TW569376B - Multi(dual)-piece wafer retaining ring and method for fabricating the same - Google Patents

Abstract

A multi(dual)-piece wafer retaining ring and method for fabricating the same are disclosed. The retaining ring comprises a metal ring with fixing portions. A molding plastic ring is formed on a surface of the metal ring with forming fixing portions. The molding plastic ring has a central opening for fixing a wafer. The molding plastic ring covers the fixing portions of the metal ring during molding process so as to bonding together rapidly and fixedly.

Description

569376 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a chemical mechanical polishing apparatus, and particularly relates to a multiple [double] piece wafer restraint ring and a manufacturing method thereof. The restraint ring can be used for the grinding base of the chemical mechanical grinding equipment. [Previous technology] It is known that integrated circuit systems are manufactured in large quantities in the manufacturing process of four-kwwerj integrated circuits. Chemical mechanical polishing, CMP is an indispensable step. After the lines are formed by deposition and money engraving, the processed surface of the wafer is no longer kept flat, which will make subsequent exposure and development appear inaccurate. Chemical mechanical polishing uses chemical reaction and mechanical action to planarize the wafer surface. Traditional chemical mechanical polishing equipment mainly includes a polishing platform. A polishing pad is provided on the polishing platform, corresponding to three polishing heads above the polishing pad. The conventional polishing head system includes a polishing base, an adsorption device (chuck), A buffering film backing film and a restraint ring "Seven ^^ ing Wan ... etc." The restraint ring clamps the edge of the wafer to fix the wafer so that the polished surface of the wafer can resist grinding. In the CMP [Chemical Mechanical Polishing] treatment, the ring surface under the T-Rimi J-shirt was also in contact with the polishing pad, so the restraint ring system was replaced with the same as the polishing pad. ^ ^^ Day 1 Consumable materials need to be regularly disclosed in the Republic of China patent with a multi-layered fixing ring [or fixed bulletin No. 48 5089 "grinding head", which exposes the%, maintenance ring, positioning chemical mechanical polishing, etc. [ Double] piece wafer ring or edge lamination ring],

Page 6 569376 V. Description of the invention (2) As shown in Figure 1, the restraint ring 11 0 series includes a stainless steel upper ring 11 2 and a tubular PPS lower ring 111 [PPS is Polyphenylene sulphide [polyphenylsulfide] project Abbreviation of plastic], the upper ring 11 2 and the lower ring 11 1 are bonded with an adhesive layer 11 3. The restraint ring 110 is installed on the grinding base 160 of the CMP equipment, and the restraint ring 11 0 is ground and ground. Between the bases 160, a spacer soft film 1 3 4 is arranged. The inner edge of the soft film 1 3 4 is provided with a supporting member 1 300. The upper clamp 133 and the lower clamp 132 are under the supporting member 130. A support plate 131 is provided below. The support plate 131 is a buffer film 120 of the supporting building to form a polishing head. When a wafer 140 is fixed to the polishing head, the edge of the wafer 140 is bound by a ring 110. The tubular PPS lower ring 111 is fixed, and the upper surface of the wafer 140 (generally the back surface or the front surface) is in contact with the buffer film 1 2 0 ′, thereby positioning the wafer 1 4 0 and making the wafer 1 The surface below 40 is in contact with a polishing pad 150, and chemical mechanical polishing is performed. As shown in Figure 2, as in steps 1 〇1 and 〇2, first prepare a stainless steel upper ring 1 12 and a tubular PPS lower ring 1 1 1 separately, and then perform the upper and lower ring pressing step 1 03, the stainless steel upper ring 1 1 2 and a tubular pps lower ring 111 are formed with a thermosetting epoxy adhesive and pressed together. The pressing step 1 〇3-generally takes about three working days, and then the baking step is performed. The oxygen viscose is completely thermally cured into the viscose layer 1 1 3. This baking step 1 0 4 requires another two working days, and then the finishing step 1 0 5 is performed, so that the stainless steel upper ring 11 2 can be firmly combined. And tubular PPS lower ring 1 π, otherwise the stainless steel upper ring 112 and tubular pps lower ring ill may be delaminated due to grinding torsion, resulting in failure to use. This manufacturing is not only slow and time-consuming, but also expensive. In the Republic of China Patent Bulletin No. 4 9 7 5 2 3 "Wafer Polishing Locating Ring Structure

