Abrasive tool making process – material – or composition – With synthetic resin
Reexamination Certificate
2000-01-18
2002-09-24
Marcheschi, Michael (Department: 1755)
Abrasive tool making process, material, or composition
With synthetic resin
C051S307000, C051S308000, C051S309000, C106S003000, C438S692000, C438S693000, C252S079100, C524S443000, C216S089000
Reexamination Certificate
active
06454819
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to composite particles and a production process thereof, as well as to an aqueous dispersion containing the composite particles and water, to an aqueous dispersion composition for chemical mechanical polishing (hereunder referred to as “CMP slurry”), and to a process for manufacture of semiconductor device.
The composite particles of the invention have improved strength and hardness, excellent heat resistance, and can be utilized as cosmetics, electronic materials, magnetic materials, coating materials, paints, spacers, optical materials, catalysts, photocatalysts, fillers, electronic material film lubricants, diagnostic agents, drugs, conductive materials, sensor materials, toners, resin modifiers, inks, adsorbing agents, ultraviolet-resistant materials, and masking materials, for example, and may be in the form of an aqueous dispersion to be used as a polishing material for magnetic disks or wafers. The CMP slurry of the present invention can also be suitably used for manufacture of various semiconductor device.
2. Description of the Background
Polymer particles have conventionally been used for standard particles, diagnostic agent carrier particles, and lubricants, for example with a narrow particle size distribution obtained by copolymerizing vinyl monomers or the like. However, such polymer particles do not always exhibit sufficient strength and heat resistance, and when used as standard particles or lubricants, application of excess shear stress or exposure to high temperature can cause deformation or destruction of the particles, and therefore their uses are limited. In order to address these problems there have been proposed particles made of copolymers of crosslinkable vinyl monomers, for example, that are copolymerized with a high degree of crosslinking. However, particles made of such crosslinked polymers have lower hardness and insufficient heat resistance compared to inorganic-based particles, and therefore are not suitable for a very wide range of uses.
For uses such as electronic materials, magnetic materials, and heat-resistant materials, for example, there have been employed particles made of numerous metal compounds, and a variety of composite particles have been proposed for diverse purposes. As such types of composite particles there may be mentioned composite particles comprising iron oxide particles coated with silicon compounds, so that in production of filamentous magnetic bodies by heat treatment it is possible to prevent shape collapsing and sintering between magnetic bodies; composite particles comprising iron powder coated with copper as a high strength material for powder metallurgy; and composite particles comprising iron oxide particles coated with antimony oxide and aluminum oxide for improved heat resistance. However, since such composite particles are all composed of metal compounds, they are too hard and are not always adequately suited for diverse purposes. The development of composite particles with appropriate hardness has thus become a necessity particularly in the fields of electronic materials, magnetic materials, optical materials, polishing materials, and so forth.
Aqueous dispersions of oxide particles such as colloidal silica or colloidal alumina have been commonly used as polishing materials for chemical mechanical polishing of semiconductor element surfaces and semiconductor element interlayer insulating films in semiconductor devicees, and particularly as polishing materials for wafer surfaces. However, aqueous dispersions of such oxide particles tend to form aggregates due to their low dispersion stability, and the aggregates create surface defects (hereunder referred to as “scratches”) in polishing surfaces, that result in reduced yields of the semiconductor products. As a method of addressing this problem there have been proposed a method of adding surfactants to oxide particle dispersions, a method of using homogenizers or the like for more even dispersion, and a method of removing the aggregates with filters. However, these measures not only fail to improve the polishing materials themselves, but can also create new problems, such as lower polishing rates and contamination of polishing surfaces by metal ions.
Japanese Laid-open Patent Publication No. Hei-7-86216 discloses a process for production of a semiconductor device by chemical mechanical polishing using particles made of an organic polymer compound. In this process, the residual polishing particles can be fired and removed after polishing, to thus avoid imperfections in semiconductor devicees by those residual particles. Nevertheless, since the particles made of this organic polymer compound have lower hardness than silica or alumina particles, it has not been possible to achieve high polishing rates therewith.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide composite particles that exhibit adequate strength and hardness, excellent heat resistance, and suitable flexibility by providing metal compound sections in the interior and on the surface of the polymer particles, thus allowing their use for the wide range of purposes mentioned above, as well as a production process thereof.
It is another object of the present invention to provide an aqueous dispersion containing these composite particles and water, which is useful for a variety of purposes such as electronic materials, magnetic materials, optical materials, and the like, and particularly an aqueous dispersion to be used for polishing of magnetic disks.
It is still another object of the present invention to provide a CMP slurry wherein a silicon compound section or metal compound section is provided in the polymer particles to give the surface thereof adequate strength and hardness, excellent heat resistance and suitable flexibility and to increase the polishing rate while also preventing scratches, and by providing a process for manufacture of semiconductor devices using the CMP slurry. The CMP slurry is useful for chemical mechanical polishing in the manufacture of semiconductor devicees, and especially chemical mechanical polishing of wafer surfaces.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The composite particles of the present invention are characterized by having polymer particles and at least one of a metal compound portion or section which is at least one of a metalloxane bond-containing section and a metal oxide particle section, provided that titanium is not the metal of the metalloxane bond-containing section, and a silica particle portion or section formed directly or indirectly on the polymer particles.
The production process for the composite particles of the present invention is characterized by chemically bonding part of a coupling compound to polymer particles and then at least one of (1) chemically bonding or chemically bonding and polycondensing a compound of {circle around (1)} described below and (2) chemically bonding a compound of {circle around (2)} described below to another part of the coupling compound to form at least one of a metal compound section and a silica particle section indirectly on the polymer particles.
{circle around (1)} A compound having the formula R
n
M(OR′)
z-n
(Compound {circle around (1)} and {circle around (2)} are: where R is a monovalent organic group of 1-8 carbon atoms, R′ is an alkyl group of 1-5 carbon atoms, an acyl group of 2-6 carbon atoms or an aryl group of 6-9 carbon atoms; M is Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Zr, Nb, Mo, Sn, Sb, Ta, W, Pb or Ce; and z is the valency of M. Also, n is an integer of 0 to (z−1), and when n is 2 or greater, each R may be the same or different. When (z−n) is 2 or greater, each R′ may be the same or different.
{circle around (2)} At least one compound from among colloidal alumina, colloidal titania, colloidal zirconia, colloidal ceria and colloidal silica.
Further, the production process for the composite particles according to the present invention is cha
Hattori Masayuki
Iio Akira
Matsui Yukiteru
Minamihaba Gaku
Motonari Masayuki
Kabushiki Kaisha Toshiba
Marcheschi Michael
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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