Defects in Microwave Devices

The electric performances of devices such as MOS or SiGe HBT, specified for analog and analog-digital circuits and working in the radiofrequency range, can be penalized by the presence of defects inherent to the complex structure shrinking. This work is focused on the identification of defects responsible for the current fluctuations at the origin of low frequency noise (LFN) or Random Telegraphic Signals in industrial submicronic BiCMOS technologies. For instance, Gummel characteristics are simulated in order to identify generation-recombination or trap assisted tunnelling process in the base current.

From theoretical point of view, numerical method for analysing heterostructure semiconductor devices is described. Simulations and modeling both have to be performed and followed by electrical parameter extraction. Often, this noise can be very inconvenient since, from non-linearities, it is cumbersome for circuits, systems, working with such devices in the radiofrequency range. It is worth noticing that LFN characterization is not only a useful tool to analyze complex devices, but it seems indispensable at circuit and system level.

Keywords: Devices, microwave, defects, deep traps, modeling, transport equations, heteojunction bipolar transistor, electrical characteristics, first and second order, parameter extraction, compact models, noise spectra, RTS noise, carrier density and field fluctuations.