Emitter Area Reduction
Original Publication Date: 1980-Aug-01
Included in the Prior Art Database: 2005-Feb-13
The reduction of the active base area in complementary transistor structures having a lateral PNP transistor and a vertical NPN transistor is very desirable. Unless, however, the performance of the lateral PNP (LPNP) transistor is also improved, it will exert a drag on the improvement. Because of the ease of integration of LPNP transistors with NPN transistors, it is advantageous to continue using the LPNP transistors. One of the main problems associated with LPNP transistors is that only the sidewalls of the emitter are useful, while the bottom emitter to base area represents a stray diode. Therefore, a reduction of this bottom emitter area will result in the performance improvement of the LPNP transistor.