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  Cmp conditionerUSPTO Application #: 20070259609Title: Cmp conditioner Abstract: In a CMP conditioner in which abrasive grains are fixed to a protrusion protruded from an upper surface of a base, the abrasive grains are stably fixed to prevent a scratch from being generated due to detachment of the abrasive grains and a space for holding a polishing fluid is surely ensured between a protrusion section of the protrusion surrounding the abrasive grains and the pad upon dressing. In the CMP conditioner in which protrusions are protruded from an upper surface of a base which rotates around an axis line and a plurality of abrasive grains is fixed to the protrusions, the abrasive grains are fixed such that the abrasive grains are not protruded from a virtual extending surface which extends from the peripheries of protrusion sections, which face protrusion directions of the protrusions, along the axis line. (end of abstract) Agent: Darby & Darby P.C. - New York, NY, US Inventors: Hiroshi Iiyoshi, Takashi Kimura, Tuguhisa Koyama, Hiroaki Iizuka USPTO Applicaton #: 20070259609 - Class: 451443000 (USPTO) Related Patent Categories: Abrading, Accessory, Dressing The Patent Description & Claims data below is from USPTO Patent Application 20070259609. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS REFERENCE TO PRIOR APPLICATION [0001] This is a U.S. national phase application under 35 U.S.C. .sctn.371 of International Application No. PCT/JP2005/005926 filed Mar. 29, 2005 and claims the benefit of Japanese Applications No. 2004-106414, filed Mar. 31, 2004 and 2005-035729, filed Feb. 14, 2005. The International Application was published in Japanese on Oct. 13, 2005 as International Publication No. WO 2005/095056 under PCT Article 21(2). FIELD OF THE INVENTION [0002] The present invention relates to a chemical mechanical polishing (CMP) conditioner used for dressing (toothing) of an abrasive pad of a CMP apparatus for polishing a semiconductor wafer or the like. BACKGROUND ART [0003] As such a kind of a CMP conditioner, for example, in Japanese Unexamined Patent Application Publication No. 2001-71269 ("Patent Document 1"), a CMP conditioner in which a plurality of substantially cylindrical protrusions is formed on an upper surface of a circular-plate-shaped base (base metal) at an interval and a plurality of abrasive grains such as diamond is fixed on the surface of the protrusion by a metal plating phase is suggested. Accordingly, according to such a CMP conditioner, a high polishing pressure can be maintained against the abrasive grains, without entirely bringing the upper surface of the base of the conditioner fixed with the abrasive grains into contact with the pad of a CMP apparatus and thus sharpness can be improved. In addition, a polishing fluid can be held in concave portions between the protrusions and thus dischargeability of chips can be improved. [0004] In Japanese Unexamined Patent Application Publication No. 2002-337050 ("Patent Document 2"), a CMP conditioner in which a plurality of small abrasive grain layer parts protruded in a convex curve shape is arranged on an upper surface of a base at an interval, ring-shaped circumferential abrasive grain layer parts protruded in the same height as the small abrasive grain layer parts are provided on the outer circumference of the small abrasive grain layer parts, and a plurality of abrasive grains are fixed on the surface of the abrasive layer parts by a metal plating phase is suggested. Among them, the circumferential abrasive grain layer parts come in surface contact with a pad such that the surface pressure of the conditioner is prevented from greatly increasing and a polishing process can be performed by the small abrasive grain layer parts with good sharpness. Accordingly, over-polishing of the pad or fracturing of the abrasive grains is suppressed and thus the good sharpness due to appropriate depth of cut can be ensured. [0005] The outer circumferential side of the circumferential abrasive grain layer part of the base has a convex curve shape or a taper shape of a cut plane R having a slant slower than the sidewall of an inner side and thus the pad can be prevented from being peeled upon start-up of polishing. DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention [0006] However, in Patent Documents 1 and 2, in order to fix the plurality of abrasive grains on the surface of the protrusion protruded from the upper surface of the base, such as the protrusion of Patent Document 1 or the small abrasive grain layer part and the circumferential abrasive grain layer part of Patent document 2, by the metal plating phase, masking is performed on the upper surface of the base except a rising part which becomes the