TW561542B - Process and apparatus for grinding a wafer backside - Google Patents

Abstract

A process and an apparatus for grinding a wafer backside are disclosed. According the process, a wafer is kept to suck onto a grinding chuck after grinding the wafer backside, then a positioner for dicing wafer is attached on the wafer backside. The wafer is unloaded and transported by mean of the positioner for the follow-up step of de-taping or wafer-dicing. Therefore, process is integrated and wafer crack caused by wafer warpage during unloading or transporting after grinding is avoided.

Description

561542

[Field of the invention] Kind of preparation [Previous technology] With the trend of thinning the semiconductor package structure, the wafers in the package structure also need to conform to a thinner thickness, so a wafer backside polishing process is proposed. After the integrated circuit manufacturing process and before the circular cutting process, multiple wafers on the wafer can be thinned at one time. The flow of the wafer back grinding process and wafer dicing process is shown in the figure, as shown in the figure! As shown in FIG. 2, in the step of “providing the wafer” U, the wafer 20 is supplied. The wafer 20 has an active surface 21 on which an integrated circuit is formed and a corresponding back surface 22, usually on the wafer 2. The active surface 21 of 〇 is attached with a protective tape 23, and then, in the step of "loading the wafer" 12, the active surface 21 is polished toward the adsorption and fixing wafer 20, and the back surface 22 is mounted on the system 22, and then polished out. "Move to tape" 15-direction grinding and grinding are carried on one to reveal the back surface 22 "Unloading the circle 20" tape step] wafer 31 [grinding chuck] way, the wafer 20 disk 31, the conventional system is the vacuum adsorption method For the conventional wafer back grinding equipment, at this time, the wafer 2 0 'in the step of "grinding the wafer" 13 with a grinding head' to form a thinner polished back 2 1 1, "Wafer" 1 4 steps, with a suction device (the back side 221 in the figure), remove the wafer 20 from the grinding equipment, remove the mounting platform to remove the protective tape 23 [that is, "remove" on the back side of the wafer 20 2 21 Stick another positioning tape

561542 V. Description of the invention (2) [ie 6 steps of “wafer positioning before dicing”], after that, the wafer 20 is moved to a wafer dicing equipment, and the step of “cutting the wafer” 17 is performed. The steps from “Wafer” 14 to “Slicing Wafer” 17 require multiple handling operations to change the machine. Because the conventional small-size wafers [4 or 6] are polished, the crystals are polished. Wafer warpage [wafer warpage] is still not obvious, especially in the acceptable range, but with the increase of wafer size [more than 6 o'clock] or more stringent requirements for grinding thickness [less than 12 mil], As shown in Figure 2, the warpage of the wafer 20 after grinding is quite obvious. The occurrence of this warpage is even more serious due to the residual stress of the wafer integrated circuit manufacturing process and the thinning of semiconductor substrates such as silicon. "Unloading the wafer" 14 or subsequent handling steps can easily cause the wafer 20 to crack. . In the patent case No. 420845 "wafer dicing and polishing process" of the Republic of China, the wafer dicing and polishing process disclosed is to cut the wafer before grinding, and the back side of the wafer is adhered to the first tape. The active surface of the wafer is pasted with the second tape, and then the first tape is removed. After grinding, the wafer is formed into multiple wafers. After the wafers are thinned, the first tape is adhered to the back and the second tape is removed. Therefore, the number of inversions and transfers is quite frequent. The wafer alignment needs strict requirements. In addition, when t is required to be excessively polished, the wafer that has been separated from the second tape may have displacement deviation or collision damage from time to time due to adhesion. . 1 $ [Objective and Summary of the Invention] The main object of the present invention is to provide a wafer backside polishing process, which is to adsorb the wafer i on a polishing disc for polishing and attaching positioning parts. After the wafer is unloaded, The positioning system can be used for wafer cutting to achieve the manufacturing process.

