Investigation of the electrical performance of hfo2 dielectrics deposited on passivated germanium substrates

Abstract

Propanethiol solution (0.1 M) in 2-propanol, octanethiol solution (0.1 M) in 2-propanol and 20% (NH4)2S solution in water were used to passivate the germanium substrates. HfO2 thin films of 150 ALD cycles were then deposited on the passivated germanium substrates. The morphology of the thin films was investigated by X-ray diffraction and it was found that the morphology of the thin films was not affected by the chemical treatments. A lower leakage current density was observed in the passivated samples compared with the witness one. In addition, the interface quality and long-time stress reliability of the passivated samples were improved when the samples were annealed in forming gas ambient.