Effects of Ambient Temperature on the Electrical Characteristics of Thin La2O3Film Grown by E-Beam Evaporation

In this work, the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of thin La2O3film deposited by e-beam evaporation were measured at several different temperatures ranging from 200 to 400 K and after constant-voltage stressing. Stressing experiment indicates significant generation of traps at duration less than 30 min. Strong temperature dependences were found both for I-V and C-V characteristics. The strong field and temperature dependence I-V curves suggested that the current conduction in the La2O3film is most likely governed by the phonon-assisted conduction. Temperature dependence high-frequency C-V curves indicate that there are a lot of shallow traps in the bulk of La2O3film and at the La2O3/Si interface. Most of the charges trapped at the interface states can be depopulated at 400 K. Those instabilities will cause serious reliability problems for MOS device operations and have to be minimized.