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569376 V. Description of the invention (3) = None: Another ring of multiple [double] wafer restraint rings, including the inner ring of the end ring, which has a thickness and outer diameter smaller than the ring ring body, and steel without steel without end ring =; = The inner diameter of the ring body 'a plastic layer covering the upper surname constitutes% body, because the steel endless ring system is buried in the plastic layer, using two = ☆ the strength should not be restricted to two layers Ring 1 1 0, in the lower layer structure [/ I abrasion thickness should not be two-layered restraint ring 11 10 is thicker: I abrasion utilization layer is thinner], and because the steel endless ring is covered and positioned The humerus is a plastic layer, and it is difficult to identify the wear point. When it is abraded to the endless steel 5 r soil / defective wafer, the chemical mechanical polishing fails, so the wafer restraint system failed to fully utilize the multi-piece composite The characteristics of combination materials. [Summary of the Invention] The main purpose of the four books and one Ming is to provide a multiple [double] piece wafer restraint ring. The lower part of the metal ring is covered with a molded plastic ring, so that the two are fast and stable. It has the effect of fast manufacturing and stable combination. 4. A second object of the present invention is to provide a method for manufacturing a multiple [double] piece wafer restraint ring t, which uses a molded plastic ring to mold a [molding] covering a fitting portion on a lower surface of a metal ring, so that the plastic ring is molded. It is quickly and firmly bonded to the metal ring when it is formed, which has the effect of making it fast and stable. According to the wafer restraint ring of the present invention, the restraint ring system includes a metal ring such as stainless steel, and the lower surface of the metal ring has a fitting portion, such as a ring-shaped fitting protrusion or groove. Preferably, the fitting ring The joint is formed with a radial fitting groove. The lower surface of the metal ring is molded with a molded plastic ring, such as PP S engineering plastic. The molded plastic ring has a central opening for positioning a wafer.

Page 8 569376 V. Description of the invention (4) '' The molded plastic ring is covered with the fitting part of the metal ring during the molding process to build a fast and stable integrated combination, preferably, the surface under the metal ring A pre-molding treating layer is formed, such as surface coating or interface bonding material. According to the method for manufacturing a wafer restraint ring according to the present invention, a metal ring is first provided. The metal ring has an upper surface and a lower surface, wherein the upper surface is for mounting on a grinding base, and the lower surface is formed with At least one fitting portion; afterwards, 'mold a molded plastic ring on the lower surface of the metal ring, which is formed by injection-molding PPS engineering plastic on a mold formed by the metal ring and a mold' After the coupling portion covering the metal ring is formed into a molded plastic ring combined with the metal ring, the plastic ring has a central opening for positioning a wafer to be ground. [Embodiment] Please refer to the attached drawings. The present invention will enumerate the following embodiment description. According to a specific embodiment of the present invention, as shown in FIG. 3, the circular restraint ring 1 of the present invention is mostly [Double] -piece assembly for mounting on a polishing base of a chemical machine CMP [CMP] equipment to form a polishing head for restraining and positioning a wafer to be polished. The wafer restraint ring 丨 mainly includes a The metal ring 10 in the upper position and a molded plastic ring 20 in the lower part. The ring 10 in the basin can be made of non-steel material or other hard materials. The metal ring series has an upper surface and a lower surface. Surface 12, the figure is provided for grinding the base. For example, screw holes 13 and two kings can be provided on the upper surface 11, and as shown in FIGS. 3 and 4, the lower surface i of the metal ring 10 is formed. There is a fitting portion ", such as integrally formed on the lower surface 12 :: =

