US20090045410A1 - GaN SUBSTRATE AND SEMICONDUCTOR DEVICE PREPARED BY USING METHOD AND APPARATUS OF POLISHING GaN SUBSTRATE - Google Patents
GaN SUBSTRATE AND SEMICONDUCTOR DEVICE PREPARED BY USING METHOD AND APPARATUS OF POLISHING GaN SUBSTRATE Download PDFInfo
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- US20090045410A1 US20090045410A1 US12/254,360 US25436008A US2009045410A1 US 20090045410 A1 US20090045410 A1 US 20090045410A1 US 25436008 A US25436008 A US 25436008A US 2009045410 A1 US2009045410 A1 US 2009045410A1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
- H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02002—Preparing wafers
- H01L21/02005—Preparing bulk and homogeneous wafers
- H01L21/02008—Multistep processes
- H01L21/0201—Specific process step
- H01L21/02024—Mirror polishing
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- 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
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- 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
- B24B37/10—Lapping machines or devices; Accessories designed for working plane surfaces characterised by the movement of the work or lapping tool for single side lapping
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- 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
- B24B7/00—Machines or devices designed for grinding plane surfaces on work, including polishing plane glass surfaces; Accessories therefor
- B24B7/20—Machines or devices designed for grinding plane surfaces on work, including polishing plane glass surfaces; Accessories therefor characterised by a special design with respect to properties of the material of non-metallic articles to be ground
- B24B7/22—Machines or devices designed for grinding plane surfaces on work, including polishing plane glass surfaces; Accessories therefor characterised by a special design with respect to properties of the material of non-metallic articles to be ground for grinding inorganic material, e.g. stone, ceramics, porcelain
- B24B7/228—Machines or devices designed for grinding plane surfaces on work, including polishing plane glass surfaces; Accessories therefor characterised by a special design with respect to properties of the material of non-metallic articles to be ground for grinding inorganic material, e.g. stone, ceramics, porcelain for grinding thin, brittle parts, e.g. semiconductors, wafers
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- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/40—AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
- C30B29/403—AIII-nitrides
- C30B29/406—Gallium nitride
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- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B33/00—After-treatment of single crystals or homogeneous polycrystalline material with defined structure
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- Inorganic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Ceramic Engineering (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
- Grinding-Machine Dressing And Accessory Apparatuses (AREA)
Abstract
In a polishing method of a GaN substrate according to this invention, first, while supplying a polishing solution 27 containing abrasives 23 and a lubricant 25, onto a platen 101, the GaN substrate is polished using the platen 101 and the polishing solution 27 (first polishing step). Then the GaN substrate is polished using the platen 101 in which abrasives 29 are buried, while supplying a lubricant 31 onto the platen 101 in which the abrasives 29 are buried (second polishing step).
Description
- The present invention relates to a method of polishing a GaN substrate.
- For example, the method described in
Patent Document 1 is known as a polishing method of a magnetic head slider. A lapping oil composition for final polishing, for example, described in Patent Document 2 is known as a polishing solution for polishing the magnetic head slider. - Incidentally, the method described in
Non-patent Document 1, for example, is known as a polishing method of a GaN substrate (gallium nitride substrate) instead of the magnetic head slider. This method is to polish the GaN substrate, using a diamond paste of the grain size of 0.1 μm and a pad of a suede type, and thereafter to chemically polish the GaN substrate, using a mixed solution of KOH and NaOH. - Another known polishing method of the GaN substrate is, for example, the method described in Patent Document 3. This method is to polish the GaN substrate by free abrasive grains supplied onto a platen. Specifically, while gradually decreasing the grain sizes of free abrasive grains, the GaN substrate is polished at decreasing polishing speeds.
- Non-patent Document 1: J. L. Weyher and three others, “Chemical polishing of bulk and epitaxial GaN,” Journal of Crystal Growth, vol. 182, 1997, pp. 17-22.
- However, when the GaN substrate is polished using the free abrasive grains, the free abrasive grains flocculate together to coarsen on the platen and the coarsened particles scratch the GaN substrate.
- An object of the present invention is to provide a polishing method of a GaN substrate capable of suppressing occurrence of the scratch.
- In order to achieve the above object, a polishing method of a GaN substrate according to the present invention is a method of polishing a GaN substrate, comprising: a first polishing step of polishing the GaN substrate, using a first platen and a polishing solution, while supplying the polishing solution containing first abrasives and a first lubricant, onto the first platen; and a second polishing step of polishing the GaN substrate, using a second platen in which second abrasives are buried, while supplying a second lubricant onto the second platen in which the second abrasives are buried, after the first polishing step.
- Here the second platen may be the first platen, or another platen different from the first platen. The second abrasives may be the first abrasives, or other abrasives different from the first abrasives. For example, the “second platen in which the second abrasives are buried” may be the first platen in which the first abrasives are buried, or the first platen in which other abrasives different from the first abrasives are buried, or another platen different from the first platen, in which other abrasives different from the first abrasives are buried.
- In the polishing method of the GaN substrate of the present invention, the second abrasives are buried in the second platen in the second polishing step. For this reason, the second abrasives are prevented from flocculating together. Therefore, the second polishing step is able to polish the GaN substrate while suppressing the occurrence of scratch.
- Preferably, a peripheral speed of the first platen and a peripheral speed of the second platen are not less than 7 m/min nor more than 57 m/min.
- In this case, the polishing speed of the GaN substrate can be larger in the first and second polishing steps than in the case where the peripheral speed is less than 7 m/min. In addition, it becomes easier to stabilize rotation of the first platen and rotation of the second platen than in the case where the peripheral speed is larger than 57 m/min.
- Preferably, the first abrasives are diamond grains. This can increase the polishing efficiency of the GaN substrate in the first polishing step.
