Method for Fabricating a Self Aligned Vertical PNP Transistor
Original Publication Date: 1980-Jan-01
Included in the Prior Art Database: 2005-Feb-13
The performance of pnp transistors is important in circuits where pnp transistors are employed. One of the major difficulties in fabricating vertical pnp transistors is the very fast diffusion of the boron in the emitter which makes control of the base width very difficult. In the conventional pnp transistor structure, the only way to control the base width is to make the emitter very shallow. However, the conventional metal contact to the emitter requires a relatively deep emitter junction to prevent metal penetration of the emitter junction.