WO2022231308A1 - Double side grinding apparatus having convex polygon-shaped abrasive members - Google Patents

Double side grinding apparatus having convex polygon-shaped abrasive members Download PDF

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Publication number
WO2022231308A1
WO2022231308A1 PCT/KR2022/006034 KR2022006034W WO2022231308A1 WO 2022231308 A1 WO2022231308 A1 WO 2022231308A1 KR 2022006034 W KR2022006034 W KR 2022006034W WO 2022231308 A1 WO2022231308 A1 WO 2022231308A1
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WO
WIPO (PCT)
Prior art keywords
set forth
base
wafer
grinding
engaging surface
Prior art date
Application number
PCT/KR2022/006034
Other languages
English (en)
French (fr)
Inventor
Cheulwon CHOI
Jongsun Kim
Hyoshik KWEON
Jaehoon Lee
Byungchul Lee
Minkyu Lee
Original Assignee
Globalwafers Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Globalwafers Co., Ltd. filed Critical Globalwafers Co., Ltd.
Priority to JP2023566021A priority Critical patent/JP2024518332A/ja
Priority to EP22796140.6A priority patent/EP4329982A1/en
Priority to KR1020237040301A priority patent/KR20230175281A/ko
Priority to CN202280037766.XA priority patent/CN117460597A/zh
Publication of WO2022231308A1 publication Critical patent/WO2022231308A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B37/00—Lapping machines or devices; Accessories
    • B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
    • B24B37/07—Lapping machines or devices; Accessories designed for working plane surfaces characterised by the movement of the work or lapping tool
    • B24B37/08—Lapping machines or devices; Accessories designed for working plane surfaces characterised by the movement of the work or lapping tool for double side lapping
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B37/00—Lapping machines or devices; Accessories
    • B24B37/11—Lapping tools
    • B24B37/20—Lapping pads for working plane surfaces
    • B24B37/24—Lapping pads for working plane surfaces characterised by the composition or properties of the pad materials