- Preferably, a constituent material of the first platen and a constituent material of the second platen are an alloy containing tin 50 or more % by mass. Since the alloy containing tin 50 or more % by mass is soft, a protruding amount of the first abrasives in the first platen and a protruding amount of the second abrasives in the second platen both become smaller. For this reason, it is feasible to keep small both surface roughness of the GaN substrate after the first polishing step and surface roughness of the GaN substrate after the second polishing step. It is also feasible to suppress the occurrence of scratch.
- Preferably, the polishing method of the GaN substrate further comprises a facing step of cutting the second platen so as to achieve flatness of not more than 10 Sun, before the second polishing step; and a charging step of burying third abrasives for forming the second abrasives, into the second platen, after the facing step and before the second polishing step.
- Here the “flatness” means a difference between a maximum and a minimum among thicknesses of an object to be measured. The facing step and the charging step may be carried out before the first polishing step, or may be carried out after the first polishing step and before the second polishing step. In another possible arrangement, the facing step is carried out before the first polishing step, and the charging step is carried out after the first polishing step and before the second polishing step.
- When the second platen is another platen different from the first platen, the “second platen in which the second abrasives are buried” is obtained, for example, by burying the third abrasives in the platen. When the first platen is also used as the second platen and when the charging step is carried out after the first polishing step, the “second platen in which the second abrasives are buried” is obtained, for example, by burying the third abrasives in the first platen. When the first platen is also used as the second platen and when the charging step is carried out before the first polishing step, the “second platen in which the second abrasives are buried” is obtained, for example, by first burying the third abrasives in the first platen and thereafter carrying out the first polishing step.
- In this case, since the facing step is carried out, the flatness of the GaN substrate after the second polishing step is improved. Since the charging step is carried out, in-plane variation can be reduced in the protruding amount of the second abrasives. For this reason, in-plane variation is reduced in the polishing speed and surface roughness of the GaN substrate in the second polishing step.
- Preferably, the first lubricant and the second lubricant consist primarily of ethylene glycol and water. In this case, it becomes easier to clean the GaN substrate, the first platen, and others after the first polishing step and to clean the GaN substrate, the first and second platens, and others after the second polishing step. Since the first lubricant and the second lubricant contain ethylene glycol, the first lubricant is prevented from evaporating in the first polishing step, and it is feasible to achieve anticorrosion of the first platen. In addition, the second lubricant is prevented from evaporating in the second polishing step, and it is also feasible to achieve anticorrosion of the second platen.
- Preferably, the second polishing step uses the first platen as the second platen. In this case, there is no need for consideration to the individual difference between the first platen and the second platen, and thus the surface shape of the GaN substrate fits the surface shape of the second platen on the occasion of polishing the GaN substrate on the second platen after polished on the first platen. For this reason, it is feasible to suppress the occurrence of scratch.
- In the case where the first platen is used as the second platen in the second polishing step, the polishing method of the GaN substrate preferably further comprises a cleaning step of cleaning foreign matter on the first platen, after the first polishing step and before the second polishing step. This decreases the occurrence of scratch and the surface roughness due to the foreign matter on the first platen, in the second polishing step.
- The polishing method of the GaN substrate of the present invention is able to suppress the occurrence of scratch.
-
FIG. 1 is a schematic perspective view showing an example of polishing apparatus suitably applied to the polishing method of the GaN substrate according to an embodiment of the present invention. -
FIG. 2 is a schematic perspective view of a polishing jig shown inFIG. 1 . -
FIG. 3 is a vertical sectional view along line III-III shown inFIG. 2 . -
FIG. 4 is a drawing schematically showing a crystal structure of a GaN crystal forming a GaN substrate. -
FIG. 5 is a flowchart showing an example of the polishing method of the GaN substrate according to an embodiment of the present invention. -
FIG. 6 is a schematic perspective view for explaining a facing step. -
FIG. 7 is schematic perspective views for explaining the first and second polishing steps. -
FIG. 8 is schematic sectional views for explaining the first and second polishing steps. -
FIG. 9 is a graph showing relationship between the surface roughness Ra of GaN substrate after the first and second polishing steps, and the average grain size of abrasives. - 1 GaN substrate; 21 third abrasives; 23 first abrasives; 25 first lubricant; 27 polishing solution; 29 second abrasives; 31 second lubricant; 101 first and second platens.
- Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, identical or equivalent elements will be denoted by the same reference symbols, without redundant description.
