Patent ID: 7319158

Claim:
A process for producing a high-purity hafnium amide, comprising the steps of: (a) adding a compound which contains a carbonyl group or sulfonyl group and is represented by the formula of A(O y XO n R f ) m , where A represents a hydrogen atom, oxygen atom or hafnium atom, where X represents a carbon atom or sulfur atom when A represents a hydrogen atom or oxygen atom, where X represents a sulfur atom when A represents a hafnium atom, where each of m, n and y represents 1 when A and X respectively represent a hydrogen atom and a carbon atom, where m, n and y respectively represent 1, 2 and 1 when A and X respectively represent a hydrogen atom and a sulfur atom, where m, n and y respectively represent 2, 1 and 0 when A represents an oxygen atom and when X represents a carbon atom, where m, n and y respectively represent 2, 2 and 0 when A represents an oxygen atom and when X represents a sulfur atom, where m, n and y respectively represent 4, 2 and 1 when A represents a hafnium atom, where R f is a C 1 -C 12 alkyl group, C 1 -C 12 perfluoroalkyl group, C 6 -C 12 aryl group, or C 4 -C 12 heteroaryl group, when A represents a hydrogen atom or oxygen atom, and where R f is a C 1 -C 12 perfluoroalkyl group when A represents a hafnium atom, to a crude hafnium amide which is represented by the formula of Hf[N(R 1 )(R 2 )] 4 , where each of R 1 and R 2 independently represents a methyl group or ethyl group, and which contains a zirconium component as an impurity; and (b) subjecting a product of the step (a) to a distillation under reduced pressure, thereby removing the zirconium component from the crude hafnium amide.