A and Figure 7B , a front opening unified pod (FOUP) carrying a frame wafer 201 ( Fig. 7A and Figure 7B Not shown) is loaded into the feed port ( Fig. 7A and Figure 7B (not shown), the front side of the wafer carried by the FOUP faces upward (the back side of the wafer 206 faces the porous chuck), and the robot 218 takes out the frame wafer 201 from the FOUP, at which time the back side of the wafer 206 of the frame wafer 201 faces the porous chuck.

[0062] refer to Fig. 8A and Figure 8B The robot 218 flips FL 180 degrees along the X direction, and the frame wafer 201 carried by the robot 218 flips 180 degrees along the X direction, so that the front side of the wafer 206 faces the multi-hole chuck.

[0063] Further, refer to Figure 4A and Figure 4B The robot 218 places the flipped frame wafer 201 on the porous chuck 202 (refer to Figure 3A ) so that the front side of the wafer 206 does not contact the second area 2022 of the porous chuck 202.

[0064] Fig. 9 A three-dimensional perspective schematic diagram of the ejector pin and its driving device provided in an embodiment of the present application.

[0065] refer to Fig. 9 In some embodiments, each ejector pin 2023 is connected to a driving device 2025; the driving device 2025 is used to control the raising / lowering of the ejector pin.

[0066] In some embodiments, the top surface of each ejector pin 2023 is higher than the top surface of the second region, and the height difference between the top surface of each ejector pin 2023 and the top surface of the second region is greater than the sum of the thicknesses of the dicing film 208 and the wafer 206 .

[0067] In some embodiments, each ejector pin 2023 can be independently controlled by a corresponding driving device 2025 to adjust the top surface height of each ejector pin 2023. The flatness of the frame wafer 201 located at the plurality of ejector pins 2023 can be finely adjusted, and the front surface of the wafer 206 is prevented from contacting the second area 2022 of the porous chuck 202, and further a spacing CA1 is achieved between the front surface S1 of the supported wafer 206 and the second area 2022. In some embodiments, the driving device 2025 can be an electric motor.

[0068] Fig.10 A cross-sectional schematic diagram of another wafer cutting device provided in an embodiment of the present application.

[0069] In some embodiments, the wafer cutting device 200 further includes a second visual system 212; the second visual system 212 and the cutting system 214 are located on the same side of the multi-hole chuck 202. Fig.10 (not shown) is lowered to make contact between the wafer back side S2 supported by the frame wafer and the second region 2022, and through a plurality of hole structures ( Fig.10 The vacuum pump 214 (not shown) is used to make the wafer 206 in an attached state; the second visual system 212 is used to locate the cutting path of the wafer front side S1; and the cutting system 214 is used to cut the wafer 206 in an attached state along the cutting path of the wafer front side S1. In this way, the wafer cutting device 200 can achieve the following FIG. 4A to FIG. 4C The SDTT process shown, and Fig.10 Compatible with the SDAG process shown.

[0070] In some embodiments, the wafer cutting device 200 further includes a sealing structure 216, which is used to form a cavity CA3 between the frame wafer 201 and the porous chuck 202; wherein, through the exhaust of the plurality of hole structures 2024, it is used to provide suction in the cavity CA3, and the suction forces the wafer 206 to be in an attached state (the back side of the wafer with the cutting film attached is at least partially in contact with the second area of ​​the porous chuck). The specific situation of the cavity CA3 can be understood by referring to the detailed description of the cavity CA2 above, which will not be repeated here.

[0071] In each embodiment of the present application, the wafer cutting equipment is configured to have a distance between the front side of the wafer supported by the frame wafer and the porous chuck used to support the frame wafer. Since the wafer directly or indirectly contacts the porous chuck supporting the frame wafer, the risk of wafer particle residue and scratches can be reduced or avoided during the hidden wafer cutting process. At the same time, there is no need to use a porous protective film on the porous chuck to reduce cost consumption.

[0072] Fig.11 A schematic flow chart of a wafer cutting method is provided for an embodiment of the present application.

