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

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.