Electrical properties of ZrO2 gate dielectric on SiGe

We report the electrical properties of a high dielectric constant (high-k) material, ZrO2, deposited directly on SiGe, without the use of a Si buffer layer or a passivation barrier. ZrO2 thin films of equivalent oxide thickne ss (EOT) down to 16.5 Angstrom were deposited on strained SiGe layers by re active sputtering. Results indicate that ZrO2 films on SiGe have good inter facial properties and low leakage currents. Sintering in forming gas at 350 degrees C for 1 h could further improve the film quality. Although thresho ld voltage stability and dielectric dispersion become a concern for thick Z rO2 films, thin ZrO2 films of EOT less than 20 Angstrom exhibit excellent e lectrical properties making them a good candidate for SiGe applications. (C ) 2000 American Institute of Physics. [S0003-6951(00)01002-0].