| 摘要 |
PURPOSE:To form the corners of the bottom of an emitter diffused region in a square shape and to flatten the bottom of the emitter diffused region by rediffusing a phosphorus implanted at an oxide film forming time by forming the emitter diffused region in a base diffused region, forming an oxide film having a hole smaller than the emitter region, and the heat treating. CONSTITUTION:A buried layer 12 and an epitaxial layer 13 are formed on a substrate 11, separated by a separating region 14, a base diffused region 15 is formed, and an emitter hole 17 and a collector hole 18 are formed at an oxide film 16 on the surface of the layer 13. Then, when the first heat treatment is performed, an emitter diffused region 19 is formed in the region 15 and a collector leading region 20 is formed in a region 131, and an oxide film 21 is formed on the surface of the regions 19, 20. Then, a hole 23 is formed by displacing 2mum inside from the region 19 by using a photoresist 22 to form the film 21 on the region 19. Then, when the photoresist 22 is removed and the second heat treatment is achieved, the region 19 is redistributed deeply in the region 19, but the diffusing velocity apparently becomes fast by rediffusing a phosphorus implanted at the film 21 forming time in the periphery in which the film 21 remains on the surface to be deeply diffused. As a result, the angle of the bottom of the rounded region 19 is corrected to a square shape, and the bottom is flattened. |