Page 6 561542 V. Description of the invention (3) Process integration and reduction of cracks. The process of the present invention is that the grinding disk system retaining member can be used as a process of removing the present invention due to warpage. The crystal positioning member system includes a wafer larger than the wafer and the wafer is warped through the opening. The wafer after bending is unloaded to perform wafer cutting. The transportation operation of the present invention and to prevent the wafer from being warped after grinding are broken. The purpose is to unload and transport the wafer after grinding in the same pair of wafers. Grinding discs are adsorbed and transported. Another purpose is to round the backside of the grinding equipment. There is an opening in the size of a positioning ring to attach the wafer stress. The round trip fragmentation is used for positioning on a wafer to flatly attach the carrier to avoid cracking and damage. A tape for positioning wafers is provided. The tape is used to carry the wafer cracks in the positioning, and it can be prepared to use a grinding disc to move between the wafers and provide an integration after grinding to reduce the movement of the wafer. Work is broken and damaged. Another object of the present invention is to provide a positioning member packaged with a positioning member to attach a wafer. The positioning ring system has a larger size than the crystal in order to provide a wafer loading, grinding, and unloading positioning member attaching station. Effect, thereby preventing the grinding of the back grinding product from attaching and attaching the positioning member. After the wafer is ground, the grinding process of the back of the wafer is ground and attached. The positioning ring system has a tape attached to the positioning ring to absorb the grinding, effectively avoiding the grinding. Positioning parts are directly polished on the backside and other workstations to achieve wafer warpage after the process. A wafer attachment workstation is provided in the grinder, which contains a positioning ring and a positioning tape with a circular opening. The backside grinding is set up as a station. After that, use ~ shed name / Mody

561542 V. Description of the invention (4) Attached to the positioning ring and attached to the back of the wafer through the opening, the positioning tape is used to absorb the stress of the wafer surface after grinding and carry the wafer with the positioning ring 'effectively avoid After grinding, the wafer is chipped or damaged during the unloading or transportation process, and the wafer can be directly diced by the positioning member. The wafer backside grinding process according to the present invention includes at least the following steps: a) The "provide wafer" is performed. The provided wafer has an active side and a back side. Preferably, the active side of the wafer is Attach a protective tape first on the surface; b) on the back of the wafer circle; c) on the surface; more than d) on the wafer, the ring system has the positioning mechanism; e) make the [invention please perform The surface reveals that "the best place to implement, the" back of the circle should be positioned with a large ring and it is suitable for the implementation of the "wafer can be referred to the loaded wafer", grinding equipment grinding; grinding wafer ", the grinding operation is divided into The positioner attaches the "surface. When attaching, the part includes a wafer that is attached to the wafer by the opening and cut and unloaded from the wafer size." Mount the wafer in a fixed manner, such as vacuum adsorption, so that the wafer grinds the back of the wafer on the grinding disc for coarse grinding and fine grinding; 'Attach a positioning member on the grinding disc' to the grinding disc It keeps the suction positioning ring on the wafer and Positioning tape, the positioning opening, the positioning tape is attached to the back of the wafer, preferably, the positioning member of the fixed range; and by removing the adsorption force of the grinding disc, the positioning member moves the Wafer. The description of the following embodiments will be enumerated. 1 ^ 1 Page 8 561542 V. Description of the invention (5) A specific embodiment of the present invention, a process flow chart of wafer back grinding and wafer cutting is shown in Figure 3. As shown, the wafer back grinding process mainly includes "provide wafers" 41, "load wafers" 42, "polished wafers" 43, "attachment of positioning elements" 44 and "unload wafers" 4 5 , Which are explained in order as follows. In the step of “providing wafer” 41, as shown in FIG. 4A, a wafer 50 is prepared. The wafer 50 has an active surface 51 and a corresponding back surface 52. The active surface 51 has been completed. Fabrication of integrated circuits, such as microprocessors, microcontrollers, memory or special application integrated circuits, preferably, the wafer 50 is a random memory such as DDR, Rambus, TDR or QDR Access to memory 'The wafer 50 can be 4, 5, 6, 8 or 12 inches, preferably, the wafer 50 is 8 pairs or 12 inches, on the active side 5 of the wafer 50. 1 It is better to attach a peelable adhesive protective tape 53. In step 42 of "loading the wafer", as shown in Fig. 4B, the wafer 50 is loaded [i0a (iing) on the wafer back grinding device 90 [grinding chuck] by means of adsorption and solidification. For example, methods such as vacuum adsorption or electrostatic adsorption make the back surface 52 of the wafer 50 exposed, as shown in FIGS. 5 and 6. The polishing disc 61 is mounted on the wafer backside polishing equipment 90 at the loading station 91, and is loaded using The movement of the arm 91 places the wafer 50 on the polishing disc 61, and then the 'polishing disc 61' is rotated along one axis to the rough polishing station 9 2 to perform "polishing the wafer" 43. In this implementation In the example, the "grinding wafer" 4 and 3 series include the operations of "rough polishing" 431 and "fine polishing" 432 in more detail. As shown in Figs. "Fine grinding" 432

