Pulsed Capacitance-Voltage Measurements on Al2O3-based MOS Capacitors

L. SAMBUCO SALOMONE; J. LIPOVETZKY; S.H. CARBONETTO, M.A. GARCIA-INZA, E.G. REDIN, F. CAMPABADAL, AND A. FAIGÓN

Conferencia; Micro-Nanoelectronics, Technology and Applications (EAMTA), 2014 Argentine Conference on; 2014

Pulsed capacitance-voltage (C-V) technique wasapplied to the study of electron trapping in MOS capacitors withamorphous Al2O3 as insulating layer. This technique allows toobserve fast trapping/detrapping processes as it measures a C-Vcurve in a few hundred of microseconds. The dependences of theC-V curve with the applied bias and the charging time wasinvestigated. A positive displacement of the voltage valuecorresponding to a constant capacitance (VC) was observed as thetop level of the pulsed signal is increased and a linear dependencewas obtained. Regarding the charging time, the positive VC-shiftshowed a logarithmic dependence, evidencing the presence of atunneling front advancing into the dielectric. Moreover, a fixedVC-shift was observed after charging with long times (~500 ms),related to traps that can not be discharged betweenmeasurements.