Reliability aspects of TiSi-Schottky barrier diodes in a SiGe BiCMOS technology

Schottky barrier diodes (SBD) were integrated in a 0.25 μm SiGe BiCMOS technology. The SBDs were realized without additional process steps using the titanium silicide (TiSi) phase of the standard contact formation for the anode Schottky barrier. We observe a specific parameter degradation after reverse anode voltage operation. Different parameters as series resistance R_s, forward and leakage currents (I_A, I_r) and design parameters like anode area, contact edge lengths and corners were evaluated in order to decrease this degradation. The on-resistance R_on and capacitance C_off were extracted by s-parameter measurements and show an obvious decreased degradation. Finally maximum reverse operating voltages for a ten year life time and a maximum change of 10% for critical parameters were extrapolated for the worst operation conditions.