Abstract: A chemical-mechanical polishing/planarization pad conditioner body made from diamond-reinforced reaction bonded silicon carbide, with diamond particles protruding or “standing proud” of the rest of the surface, and uniformly distributed on the cutting surface. In one embodiment, the diamond particles are approximately uniformly distributed throughout the composite, but in other embodiments they are preferentially located at and near the conditioning surface. The tops of the diamond particles can be engineered to be at a constant elevation (i.e., the conditioner body can be engineered to be very flat). Exemplary shapes of the body may be disc or toroidal. The diamond particles can be made to protrude from the conditioning surface by preferentially eroding the Si/SiC matrix. The eroding may be accomplished by electrical discharge machining or by lapping/polishing with abrasive.

Abstract: In a deterministic setting for finishing the support surface of a chuck such as a wafer chuck, the treatment tool may have a contacting surface shaped as a ring, annulus, or toroid, or at least such will be the form of contact when the treatment tool is brought into contact with a flat surface. The treatment tool may have about the same hardness as the work piece (e.g., the wafer chuck) that is being finished. In one embodiment, the treatment tool, or at least the flat contacting surface, is made from silicon carbide (SiC), or contains SiC, for example, in the form of a composite material such as reaction-bonded SiC.

Abstract: A method for decontaminating support surfaces of a wafer chuck, such as a wafer chuck, entails lightly passing a treatment tool having a nominally flat contacting surface over the regions of the chuck where contaminants are to be removed. The treatment tool and the chuck surface may have about the same hardness. The treatment tool may be minimally constrained so that it may conform to the surface being processed. When the treatment tool is contacted to a flat surface, the locust of contact may be in the form of a circle, ring or annulus. At higher application pressures, the treatment tool will abrade the chuck, which here is to be avoided, or at least minimized. Thus, the instant inventors have discovered that the same treatment tool that is used to engineer the elevation or profile of the surface, and its roughness, at lower application pressures can be used to remove grinding debris and other contaminants from the surface.

Abstract: Grinding, lapping and polishing basically work by making scratches in the body being ground, lapped or polished. The scratches typically are linear. The scratches gives rise to a directionality component of friction: the friction coefficient is less in the direction along the scratch than in a direction orthogonal, or across, the scratch. In a wafer handling/chucking situation, one wants the wafer to settle on the chuck, which involves the outer regions of the wafer moving radially with respect to the chuck. One can reduce friction in the radial direction by giving the lapping scratches a preferred orientation, namely, radial. This can be achieved by making the final passes of the lapping tool move predominantly in radial directions.

Abstract: A machine featuring a treatment tool that grinds a surface to a desired profile, imparts a desired roughness to that surface, and removes contamination from the surface, the machine configured to control multiple independent input variables simultaneously, the controllable variables selected from the group consisting of (i) velocity, (ii) rotation, and (iii) dither of the treatment tool, and (iv) pressure of the treatment tool against the surface. The machine can move the treatment tool with six degrees of freedom.

Abstract: In a wafer chuck design featuring pins or “mesas” making up the support surface, engineering the pins to have an annular shape, or to contain holes or pits, minimizes sticking of the wafer, and improves wafer settling. In another aspect of the invention is a tool and method for imparting or restoring flatness and roughness to a surface, such as the support surface of a wafer chuck. The tool is shaped such that the contact to the surface being treated is a circle or annulus. The treatment method may take place in a dedicated apparatus, or in-situ in semiconductor fabrication apparatus. The tool is smaller than the diameter of the wafer pin chuck, and may be approximate to the spatial frequency of the high spots to be lapped. The movement of the tool relative to the support surface is such that all areas of the support surface may be processed by the tool, or only those areas needing correction.

Abstract: In a wafer chuck design featuring pins or “mesas” making up the support surface, engineering the pins to have an annular shape, or to contain holes or pits, minimizes sticking of the wafer, and improves wafer settling. In another aspect of the invention is a tool and method for imparting or restoring flatness and roughness to a surface, such as the support surface of a wafer chuck. The tool is shaped such that the contact to the surface being treated is a circle or annulus. The treatment method may take place in a dedicated apparatus, or in-situ in semiconductor fabrication apparatus. The tool is smaller than the diameter of the wafer pin chuck, and may be approximate to the spatial frequency of the high spots to be lapped. The movement of the tool relative to the support surface is such that all areas of the support surface may be processed by the tool, or only those areas needing correction.