[0073] In a second aspect, the present application provides a wafer cutting method, referring to Fig.11 , the wafer cutting method comprises the following steps:

[0074] S101, providing a frame wafer;

[0075] S102, raising a plurality of ejector pins in the porous chuck so that top surfaces of the plurality of ejector pins are higher than top surfaces of a plurality of hole structures in the porous chuck; wherein the porous chuck comprises a first region and a second region surrounded by the first region; the first region comprises a plurality of ejector pins, and the second region comprises a plurality of hole structures;

[0076] S103, placing the frame wafer on a plurality of ejector pins so that there is a distance between the front side of the wafer supported by the frame wafer and the plurality of hole structures; and,

[0077] S104, blowing air toward the wafer through the plurality of hole structures, so that the wafer is in a flat state;

[0078] S105, using a first vision system to locate the cutting path on the front side of the wafer;

[0079] S106, using a cutting system to implicitly cut the wafer in a flat state along the back side of the wafer corresponding to the cutting path.

[0080] In some embodiments, step S105, using a first vision system to locate the cutting path on the front side of the wafer, includes: using a first vision system located on the first side to locate the cutting path on the front side of the wafer through the second area; wherein the second area is a transparent material; the cutting system is located on the second side; the first side and the second side are opposite sides of the porous chuck; or, using a first vision system located on the same side of the porous chuck as the cutting system to locate the cutting path on the front side of the wafer through the wafer.

[0081] In some embodiments, step S101, providing a frame wafer includes: providing a wafer; the back of the wafer includes a substrate; the front of the wafer includes a cutting path; sticking a cutting film on the back of the wafer, and fixing the wafer in a ring frame through the cutting film to obtain a frame wafer; placing the frame wafer on multiple ejector pins, including: a robot carries the frame wafer, flips the frame wafer and places it on multiple ejector pins, with the front of the wafer facing multiple hole structures; using a cutting system to implicitly cut the wafer in a flat state along the back of the wafer corresponding to the cutting path, including: the cutting system penetrates the cutting film and implicitly cuts the wafer in a flat state along the substrate corresponding to the cutting path.

[0082] Exemplarily, the wafer cutting method (which may be referred to as backside hidden cutting process, through-film hidden cutting process or SDTT process) includes the following steps:

[0083] A wafer is provided; the back side of the wafer includes a substrate; the front side of the wafer includes a dicing line;

[0084] A dicing film is attached to the back of the wafer, and the wafer is fixed in a ring frame by the dicing film to obtain a frame wafer;

[0085] Raising a plurality of ejector pins, wherein the plurality of ejector pins support an annular frame, so that the front side of the wafer is isolated from the porous chuck; wherein the outer periphery of the porous chuck includes a plurality of ejector pins, and the outer periphery of the porous chuck includes a plurality of hole structures;

[0086] The robot carries the frame wafer, flips the frame wafer and places it on the porous chuck, with the front side of the wafer facing the porous chuck;

[0087] The sealing ring surrounds the outer circumference of the frame wafer and the porous chuck, so that a cavity is formed between the frame wafer and the porous chuck;

[0088] Blowing air through multiple hole structures keeps the wafer in a flat state;

[0089] A first vision system located on the first side locates the cutting path through the multi-hole chuck;

[0090] An infrared laser located on the second side cuts the wafer through the dicing film.

[0091] Fig.12 A flow chart of another wafer cutting method is provided for an embodiment of the present application.

[0092] In a third aspect, the present application provides another wafer cutting method, referring to Fig.12 , the wafer cutting method comprises the following steps:

[0093] S201, providing a frame wafer;

[0094] S202, lowering a plurality of ejector pins in the porous chuck so that top surfaces of the plurality of ejector pins are not higher than top surfaces of a plurality of hole structures in the porous chuck; wherein the porous chuck comprises a first region and a second region surrounded by the first region; the first region comprises a plurality of ejector pins, and the second region comprises a plurality of hole structures;

[0095] S203, placing the frame wafer on the plurality of hole structures so that the back side of the wafer supported by the frame wafer is in contact with the second region; and

[0096] S204, extracting air from the wafer through the plurality of hole structures, so that the wafer is in an attached state;

[0097] S205, using a second vision system to locate the cutting path on the front side of the wafer;

[0098] S206, using a cutting system to implicitly cut the wafer in an attached state along a cutting path on the front side of the wafer; the second vision system and the cutting system are located on the same side of the multi-hole chuck.