Page 9 569376

Or a recessed groove, which is seated in this embodiment to facilitate machining and not to be the # position of the% -shaped indented convex joint portion 14 / the distribution position of the shirt ring screw hole 13, the inlayed ground, as in Section 4 And R ^, can be inverted "T" shape or dovetail shape, etc., it is better to recess 1 5 and Er Suo. The lower surface of the fitting portion 14 is formed with a radial indentation. The binding properties of the molded plastic ring 20, and the indulgence of the molded plastic # ring 20 is molded [_1Η · Ί ... Mouth moulding t plastic 19 broadcast I [moldlng] is formed on the lower surface K of the metal ring 10, mold I plastic ring 20 series can be 1 > 1 ^ Zhou1 > 〇1 丫 1) 1 ^ 1 ^ 161 ^ su 1 phi de like stupid sulfide] or other soft engineering plastics and other materials, the material is based on chemical mechanical grinding The process has sufficient passivation and stability to stop the quilt. The particles and the wafer have an effect during grinding. The molded plastic ring 20 covers the fitting portion 14 of the metal ring 10, and the molding The plastic ring 20 is provided with a middle opening 21 ′ for positioning a wafer to be polished. The direct test system of the central opening can be four, six, eight, or twelve inches. Preferably, the metal ring 1 Below 0 The surface 12 is formed with a pre-mold processing layer pre-m〇1 ding treating layer, such as coarse sugar surface, "surafce" or interface bonding material, to improve the bonding with the molded plastic ring. . The manufacturing process of the above-mentioned wafer restraint ring is shown in FIG. 6. First, in the preparation step 31, a metal ring 10 having a fitting portion 14 is provided as a hard upper ring of the wafer restraint ring 1. The metal ring 10 is formed into a fitting portion 14 of a predetermined shape by processing or other methods. After that, a molding step 32 is performed, and the metal ring 10 is placed in a mold. The lower surface 12 of the metal ring 10 Form a cavity with the mold, inject PPS engineering plastic into the cavity, and cover the fitting portion 14 of the metal ring 1 (), and

Page 10 569376 V. Description of the invention (6) The PPS engineering plastic is formed into a molded plastic ring 20 after curing. This molding step 32 is generally completed in just a few hours. After the molding step 32, the mold The plastic ring 20 is firmly combined with the metal ring 10, and after a finishing step 33 is performed, a wafer restraint ring 1 is manufactured, which is faster in manufacturing and is firmly bonded between the upper and lower rings. The protection scope of the present invention shall be determined by the scope of the appended patent application. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the present invention. .

Page 11 569376 Simple illustration of the drawings [Simplified illustration of the drawings] Figure 1: Sectional view of the traditional multiple [double] -piece wafer restraint ring; Figure 2: Manufacturing of the traditional multiple [double] -piece wafer restraint ring Flow chart; Figure 3: According to a specific embodiment of the present invention, a cross section of a wafer restraint ring is not intended, Figure 4: A schematic diagram of a lower surface of a metal ring of the wafer restraint ring according to a specific embodiment of the present invention Figure 5: According to a specific embodiment of the present invention, along the line 5-5 of Figure 4 is not intended to cut, and Figure 6: According to a specific embodiment of the present invention, the manufacturing process of the wafer restraint ring . [Simplified description of component symbols] 1 Wafer restraint 10 Metal ring 11 Upper surface 12 Lower surface 13 Screw hole 14 Fitting portion 15 Radial fit groove 20 Molded plastic layer 21 Center opening 31 Provide a metal with a fitting portion Ring 32 Molded a molded plastic ring on the lower surface of the metal ring and covers the fitting portion 33 Finishing 101 Provides a non-recorded steel upper ring 102 Provides a tubular PPS > ring 103 Presses the upper and lower rings I 0 4 Baked glue 1 0 5 Finishing II 0 Restraint ring 111 Lower ring 11 2 Upper ring

