| 摘要 |
PURPOSE:To obtain a junction-break type memory that requires less energy for writing by making the space between the base-collector junction and the base-emitter junction approximately fixed in the direction of the surface, side and depth of the base layer. CONSTITUTION:The N<+> embedded collector layer 2, N epitaxial layer 3, shallow P-type base layer 4, N<+> emitter layer 5, collector electrode layer 6 and SiO2 film 7 that is selectively oxidized by the use of Si3N4 masks are formed on the P-type substrate 1. Also the base layer 4 and the emitter layer 5 are formed the same opening by a diffusion process. In this way, the oxidation proceeds also in the lateral direction of the substrate when selectively oxidized by the use of Si3N4 masks, the effective junction area can be made less than the designed value. Also, since the emitter-base junction is formed by self-matching, the element area can be reduced. Accordingly energy required for the writing can be reduced, a junction- break type PROM that has a high integration and is capable of high speed operation can be obtained. |
