Electrical characteristics of highly reliable ultrathin hafnium oxide gatedielectric

Electrical and reliability properties of ultrathin HfO2 have been investiga ted. Pt electroded MOS capacitors with HfO2 gate dielectric (physical thick ness similar to 45-135 Angstrom and equivalent oxide thickness similar to 1 3.5-25 Angstrom) were fabricated. HfO2 was deposited using reactive sputter ing of Hf target with O-2 modulation technique. Leakage current of the 45 A ngstrom HfO2 sample was about 1 x 10(-4)A/cm(2) at +1.0 V with a breakdown field similar to 8.5 MV/cm. Hysteresis was <100 mV after 500 degrees C anne aling in N-2 ambient and there was no significant frequency dispersion of c apacitance (<1%/dec.). It was also found that HfO2 exhibits negligible char ge trapping and excellent TDDB characteristics with more than ten Sears lif e- time even at V-DD = 2.0 V.