| 摘要 |
PROBLEM TO BE SOLVED: To obtain wafer having good heat radiating property and excellent in cooling by vapor-depositing and laminating a semiconductor layer onto a ceramic layer by chemical or physical method. SOLUTION: CaO in an amount of 0. 5-5 wt.% and Y2 O3 in an amount of 0.5-5 wt.% are added as sintering auxiliaries to AlN powder having <=2 wt.% oxygen content and further, an organic solvent is added thereto and these components are mixed. The mixture is subjected to pressure forming and defatting treatment to form AlN formed product and the formed product is baked for 1-6 hr in an inert gas atmosphere such as Ar by using a carbon furnace capable of obtaining carbon reducing atmosphere. Then, the baking atmosphere is changed to N2 gas and the formed product is further baked for 1-24 hr to prepare a ceramic substrate such as AlN. Monosilane such as SiH4 is thermally decomposed at >=550 deg.C by CVD method for the like and a semiconductor layer of polycrystal silicon or the like is laminated. Si3 N4 , SiC or the like is used in addition to AlN as the ceramics. |
