Achieving high-performance Ge MOS devices using high-к gate dielectrics Ga2O3(Gd2O3) of sub-nm EOT

In this work, without employing any IPL, excellent electrical performances for the Ge MOS devices, i.e. MOSCAPs and MOSFETs, have been demonstrated using ultra high vacuum (UHV) deposited Ga₂O₃(Gd₂O₃) [GGO] directly on Ge (100) with the incorporation of fluorine. The GGO/Ge interface is atomically abrupt with negligible Ge inter-diffusion and highly thermodynamically stable withstanding high temperature anneals as previously reported. We firstly fabricated the MOS devices with a thick GGO layer (~14nm) to carry out the charge pumping measurement for the extraction of convincing D_it´s, along with the measurements on the MOSFET Furthermore, we examined the scalability of the GGO layer by reducing its thickness to ~3.5 nm with a thin Al₂O₃ cap for protection. Very good C-V characteristics and a GGO EOT of <; 1 nm have been achieved.