Hints, Tips and Solutions

Q. How can I characterize the parasitic BJT behavior of SOI devices using UTMOST III.

A. UTMOST III SOI module has three routines for characterization of the parasitic BJTs of SOI devices. These routines are “IC/VCE”, “Gummel” and “INT_BJT” All routines require to have 5 terminal devices with bulk connection for data collection.

The “Gummel” routine sweeps the voltage for the bulk terminal and keeps a constant voltage for the gate, source, drain and backgate terminals. The measured currents are drain and bulk currents. However during this measurement the bulk and drain diodes can be on and the diode current can be added to the bulk current. This additional diode current prevents the user from characterizing the pure intrinsic bipolar device.