title: Role of confinement on carrier transport in Ge-Si(x)Ge(1-x) core-shell nanowires.
abstract: We examine the impact of shell content and the associated hole confinement on carrier transport in Ge-Si(x)Ge(1-x) core-shell nanowires (NWs). Using NWs with different Si(x)Ge(1-x) shell compositions (x = 0.5 and 0.7), we fabricate NW field-effect transistors (FETs) with highly doped source/drain and examine their characteristics dependence on shell content. The results demonstrate a 2-fold higher mobility at room temperature, and a 3-fold higher mobility at 77K in the NW FETs with higher (x = 0.7) Si shell content by comparison to those with lower (x = 0.5) Si shell content. Moreover, the carrier mobility shows a stronger temperature dependence in Ge-Si(x)Ge(1-x) core-shell NWs with high Si content, indicating a reduced charge impurity scattering. The results establish that carrier confinement plays a key role in realizing high mobility core-shell NW FETs.
authors: Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas, Austin, Texas 78758, USA.
authors: Junghyo
authors: J
authors: Nah
authors: David C
authors: DC
authors: Dillen
authors: Kamran M
authors: KM
authors: Varahramyan
authors: Sanjay K
authors: SK
authors: Banerjee
authors: Emanuel
authors: E
authors: Tutuc
mesh_terms: D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D004579:Electron Transport; D005857:Germanium / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D014173:Transistors, Electronic
chemical_list: D005857:Germanium; D012825:Silicon