We propose an oxygen scavenging technique based on thermodynamic considerations of metal and oxygen systems to stabilize the ferroelectric phase and enhance the ferroelectricity in Hf-based oxides. By using an oxygen scavenging metal to control the oxygen vacancy concentration in Hf-based oxides, the effect of this oxygen scavenging technique in ferroelectric Hf-based oxides was systematically investigated. It was revealed that controlling the oxygen vacancies during the crystallization process is of vital importance to stabilizing the ferroelectric properties. This oxygen scavenging technique is an effective method of improving the performance of Hf-based ferroelectric materials without employing any dopant in Hf-based oxides.

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In this paper, we have demonstrated the high hole mobility in accumulation-mode Ge-on-insulator (AM-GeOI) pMOSFETs with back interface engineering by low-temperature H2 annealing. The hole mobility of 227 cm2/Vs was obtained for the device annealed at 400 oC in H2 ambient, which is 32% higher than that of control device. A significant improvement in carrier mobility was attributed to two main factors: 1) the atomic rearrangement of Si and Ge in the intermixing layer located at the back interface, and 2) partial relaxation of tensile strain by thermal treatment.