Abstract: A diamond-reinforced SiC ceramic composite material and shaped article. The addition of diamond to the microstructure greatly enhances properties such as hardness and Young's modulus. Such a composite material has considerable promise as an armor material. In particular, significant increases in ballistic performance can be achieved versus a non-diamond-containing composite, particularly versus the M993 threat. Reaction bonded silicon carbide (RBSC) ceramics with 7% diamond were shown to offer ballistic performance levels that matched the best commercial ceramics tested on the program.

Abstract: Current top performing SAPI systems are B4C-containing (hot pressed B4C or reaction bonded B4C). These systems will not function well versus future WC/Co threats due to the inability of B4C to withstand high pressure impacts. New approaches will be needed for next generation SAPI ceramics. Three related concepts are disclosed herein, each of which will lead to improved reaction bonded ceramics for next generation SAPI applications. The first concept aims to reactively heat treat reaction bonded B4C, causing. SiC and SiB6 to form at the expense of B4C. The second approach will add Ti to the system, thus allowing TiC and TiB2 to form at the expense of B4C. Finally, the third concept will evaluate the use of finer particle sizes, thus improving the static properties of the ceramics (with the aim of enhancing multi-hit performance). In all cases, preliminary work has been conducted to demonstrate the viability of the concepts. This will lead to a new family of advanced armor ceramics.

Abstract: A composite body produced by a reactive infiltration process that possesses high mechanical strength, high hardness and high stiffness has applications in such diverse industries as precision equipment and ballistic armor. Specifically, the composite material features a boron carbide filler or reinforcement phase, and a silicon component with a porous mass having a carbonaceous component. Potential deleterious reaction of the boron carbide with silicon during infiltration is suppressed by alloying or dissolving boron into the silicon prior to contact of the silicon infiltrant with the boron carbide. In a preferred embodiment of the invention related specifically to armor, good ballistic performance can be advanced by loading the porous mass or preform to be infiltrated to a high degree with one or more hard fillers such as boron carbide, and by limiting the size of the largest particles making up the mass.

Abstract: A mirror having low density, low CTE, high thermal conductivity, high elastic modulus, and a reflective, polishable surface. The instant mirror features a silicon-based metal coating as the reflective surface, and a composite body as a support or substrate for the reflecting surface. The composite body features carbon fibers reinforcing a matrix containing silicon metal and optionally some silicon carbide. The metal coating can be elemental silicon metal, possibly in amorphous form, and can be applied by a vapor deposition process such as chemical vapor deposition (e.g., plasma enhanced CVD) or physical vapor deposition such as evaporation or electron beam PVD.

Abstract: A silicon-containing composite body that would otherwise be brittle can be engineered to exhibit enhanced fracture toughness. Specifically, a silicon-ceramic composite body is produced, preferably by a reactive infiltration technique. The ceramic is selected such that it has a higher coefficient of thermal expansion (CTE) than does the silicon phase. At least at some point during processing, the silicon phase is at a temperature above its normal ductile/brittle transition temperature of about 500° C., and preferably above its melting point. The formed composite body containing the silicon phase is then cooled below its ductile/brittle transition. During cooling, the ceramic phase shrinks more than does the silicon phase, thereby placing the latter in a state of compressive stress. By the time the composite body has cooled to substantially ambient temperature, the induced compressive stress in the silicon phase is sufficient as to impart a measurable degree of semi-ductile character to the silicon phase.

Abstract: Improved silicon carbide composites made by an infiltration process feature a metal phase in addition to any residual silicon phase. Not only are properties such as mechanical toughness improved, but the infiltrant can be so engineered as to have much diminished amounts of expansion upon solidification, thereby enhancing net-shape-making capabilities. Further, multi-component infiltrant materials may have a lower liquidus temperature than pure silicon, thereby providing the practitioner greater control over the infiltration process. In particular, the infiltration may be conducted at the lower temperatures, where low-cost but effective bedding or barrier materials can terminate the infiltration process once the infiltrant has migrated through the permeable mass up to the boundary between the mass and the bedding material.

Abstract: Ceramic-containing bodies can be bonded to other ceramic-containing bodies, or to metals or metal-containing bodies, by way of an aluminum-silicon brazing alloy. Such alloys feature high thermal conductivity and a melting range intermediate to Cu—Sil and Au—Si. By depositing a layer of silicon or aluminum, e.g., by vapor deposition, onto a surface of the ceramic-containing body, the formation of deleterious intermetallic phases at the brazing interface is avoided. This technique is particularly useful for joining reaction-bonded silicon carbide (RBSC) composite bodies, and particularly such composite bodies that contain appreciable amounts of aluminum as a metallurgical modification of the residual silicon phase. When the RBSC body contains minor amounts of the aluminum alloying constituent, or none, the metallization layer is not required. The resulting bonded structures have utility as mirrors, as packaging for electronics, and in semiconductor lithography equipment, e.g.