- (Polishing Apparatus of GaN Substrate)
-
FIG. 1 is a schematic perspective view showing an example of polishing apparatus suitably applied to the polishing method of the GaN substrate according to an embodiment of the present invention. The polishingapparatus 100 shown inFIG. 1 has aplaten 101 placed on a table 113, and a polishingjig 10 mounted on asurface 101 a of theplaten 101. In thepolishing apparatus 100, a GaN substrate is placed between theplaten 101 and the polishingjig 10, and the GaN substrate is polished with rotation of theplaten 101 and polishingjig 10. The GaN substrate is suitably used, for example, for devices such as LEDs and LDs. - The
platen 101 is, for example, a disk having a center point O and a radius r. Theplaten 101 rotates, for example, counterclockwise at a peripheral speed v. Achiller 111 for chilling theplaten 101 is connected to theplaten 101. By using thechiller 111, the temperature of theplaten 101 can be controlled to a temperature (e.g., 20° C.) equivalent to room temperature. In this case, theplaten 101 is prevented from generating heat or from being deformed during polishing. - A
motor 103 for rotating and swinging the polishingjig 10 is connected to the polishingjig 10. Themotor 103 is located on the table 113. The polishingjig 10 is preferably arranged to rotate in the same direction as the rotating direction of theplaten 101, e.g., counterclockwise. - The following devices are placed on the table 113: a facing mechanism 119 for cutting the
surface 101 a of theplaten 101; a dropping device (dispenser) 105 for dropping apolishing solution 27 onto thesurface 101 a of theplaten 101; a dropping device (dispenser) 107 for dropping alubricant 31 onto thesurface 101 a of theplaten 101. Each of the droppingdevices drop nozzle drop nozzles solution 27 orlubricant 31. The polishingsolution 27 is, for example, like a slurry. The polishingsolution 27 andlubricant 31 are water-soluble, for example. -
FIG. 2 is a schematic perspective view of the polishingjig 10 shown inFIG. 1 .FIG. 3 is a vertical sectional view along line III-III shown inFIG. 2 . The polishingjig 10 has aplate 17 to which aGaN substrate 1 is attached, and adrive ring 15 surrounding theplate 17. Aweight 13 and asupport rod 11 are placed in order on theplate 17. - The
plate 17 is made, for example, of ceramic. TheGaN substrate 1 is preferably bonded to theplate 17 with an adhesive such as wax. TheGaN substrate 1 is uniformly pressed through theplate 17 onto theplaten 101 by theweight 13. For example,grooves 15 b are radially formed in alower surface 15 a of thedrive ring 15. The polishingjig 10 is so arranged that asurface 1 a of theGaN substrate 1 is in contact with thesurface 101 a of the platen 101 (cf.FIG. 1 ). -
FIG. 4 (a) andFIG. 4 (b) are views schematically showing the crystal structure of the GaN crystal forming theGaN substrate 1. The GaN crystal has the wurtzite crystal structure of the hexagonal system as shown inFIG. 4 (a). A GaN crystal body consisting of such a GaN crystal has the (0001) plane and (000-1) plane as shown inFIG. 4 (b). The (0001) plane is a Ga surface, and the (000-1) plane an N surface. The Vickers hardness of the Ga surface is 1250 kg/mm2, and the Vickers hardness of the N surface 1150 kg/mm2. The Ga surface has higher chemical resistance to KOH than the N surface. - Where the
GaN substrate 1 is a stripe core substrate, the Ga surfaces and N surfaces are arranged in a stripe pattern in thesurface 1 a of the GaN substrate 1 (cf.FIG. 3 ). It is noted that theGaN substrate 1 is not limited to the stripe core substrate. The “stripe core substrate” herein refers to a substrate in a surface of which low-crystal-defect regions extending linearly and having a predetermined width and high-crystal-defect regions extending linearly and having a predetermined width are alternately arranged. The details of the stripe core substrate are described, for example, in Japanese Patent Application Laid-Open No. 2004-335646. - (Polishing Method of GaN Substrate)
- The polishing method of the GaN substrate according to the present embodiment is suitably carried out with the above-described
polishing apparatus 100. -
FIG. 5 is a flowchart showing an example of the polishing method of the GaN substrate according to the present embodiment. In this polishing method of the GaN substrate, for example, a facing step (step S1), a charging step (step S2), a first polishing step (step S3), a cleaning step (step S4), and a second polishing step (step S5) are carried out in order. The present embodiment is based on the assumption that theplaten 101 used in the first polishing step is also used as a platen used in the second polishing step. - Each of the steps S1 to S5 will be described below in detail with reference to
FIGS. 6 to 8 .FIG. 6 is a schematic perspective view for explaining the facing step.FIG. 7 (a) andFIG. 7 (b) are schematic perspective views for explaining the first and second polishing steps, respectively.FIG. 8 (a) andFIG. 8 (b) are schematic sectional views for explaining the first and second polishing steps, respectively. - (Facing Step)
- The
surface 101 a of theplaten 101 may be cut so that the flatness of the platen 101 (TTV: Total Thickness Variation) becomes not more than 10 μm, as shown inFIG. 6 , as occasion may demand. With the use of thisplaten 101, for example, theGaN substrate 1 of the diameter of 2 inches can be suitably polished. The shape of thesurface 101 a of theplaten 101 is transferred onto thesurface 1 a of theGaN substrate 1. More preferably, thesurface 101 a of theplaten 101 is cut so that the flatness of the part from the center point O to the periphery of the platen 101 (radial part) becomes not more than 5 μm. Particularly, in a case where the polishing is carried out using abrasives having a small average grain size, it is preferable to make the flatness of theplaten 101 small. - For the cutting, it is preferable to use a
diamond turning tool 109 a. Thediamond turning tool 109 a constitutes the major part of the facing mechanism 109 (cf.FIG. 1 ). Thediamond turning tool 109 a moves along a radial direction X from the center point O to the periphery of theplaten 101. The cutting is performed by moving thediamond turning tool 109 a while rotating theplaten 101. The rotating speed of theplaten 101 is, for example, 400 rpm. InFIG. 6 , thesurface 101 a of theplaten 101 consists of an already-cutsurface 101 b and a yet-cutsurface 101 c. After the cutting, thesurface 101 a of theplaten 101 is preferably cleaned as needed. - (Charging Step)
- As shown in
FIG. 7 (a), abrasives 21 (third abrasives) may be buried in theplaten 101 as occasion may demand. Specifically, for example, while supplying a polishing solution (not shown) containing theabrasives 21 and a lubricant (not shown) onto thesurface 101 a of theplaten 101, the polishing jig 10 (cf.FIGS. 2 and 3 ) in a state in which theGaN substrate 1 is not bonded, and theplaten 101 are rotated. In the present embodiment, theabrasives 21 are one for formingabrasives 29 in the second polishing step, as described later. - An example of charging conditions is presented below.
