| 摘要 |
PURPOSE:To prevent the formation of channel and to obtain a walled emitter construction by self-alignment in the semiconductor device by a method wherein a field insulating film and a base lyer obtained by ion implantation are provided using a double layers mask, and an emitter layer is provided at the part wherein the double layers mask is removed. CONSTITUTION:A film 11 made of SiO2 and Si3N4 and a PSG layer 12 are laminated on an N type Si epitaxial layer 2, and the PSG layer is made to have the smaller size than the film 11. After the field oxide film 3 is formed by oxidation with pressure, the films 11, 12 are removed selectively by sputter etching. The P type base layer 5 is provided by B ion implantation, and a step type junction 16 is formed. Then the film 12 is remoed and is annealed, it is covered with an SiO2 film 17, the film 11 is removed and an opening 18 is formed, and when the N type emitter layer 4 is formed by P ion implantation, one end thereof is made to come in contact with the field oxide film 3. After then an opening is formed in the SiO2 film 17 and electrodes 9B, 9E are adhered as usual. By this constitution, the generation of N type inversion channel can be prevented by making density at the base end part 5a and the interface of field oxide film as 10<17>/cm<2> or lmore, and because the long walled emitter structure can be formed, the withstand voltage between the emitter and the collector can be enhanced. |
