| 摘要 |
PURPOSE:To prevent to punch-through at a junction of an electrode metal, and to enable to form lateral directional size thereof minutely at a semiconductor device by a method wherein a polycrystalline Si layer is made to remain on the circumference of the emitter region. CONSTITUTION:A double film 3 consisting of an oxide film 3-1, an Si nitride film 3-2 is formed in the emitter formation programmed region of an oxide film 2 on the surface of a semiconductor substrate 1. Then the outside base region 4 is formed. An oxide film 5 is formed on the region 4, and B<+> ions are implanted to form the inside base region 6. After the film 3-1 is removed, the polycrystalline Si layer 7 containing As is adhered thereon. A laser beam is irradiated onto the surface of the layer 7 to anneal the layer 7 and the region 6. The layer 7 on the emitter diffusion hole is converted into a single crystal by annealing thereof, while the layer on the films 2, 5 remains as polycrystal as it is. When the substrate 1 thereof is etched, the layer 7 on the films 2, 5 is removed leaving the single crystal emitter 8 in the emitter region. Accordingly minute formation of lateral directional size of the emitter can be attained easily. |