- Drop rate of polishing solution: 5 cc/min
Rotating speed of drive ring 15: 60 rpm
Pressure of weight 13: 1.96×104 Pa (200 g/cm2)
Charging time: 60 min or more - (First Polishing Step)
- As shown in
FIG. 7 (a), while supplying apolishing solution 27 containing abrasives 23 (first abrasives) and a lubricant 25 (first lubricant) onto thesurface 101 a of theplaten 101, theGaN substrate 1 is polished using theplaten 101 and the polishingsolution 27. During the polishing, theplaten 101 and polishingjig 10 are preferably rotated. The polishingsolution 27 is preferably dropped from the droppingnozzle 105 a of the droppingdevice 105 onto thesurface 101 a of theplaten 101. In the first polishing step theGaN substrate 1 is polished by theabrasives FIG. 8 (a). Thelubricant 25 is filled between theGaN substrate 1 and theplaten 101. - Most of the
abrasives 21 are abrasive grains buried and fixed in the platen 101 (hereinafter also referred to as fixed grains), and most of theabrasives 23 are free grains not buried in the platen 101 (hereinafter also referred to as free abrasive grains). However, theabrasives 21 may be released in part to become free abrasive grains, or theabrasives 23 may be buried in part in theplaten 101 to become fixed grains. The protruding amount tw1 of theabrasives abrasives 23 as free abrasive grains, as shown inFIG. 8 (a). - An example of polishing conditions in the first polishing step is presented below.
- GaN substrate 1: GaN single-crystal substrate having the diameter (φ) of 50.8 mm and the thickness of 400 μm
Drop rate of polishing solution 27: 5 cc/min
Maximum grain size of abrasives 23: 1 μm or less
Diameter (φ) of platen 101: 450 mm
Constituent material of platen 101: tin
Rotating speed of drive ring 15: 30 rpm
Swing speed of drive ring 15: 10 swings/min
Swing stroke: 30 mm
Pressure of weight 13: 1.96×104 Pa (200 g/cm2)
Polishing time: 60 min - After the
GaN substrate 1 is polished using theabrasives solution 27 attached to theplate 17 and drive ring 15 (cf.FIGS. 2 and 3 ) is removed, if necessary, to clean the polishingjig 10. A cleaning method is, for example, ultrasonic cleaning using ultrapure water. - (Cleaning Step)
- The
surface 101 a of theplaten 101 may be cleaned by removing foreign matter on theplaten 101 as occasion may demand. The foreign matter is, for example, cut chips ofGaN substrate 1, free abrasive grains, etc. after the first polishing step. For the cleaning, it is preferable to use ultrapure water and a wiper that produces neither dust nor chips. However, even after the cleaning with this wiper, free abrasive grains could remain on thesurface 101 a of theplaten 101 in some cases. In such cases, in order to bury the free abrasive grains into theplaten 101, the polishingjig 10 without theGaN substrate 1 may be rotated on theplaten 101, while rotating theplaten 101. The cleaning step may be omitted if the polishing time in the first polishing step is short or if the concentration of theabrasives 23 in thepolishing solution 27 is low. - When the cleaning step is carried out after the first polishing step and before the second polishing step, it is feasible to reduce the surface roughness Ra and the occurrence of scratch due to the foreign matter produced in the first polishing step.
- (Second Polishing Step)
- As shown in
FIG. 7 (b), while supplying a lubricant 31 (second lubricant) onto theplaten 101 in which the abrasives 29 (second abrasives) are buried, theGaN substrate 1 is polished using theplaten 101 in which theabrasives 29 are buried. During the polishing, it is preferable to rotate theplaten 101 and the polishingjig 10. In the second polishing step, theGaN substrate 1 is polished with theabrasives 29, as shown inFIG. 8 (b). Thelubricant 31 is filled between theGaN substrate 1 and theplaten 101. - The
abrasives 29 are the abrasives buried in theplaten 101, among theaforementioned abrasives abrasives 21 buried in theplaten 101 in the charging step may also be used as theabrasives 29. Since theabrasives 29 are fixed grains, the protruding amount tw2 of theabrasives 29 is smaller than the protruding amount tw1 of theabrasives FIG. 8 (a) andFIG. 8 (b). The smaller the protruding amount of the abrasives, the smaller the surface roughness Ra becomes. Therefore, the surface roughness Ra of theGaN substrate 1 after the second polishing step becomes smaller than the surface roughness Ra of theGaN substrate 1 after the first polishing step. Let Hp be the hardness of the platen, Hw be the hardness of the workpiece, and φd be the average grain size of the abrasives, and then the surface roughness Ra of the workpiece after polished is expressed, for example, by Eq (1) below. -
Ra=φd ×H p/4H w (1) -
FIG. 9 is a graph showing the relationship between the surface roughness Ra of the GaN substrate after the first and second polishing steps, and the average grain size of the abrasives. Points in region P1 inFIG. 9 indicate the surface roughness Ra of theGaN substrate 1 after the first polishing step, and points in region P2 the surface roughness Ra of theGaN substrate 1 after the second polishing step. Values of surface roughness Ra are values measured with an atomic force microscope (AFM). As apparent from this graph, the surface roughness Ra and variation of surface roughness Ra are smaller in theGaN substrate 1 after the second polishing step than in theGaN substrate 1 after the first polishing step. - An example of polishing conditions in the second polishing step is presented below.
