THE 2-DIMENSIONAL MODEL FOR THE BASE SURFACE CURRENT IN INTEGRATED BIPOLAR-TRANSISTORS AND ITS APPLICATIONS

The recombination of minority carriers at the Si-SiO2 interface has a great effect on bipolar devices. In this paper, the surface electrical properties of capacitors (MOS Dr MNOS) and gate-controlled npn transi stors which are passivated by SiO2 and SiO2-Si3N4 films, respectively, are studied, and it is found that the SiO2-Si3N4 dual dielectrical fi lms can reduce the surface current in the base region. An improved the oretical model of the base surface current versus surface potential or gate voltage is set up on the basis of the work of Hillen and Holsbri nk [Solid St. Electron. 26, 453-463 (1983)] for integrated bipolar tra nsistors. The model successfully explains the experimental results of the variation of the base surface current of the gate-controlled integ rated bipolar npn transistors with the gate voltage and provides a mor e accurate model for the computer simulation and the reliability analy sis of the devices.