BIPOLAR TRANSISTOR AND MANUFACTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To suppress the operation of a parasitic bipolar transistor by forming an emitter impurity layer on the centers of a conductivity type wells and forming a base impurity layer which surrounds the emitter impurity layer and includes a conductivity type heavily doped collector impurity layer with keeping a fixed spacing. SOLUTION: On a semiconductor substrate 80 n- and p-type wells 82, 84, and emitter impurity layer 123 is formed on the centers of the wells 82, a base impurity layer 106 completely surrounding the layer 123 is formed, and n-type heavily doped collector impurity layer is formed annularly along the edges of the wells 82 with keeping fixed spacing from the layer 106, thereby suppressing the operation of a parasitic bipolar transistor with a low collector resistance.