- Drop rate of lubricant 31: 5 cc/min
Peripheral speed v of platen 101: 28 m/min
Pressure of weight 13: 1.96×104 Pa (200 g/cm2)
Polishing time: 60 mm - In the polishing method of the GaN substrate according to the present embodiment, as described above, the
abrasives 29 are buried in theplaten 101 in the second polishing step. For this reason, theabrasives 29 are prevented from flocculating together. In the second polishing step the protruding amount tw2 of theabrasives 29 is small and uniform. Therefore, the second polishing step is able to polish theGaN substrate 1 while suppressing the occurrence of scratch. Furthermore, it is also feasible to made the surface roughness Ra of theGaN substrate 1 small after the second polishing step and to reduce the in-plane variation of surface roughness Ra. On the other hand, the polishing speed of theGaN substrate 1 can be set large in the first polishing step and, therefore, it is feasible to efficiently eliminate a mechanically damaged layer which is formed in theGaN substrate 1 by preprocessing such as slicing or cutting before the first polishing step. The GaN substrate in which the occurrence of scratch is suppressed well can be suitably produced by the polishing method of the GaN substrate according to the present embodiment. - In the first and second polishing steps, the peripheral speed v of the
platen 101 shown inFIG. 1 is preferably not less than 7 m/min nor more than 57 m/min. The polishing speed of theGaN substrate 1 can be made larger in the case of the peripheral speed v of not less than 7 m/min than in the case of the peripheral speed v of less than 7 m/min, and productivity is also higher. In addition, it becomes easier to stabilize the rotation of theplaten 101 and polishingjig 10 in the case of the peripheral speed v of not more than 57 m/min. Specifically, it is feasible to suppress fluctuation in the thrust direction (the axial direction ofsupport rod 11 of polishing jig 10) which could cause scratches. For this reason, the number of scratches can be reduced when compared with the case where the peripheral speed v is larger than 57 m/min. - In the first and second polishing steps, the rotating speed of the
platen 101 is preferably not less than 5 rpm nor more than 40 rpm. The polishing speed of theGaN substrate 1 can be made larger in the case of the rotating speed of not less than 5 rpm than in the case of the rotating speed of less than 5 rpm; therefore, productivity is higher. Since it becomes easier to stabilize the rotation of theplaten 101 in the case of the rotating speed of not more than 40 rpm, the number of scratches can be reduced when compared with the case where the rotating speed is larger than 40 rpm. - As an example, Table 1 presents the results of measurements of the peripheral speed v of the
platen 101, the rotating speed of theplaten 101, and the number of scratches in the first polishing step. In Table 1, the “number of scratches” indicates the number of scratches produced in the surface of the GaN substrate having the diameter (φ) of 50.8 mm. The number of scratches was measured by visual inspection under a light-collecting lamp. -
TABLE 1 Peripheral Speed of Rotating Speed of Number of Scratches Platen (m/min) Platen (rpm) (Scratches) 7 5 2 28 20 5 57 40 7 84 60 17 140 100 30 - Next, as an example, Table 2 presents the results of measurements of the peripheral speed v of the
platen 101, the rotating speed of theplaten 101, and the number of scratches in the second polishing step. In Table 2, the “number of scratches” indicates the number of scratches produced in the surface of the GaN substrate having the diameter (φ) of 50.8 mm. The number of scratches was measured by visual inspection under a light-collecting lamp. -
TABLE 2 Peripheral Speed of Rotating Speed of Number of Scratches Platen (m/min) Platen (rpm) (Scratches) 7 5 0 28 20 0 57 40 0 84 60 5 140 100 10 - The Vickers hardnesses of the
abrasives abrasives abrasives GaN substrate 1 in the first polishing step. Where theabrasives 29 are diamond grains, an improvement can be made in the polishing efficiency of theGaN substrate 1 in the second polishing step. - The constituent material of the
platen 101 is preferably an alloy containing tin 50 or more % by mass. Theplaten 101 may have a coating layer made of an alloy containing tin 50 or more % by mass. The alloy containing tin 50 or more % by mass is softer than metal such as copper, and thus the protruding amount tw1 of theabrasives abrasives 29 in the platen 101 (cf.FIG. 8 ) become smaller. For this reason, the surface roughness Ra of theGaN substrate 1 after the first and second polishing steps can be made smaller and it is feasible to suppress the occurrence of scratch. - As an example, Table 3 presents the results of measurements of the constituent material of the
platen 101, the surface roughness Ra of theGaN substrate 1, and the number of scratches in the second polishing step. In Table 3, the “number of scratches” indicates the number of scratches produced in the surface of the GaN substrate having the diameter (φ) of 50.8 mm. The number of scratches was measured by visual inspection under a light-collecting lamp. The surface roughness Ra was measured with an atomic force microscope (AFM). -
TABLE 3 Surface Roughness Constituent Material Ra of GaN Substrate Number of Scratches of Platen (nm) (Scratches) tin ≧ 99 mass % 1 0 tin 70 mass % 2 0 lead 30 mass % tin 50 mass % 5 0 lead 50 mass % tin 30 mass % 10 10 or more lead 70 mass % tin 95 mass % 1.5 0 bismuth 5 mass %tin 97 mass % 1.5 0 stibium 3 mass % - As shown in Table 3, the constituent material of the
platen 101 is preferably an alloy containing tin 50 or more % by mass. The GaN substrates with the surface roughness Ra of not more than 5 nm and with the number of scratches of 0 can be suitably applied to such devices as LEDs and LDs. Use of bismuth or antimony is rather preferable than lead, in order to prevent environment pollution. - When the
platen 101 is made of tin, theabrasives platen 101 where theabrasives - Since the polishing method of the GaN substrate according to the present embodiment involves carrying out the facing step as described above, an improvement is made in the flatness of the
GaN substrate 1 after the first and second polishing steps. In the facing step, preferably, grooves (not shown) of spiral shape or concentric circular shape with the center on the center point O are preferably formed in thesurface 101 a of theplaten 101. They decrease the friction resistance between theGaN substrate 1 and theplaten 101 and facilitates supply of the polishingsolution 27 orlubricant 31 to between theGaN substrate 1 and theplaten 101, in the first and second polishing steps. - Since the polishing method of the GaN substrate according to the present embodiment involves carrying out the charging step as described above, the in-plane variation can be reduced in the protruding amount tw2 of the
abrasives 29. This decreases the in-plane variation of the polishing speed and surface roughness Ra of theGaN substrate 1 in the second polishing step. Further, it also suppresses the occurrence of scratch. When the charging step is carried out before the first polishing step, the polishing speed in the first polishing step is stabilized at a start of polishing. - The
lubricants - In the above-described case, since the
lubricants GaN substrate 1, and thepolishing apparatus 100 such as theplaten 101 after the first and second polishing steps. Since GaN does not react with water, the water-soluble lubricants can be used. This enhances workability of cleaning and also decreases cleaning cost. When thelubricants lubricants platen 101. - Since the present embodiment uses the
platen 101 used in the first polishing step, as the platen used in the second polishing step, there is no need for consideration to the individual difference between platens (e.g., difference in surface shape or the like). Therefore, when theGaN substrate 1 after polished on theplaten 101 in the first polishing step is polished on theplaten 101 in the second polishing step, the shape of thesurface 1 a of theGaN substrate 1 fits the shape of thesurface 101 a of theplaten 101. For this reason, it is feasible to suppress the occurrence of scratch after the second polishing step. - The preferred embodiment of the present invention was described above in detail, but the present invention is by no means limited to the above embodiment.