Abstract: A composite body produced by a reactive infiltration process that possesses high mechanical strength, high hardness and high stiffness has applications in such diverse industries as precision equipment and ballistic armor. Specifically, the composite material features a boron carbide filler or reinforcement phase, and a silicon carbide matrix produced by the reactive infiltration of an infiltrant having a silicon component with a porous mass having a carbonaceous component. Potential deleterious reaction of the boron carbide with silicon during infiltration is suppressed by alloying or dissolving boron into the silicon prior to contact of the silicon infiltrant with the boron carbide. In a preferred embodiment of the invention related specifically to armor, good ballistic performance can be advanced by loading the porous mass or preform to be infiltrated to a high degree with one or more hard fillers such as boron carbide, and by limiting the size of the largest particles making up the mass.

Abstract: Techniques to bond two or more smaller bodies or subunits to produce a unitary SiC composite structure extend the capabilities of reaction-bonded silicon carbide, for example, by making possible the fabrication of complex shapes. In a first aspect of the present invention, two or more preforms are bonded together with a binder material that imparts at least strength sufficient for handling during subsequent thermal processing. In a second aspect of the present invention, instead of providing the subunits to be bonded in the form of preforms, the subunits may be dense, SiC composite bodies, e.g., RBSC bodies. In each of the above embodiments, a preferable means for bonding two or more subunits combines aspects of adhesive and mechanical locking characteristics. One way to accomplish this objective is to incorporate a mechanical locking feature to the joining means, e.g., a “keyway” feature.

Abstract: A composite adhesive featuring a matrix phase that includes a cyanate ester and a filler or reinforcement phase that includes a plurality of bodies of at least one material comprising a high shear strength and/or high modulus material. Preferably, the filler also possesses at least one of high thermal conductivity and low coefficient of thermal expansion. Unlike certain commercially available cyanate esters, those of the instant invention substantially maintain or even increase in strength upon addition of the filler to the system. The instant composite adhesives may also display reduced coefficients of moisture expansion relative to the unfilled or “neat” resin. Such a composite adhesive is extremely useful for joining articles where high strength and minimal swelling in moist environments are required, such as in the precision equipment industry.

Abstract: Silicon infiltration technology is used to produce ceramic bodies having utility as ballistic armor. In a first aspect of the invention, the ballistic armor includes a reaction-bonded silicon carbide body (RBSC). Good ballistic performance can be advanced by loading the permeable mass or preform to be infiltrated to a high degree with one or more hard fillers, and by limiting the size of the largest particles making up the mass. In a second aspect, the silicon infiltration technology, e.g., siliconizing or reaction-bonding, is used to bond silicon carbide fibers to at least the back surface of a ceramic armor body, thereby enhancing ballistic stopping power. A third aspect of the invention pertains to the ability to engineer RBSC bodies such that there is little dimensional change during processing, thereby permitting high dimensional reproducibility in large-scale production.

Abstract: Silicon infiltration technology is used to produce ceramic bodies having utility as ballistic armor. In a first aspect of the invention, the ballistic armor includes a reaction-bonded silicon carbide body (RBSC). Good ballistic performance can be advanced by loading the permeable mass or preform to be infiltrated to a high degree with one or more hard fillers, and by limiting the size of the largest particles making up the mass. In a second aspect, the silicon infiltration technology, e.g., siliconizing or reaction-bonding, is used to bond silicon carbide fibers to at least the back surface of a ceramic armor body, thereby enhancing ballistic stopping power. A third aspect of the invention pertains to the ability to engineer RBSC bodies such that there is little dimensional change during processing, thereby permitting high dimensional reproducibility in large-scale production.

Abstract: Improved silicon carbide composites made by an infiltration process feature a metal phase in addition to any residual silicon phase. Not only are properties such as mechanical toughness improved, but the infiltrant can be so engineered as to have much diminished amounts of expansion upon solidification, thereby enhancing net-shape-making capabilities. Further, multi-component infiltrant materials may have a lower liquidus temperature than pure silicon, thereby providing the practitioner greater control over the infiltration process. In particular, the infiltration may be conducted at the lower temperatures, where low-cost but effective bedding or barrier materials can terminate the infiltration process once the infiltrant has migrated through the permeable mass up to the boundary between the mass and the bedding material.