Definitions

  • the field of the disclosure relates generally to simultaneous double side grinding of semiconductor wafers and more particularly to double side grinding apparatus and methods for double side grinding.
  • IC integrated circuit
  • Semiconductor wafers are commonly used in the production of integrated circuit (IC) chips on which circuitry is printed.
  • the circuitry is first printed in miniaturized form onto surfaces of the wafers, then the wafers are broken into circuit chips. But this smaller circuitry requires that wafer surfaces be extremely flat and parallel to ensure that the circuitry can be properly printed over the entire surface of the wafer.
  • a grinding process is commonly used to improve certain features of the wafers (e.g., flatness and parallelism) after they are cut from an ingot.
  • Simultaneous double side grinding operates on both sides of the wafer at the same time and produces wafers with highly planarized surfaces. It is therefore a desirable grinding process. While this grinding process significantly improves flatness and parallelism of the ground wafer surfaces, it can also cause degradation of the topology and nanotopography (NT) of the wafer surfaces.
  • NT nanotopography
  • One aspect of the present disclosure is directed to a method for double side grinding a semiconductor structure.
  • the semiconductor structure is positioned between first and second grinding wheels.
  • Each grinding wheel includes a support wheel and a plurality of abrasive members that extend axially outward from the support wheel.
  • Each abrasive member has a wafer-engaging surface.
  • the wafer-engaging surface is shaped as a convex polygon with at least five sides.
  • the semiconductor structure is ground by contacting the first and second grinding wheels with the semiconductor structure and rotating the first and second grinding wheels relative to each other.
  • the semiconductor structure is positioned between first and second grinding wheels.
  • Each grinding wheel includes a support wheel and a plurality of abrasive members that extend axially outward from the support wheel.
  • Each abrasive member has a wafer-engaging surface.
  • the wafer-engaging surface includes a base.
  • the base is a first side of the wafer-engaging surface.
  • the wafer-engaging surface includes a second side having a first end and a second end.
  • the second side is connected to the base at its first end.
  • the second side and base form an obtuse angle.
  • the wafer-engaging surface includes a third side having a first end and a second end.
  • the third side is connected to the base at its first end.
  • the third side and base form an obtuse angle.
  • the semiconductor structure is ground by contacting the first and second grinding wheels with the semiconductor structure and rotating the first and second grinding wheels relative to each other.
  • a further aspect of the present disclosure is directed to a double side grinding apparatus.
  • the apparatus includes first and second grinding wheels.
  • Each grinding wheel has a rotational axis and includes a support wheel and a plurality of abrasive members that extend axially outward from the support wheel.
  • Each abrasive member has a wafer-engaging surface.
  • the wafer-engaging surface includes a base.
  • the base is a first side of the wafer-engaging surface.
  • the wafer-engaging surface includes a second side having a first end and a second end.
  • the second side is connected to the base at its first end.
  • the second side and base form an obtuse angle.
  • the wafer-engaging surface includes a third side having a first end and a second end.
  • the third side is connected to the base at its first end.
  • the third side and base form an obtuse angle.
  • Each side of the wafer-engaging surface has an average distance from the rotational axis.
  • the average distance of the base from the rotational axis is less than the average distance of each of the other sides from the rotational axis.
  • Figure 1 is a perspective exploded view of a double side grinding apparatus
  • Figure 2 is a cross-section view of a grinding wheel of the double side grinding apparatus
  • Figure 3 is a top view of a support wheel of the grinding wheel
  • Figure 4 is a top view of the grinding wheel
  • Figure 5 is a detailed top view of the grinding wheel showing abrasive members
  • Figure 6 is a top view of an abrasive member of the grinding wheel
  • Figure 7 is a top view of another embodiment of a grinding wheel
  • Figure 8 is a detailed top view of the grinding wheel showing abrasive members
  • Figure 9 is a top view of an abrasive member of the grinding wheel
  • Figure 10 illustrates box plots of peak to valley nanotopography for semiconductor structures simultaneous double side ground by convex polygon-shaped abrasive members and by conventional abrasive members;
  • Figure 11 illustrates box plots of peak to valley nanotopography in a 10 mm x 10 mm window for semiconductor structures simultaneous double side ground by convex polygon-shaped abrasive members and by conventional abrasive members;
  • Figure 12 shows wafer images for semiconductor structures simultaneous double side ground by convex polygon-shaped abrasive members and by conventional abrasive members;
  • Figure 13 illustrates box plots of bow for semiconductor structures after being simultaneous double side ground by convex polygon-shaped abrasive members and by conventional abrasive members;
  • Figure 14 illustrates box plots of the change in bow before and after the simultaneous double side grind (delta) for semiconductor structures simultaneous double side ground by convex polygon-shaped abrasive members and by conventional abrasive members;
  • Figure 15 is a time series plot of the current of the left grinding wheel for semiconductor structures simultaneous double side ground by convex polygon-shaped abrasive members and by conventional abrasive members;
  • Figure 16 is a time series plot of the current of the right grinding wheel for semiconductor structures simultaneous double side ground by convex polygon-shaped abrasive members and by conventional abrasive members;
  • Figure 17 shows the accumulated percentage of particle count (DIC mode) for count 0 for semiconductor structures simultaneous double side ground by convex polygon-shaped abrasive members and by conventional abrasive members;
