Sintered aluminum nitride and semi-conductor device using the same

Sintered aluminum nitride having a thermal conductivity at room temperature of 0.2 cal/cm.sec..degree.C. or higher, which comprises at least 65% by weight of aluminum nitride and at least one of lithium and lithium compound, with 0.05-5% by weight of at least one of the lithium and the lithium compound in terms of lithium atom being contained in the aluminum nitride on the basis of aluminum nitride.

Sintered aluminum nitride having a thermal conductivity at room temperature of 0.2 cal/cm.sec..degree.C. or higher, which consists essentially of at least 65% by weight of aluminum nitride, not more than 5% by weight of at least one of Y.sub.2 O.sub.3, MgO, Al.sub.2 O.sub.3 and SiO.sub.2 in terms of atoms on the basis of aluminum nitride and at least one of beryllium, beryllium compound, lithium and lithium compound.

Sintered aluminum nitride having a thermal conductivity at room temperature of 0.2 cal/cm.sec..degree.C. or higher, which comprises at least 65% by weight of aluminum nitride and at least one of lithium and lithium compound selected from the group consisting of lithium oxide, lithium chloride, lithium fluoride, lithium nitrate, lithium carbonate, lithium sulfate and a mixture thereof.