| 摘要 |
PURPOSE:To reduce the size of a sdmiconductor device and to increase the electric power of the device by burying a polycrystalline semiconductor region in a single crystal semiconductor substrate. CONSTITUTION:Numeral 11 designates an N type silicon substrate, 12a a P type impurity diffused layer contained in the buried polycrystalline silicon 12, 13 an insulating film, and 14 an electrode. The layer 12 is formed by covering a polycrystalline silicon by a CVD method in a fine groove formed on the substrate 11, and it is necessary to form a polycrystalline silicon film on the side face of the groove of the substrate silicon. In a bipolar semiconductor device thus formed, in case of large electric power, the depth of the groove is increased, even if the width of the groove is fine, and the surface of the diffused layer 12a may be increased. Then, large electric power can be readily provided with small area. |