- For example, the above embodiment may be arranged without one or more of the facing step, the charging step, and the cleaning step. When the charging step is omitted, the
abrasives 21 are not buried in theplaten 101 in the first polishing step. At this time, theabrasives 23 are gradually buried into theplaten 101 during the polishing in the first polishing step, and thus the buriedabrasives 23 become fixed grains. The fixed grains work as theabrasives 29 in the second polishing step. - The facing step and the charging step may also be carried out after the first polishing step and before the second polishing step. Alternatively, the facing step may be carried out before the first polishing step, and the charging step may be carried out after the first polishing step and before the second polishing step. The same effect as in the above embodiment is also achieved in either case. In these cases, the
abrasives 21 work as theabrasives 29. - The above embodiment used the
platen 101 used in the first polishing step, as the platen used in the second polishing step, but it is also possible to use different platens as the platen used in the first polishing step (first platen) and as the platen used in the second polishing step (second platen). In this case, the facing step and the charging step may be carried out on the first platen before the first polishing step, or may be carried out on the second platen before the second polishing step. The same effect as in the above embodiment is also achieved in either case.
Claims (17)
1-8. (canceled)
9. A GaN substrate prepared by a method of polishing a GaN substrate of which surface to be polished has Ga portions and N portions alternatively arranged, the method comprising:
a first polishing step of polishing the GaN substrate held by a polishing jig, using a first platen made of a material including tin and a polishing solution, while supplying the polishing solution containing first abrasives and a first lubricant, onto the first platen;
a second polishing step of polishing the GaN substrate held by the polishing jig, using a second platen, made of a material including tin, in which second abrasives are buried, while supplying a second lubricant onto the second platen in which the second abrasives are buried, after the first polishing step; and
in at least one of the first and second polishing steps, rotating the first or second platen and the polishing jig in the same direction,
wherein a surface roughness Ra of the GaN substrate is reduced to not more than 5 nm.
10. A semiconductor device formed on the GaN substrate of claim 9 .
11. The GaN substrate of claim 9 ,
wherein a surface roughness Ra of the GaN substrate is further reduced to not more than 0.2 nm.
12. A semiconductor device formed on the GaN substrate of claim 11 .
13. A GaN substrate prepared by a method of polishing a GaN substrate, the method comprising:
a first polishing step of polishing the GaN substrate held by a polishing jig, using a first platen and a polishing solution, while supplying the polishing solution containing first abrasives and a first lubricant, onto the first platen;
a second polishing step of polishing the GaN substrate held by the polishing jig, using a second platen in which second abrasives are buried, while supplying a second lubricant onto the second platen in which the second abrasives are buried, after the first polishing step; and
in at least one of the first and second polishing steps, rotating the first or second platen and the polishing jig in the same direction, wherein
the first step including supplying the polishing solution between the GaN substrate and the first platen through grooves arranged in a surface of the polishing jig where the GaN substrate is held, and
the second step including supplying the second lubricant between the GaN substrate and the first platen through the grooves,
wherein a surface roughness Ra of the GaN substrate is reduced to not more than 5 nm.
14. A semiconductor device formed on the GaN substrate of claim 13 .
15. The GaN substrate of claim 13 ,
wherein a surface roughness Ra of the GaN substrate is further reduced to not more than 0.2 nm.
16. A semiconductor device formed on the GaN substrate of claim 13 .
17. A GaN substrate prepared by using a polishing apparatus for a GaN substrate of which surface to be polished has Ga portions and N portions alternatively arranged, the polishing apparatus comprising:
a polishing jig for rotatably holding the GaN substrate; and
a platen made of a material including tin and configured to be rotated in the same direction as the polishing jig to polish the GaN substrate held between the polishing jig and the platen,
wherein a surface roughness Ra of the GaN substrate is reduced to not more than 5 nm.
18. A semiconductor device formed on the GaN substrate of claim 17 .
19. The GaN substrate of claim 18 ,
wherein a surface roughness Ra of the GaN substrate is further reduced to not more than 0.2 nm.
