Zhang, Jianjun; Katsaros, GeorgiosIST Austria; Montalenti, Francesco; Scopece, Daniele; Rezaev, Roman O; Mickel, Christine H; Rellinghaus, Bernd; Miglio, Leo P; De Franceschi, Silvano; Rastelli, Armando; Schmidt, Oliver G
Self-assembled Ge wires with a height of only 3 unit cells and a length of up to 2 micrometers were grown on Si(001) by means of a catalyst-free method based on molecular beam epitaxy. The wires grow horizontally along either the  or the  direction. On atomically flat surfaces, they exhibit a highly uniform, triangular cross section. A simple thermodynamic model accounts for the existence of a preferential base width for longitudinal expansion, in quantitative agreement with the experimental findings. Despite the absence of intentional doping, the first transistor-type devices made from single wires show low-resistive electrical contacts and single-hole transport at sub-Kelvin temperatures. In view of their exceptionally small and self-defined cross section, these Ge wires hold promise for the realization of hole systems with exotic properties and provide a new development route for silicon-based nanoelectronics.
Physical Review Letters
We acknowledge the financial support by the DFG SPP1386, P. Chen and D. J. Thurmer for MBE assistance, R. Wacquez for providing the ultrathin SOI wafers, and G. Bauer, Y. Hu, X. Jehl, S. Kiravittaya, C. Klöffel, E. J. H. Lee, F. Liu, D. Loss, and S. Mahapatra for helpful discussions. G. K. acknowledges support from the European commission via a Marie Curie Carrer Integration Grant. S. D. F. acknowledges support from the European Research Council through the starting grant program
Zhang J, Katsaros G, Montalenti F, et al. Monolithic growth of ultrathin Ge nanowires on Si(001) . Physical Review Letters. 2012;109(8). doi:10.1103/PhysRevLett.109.085502
Zhang, J., Katsaros, G., Montalenti, F., Scopece, D., Rezaev, R., Mickel, C., … Schmidt, O. (2012). Monolithic growth of ultrathin Ge nanowires on Si(001) . Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.109.085502
Zhang, Jianjun, Georgios Katsaros, Francesco Montalenti, Daniele Scopece, Roman Rezaev, Christine Mickel, Bernd Rellinghaus, et al. “Monolithic Growth of Ultrathin Ge Nanowires on Si(001) .” Physical Review Letters. American Physical Society, 2012. https://doi.org/10.1103/PhysRevLett.109.085502.
J. Zhang et al., “Monolithic growth of ultrathin Ge nanowires on Si(001) ,” Physical Review Letters, vol. 109, no. 8. American Physical Society, 2012.
Zhang J, Katsaros G, Montalenti F, Scopece D, Rezaev R, Mickel C, Rellinghaus B, Miglio L, De Franceschi S, Rastelli A, Schmidt O. 2012. Monolithic growth of ultrathin Ge nanowires on Si(001) . Physical Review Letters. 109(8).
Zhang, Jianjun, et al. “Monolithic Growth of Ultrathin Ge Nanowires on Si(001) .” Physical Review Letters, vol. 109, no. 8, American Physical Society, 2012, doi:10.1103/PhysRevLett.109.085502.