Page 12 569376 Brief description of the diagram 113 Adhesive layer 120 131 Support plate 132 134 Spacer film 140 160 Grinding base Buffer film 130 Supporting lower fixture 133 Upper fixture Wafer 150 Polishing pad in ·· page 13

Claims (1)

569376 6. Scope of patent application [Scope of patent application] 1. A wafer restraint ring, comprising: a metal ring with an upper surface and a lower surface, wherein the upper surface is provided for mounting on a grinding base, and the lower surface The surface is formed with at least one fitting portion; and a molded plastic ring is molded on the lower surface of the metal ring and covers the fitting portion. The molded plastic ring has a central opening for: Position a wafer to be ground. 2. The wafer restraint ring according to item 1 of the scope of the patent application, wherein the embedded part is integrally formed on the metal ring. 3. The wafer restraint ring as described in item 2 of the scope of patent application, wherein the embedding portion is an assembling protrusion. 4. The wafer restraint ring as described in item 3 of the scope of patent application, wherein the fitting portion is a ring-shaped fitting protrusion. 5. The wafer restraint ring according to item 1 or 4 of the scope of patent application, wherein a radial fitting groove is formed on the lower surface of the fitting protrusion. 6. The wafer restraint ring described in item 1 of the scope of patent application, wherein the molded plastic ring is PPS engineering plastic. 7. The wafer restraint ring described in item 1 of the scope of patent application, wherein a pre-mold processing layer is formed on the lower surface of the metal ring to improve the bonding with the molded plastic ring. 8. The wafer restraint ring according to item 7 of the scope of patent application, wherein the pre-mold processing layer is a rough surface. 9. The wafer restraint ring described in item 7 of the scope of patent application, wherein the Page 14 569376 VI. Scope of patent application The mold treatment layer is an interface bonding material. .10 ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,-,,,,,,,,,,,,,-,,, Passive state during the CMP process to prevent interaction with the wafer. 11. According to the wafer restraint ring described in item 丨 of the scope of patent application, the central opening diameter of the bean-molded plastic ring is four, six or eight inches. 8 1 2. As for the wafer restraint ring described in item 丨 of the patent application scope, the center opening diameter of the molded plastic ring is twelve inches. A method for manufacturing a wafer restraint ring includes: providing a metal ring, the metal ring system having an upper surface and a lower surface; right. The i surface is provided for mounting on a grinding base, and the lower surface is formed with at least one fitting portion; and a molded plastic ring is molded on the lower surface of the metal ring, and the engineering plastic is injection-molded on the lower surface. Formed by metal ring and mold = cavity, the PPS engineering plastic is covering the fitting part of the metal ring, and ^ Cheng plastic is molded into a combination with the metal ring molding ~ 疖 疖 rolled in and died ^ 依 衣 f After repairing the clothes, the molded J gel% has a central opening for positioning a wafer to be polished. 14. The wafer restraint ring according to item 13 of the patent application scope, wherein the fitting portion is integrally formed on the metal ring. k: Special person of Zhongshen Λ? The manufacturing method of the wafer restraint ring described in 1st 1st ... wherein the 忒 fitting part is a fitting protrusion. 2. Ershen Λ Special: The manufacturer of the wafer restraint ring described in the 15th range of i, wherein the coupling part is a ring-shaped fitting protrusion. • See? JC! Method 15 method, 16 method, ΦΦ 569376 6. Application for patent scope 1 7. Manufacturing method of wafer restraint ring as described in item 13 or 16 of patent application scope, wherein the lower surface of the fitting protrusion is formed There are radial fitting grooves. 18. The method for manufacturing a wafer restraint ring as described in item 13 of the scope of the patent application, wherein before the molding step, a pre-mold processing layer is formed on the lower surface of the metal ring to enhance contact with the mold. Combination of plastic rings. 19. The method for manufacturing a wafer restraint ring as described in item 18 of the scope of patent application, wherein the pre-mold processing layer is a rough surface. 20. The method for manufacturing a wafer restraint ring as described in item 18 of the scope of patent application, wherein the pre-mold processing layer is an interface bonding material. Page 16