20. A semiconductor device formed on the GaN substrate of claim 19 .
21. A GaN substrate prepared by using a polishing apparatus for a GaN substrate, the polishing apparatus comprising:
a polishing jig for rotatably holding the GaN substrate; and
a platen configured to be rotated in the same direction as the polishing jig to polish the GaN substrate held between the polishing jig and the platen, wherein
the polishing jig has radially extending grooves arranged in an area surrounding the GaN substrate,
wherein a surface roughness Ra of the GaN substrate is reduced to not more than 5 nm.
22. A semiconductor device formed on the GaN substrate of claim 21 .
23. The GaN substrate of claim 21 ,
wherein a surface roughness Ra of the GaN substrate is further reduced to not more than 0.2 nm.
24. A semiconductor device formed on the GaN substrate of claim 23 .
Priority Applications (1)
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US12/254,360 US20090045410A1 (en) | 2005-01-12 | 2008-10-20 | GaN SUBSTRATE AND SEMICONDUCTOR DEVICE PREPARED BY USING METHOD AND APPARATUS OF POLISHING GaN SUBSTRATE |
Applications Claiming Priority (5)
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JPP2005-005497 | 2005-01-12 | ||
JP2005005497A JP5065574B2 (en) | 2005-01-12 | 2005-01-12 | Polishing method of GaN substrate |
PCT/JP2005/024057 WO2006075527A1 (en) | 2005-01-12 | 2005-12-28 | METHOD FOR ABRASING GaN SUBSTRATE |
US11/486,012 US7452814B2 (en) | 2005-01-12 | 2006-07-14 | Method of polishing GaN substrate |
US12/254,360 US20090045410A1 (en) | 2005-01-12 | 2008-10-20 | GaN SUBSTRATE AND SEMICONDUCTOR DEVICE PREPARED BY USING METHOD AND APPARATUS OF POLISHING GaN SUBSTRATE |
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US11/486,012 Continuation US7452814B2 (en) | 2005-01-12 | 2006-07-14 | Method of polishing GaN substrate |
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US20090045410A1 true US20090045410A1 (en) | 2009-02-19 |
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US11/486,012 Expired - Fee Related US7452814B2 (en) | 2005-01-12 | 2006-07-14 | Method of polishing GaN substrate |
US12/254,360 Abandoned US20090045410A1 (en) | 2005-01-12 | 2008-10-20 | GaN SUBSTRATE AND SEMICONDUCTOR DEVICE PREPARED BY USING METHOD AND APPARATUS OF POLISHING GaN SUBSTRATE |
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US (2) | US7452814B2 (en) |
EP (1) | EP1814149B1 (en) |
JP (1) | JP5065574B2 (en) |
KR (1) | KR100858948B1 (en) |
CN (3) | CN101274419B (en) |
HK (1) | HK1100101A1 (en) |
TW (1) | TW200633045A (en) |
WO (1) | WO2006075527A1 (en) |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
TWI452617B (en) * | 2006-07-26 | 2014-09-11 | Freiberger Compound Mat Gmbh | Process for smoothening iii-n substrates |
KR101363316B1 (en) * | 2006-07-26 | 2014-02-14 | 프라이베르게르 컴파운드 마터리얼스 게엠베하 | Method for smoothing iii-n substrates |
US7585772B2 (en) | 2006-07-26 | 2009-09-08 | Freiberger Compound Materials Gmbh | Process for smoothening III-N substrates |
JP2008066355A (en) * | 2006-09-05 | 2008-03-21 | Sumitomo Electric Ind Ltd | Manufacturing method of group iii nitride substrate, group iii nitride substrate, group iii nitride substrate with epitaxial layer, group iii nitride device, manufacturing method of group iii nitride substrate with epitaxial layer, and manufacturing method of group iii nitride device |
JP5353711B2 (en) * | 2007-12-05 | 2013-11-27 | 株式会社リコー | Crystal manufacturing method and crystal manufacturing apparatus for group III nitride crystal |
JP4333820B1 (en) * | 2009-01-19 | 2009-09-16 | 住友電気工業株式会社 | Compound semiconductor substrate |
DE102009025243B4 (en) | 2009-06-17 | 2011-11-17 | Siltronic Ag | Method for producing and method of processing a semiconductor wafer made of silicon |
CN103506928B (en) * | 2012-06-19 | 2016-02-10 | 上海硅酸盐研究所中试基地 | Superhard polishing semiconductor materials method |
US20160013085A1 (en) * | 2014-07-10 | 2016-01-14 | Applied Materials, Inc. | In-Situ Acoustic Monitoring of Chemical Mechanical Polishing |
CN107263301B (en) * | 2017-06-26 | 2019-05-14 | 镓特半导体科技(上海)有限公司 | A kind of method of grinding-chemically mechanical polishing gallium nitride wafer piece |
US11078380B2 (en) * | 2017-07-10 | 2021-08-03 | Entegris, Inc. | Hard abrasive particle-free polishing of hard materials |
CN107953154B (en) * | 2017-12-27 | 2020-03-10 | 武汉华星光电半导体显示技术有限公司 | Method and apparatus for polishing glass substrate |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5743788A (en) * | 1996-12-02 | 1998-04-28 | Motorola, Inc. | Platen coating structure for chemical mechanical polishing and method |
US6136138A (en) * | 1996-03-18 | 2000-10-24 | Nippon Steel Semiconductor Corporation | Method and apparatus for chemical mechanical polishing of a semiconductor wafer |
US20020031979A1 (en) * | 2000-01-28 | 2002-03-14 | Tdk Corporation | Method of polishing a magnetic head slider |
