H. Higashi; K. Kasahara; K. Kudo; H. Okamoto; K. Moto; J. -H. Park; S. Yamada; T. Kanashima; M. Miyao; I. Tsunoda; K. Hamaya
APPLIED PHYSICS LETTERS AMER INST PHYSICS 106 (4) 041902-1 0003-6951 2015/01
[Refereed] We demonstrate large-area (similar to 600 mu m), (111)-oriented, and high-crystallinity, i.e., pseudo-single-crystalline, germanium (Ge) films at 275 degrees C, where the temperature is lower than the softening temperature of a flexible substrate. A modulated gold-induced layer exchange crystallization method with an atomic-layer deposited Al2O3 barrier and amorphous-Ge/Au multilayers is established. From the Raman measurements, we can judge that the crystallinity of the obtained Ge films is higher than those grown by aluminum-induced-crystallization methods. Even on a flexible substrate, the pseudo-single-crystalline Ge films for the circuit with thin-film transistor arrays can be achieved, leading to high-performance flexible electronics based on an inorganic-semiconductor channel. (C) 2015 AIP Publishing LLC.