| 摘要 |
PURPOSE:To obtain a substrate having a smooth surface and high heat conductivity without carrying out polishing by forming the compsn. of a grain boundary phase except inevitably contained impurities from Al2O3 and Y2O3, and specifying the Y2O3 content and the molar ratio of Al2O3 to Y2O3. CONSTITUTION:This AlN substrate is made of an AlN sintered body having a grain boundary phase whose compsn. except for inevitably contained impurities is represented by xAl2O3.yY2O3 and has a smooth uniform surface and high heat conductivity. The Y2O3 content is 1.8-3.2wt.% and the molar ratio (x/y) of Al2O3 to Y2O3 is 0.08-0.32. In case of <1.8wt.% Y2O3, unsatisfactory sintering is liable to occur. In case of >3.2wt.% Y2O3, surface roughness is increased. In case of <0.08 molar ratio (x/y), coloring and unsatisfactory sintering occur. In case of >0.32 molar ratio (x/y), starry abnormality in appearance is liable to occur. |
