Hysteresis in metal insulator semiconductor structures with high temperature annealed ZrO2/SiOx layers

Hysteresis behaviour in sandwich structure — zirconium oxide/chemical silicon oxide, annealed at temperature of 850 °C in oxygen ambient, was studied. Formation of thin ZrSixOy layer due to the high temperature annealing was found. Metal–insulator–semiconductor (MIS) capacitors using ZrO2/ZrSixOy/SiOx insulator were studied. High-frequency capacitance–voltage (HF C–V), current–voltage (I–V) and current–time (I–t) measurements were carried out on the Al/ZrO2/ZrSixOy/SiOx/Si capacitors.Two leakage current components were identified — tunneling current component at high electric fields and transient current component at low fields. The transient leakage currents are due to charge trapping phenomena. The measured I–t characteristics are related with charging/discharging and dielectric relaxation phenomena. A counter-clockwise HF C–V hysteresis, larger than 2 V at thickness of the stack structure of about 50 nm was observed.Metal–insulator–semiconductor field effect transistors (MISFETs) using ZrO2/ZrSixOy/SiOx-gate insulator were studied. P-channel MISFETs with aluminum gate electrode were fabricated on standard n-type silicon substrates. Due to charging/discharging phenomena in the gate dielectric the transistors can be switched between On- and Off-state with the polarity of applied stress voltage.