In this paper we review the state of the art of high n-type doping techniques in germanium alternative to ion implantation. We discuss a novel technique for achieving ultra-high doping based on adsorption and thermal incorporation of P atoms from PH3 or P2 molecules into a Ge surface and subsequent encapsulation by Ge homoepitaxial growth. This process results in the formation of spatially-confined P -layers with planar electrically active densities as high as 1×1014 cm-2. Owing to the high morphological quality of the crystal matrix, it is possible to stack an arbitrary number of -layers and tailor the thickness of spacer layers in between to build an electrically active donor density in excess of 1020 cm-3 in a bottom-up process.
Capellini, G., Klesse, W.m., Mattoni, G., Simmons, M.y., Scappucci, G. (2014). Alternative High n-Type Doping Techniques in Germanium. ??????? it.cilea.surplus.oa.citation.tipologie.CitationProceedings.prensentedAt ??????? 2014 ECS and SMEQ Joint International Meeting, Cancun [10.1149/06411.0163ecst].