In this paper we demonstrate the fabrication of multiple, narrow, and closely spaced delta-doped P layers in Ge. The P profiles are obtained by repeated phosphine adsorption onto atomically flat Ge(001) surfaces and subsequent thermal incorporation of P into the lattice. A dual-temperature epitaxial Ge overgrowth separates the layers, minimizing dopant redistribution and guaranteeing an atomically flat starting surface for each doping cycle. This technique allows P atomic layer doping in Ge and can be scaled up to an arbitrary number of doped layers maintaining atomic level control of the interface. Low sheet resistivities (280 Omega/square) and high carrier densities (2 x 10(14) cm(-2), corresponding to 7.4 x 10(19) cm(-3)) are demonstrated at 4.2 K.
Scappucci, G., Capellini, G., Klesse, W.m., Simmons, M.y. (2011). Phosphorus atomic layer doping of germanium by the stacking of multiple delta layers. NANOTECHNOLOGY, 22(37) [10.1088/0957-4484/22/37/375203].
Phosphorus atomic layer doping of germanium by the stacking of multiple delta layers
CAPELLINI, GIOVANNI;
2011-01-01
Abstract
In this paper we demonstrate the fabrication of multiple, narrow, and closely spaced delta-doped P layers in Ge. The P profiles are obtained by repeated phosphine adsorption onto atomically flat Ge(001) surfaces and subsequent thermal incorporation of P into the lattice. A dual-temperature epitaxial Ge overgrowth separates the layers, minimizing dopant redistribution and guaranteeing an atomically flat starting surface for each doping cycle. This technique allows P atomic layer doping in Ge and can be scaled up to an arbitrary number of doped layers maintaining atomic level control of the interface. Low sheet resistivities (280 Omega/square) and high carrier densities (2 x 10(14) cm(-2), corresponding to 7.4 x 10(19) cm(-3)) are demonstrated at 4.2 K.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
