Ultra-doped n-type germanium thin films for sensing in the mid-infrared

Abstract

A key milestone for the next generation of high-performance multifunctional microelectronic devices is the monolithic integration of high-mobility materials with Si technology. The use of Ge instead of Si as a basic material in nanoelectronics would need homogeneous p- and n-type doping with high carrier densities. Here we use ion implantation followed by rear side flash-lamp annealing (r-FLA) for the fabrication of heavily doped n-type Ge with high mobility. This approach, in contrast to conventional annealing procedures, leads to the full recrystallization of Ge films and high P activation. In this way single crystalline Ge thin films free of defects with maximum attained carrier concentrations of 2.20 ± 0.11 × 1020 cm−3 and carrier mobilities above 260 cm2/(V·s) were obtained. The obtained ultra-doped Ge films display a room-temperature plasma frequency above 1,850 cm−1, which enables to exploit the plasmonic properties of Ge for sensing in the mid-infrared spectral range.

Strain and Band-Gap Engineering in Ge - Sn Alloys via P Doping

“…During recent years, flash lamp annealing (FLA) has been used as an annealing method in the ms-range for many purposes, especially driven by the needs of advanced semiconductor processing, see Refs. 14-16 for recent reviews, and more specific, also those of Ge-based materials research: shallow junctions [17], nanoclusters [18], advanced processing [10,19] etc.…”

“…The ultra-doped n-type GeSn layer-on-Si is fabricated by ion implantation of Sn and P into Ge-on-Si wafers followed by non-equilibrium ms-range rear-side flash-lamp annealing (r-FLA). Recrystallization of the implanted layer and the electrical activation of P induce explosive solid-phase epitaxy (ESPE) regrowth [10,11].…”

Superconductivity in single-crystalline aluminum- and gallium-hyperdoped germanium

“…For a short moment (in the sub-microsecond range), the surface is much hotter than the amorphous/crystalline interface. Also, the threshold energy needed for crystalline seed nucleation is lower than the energy needed for the epitaxial regrowth [32]. Therefore, during f-FLA, the recrystallization of the implanted layer starts from the surface and a polycrystalline layer is formed.…”

“…Since the discovery of superconductivity in diamond [1] with a boron content above the equilibrium solid solubility (ESS) many studies have been performed to find new "superconducting semiconductors". Such a materials class would enable the monolithic integration of quantum and conventional electronics [2]. Indeed, several groups found superconductivity, even in the technologically more relevant semiconductors like Si [3], Ge [4] or SiC [5], after a heavy hole doping.…”

Mapping the electromagnetic field confinement in the gap of germanium nanoantennas with plasma wavelength of 4.5 micrometers

“…Nanoantennas have indeed been realized in the n-Ge material system epitaxially grown on the Si wafers; 20 however in that case, doping levels of about 0.2 Â 10 20 cm À3 , obtained by co-deposition of the dopant P and Ge, have still limited the nanoantenna operation at k > 11 lm with k p ¼ 9.3 lm. Very recently, 21 a shorter k p ¼ 5.5 lm was reported for the ion-implanted n-Ge thin films, but no antenna structures were fabricated in that case.…”