[0099] In some embodiments, step S201, providing a frame wafer includes: providing a wafer; the back of the wafer includes a substrate; the front of the wafer includes a cutting path; sticking a cutting film on the back of the wafer, and fixing the wafer in a ring frame through the cutting film to obtain a frame wafer; placing the frame wafer on multiple hole structures, including: a robot carries the frame wafer and places it on multiple hole structures, with the back of the wafer facing the multiple hole structures.

[0100] Exemplarily, the wafer cutting method (which may be referred to as the front hidden cutting process, SDAG process) includes the following steps:

[0101] A wafer is provided; the back side of the wafer includes a substrate; the front side of the wafer includes a dicing line;

[0102] A dicing film is attached to the back of the wafer, and the wafer is fixed in a ring frame by the dicing film to obtain a frame wafer;

[0103] Lowering a plurality of ejector pins in the porous chuck so that the top surfaces of the plurality of ejector pins are not higher than the top surfaces of the plurality of hole structures in the porous chuck; wherein the outer periphery of the porous chuck includes the plurality of ejector pins, and the outer periphery of the porous chuck includes the plurality of hole structures;

[0104] The robot carries the frame wafer and places the frame wafer on the plurality of hole structures so that the back side of the wafer carried by the frame wafer contacts the second area;

[0105] The sealing ring surrounds the outer circumference of the frame wafer and the porous chuck, so that a cavity is formed between the frame wafer and the porous chuck;

[0106] Air is extracted from the wafer through the plurality of hole structures so that the wafer is in an attached state (the back side of the wafer with the dicing film attached is in contact with the second area of ​​the porous chuck);

[0107] A second vision system located on the second side locates the scribe line on the front side of the wafer;

[0108] The cutting system located on the second side cuts the attached wafer along the cutting path on the front side of the wafer.

[0109] The wafer cutting equipment used in the wafer cutting methods provided in the second and third aspects of the embodiments of the present application is similar to the wafer cutting equipment provided in the first aspect above. For the technical features not fully disclosed in the embodiments of the present application, please refer to the wafer cutting equipment in the various embodiments of the first aspect above for understanding, and no further details will be given here.

[0110] The above description is only a preferred implementation mode of the present application, and does not limit the protection scope of the present application. All equivalent structural changes made by using the contents of the present application specification and drawings under the inventive concept of the present application, or directly / indirectly applied in other related technical fields are included in the protection scope of the present application.

Claims

1. A wafer cutting device, characterized in that: include: A multi-hole chuck, comprising a first area and a second area surrounded by the first area; the first area comprises a plurality of ejector pins, and the second area comprises a plurality of hole structures; wherein the plurality of ejector pins are raised to allow a distance between the front side of a wafer carried by a frame wafer and the second area, and air is blown through the plurality of hole structures to allow the wafer to be in a flat state; A first vision system, used for locating a scribe line on the front side of the wafer; A cutting system is used for implicitly cutting the wafer in the flat state along the back side of the wafer corresponding to the cutting path.

2. The wafer cutting equipment according to claim 1, characterized in that: The second area is made of a transparent material; the first visual system is located on the first side, and is used to locate the cutting path on the front side of the wafer through the second area; the cutting system is located on the second side; the first side and the second side are opposite sides of the multi-hole chuck; or, The first vision system and the cutting system are located on the same side of the multi-hole chuck; the first vision system is used to locate the cutting path on the front side of the wafer through the wafer.

3. The wafer cutting equipment according to claim 1, characterized in that: The wafer cutting device further comprises a sealing structure located at the periphery of the frame wafer and the porous chuck; the sealing structure is used to form a cavity between the frame wafer and the porous chuck; The air blowing through the multiple hole structures is used to create a lift in the cavity, and the lift makes the wafer in the flat state.

4. The wafer cutting equipment according to claim 1, characterized in that: Each of the hole structures comprises a pressure regulating valve for independently controlling the airflow; the different blowing states of the plurality of hole structures are adjusted by the plurality of pressure regulating valves so that the wafers are at different flatnesses; The wafer cutting equipment also includes a distance measuring system; the distance measuring system is used to detect the flatness, and according to the flatness being less than a preset threshold, stop adjusting the plurality of pressure regulating valves to fix the blowing state of the plurality of hole structures, so that the wafer is in the flat state.

5. The wafer cutting equipment according to claim 1, characterized in that: The frame wafer comprises an annular frame and the wafer fixed in the annular frame by a cutting film; the back side of the wafer comprises a substrate; the cutting film is attached to the substrate; The cutting system is used for cutting the wafer in the flat state through the cutting film and along the substrate corresponding to the cutting path.