US6488767B1 (en) * | 2001-06-08 | 2002-12-03 | Advanced Technology Materials, Inc. | High surface quality GaN wafer and method of fabricating same |
US20050029539A1 (en) * | 2002-03-26 | 2005-02-10 | Sanyo Electric Co., Ltd. | Nitride-based semiconductor device and method of fabricating the same |
US20060226124A1 (en) * | 2005-04-08 | 2006-10-12 | Ohara Inc. | Substrate and a method for polishing a substrate |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62102970A (en) * | 1985-10-31 | 1987-05-13 | Hitachi Metals Ltd | Hard sn lapping surface plate |
JP2001322899A (en) * | 2000-05-11 | 2001-11-20 | Matsushita Electric Ind Co Ltd | Gallium nitride-based compound semiconductor substrate and method of producing the same |
US6467537B1 (en) * | 2000-05-17 | 2002-10-22 | Carrier Corporation | Advanced starting control for multiple zone system |
JP2002064099A (en) * | 2000-08-16 | 2002-02-28 | Nanotekku Machines:Kk | Manufacturing method of embedded wiring structure body |
JP2003305638A (en) * | 2002-04-12 | 2003-10-28 | Fujitsu Ltd | Polishing device and polishing method |
JP2003326453A (en) * | 2002-05-01 | 2003-11-18 | Hitachi Ltd | Magnetic head, magnetic disk device, manufacturing method of magnetic head and polishing device |
JP2004058220A (en) | 2002-07-30 | 2004-02-26 | Tokyo Magnetic Printing Co Ltd | Lapping oil composition for finish polishing and finish polishing method for composite material |
JP2004281865A (en) * | 2003-03-18 | 2004-10-07 | Namiki Precision Jewel Co Ltd | POLISHING METHOD OF GaN AND POLISHING AGENT FOR GaN |
JP3534115B1 (en) * | 2003-04-02 | 2004-06-07 | 住友電気工業株式会社 | Edge-polished nitride semiconductor substrate, edge-polished GaN free-standing substrate, and edge processing method for nitride semiconductor substrate |
JP4363890B2 (en) * | 2003-04-30 | 2009-11-11 | 共栄社化学株式会社 | Water-based polishing fluid |
JP2004335646A (en) | 2003-05-06 | 2004-11-25 | Sumitomo Electric Ind Ltd | GaN SUBSTRATE |
JP4518746B2 (en) * | 2003-05-06 | 2010-08-04 | 住友電気工業株式会社 | GaN substrate |
KR100550491B1 (en) * | 2003-05-06 | 2006-02-09 | 스미토모덴키고교가부시키가이샤 | Nitride semiconductor substrate and processing method of nitride semiconductor substrate |
JP4155872B2 (en) * | 2003-05-26 | 2008-09-24 | 一正 大西 | Lapping machine manufacturing method |
-
2005
- 2005-01-12 JP JP2005005497A patent/JP5065574B2/en active Active
- 2005-12-28 CN CN200810086581XA patent/CN101274419B/en not_active Expired - Fee Related
- 2005-12-28 EP EP05822594A patent/EP1814149B1/en active Active
- 2005-12-28 CN CN2008101454275A patent/CN101350302B/en not_active Expired - Fee Related
- 2005-12-28 CN CNB2005800017073A patent/CN100421224C/en active Active
- 2005-12-28 WO PCT/JP2005/024057 patent/WO2006075527A1/en active Application Filing
- 2005-12-28 KR KR1020067012231A patent/KR100858948B1/en not_active IP Right Cessation
-
2006
- 2006-01-03 TW TW095100221A patent/TW200633045A/en unknown
- 2006-07-14 US US11/486,012 patent/US7452814B2/en not_active Expired - Fee Related
-
2007
- 2007-07-20 HK HK07107890.9A patent/HK1100101A1/en not_active IP Right Cessation
-
2008
- 2008-10-20 US US12/254,360 patent/US20090045410A1/en not_active Abandoned
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6136138A (en) * | 1996-03-18 | 2000-10-24 | Nippon Steel Semiconductor Corporation | Method and apparatus for chemical mechanical polishing of a semiconductor wafer |
US5743788A (en) * | 1996-12-02 | 1998-04-28 | Motorola, Inc. | Platen coating structure for chemical mechanical polishing and method |
US20020031979A1 (en) * | 2000-01-28 | 2002-03-14 | Tdk Corporation | Method of polishing a magnetic head slider |
US6488767B1 (en) * | 2001-06-08 | 2002-12-03 | Advanced Technology Materials, Inc. | High surface quality GaN wafer and method of fabricating same |
US20020185054A1 (en) * | 2001-06-08 | 2002-12-12 | Advanced Technology Materials Inc. | High surface quality gan wafer and method of fabricating same |
US20050029539A1 (en) * | 2002-03-26 | 2005-02-10 | Sanyo Electric Co., Ltd. | Nitride-based semiconductor device and method of fabricating the same |
US20060226124A1 (en) * | 2005-04-08 | 2006-10-12 | Ohara Inc. | Substrate and a method for polishing a substrate |
Also Published As
Publication number | Publication date |
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EP1814149A4 (en) | 2009-04-29 |
JP2006196609A (en) | 2006-07-27 |
TW200633045A (en) | 2006-09-16 |
EP1814149B1 (en) | 2011-09-14 |
US20060283840A1 (en) | 2006-12-21 |
CN101274419B (en) | 2011-03-23 |
KR100858948B1 (en) | 2008-09-18 |
US7452814B2 (en) | 2008-11-18 |
CN101274419A (en) | 2008-10-01 |
EP1814149A1 (en) | 2007-08-01 |
CN1906739A (en) | 2007-01-31 |
CN101350302B (en) | 2011-01-19 |
HK1100101A1 (en) | 2007-09-07 |
JP5065574B2 (en) | 2012-11-07 |
CN100421224C (en) | 2008-09-24 |
WO2006075527A1 (en) | 2006-07-20 |
KR20060135672A (en) | 2006-12-29 |
CN101350302A (en) | 2009-01-21 |
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