AVS 45th International Symposium
    Nanometer-scale Science and Technology Division Tuesday Sessions
       Session NS-TuA

Paper NS-TuA1
Self-organized Ge Quantum Wires on Si (111) Substrate

Tuesday, November 3, 1998, 2:00 pm, Room 321/322/323

Session: Quantum Wires and Quantum Dots
Presenter: G. Jin, University of California, Los Angeles
Authors: G. Jin, University of California, Los Angeles
Y.S. Tang, University of California, Los Angeles
J.L. Liu, University of California, Los Angeles
K.L. Wang, University of California, Los Angeles
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Self-organized nanostructures have been of considerable interest recently due to the fact that self-organization provides a possible way to realize nanostructures without process-induced damage as frequently seen in those defined by electron beam lithography and reactive ion etching. However, very few work has been reported on self-organized quantum wires. In this work, self-organized Ge quantum wires on Si (111) substrate grown by MBE have been realized and studied. Regular surface steps were formed on cleaned Si (111) substrate after annealing at 870°C in a UHV MBE system, then selforganized Ge quantum wires were formed on the substrate after growing 300 nm Si buffer layer. Atomic force microscopy (AFM) studies showed that regular surface steps were formed along [11 -2] direction and the terrace width was about 120 nm and the step height was about 0.6 nm. The self-organized Ge quantum wires with the width of about 65 nm and the height of about 5.5 nm were parallel to the direction of [11 -2] with the pitch close to the terrace width, or about 120 nm. The uniformity of the quantum wires was found to be reasonably good. Raman studies indicated that the peak of Ge-Ge mode shifted to a higher energy. This suggests that the Ge quantum wires are tensilely strained on the edge sites of the steps. The result of polarized Raman studies confirmed the existence of the wires and the wire orientation which is consistent with the AFM result. The size distribution and the optical properties of the Ge quantum wires are also under study. @FootnoteText@ The work was supported in past by National Science Foundation (DMR-9520893)