protrusion or the abrasive grain layer part, and the abrasive grains are then fixed by electroplating. Accordingly, the abrasive grains are fixed on the protrusion or the abrasive grain layer part over the whole surface. To this end, in the CMP conditioners of Patent Documents 1 and 2, for example, the abrasive grains are also fixed to a cross ridge line between a circular protrusion section for configuring the cylindrical protrusion and the cylindrical outer circumferential wall surface, which rises from the upper surface of the base, of Patent Document 1 or the periphery of a cross ridge line between the ring-shaped (annular) protrusion section for configuring the circumferential abrasive grain layer part and the inner sidewall, which rises from the upper surface of the base, of Patent Document 2. [0007] The cross ridge line between the wall surface which steeply rises from the upper surface of the base, such as circumferential wall surface of the protrusion or the inner sidewall of the circumferential abrasive grain layer part, and the protrusion section which is parallel to the upper surface of the base has a cross angle smaller than that of the cross ridge line between the protrusion section of the circumferential abrasive grain layer part and the convex curve having a slow slant of the outer circumference thereof of Patent document 2, that is, is a pin angle state. Accordingly, when the abrasive grains are fixed on the cross ridge line or when the abrasive grains are fixed to be protruded from the cross ridge line even on the protrusion section or the wall surface, the protruded abrasive grains cannot be supported by the base through the metal plating phase. To this end, these abrasive grains may be unstably fixed and, when the unstable abrasive grains are detached when dressing the pad, the polished semiconductor wafer may be scratched. [0008] When the abrasive grains are fixed over the whole surface of the protrusion and, more particularly, the cross ridge line between the protrusion section and the wall surface, the abrasive grains are positioned on the periphery of the protrusion section, which is in contact with the pad at the time of dressing. Accordingly, it is difficult to sufficiently ensure a space for holding the polishing fluid between the protrusion section surrounding the abrasive grains positioned in the periphery and the pad at the time of dressing. However, the abrasive grains positioned in the periphery of the protrusion section of the protrusion are cut into the surface of the pad earlier than the other abrasive grains fixed to the protrusion section to perform the dressing. Accordingly, when the polishing fluid is not sufficiently held in the vicinity of such abrasive grains, abrasion of the abrasive grains are significantly accelerated, a polishing rate of the pad is reduced, and thus polishing efficiency of the semiconductor wafer using the CMP apparatus deteriorates or the life span of the conditioner is reduced. [0009] The present invention is made under such a background, and an object of the present invention is to provide a CMP conditioner which can stably fix abrasive grains to prevent a scratch from being generated due to detachment of the abrasive grains and surely ensure a space for holding polishing fluid between a protrusion section surrounding the abrasive grains and a pad at the time of dressing in a CMP conditioner in which the abrasive grains are fixed to a protrusion protruded on an upper surface of a base. MEANS FOR SOLVING THE PROBLEMS [0010] In order to solve the problems and to accomplish such an object, there is provided a CMP conditioner in which a protrusion is protruded from an upper surface of a base which rotates around an axis line and a plurality of abrasive grains is fixed to the protrusion, wherein the abrasive grains are fixed such that the abrasive grains are not protruded from a virtual extending surface which extends from the periphery of a protrusion section, which faces a protrusion direction of the protrusion, along the axis line. EFFECTS OF THE INVENTION [0011] In the CMP conditioner described above, since the plurality of abrasive grains fixed to the protrusion section of the protrusion protruded from the upper surface of the base is not protruded from the virtual extending surface of the periphery of the protrusion section, although some abrasive grains is positioned on the periphery, the protrusion section of the protrusion necessarily exists at the opposite side, that is, the base side, of the protrusion direction of the abrasive grains, and thus such abrasive grains can be surely and stably supported by the protrusion section and strongly fixed. Since the plurality of abrasive grains is fixed such that the protrusion section is disposed at the base