Peer-Reviewed Journal Details
Mandatory Fields
Murphy-Armando, F;Fahy, S
2011
June
Journal of Applied Physics
Giant enhancement of n-type carrier mobility in highly strained germanium nanostructures
Validated
WOS: 38 ()
Optional Fields
BAND-STRUCTURE ROOM-TEMPERATURE SEMICONDUCTORS TRANSPORT GE NANOWIRES STRENGTH SI
109
First-principles electronic structure methods are used to predict the rate of n-type carrier scattering due to phonons in highly-strained Ge. We show that strains achievable in nanoscale structures, where Ge becomes a direct bandgap semiconductor, cause the phonon-limited mobility to be enhanced by hundreds of times that of unstrained Ge, and over a thousand times that of Si. This makes highly tensile strained Ge a most promising material for the construction of channels in CMOS devices, as well as for Si-based photonic applications. Biaxial (001) strain achieves mobility enhancements of 100 to 1000 with strains over 2%. Low temperature mobility can be increased by even larger factors. Second order terms in the deformation potential of the Gamma valley are found to be important in this mobility enhancement. Although they are modified by shifts in the conduction band valleys, which are caused by carrier quantum confinement, these mobility enhancements persist in strained nanostructures down to sizes of 20 nm. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3590334]
MELVILLE
0021-8979
10.1063/1.3590334
Grant Details