ALUMINUM NITRIDE POWDER AND ITS PRODUCTION

PURPOSE:To obtain high purity AlN powder of small particle size which contains little amt. of oxygen and carbon and can be sintered at a low temp. by allowing an org. Al compd. to react with NH3 in a gaseous phase to produce the amorphous precursor of AlN, calcinating and then crystallizing the precursor at a specified temp. CONSTITUTION:The org. Al compd. (preferably Al(C2H5)3) and nonoxidative carrier gas, preferably such as N2 and H2, are brought into contact with NH3 to produce precursor of AlN containing amorphous part. The precursor is then heated at 600-1300 deg.C for 1-3 hours in an atmosphere of inert gas or reductive gas containing >=20vol.% NH3 for primary calcination. The decarbonized AlN is treated in =15min and then again heated at 1400-1650 deg.C, more preferably 1450-1550 deg.C in an atmosphere of inert gas or reducing gas for secondary calcination. Thus, the obtd. AlN powder has >=8m /g specific surface area,