  • Figure 18 illustrates images of a convex polygon-shaped abrasive member along its height showing porosity thereof.
  • Figure 19 is a time series plot of the CRING value for convex polygon-shaped abrasive members and conventional abrasive members.
  • the double side grinding apparatus 100 (which may also be referred to herein as a "simultaneous double side grinding apparatus”) includes a pair of hydrostatic pads 105, 110 that generate water cushions or "pockets" 113 through a source of water 111.
  • the semiconductor structure W is guided between the water cushions 113, thereby "clamping" the wafer W in a generally vertical alignment.
  • the wafer is secured in a carrier ring 122.
  • the carrier ring 122 (and wafer W secured therein) rotates within a hydrostatic guide roller 136.
  • a pair of first and second grinding wheels 133, 135 (“left" and “right” grinding wheels) extend through the hydrostatic pads 105, 110.
  • the pair of grinding wheels 133, 135 rotate in opposite directions relative to each other.
  • the grinding wheels 133, 135 may be connected with air spindles 141, 142 and an electric motor rotates the grinding wheels 133, 135.
  • the grinding wheels 133, 135 may include full peripheral contact with the semiconductor structure as they rotate.
  • the double side grinding apparatus 100 may be adapted to process any size semiconductor structure such as structures having a diameter of 200 mm or more, 300 mm or more, or 450 mm or more.
  • the semiconductor structure may be a single crystal silicon wafer. In other embodiments, the semiconductor structure is made of silicon carbide, sapphire, or Al 2 O 3 .
  • the semiconductor structure may be a layered structure or may be a bulk wafer.
  • the grinding wheel 200 may be used as the first and second grinding wheels of the apparatus 100 because the first and second grinding wheels are typically identical.
  • the grinding wheel 200 has a rotational axis A about which the grinding wheel rotates.
  • the grinding wheel 200 include a support wheel 208 and a plurality of abrasive members 212 that extend axially outward from the support wheel 208.
  • the plurality of abrasive members 212 extend circumferentially about the support wheel 208 (about the circumference C ( Figure 3)).
  • the abrasive members 212 include an abrasive grit material such as diamond grit or cubic boron nitride (CBN) grit.
  • the abrasive members include vitrified diamond.
  • the support wheel 208 includes a circumferential recess 215 (e.g., formed from a single shoulder or two shoulders formed in the support wheel 208).
  • the plurality of abrasive members 212 are disposed within the circumferential recess 215.
  • the abrasive members 212 may connect to the support wheel 208 by any method that allows the grinding wheel to function as described herein.
  • the abrasive members 212 are connected to the support wheel 208 by an adhesive.
  • the abrasive members 212 are connected to the support wheel 208 by a mold.
  • the abrasive members are connected to a collar (not shown) that is disposed within the circumferential recess.
  • the grinding wheel 200 includes abrasive members 212 each having a wafer-engaging surface 225 ( Figure 6) that contacts the semiconductor structure during grinding. Gaps 219 ( Figure 4) may be formed between the abrasive members 212. In other embodiments, gaps are not formed between the abrasive members 212 (i.e., the wafer-engaging surfaces 225 are congruent).
  • the wafer-engaging surface 225 is shaped as a convex polygon having at least five sides.
  • the convex polygon may be a pentagon as shown in the illustrated embodiment or, as in other embodiments, may be a hexagon, heptagon, octagon or other convex polygon.
  • the convex polygon may be a regular polygon or an irregular polygon.
  • the wafer-engaging surface 225 includes a base 235 (e.g., a side from which the height may be measured that may be generally closest or furthest from the rotational axis A ( Figure 4) of the grinding wheel 200).
  • Second and third sides 239, 243 extend from the base 235 (which may also be referred to herein as a "first side" of the wafer-engaging surface 225).
  • the second side 239 includes a first end 241 and a second end 242.
  • the second side 239 is connected to the base 235 at its first end 241.
  • the second side 239 and base 235 form an angle ⁇ 1 .
  • the third side 243 includes a first end 261 and second end 263.
  • the third side 243 is connected to the base 235 as its first end 261.
  • the third side 243 and base 235 form an angle ⁇ 2 .
  • the first and second angles ⁇ 1 , ⁇ 2 are each obtuse angles.
  • the wafer-engaging surface 225 includes a fourth side 250 that connects to the first side 239 at a first end 267 of the fourth side 250.
  • the wafer-engaging surface 225 includes a fifth side 255 that connects to the second end 243 at a first end 272 of the fifth side 255.
  • the fourth and fifth sides 250, 255 connect at second sides 270, 275 of the fourth and fifth sides 250, 255.
  • the sides 235, 239, 243, 250, 255 of the convex polygon may have any length that allows the abrasive members 212 to function as described herein.
  • the second and third sides 239, 243 are each shorter than the base 235 and of each the fourth and fifth sides 250, 255.
  • one or more corners formed between the sides may be rounded corners (e.g., has one or more radii of curvature).
  • the corner 286 formed between the second side 239 and the fourth side 250 is rounded and the corner 288 formed between the third side 243 and the fifth side 255 is rounded.
  • the corner 290 formed between the fourth side 250 and fifth side 255 is also rounded (e.g., an apex opposite the base 235 is rounded).
  • the ends of the various sides of the convex polygon that terminate within a rounded corner may generally correspond to the mid-point of the rounded corner unless stated differently herein.
  • some or even none of the corners are rounded (i.e., some or all are sharp corners).
  • the corner 282 formed between the base 235 and the second side 239 is not rounded and the corner 284 formed between the base 235 and the third side 243 is not rounded.
  • the choice between round and sharp corners (and the one or more radii of rounded corners) may be made based on the performance of the abrasive member 212.
