tailieunhanh - Báo cáo hóa học: " Self-Assembled Local Artificial Substrates of GaAs on Si Substrate"

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: Self-Assembled Local Artificial Substrates of GaAs on Si Substrate | Nanoscale Res Lett 2010 5 1905-1907 DOI s11671-010-9760-5 SPECIAL ISSUE ARTICLE Self-Assembled Local Artificial Substrates of GaAs on Si Substrate S. Bietti C. Somaschini N. Koguchi C. Frigeri S. Sanguinetti Received 21 June 2010 Accepted 14 August 2010 Published online 31 August 2010 The Author s 2010. This article is published with open access at Abstract We propose a self-assembling procedure for the fabrication of GaAs islands by Droplet Epitaxy on silicon substrate. Controlling substrate temperature and amount of supplied gallium is possible to tune the base size of the islands from 70 up to 250 nm and the density from 10S. 7 to 109 cm-2. The islands show a standard deviation of base size distribution below 10 and their shape evolves changing the aspect ratio from to as size increases. Due to their characteristics these islands are suitable to be used as local artificial substrates for the integration of III-V quantum nanostructures directly on silicon substrate. Keywords Nanotechnology Molecular beam epitaxy Droplet epitaxy Integration of III-V on Si Local artificial substrate Integration of III-V semiconductor devices on silicon substrates would allow the fabrication of high efficiency optoelectronic and photonic devices using the well-established complementary metal oxide semiconductor CMOS technology. Although of the great technological interest results in this field are far from being optimized. Some issues like lattice mismatch between GaAs and Si and formation of anti-phase domain in GaAs are not yet fully solved 1 2 . One attractive approach to minimize these issues is the fabrication of local artificial substrates LAS . S. Bietti C. Somaschini N. Koguchi S. Sanguinetti L-NESS and Dipartimento di Scienza dei Materiali Universita di Milano Bicocca via Cozzi 53 20125 Milan Italy e-mail C. Frigeri Istituto CNR-IMEM Parco Area delle Scienze 37 A 43100 Parma Italy The concept of LAS lies .