Page 9561542 V. Description of the invention (6) 'S ^ · \ m Ϊ walk in the fine grinding station 93, as shown in FIG. 4C, after the grinding disc 61 疋 is located after the coarse grinding station 92 or the fine grinding station 93, Appropriate polishing head 6 2 polishes the back surface 52 of the wafer 5 0 to form a polished back surface field 521. Depending on the thickness requirements, the thickness of the polished wafer 50 can reach U dense =. m 丨 1] The following [1 chalr is about 2 5 · 4 micrometers], because the warpage of the wafer must be considered in accordance with the process of the present invention, the thickness of the wafer after grinding can reach 6 mil, 4 mils or lower, the grinding disc 6 1 is rotated to the positioner attaching station 9 4 in the "grind wafer" 43. Preferably, after the "grind wafer" 43 step, it further includes There is a "clean wafer" step, and the wafer is cleaned with deionized water, and the "clean wafer" step can be performed at the positioner attaching station 94 (ie, the positioner attaching station 94 performs wafer cleaning) Device], or handle it with an additional workstation. Sigh. In step 44 of "attachment of the positioning member", as shown in Figs. 5 and 6, the grinding disc 61 is rotated to the positioner attachment workstation 94, # 41). On the grinding disc 61, Attach a positioning member 70 to the back of the wafer 50. 52 ft. During the attaching process, the grinding disc 6 still maintains the adsorption force to the wafer 50. The Tiande wafer 50 is horizontally arranged on the wafer 50. On the polishing disc 61, to facilitate the positioning, the back surface 5 2 1 of the wafer 50 is affixed, and the positioning member 70 includes one to two tapes? 'The positioning ring 71 has an opening 72 larger than the size of the crystal: Generally speaking, the positioning ring 71 is a rigid ring, and the positioning tape 73 is attached to the positioning ring 71 and attached to the positioning ring 71 through the opening. The back surface 521 of the wafer 50 'Preferably, the positioning member 70 is a positioning member in a wafer dicing process' In this embodiment +, the positioning member working station 94 is provided with a rolling device 63 [such as Cut the picture], such as ^

561542 V. Description of the invention (7) Roller with soft rubber, "Positioning parts attaching" 44 steps are performed on the grinding disc 6 1 after positioning, the positioning ring 71 is first set on the grinding disc 61, and then by rolling The rolling device 63 rolls a large area of positioning tape 73 on the positioning ring 71 and the back surface 521 of the wafer 50, so that the positioning tape 73 covers the positioning ring 71 and the wafer 50 at the same time, and then the positioning tape is appropriately cut. 73 to form a positioning member 70 for sticking the back surface 521 of the wafer. In the step of "unloading the wafer" 45, as shown in Figs. 5 and 6, the grinding disc 61 is rotated to the unloading station 95. In this embodiment, the unloading station 95 is integrated with the loading station 91 In order to be the same workstation, the adsorption force of the grinding disc 61 is released first, so that the wafer 50 can be separated from the grinding disc η. Generally, the wafer 50 will be slightly warped when there is no adsorption force. 〇Move the wafer 50 ′ As shown in FIG. 6, in this embodiment, the removal arm 912 or other fixed positioning ring 71 of the unloading workstation 95 is not required to contact the back surface 521 of the wafer to move the wafer. 50. Unloading is performed by the wafer back-side polishing equipment 90 for subsequent processes such as "tape removal" 46 and "round" 47. °, according to the wafer backside polishing process of the present invention, the wafer backside is not ready for polishing. 'Wafer 50 is adsorbed on the polishing disk 61, and the same disk 61 is used to load "wafer wafers 42," and "grind crystals." "Circle 43", "Positioning parts for removing wafers" 45 steps "After grinding, the Japanese Yen 50 series is used to apply positioning tape 73. After the" removing wafers "45 steps and after, the positioning parts can be used for 7 ° positioning The ring 71 does not need to be connected to r: = r5r21. As shown in Figure 4F, in the subsequent "removal of tape", the positioning member 70 is used as the carrier of the wafer 50 and placed in a