side of the abrasive grains, it is possible to ensure a space for sufficiently supporting the polishing fluid between the pad and the protrusion section at the time of dressing. Accordingly, according to the above-described CMP conditioner, it is possible to surely prevent the abrasive grains from being detached at the time of dressing to prevent a semiconductor wafer from being scratched, to suppress the abrasion of the abrasive grains which are located at the periphery and precedingly cut into the pad to stably maintain the polishing rate of the pad for a long period, and to efficiently polish the semiconductor wafer and increase the life span of the conditioner. [0012] When the plurality of abrasive grains is protruded from the virtual extending surface, some abrasive grain may be fixed close to the virtual extending surface. When the plurality of abrasive grains is fixed on the protrusion section in a region separated from the virtual extending surface by at least a fourth of the average grain diameter of the abrasive grains, the stability of the abrasive grains can be more improved, the detachment of the abrasive grains can be surely prevented, and a space surrounding the abrasive grains can be more ensured to ensure the more sufficient polishing fluid. However, when the abrasive grains are fixed at a deep position of the protrusion section or a single abrasive grain is fixed to the central portion of the protrusion section, the periphery of the protrusion section is brought into contact with the pad to cause abrasion or the polishing pressure due to the abrasive grain may excessively increase. Accordingly, it is preferable that the plurality of abrasive grains is fixed to the protrusion section, and, among them, the abrasive grains fixed on the periphery of the protrusion section are fixed in a region from the virtual extending surface to a position separated from the virtual extending surface by three times the average grain diameter of the abrasive grains. [0013] For example, like the substantially cylindrical protrusion of Patent Document 1, when the protrusion is formed to be protruded from the upper surface of the base in the cylindrical shape, and has the protrusion section perpendicular to the axis line and an outer circumferential wall surface which rises from the upper surface of the base toward the protrusion section around the protrusion section, it is preferable that the abrasive grains are fixed such that the abrasive grains are not protruded outwardly from the virtual extending surface, which extends from an outer periphery of the protrusion section of the protrusion. For example, like the circumferential abrasive grain layer part of Patent Document 2, when the protrusion is formed in a substantially annular shape at an outer circumference of the upper surface of the base and has the protrusion section having a substantially annular shape and perpendicular to the axis line and an inner circumferential wall surface which rises from the upper surface of the base toward the protrusion section at an inner circumference of the upper surface of the base, it is preferable that the abrasive grains are fixed such that the abrasive grains are not protruded from the virtual extending surface, which extends from an inner periphery of the protrusion section of the protrusion, to the inside of the upper surface of the base. On the upper surface of the base, by coating at least the protrusion section of the protrusion with a tetrafluoride-based organic compound, it is possible to surely maintain the pad polishing rate although slurry having high corrosive properties or adhesion is used as the polishing fluid. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 is a plan view of a CMP conditioner according to an embodiment of the present invention when viewed from a side facing an upper surface 2 of a base 1 along an axis line O. [0015] FIG. 2 is a partial enlarged cross-sectional view of the embodiment shown in FIG. 1. [0016] FIG. 3 is a partial enlarged cross-sectional view when the embodiment shown in FIG. 1 is manufactured by a photoresist method. Continue reading... Full patent description for Cmp conditioner Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Cmp conditioner patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Cmp conditioner or other areas of interest. ### Previous Patent Application: Method and apparatus for precision polishing of optical components Next Patent Application: Ring system for guiding a medium in an abrasive disk Industry Class: Abrading ### FreshPatents.com Support Thank you for viewing the Cmp conditioner patent info. IP-related news and info Results in 8.37279 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry |
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