  • Each side 235, 239, 243, 250, 255 of the wafer-engaging surface 225 has an average distance from the rotational axis A ( Figure 4).
  • the average distance D 235 of the base 235 from the rotational axis A is less than the average distance from the rotational axis of each of the other sides 239, 243, 250, 255 (i.e., the base 235 is closer to the rotational axis A than the other sides of the convex polygon).
  • FIG. 7-8 Another embodiment of the grinding wheel 300 is shown in Figures 7-8.
  • the components shown in Figures 7-8 that are analogous to those of Figures 4-5 are designated by the corresponding reference number of Figures 4-5 plus "100" (e.g., part 212 becomes 312).
  • the orientation of the abrasive member 312 is turned 180° from the abrasive member 212 of Figures 4-6 (compare Figure 6 and 9).
  • the average distance D 335 of the base 335 from the rotational axis A is greater than the average distance from the rotational axis A of each of the other sides 239, 243, 250, 255 (i.e., the base 235 is further from the rotational axis A than the other sides of the convex polygon).
  • the abrasive member 312 may be the same as the abrasive member 212 of Figures 4-6.
  • the semiconductor structure may be double side grinded by positioning the semiconductor structure between the first and second grinding wheels ( Figure 1).
  • the semiconductor structure is ground by contacting the first and second grinding wheels with the semiconductor structure and rotating the first and second grinding wheels relative to each other (i.e., in opposite directions).
  • Convex polygonal-shaped abrasive members have more abrasive surface area relative to conventional abrasive members for holding the semiconductor structure. This reduces vibration in the horizontal direction and the slope by the contacted grinding wheel.
  • the rotating semiconductor structure may be ground under more balanced conditions and the nanotopography may be improved. Further, the abrupt step along the edge area of the semiconductor structure may be improved and distorted areas on the ground wafer may be reduced.
  • the convex polygonal-shaped abrasive members may generate less surface damage with less grinding current. Different shapes or orientations of the convex polygonal abrasive member may be used to produce different bow effects in the wafer.
  • the convex polygonal-shaped abrasive members may have a relatively consistent porosity across its length which increases the consistency of the grinding process.
  • Example 1 Nanotopography Improvement by use of a Convex Polygon-Shaped Abrasive Members
  • a first set of semiconductor structures were simultaneously double-side ground by a grinding wheel having abrasive members as shown in Figures 4-7 of U.S. Patent No. 6,692,343.
  • a second set of semiconductor structures were simultaneously double-side ground by a grinding wheel having abrasive members with a convex polygon shape (convex pentagon).
  • Figure 10 shows the peak to valley nanotopograhy
  • Figure 11 shows peak to valley of a 10 mm x 10 mm window of the wafer.
  • the pentagon-shaped abrasive members have improved nanotopography.
  • Example 2 Reduction in Distorted Area by use of a Convex Polygon-Shaped Abrasive Members
  • Figure 12 shows wafer images for a wafer ground by a grinding wheel of Figures 4-6 of the application having pentagon-shaped abrasive members "(1)" and grinding wheels having the abrasive members shown in Figures 4-7 of U.S. Patent No. 6,692,343 with "(2)" being a center pattern and "(3)" being an edge pattern.
  • the pentagon-shaped abrasive members were better able to apply holding force toward the rotating wafer surface and sustained generated slope without having to change over the grinding sequence.
  • the wafer ground with the pentagon-shaped abrasive members prevented generation of distorted area on the ground wafer, thereby improving nanotopography.
  • Example 3 Change in Bow by use of a Convex Polygon-Shaped Abrasive Members
  • Example 4 Reduction in Surface Damage by use of a Convex Polygon-Shaped Abrasive Members
  • Figure 17 shows the accumulated percentage of particle count (DIC mode) for grinding wheels having abrasive members as shown in Figures 4-7 of U.S. Patent No. 6,692,343 (left column) and for grinding wheels having pentagon-shaped abrasive members (right column). As shown in Figure 17, the pentagon-shaped abrasive members resulted in less surface damage with less grinding current (Figs. 15-16).
  • Example 5 Grinding Stability by use of a Convex Polygon-Shaped Abrasive Members
  • the convex polygon-shaped wheel involved stable grinding capability from the top layer of the convex polygon structure to the bottom layer. As shown in Figure 18, the porosity of the convex polygon-shaped wheel was consistent through-out its length. This is evidenced by Figure 19 which shows the CRING value changed (from low to high and back to low) for the abrasive members of Figures 4-7 of U.S. Patent No. 6,692,343 while the pentagon-shaped abrasive members exhibited consistent values.
  • the terms “about,” “substantially,” “essentially” and “approximately” when used in conjunction with ranges of dimensions, concentrations, temperatures or other physical or chemical properties or characteristics is meant to cover variations that may exist in the upper and/or lower limits of the ranges of the properties or characteristics, including, for example, variations resulting from rounding, measurement methodology or other statistical variation.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Mechanical Treatment Of Semiconductor (AREA)
  • Constituent Portions Of Griding Lathes, Driving, Sensing And Control (AREA)
  • Grinding Of Cylindrical And Plane Surfaces (AREA)
PCT/KR2022/006034 2021-04-27 2022-04-27 Double side grinding apparatus having convex polygon-shaped abrasive members WO2022231308A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2023566021A JP2024518332A (ja) 2021-04-27 2022-04-27 凸多角形の研磨部材を有する両面研削装置
EP22796140.6A EP4329982A1 (en) 2021-04-27 2022-04-27 Double side grinding apparatus having convex polygon-shaped abrasive members
KR1020237040301A KR20230175281A (ko) 2021-04-27 2022-04-27 볼록 다각형 형상 연마 부재를 갖는 양면 연삭 장치
CN202280037766.XA CN117460597A (zh) 2021-04-27 2022-04-27 具有凸多边形磨料部件的双面研磨设备

