Patent ID: 6689498
Filing Date: 2004-02-10
Classification: C04B,H05K,Y10T

Abstract:
An aluminum nitride substrate comprising an aluminum nitride sintered body containing a rare earth oxide as a sintering additive component;wherein a surface of said aluminum nitride substrate is machined so that an arithmetic average roughness Ra is 0.05 &mgr;m or less and a skewness Rsk is 0 or more and 1 or less, the surface comprising aluminum nitride crystal grains and aggregates of the sintering additive component containing rare earth oxide formed between the aluminum crystal grains, the size of each of the aggregates is 20 &mgr;m or less and a total area of the aggregates present in a unit area of the surface is 5% or less, and wherein the number of the aggregates of the sintering additive component and the number of pores, of which sizes are 10 &mgr;m or more in a unit area of 100Ã—100 &mgr;m of the surface, is less than or equal to 3 in the total.