LOW DOPED BASE CONTACT STRUCTURE FOR IMPROVING SWITCHING CHARACTERISTICS OF THE POWER BJT

The switching off characteristics of the power bipolar transistor, with the LDBC (low doped base contact), is presented. The simulation results for ihc resistive load circuit show that the transistor with LDBC has a shorter storage and fall time for the large reverse bias current. It is concluded that the LDBC offers a lower minimum of power loss and wider range of biasing flexibility to the designer because of the lack of tailing phenomena seriously occurred in the normal base power transistor. Experimental results proved the improvement of switching speed for the LDBC structure and make it possible to design switching transistor without life time killing technique.