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US202163180481P 2021-04-27 2021-04-27
US63/180,481 2021-04-27

Publications (1)

Publication Number Publication Date
WO2022231308A1 true WO2022231308A1 (en) 2022-11-03

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PCT/KR2022/006034 WO2022231308A1 (en) 2021-04-27 2022-04-27 Double side grinding apparatus having convex polygon-shaped abrasive members

Country Status (6)

Country Link
EP (1) EP4329982A1 (ko)
JP (1) JP2024518332A (ko)
KR (1) KR20230175281A (ko)
CN (1) CN117460597A (ko)
TW (1) TW202245033A (ko)
WO (1) WO2022231308A1 (ko)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006224201A (ja) * 2005-02-15 2006-08-31 Disco Abrasive Syst Ltd 研削ホイール
US20080020684A1 (en) * 2004-03-19 2008-01-24 Memc Electronic Materials, Incorporated Wafer Clamping Device For A Double Side Grinder
CN202088116U (zh) * 2011-04-26 2011-12-28 博深工具股份有限公司 一种钻石型金刚石磨盘
JP2018130791A (ja) * 2017-02-14 2018-08-23 株式会社ディスコ 研削ホイール
US20180290265A1 (en) * 2015-05-11 2018-10-11 Shin-Etsu Handotai Co., Ltd. Grinding wheel

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080020684A1 (en) * 2004-03-19 2008-01-24 Memc Electronic Materials, Incorporated Wafer Clamping Device For A Double Side Grinder
JP2006224201A (ja) * 2005-02-15 2006-08-31 Disco Abrasive Syst Ltd 研削ホイール
CN202088116U (zh) * 2011-04-26 2011-12-28 博深工具股份有限公司 一种钻石型金刚石磨盘
US20180290265A1 (en) * 2015-05-11 2018-10-11 Shin-Etsu Handotai Co., Ltd. Grinding wheel
JP2018130791A (ja) * 2017-02-14 2018-08-23 株式会社ディスコ 研削ホイール

Also Published As

Publication number Publication date
TW202245033A (zh) 2022-11-16
KR20230175281A (ko) 2023-12-29
CN117460597A (zh) 2024-01-26
JP2024518332A (ja) 2024-05-01
EP4329982A1 (en) 2024-03-06

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