561542

The stage 8 1 and the positioning member 70 are not found.] The device 90 and the wafer are placed on a wafer for multiple crystal systems. The fragmentation of the hair is subject to the positioning. The positioning within the surrounding area is torn off. 54. The function of Cheng integration is clear. Any of the well-known, using cutting equipment [Figure round back grinding tape 73 is attached to the wafer 50 cutting and grinding process, and then the wafer is thinly polished. The spirit and the fan protection of the circle defined by Fan Yuan °: the protective tape 53, and then, as the bad 71, the wafer 50 is transferred to ~ ~ β positioning member 70 is commonly used in the hair: month: :: circular cutting equipment, positioning Piece 70: A prepared cutting table with a cutting tool 83 will therefore apply the patent on the backside of the wafer according to the present invention, reduce the handling action and prevent grinding, especially for the ultra-protective range of large-size wafers. Those skilled in the art can be regarded as belonging to the present invention without departing from the changes and modifications of the present invention.

561542 Brief description of the drawings [Illustration of the drawings] Figure 1 • Schematic diagram of the traditional wafer back grinding and dicing process Figure 2 • In the traditional wafer back grinding process, the cross section of the wafer on the polishing disc is the third Figure • According to this article, “Ming 5: The process of wafer back grinding and dicing process is unintentional: Figures” 4A to 4G Figures • • According to the present invention, the cross section of the wafer in the wafer back grinding process and subsequent processes' Section 5 Figure • Schematic diagram of the work flow of a wafer back grinding equipment according to the present invention: Figure, and Figure 6 • Schematic diagram of the back grinding equipment of a wafer according to the present invention J [Circle No. 1 Description] 11 Provide crystals Circle 12 Load wafer 13 Grind wafer 14 Remove wafer 15 Remove tape 16 Wafer positioning before cutting 17 Cutting wafer 20 Wafer 21 Active surface 22 Back surface 221 After grinding back surface 23 Protective tape 31 Grinding disc 32 Grinding head 41 Provide wafer 42 Loading wafer 43 Grinding wafer 431 Rough grinding 432 Fine grinding 44 Positioning attachment 45 Unloading Lower wafer 46 Remove tape 47 Cut wafer 50 Wafer 51 Active surface 52 Back

561542 Brief description of the diagram 521 Back surface after grinding 53 Protective tape 54 Wafer 61 Grinding disc 62 Grinding head 70 Positioner 71 Positioning ring 72 Open σ 81 Stage 82 Cutting table 90 Wafer back grinding equipment 91 Loading station 911 Loading arm 92 Rough grinding Work station 94 Positioning unit attached to work station 63 Rolling device 73 Positioning tape 83 Cutting tool 9 1 2 Remove arm 9 3 Fine grinding station 95 Remove station

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Claims (1)

