XAFS investigation of the electronic and structural properties of Ga dopant in SiGe and pure Ge epitaxial layers for MOSFET applications

The goal of this proposal is to use X-ray absorption Fine Structure (XAFS) to investigate the electronic and structural properties of Ga atoms in series of novel Ga doped epitaxial SiGe and pure Ge epitaxial layers grown on Si that hold great promise for the development of next generation ultra-scaled p-type MOSFETs devices. This investigation will provide a better understanding of the electronic and structural properties of the Ga-based defect complexes formed in the SiGe and Ge lattices during chemical vapor deposition (CVD), as a function of the Ga concentration. Additionally, the structure of the superficial segregated Ga phases obtained at high Ga concentrations will be investigated. This will be used as input parameter to guide further the Density Functional Theory (DFT) calculations of the electronic properties and local environment of the different Ga-defect complexes formed (e.g.: Ga-vacancy, Ga-Si/Ge interstitials, Ga clusters).