| 摘要 |
PURPOSE:To obtain a high density and high speed bipolar transistor by executing selective oxidation after etching the Si layer with the oxidation resistant film used as the mask and by providing the emitter with the side placed in contact with almost vertically formed isolation oxide film. CONSTITUTION:After the N type epitaxial layer 35 and SiO2 36 on the P type Si substrate having the N<+> type buried layer are vertically etched by the reactive sputtering method using Si3N4 layer as the mask 37, the SiO2 39 and Si3N4 40 are stacked on the N layer 35. These are vertically etched and left at the side. When an insulating isolation film 41 is formed in contact with the buried layer by oxidation, a bird's beak is not generated thanks to the film 40. An opening is provided on the mask 37 and thereby the SiO2 film 42 is formed and the P layer 43 is selectively formed. The surface is covered with the poly-Si 44, the Si3N4 mask 45 is provided and an opening is provided on the film 44, the P layer 43 is etched in the shallow depth, the surface is covered with the SiO2 46, the mask 45 is removed, ion is implanted selectively, and the N emitter 47, collector connecting layer 48, and inactive base 48 are sequentially formed and the electrodes are attached. According to this structure, there is no bird's beak, parasitic capacitance at the side of emitter and a high density and high speed device can be obtained. |
