| 摘要 |
PURPOSE:To reduce the thermal resistance of a device while the mechanical strength is enhanced by a method wherein a functional region is formed at one main surface part of a semiconductor substrate, a recess which does not reach the functional region is bored in the other main surface, the metallic layer therein is filled, and the heat generated in the substrate is dissipated to the outside. CONSTITUTION:The base region 2 of a second conductivity type is diffusion-formed in the semiconductor substrate 1 of a first conductivity type serving as a collector region, an emitter region 3 of the first conductivity type is provided therein, and the entire surface is covered with an SiO2 film 4. Next, windows are opened through the film 4, and a base electrode 5 and an emitter electrode 6 which respectively make ohmic contact with the regions 2 and 3 are mounted. Thereafter, the back surface of the substrate 1 is etched by using the mixed solution of hydrofluoric acid, nitric acid and acetic acid, resulting in the formation of a recess 7 whose bottom does not reach the region 2, this part is filled with a nickel metallic layer 8a due to plating, evaporation, etc., and this surface is made to abut against a metallic plate 9 provided on a package. Thus, the thermal resistance of the dissipation route for the heat generated in the substrate 1 is reduced. |