π 丄 M2 6. Scope of patent application [Scope of patent application] 1. A wafer is provided on the back of a wafer to attract and fix a square disk, so that when the wafer is on the polishing disk, the polishing disk is Remove the [un 1 oad adhesive force for the purpose of 2, and as provided in the patent application, provide the protective tape for the wafer. 3. For example, in the case of applying for a patent, a wafer is provided. The polishing process includes: the wafer has an active surface and a back surface. The wafer is exposed on a polished back surface; the back surface of the wafer is polished; a positioning member is attached to the wafer. On the back side, the wafer's adsorption force is maintained when attached; and inS] the wafer 'moves the wafer by removing the suction member of the polishing disc. The wafer back grinding process described in item 1 is described in the step. In the step, the active surface of the wafer is attached with the wafer back grinding process described in item 1 in the step. In the step, the wafer is polished. The size is eight inches or twelve. The wafer back grinding process described in item 1 of the scope of patent application, in the grinding step, it is further divided into coarse grinding and fine grinding. 2. The wafer back grinding process according to item 1 or 4 of the scope of the patent application, wherein in the grinding step, the wafer is ground to less than 12 mils [mil]. The wafer back grinding process described in item 1 of the patent application scope, which further includes a step of cleaning / cleaning the wafer after the grinding step. The wafer back grinding process described in item 1 of the patent application scope, which Page 561 542 : ί = In the attached step, the positioning member includes a positioning ring and a certain opening / ▼, wherein the positioning ring has an opening larger than the size of the wafer =, the positioning tape is attached to the positioning ring and passes through The opening is attached to the back of the yen. According to the wafer back grinding process described in item 7 of the patent scope of the application, during the attaching step, the positioning ring is first positioned on the grinding disk, and then the positioning tape is simultaneously attached to the positioning tape by rolling. The positioning ring and the back of the crystal. A kind of Japanese yen back grinding equipment includes: a loading workstation and a grinding disk; a grinding workstation surface; at least one grinding disk for sucking and fixing a wafer; receiving the grinding disk for loading the wafer on A positioning member attaching station for receiving the grinding disc and grinding the wafer, for receiving the grinding disc and attaching a positioning member to the back of the wafer; and a unloading station 'for receiving the grinding disc and Remove the adsorption force of the grinding disc. 10. The wafer backside polishing equipment according to item 9 of the scope of the patent application, wherein the polishing workstation includes a rough polishing workstation and a fine polishing workstation. 11. The wafer back grinding device according to item 9 of the scope of patent application, wherein the positioning member attaching station includes a wafer cleaning device. 1 2. The wafer back grinding device as described in item 9 or 11 of the scope of patent application Page 16561542 6. Application scope of patent: The positioning part provided by the positioning part attaching station includes a positioning ring and a positioning tape, the positioning ring has an opening larger than the size of the wafer, and the positioning tape It is attached to the positioning ring and attached to the back of the wafer through the opening. 1 3. The wafer back grinding equipment according to item 丨 2 of the patent application scope, wherein the positioning member attaching workstation includes a rolling device for rolling the positioning tape so that the positioning tape is simultaneously attached to the positioning tape. The positioning ring and the back of the wafer. 14. The wafer back-grinding equipment according to item 9 of the scope of patent application, wherein the loading workstation and the unloading workstation are the same workstation. 15. A wafer backside grinding device 'comprising a grinding disk for attracting and fixing a wafer, the grinding table is movable between a loading station, a grinding station, and a positioning member attaching station, wherein the positioning member attaching station A positioning member is provided on the grinding disc. The positioning member includes a positioning ring and a positioning tape. The positioning ring has an opening larger than the size of the wafer. The positioning tape is attached to the positioning ring. The back of the wafer is affixed through the opening. 16. The wafer backside grinding equipment according to item 15 of the scope of the patent application, wherein the grinding disc is rotated between a loading station, a grinding station, and a positioning member attaching station along an axis. 17. A wafer backside grinding process includes at least the steps of loading wafers, grinding wafers, and positioning parts. The above steps are performed on the same grinding disk and the backside of the wafer is exposed. Its characteristics In the step of attaching the positioning member, the wafer is attracted to the polishing disc, so that 561542 has a number 17 of the positioning and continued handling circle. In the sixth process of customization, the positioning range of the patent application is flatly attached to the 18th. If the scope of the patent application is j7, it is characterized in that there is a positioning part on the positioning part. The positioning member tape, the positioning ring positioning tape is attached to the back surface, so that in the later 19th, if the patent application procedure is adopted, it is characterized in that it is suitable for the back surface of the wafer cutting wafer. In the wafer back grinding process described in the item, in the attaching step, an opening is provided on the grinding disc including a positioning ring and a positioning glue larger than the size of the wafer, and the wafer is attached through the opening. The process does not need to touch the back of the wafer. Or the wafer back grinding according to item 18, and the positioning member is a positioning member in the attachment. q Page 18