| abstract |
The bipolar transistor structure according to the invention is characterized in that the emitter zones (35) are formed by diffusion out of etching residues (11a, 11b) formed by conformal deposition of conductive material and etch-back and that these etching residues (11a, 11b) form part of the emitter connection region (9). In addition to individual transistors, the invention also enables transistor pairs with coupled emitters, which can be used in particular through the reproducible setting of emitter widths of less than 1 μm for high-precision differential amplifiers or memory cells with a small area requirement. The processes for producing the bipolar structures, since they enable completely self-aligned transistors, can be carried out largely independently of the lithography with little complex process steps. Emitter widths in the range of 0.2 to 0.5 µm can be realized. |