Numéro
J. Phys. Colloques
Volume 49, Numéro C4, Septembre 1988
ESSDERC 88
18th European Solid State Device Research Conference
Page(s) C4-387 - C4-390
DOI https://doi.org/10.1051/jphyscol:1988481
ESSDERC 88
18th European Solid State Device Research Conference

J. Phys. Colloques 49 (1988) C4-387-C4-390

DOI: 10.1051/jphyscol:1988481

MAXIMUM OPERATING VOLTAGE LIMITATIONS DUE TO PARASITIC BIPOLAR ACTION IN VLSI CMOS

D. TAKACS et M. STEGER

Siemens AG, Corporate Research and Development, Microelectronics, Otto-Hahn-Ring 6, D-8000 München 83, F.R.G.


Abstract
The influence of the PBTA (Parasitic Bipolar Transistor Action) induced by impact ionization on the maximum operating voltages as well as on the isolation performance in VLSI CMOS structures was investigated using the sensitivity of the nMOS- and bipolar-parameters to the operating voltages. Strong coupling between the MOS- and bipolar-currents exists due to the potential drop caused by the impact ionization currents of the nMOSFET. The base currents of the bipolar transistors reduce the measurable substrate current. The maximum operating voltage in CMOS is limited by the impact ionization induced PBTA. The isolation performance is reduced by the collector current of the vertical transistor.