SEMICONDUCTOR DEVICE

PURPOSE:To make it possible the permittivity of silicon carbide ceramic having high thermal conductivity to be changeable by adding alumina on the ceramic. CONSTITUTION:A metallized film is formed on a sintered insulating substrate, which contains a main component of silicon carbide, and additional components of beryllium and/or beryllium oxide and alumina. A semiconductor laser device is brazed to the metallized film. The aluminal content of the sintered compact is preferably 0.005-0.15wt.% of silicon carbide. Thermal conductivity of the sintered compact is not less than 2.0W/cm deg.C at room temperature. When this is used as a heat sink 2 of the semiconductor laser, fall of heat resistance and good heat sink effect can be obtained because of high thermal conductivity of the sintered compact. Occurrence of resonance within the package can effectively be suppressed because it is possible the permittivity of heat sink 2 to be changeable and high.