6. The wafer cutting equipment according to claim 5, characterized in that: The wafer cutting equipment also includes a robot; the robot is used to carry the frame wafer and flip the carried frame wafer so that the front side of the wafer faces the porous chuck.

7. The wafer cutting equipment according to claim 1, characterized in that: Each of the ejector pins is connected to a driving device; the driving device is used to control the raising / lowering of the ejector pin.

8. The wafer cutting equipment according to claim 1, characterized in that: The wafer cutting device further comprises a second visual system; the second visual system and the cutting system are located on the same side of the multi-hole chuck; The lowering of the plurality of ejector pins is used to make the back side of the wafer carried by the frame wafer contact with the second region, and the exhaust of the plurality of hole structures is used to make the wafer in an attached state; The second vision system is used to locate the scribe line on the front side of the wafer; The cutting system is used for implicitly cutting the wafer in the attached state along the cutting lanes on the front side of the wafer.

9. A wafer cutting method, characterized in that: include: Provide frame wafers; Raising a plurality of ejector pins in a porous chuck so that the top surfaces of the plurality of ejector pins are higher than the top surfaces of a plurality of hole structures in the porous chuck; wherein the porous chuck comprises a first region and a second region surrounded by the first region; the first region comprises a plurality of ejector pins, and the second region comprises a plurality of hole structures; placing the frame wafer on the plurality of ejector pins so that there is a gap between the front side of the wafer supported by the frame wafer and the second area; and, Blowing air toward the wafer through the plurality of hole structures so that the wafer is in a flat state; Using a first vision system to locate the dicing lane on the front side of the wafer; The wafer in the flat state is cut implicitly along the back side of the wafer corresponding to the cutting path using a cutting system.

10. The wafer cutting method according to claim 9, characterized in that: The method of using the first vision system to locate the cutting path on the front side of the wafer includes: The first visual system located on the first side is used to locate the cutting path on the front side of the wafer through the second area; wherein the second area is made of a transparent material; the cutting system is located on the second side; the first side and the second side are opposite sides of the multi-hole chuck; or, The first vision system located on the same side of the multi-hole chuck as the dicing system is used to locate the dicing street on the front side of the wafer through the wafer.

11. The wafer cutting method according to claim 9, characterized in that: The provision of a frame wafer comprises: Providing the wafer; the back side of the wafer includes a substrate; the front side of the wafer includes a dicing line; A cutting film is attached to the back of the wafer, and the wafer is fixed in a ring frame by the cutting film to obtain the frame wafer; Placing the frame wafer on the plurality of ejector pins comprises: The robot carries the frame wafer and flips the frame wafer so that the front side of the wafer faces the multiple hole structures; The method of using a cutting system to implicitly cut the wafer in the flat state along the back side of the wafer corresponding to the cutting path comprises: The cutting system cuts the wafer in the flat state through the cutting film and along the substrate corresponding to the cutting path.

12. A wafer cutting method, characterized in that: include: Provide frame wafers; Lowering a plurality of ejector pins in a porous chuck so that the top surfaces of the plurality of ejector pins are not higher than the top surfaces of a plurality of hole structures in the porous chuck; wherein the porous chuck comprises a first region and a second region surrounded by the first region; the first region comprises a plurality of ejector pins, and the second region comprises a plurality of hole structures; placing the frame wafer on the plurality of hole structures so that the back side of the wafer carried by the frame wafer is in contact with the second region; and, Extracting air from the wafer through the plurality of hole structures so that the wafer is in an attached state; Using a second vision system to locate the dicing lane on the front side of the wafer; The wafer in the attached state is implicitly cut along the cutting path on the front side of the wafer using a cutting system; the second visual system and the cutting system are located on the same side of the multi-hole chuck.

13. The wafer cutting method according to claim 12, characterized in that: The provision of a frame wafer comprises: Providing the wafer; the back side of the wafer includes a substrate; the front side of the wafer includes a dicing line; A cutting film is attached to the back of the wafer, and the wafer is fixed in a ring frame by the cutting film to obtain the frame wafer; Placing the frame wafer on the plurality of hole structures comprises: The robot carries the frame wafer and places it on the multiple hole structures, with the back side of the wafer facing the multiple hole structures.

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