Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Low-temperature fabrication of layered selforganized Ge clusters by RF-sputtering | Pinto et al. Nanoscale Research Letters 2011 6 341 http content 6 1 341 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Low-temperature fabrication of layered selforganized Ge clusters by RF-sputtering 1 1 2 4 5 Sara RC Pinto Anabela G Rolo Maja Buljan Adil Chahboun 1 Sigrid Bernstorff Nuno P Barradas Eduardo Alves5 Reza J Kashtiban6 Ursel Bangert6 and Maria JM Gomes1 Abstract In this article we present an investigation of Ge SiO2 SiO2 multilayers deposited by magnetron sputtering and subsequently annealed at different temperatures. The structural properties were investigated by transmission electron microscopy grazing incidence small angles X-ray scattering Rutherford backscattering spectrometry Raman and X-ray photoelectron spectroscopies. We show a formation of self-assembled Ge clusters during the deposition at 250 C. The clusters are ordered in a three-dimensional lattice and they have very small sizes about 3 nm and narrow size distribution. The crystallization of the clusters was achieved at annealing temperature of 700 C. Introduction Semiconductor nanocrystals NCs have shown a big potential for application in flash memory devices 1 . Most quantum dot QD flash memory research studies have used Si NCs in floating gate. However several groups have proposed systems using Ge dots 2 instead of Si dots. The band gap of Ge provides both a higher confinement barrier for retention mode and a smaller barrier for program and erase mode. This makes Ge dots a strong candidate for floating gates. However the fabrication of Ge dots on insulators is much more difficult to obtain than Si dots because of the low evaporation temperature of Ge and the difference in surface energy with respect to the oxide. Si1-xGex can offer an intermediate solution to this issue. In fact embedding silicon or silicon germanium SiGe dots in an insulator structure has been proposed for non-volatile memory devices 3-6 . Magnetron .
