US Patent 7473661 Method for preparing a sintered body of aluminum nitride

Disclosed is a method for preparing a high dense aluminum nitride (AlN) sintered body. The method includes the steps of preparing powders for the AlN sintered body comprising Y2O3 of 0.1 to 15 wt %, TiO2 of 0.01 to 5 wt % and MgO of 0.1 to 10 wt %, and obtaining the AlN sintered body with a volume resistivity of 1×1015 Ωcm or more at a normal temperature and a relative density of 99% or more. The sintered body is obtained by sintering the powders and then cooling the sintered powders or sintering the powders and then cooling the sintered powders with annealing the sintered powders during the cooling.