SEMICONDUCTOR BIPOLAR TRANISTOR HAVING BASE AND EMITTER STRUCTURE IN TRENCH AND ITS MANUFACTURE

摘要

PURPOSE: To increase an emitter area till it is larger than a chip area potentially by forming a base and an emitter of a bipolar transistor(TR) in a single trench through etching in a semiconductor surface region so as to directly handle possibility of current processing of a device integrated on one and same chip having a logic function. CONSTITUTION: A pattern of a trench is determined by photo resist in a photolithographic way, a silicon is removed up to a depth of 10μm by using the etching technology to form trenches 19, 21. Then a p<+> region 25 is diffused in the trench 19 through thermal boron coating to form the p<+> region 25 around the wall of the trench 19. Then an N-channel dopant such as phosphorus is thermally coated on polysilicon to clog the trench 19. Then a diffusion period is provided through heating, the phosphorous is implanted by a short distance up to inside of a crystal silicon of a part 27 of the layer 5 so as to provide a base and emitter region in the trench 19 and an n<+> region 29 in the other trench acting like a contact with the n-channel epitaxial layer 5.