| 摘要 |
PURPOSE:To reduce p-n-p-n gains among cells and cells, and prevent the generation of bit interference by each changing the depth of emitters in a peripheral transistor and cell transistors. CONSTITUTION:SiO2 films 12, Si3N4 films and isolation SiO2 films 14 are formed on each collector region 11 in a peripheral transistor TR110 and a TR210 for a memory cell. Base regions 16 are shaped while using photo-resists 15 as masks, the films 13 are removed, and a base section in the TR210 is coated with a photo-resist 19. The film 12 on a base in the TR110 is removed, the resist 19 is removed, and an SiO2 film 20 is grown on the surface. Consequently, the SiO2 film on the TR110 is formed in thickness thinner than said film on the TR210. The film 20 is changed into phosphorus silicate glass films 21, 21' and phosphorus is diffused, and emitter regions 22, 22' are shaped. Accordingly, since the depth of the regions 22, 22' is changed, the n-p-n gains of the TR110 are increased, p-n-p-n gains between the cell and the cell are reduced, and bit interference is difficult to be generated.
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