| 摘要 |
PURPOSE:To produce a transistor with excellent high frequency characteristics reducing the interval between P<+> layers by a method wherein the contact between N emitter and a P<+> graft base due to the locating slip in the photoetching is completely obviated. CONSTITUTION:A P layer 4 is formed on an N type Si substrate 1 by means of B ion implantation and an SiO2 film 2, an Si3 N4 film 5 are laminated on the surface opening holes 6, 7 on the film 5. Then the film 2 is opened from the hole 7 to form a compound layer 10 comprising B and Si by means of diffusing boride. Next the film 2 is opened again from the hole 6 to form an N type poly- Si layer 8 further forming another N layer 9 by heattreatment in oxide atmosphere. At this time, a new SiO2 film 11 is formed on the poly-Si layer 8. The SiO2 film 11 and the compound layer 10 are removed forming the electrodes for the N layer 9 and a P<+> layer 3. In such a constitution, the contact between the layers 3 and 9 may be prevented to improve the high gain low noise characteristics in a high frequency region producing a N-P-N small signal transistor with excellent physical property. |
