Polycrystalline aluminum nitride material and method of production thereof
AssigneeHexatech, Inc.
InventorsBaxter Moody, Rafael Dalmau, David Henshall, Raoul Schlesser
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Abstract
Methods of preparing polycrystalline aluminum nitride materials that have high density, high purity, and favorable surface morphology are disclosed. The methods generally comprises pressing aluminum nitride powders to form a slug, sintering the slug to form a sintered, polycrystalline aluminum nitride boule, and optionally shaping the boule and/or polishing at least a portion of the boule to provide a finished substrate. The sintered, polycrystalline aluminum nitride materials beneficially are prepared without the use of any sintering aid or binder, and the formed materials exhibit excellent density, AlN purity, and surface morphology.
Claims12
A polycrystalline aluminum nitride substrate, said substrate being prepared according to a method comprising:
- pressing aluminum nitride powder to form a pressed aluminum nitride slug;
- sintering the pressed aluminum nitride slug material by heating to a maximum temperature of at least about 1,500° C. at a heating rate that does not exceed 0.1° C./minute to 10° C./minute in a non-oxidizing atmosphere to form a sintered aluminum nitride boule with a thickness of at least 5 cm and with a diameter or length or width of at least 5 cm;
- and
- mechanically polishing at least a portion of the sintered aluminum nitride boule to form a polycrystalline aluminum nitride substrate,
- such that the so-formed substrate has a relative density of at least about 98%, an aluminum nitride purity of at least about 98% by weight, an rms surface roughness of less than about 80 nm, and a defect density of less than about 1,000 cm−2.
A polycrystalline aluminum nitride substrate having a relative density of at least about 98%, an aluminum nitride purity of at least about 98% by weight, an rms surface roughness of less than about 80 nm, and a defect density of less than about 1,000 cm −2.
A polycrystalline aluminum nitride boule having a relative density of at least about 98%, an aluminum nitride purity of at least about 98% by weight, a thickness of at least 5 cm, and a diameter or length or width of at least 5 cm.
Dependencies are inferred from the claim text.