| 摘要 |
PURPOSE:To reduce the size of an auxiliary semiconductor element by forming the element in a 4-layer structure, approaching the impurity density of an N type emitter layer to that of a P type base, and setting the value to become the special value or higher. CONSTITUTION:P type impurity is diffused from both sides of an N type Si to become an N type base layer 2 to form a P type emitter layer 1 and a P type base layer 3. Then, an N type impurity is diffused on the surface of the layer 3, grooves are formed to obtain divided N type emitter layers 41, 42. Then, a thermal oxide layer 5 is formed on the surfaces of the layers 4, 3, the electrode contacts are opened to form a cathode electrode 7 and a gate electrode 8, and an anode electrode 6. In this configuration, the impurity densities of the layers 4 and 3 become equal in the absolute values, and the values become 1X10<18>(1/cm<3>) or higher. Thus, since the auxiliary current of turning OFF at the high voltage time of the 4-layer semiconductor element can be controlled by the current limiting effect, an auxiliary semiconductor element can be reduced. |
