tailieunhanh - báo cáo hóa học: " Fabrication of ultrahigh-density nanowires by electrochemical nanolithography"

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: Fabrication of ultrahigh-density nanowires by electrochemical nanolithography | Chen et al. Nanoscale Research Letters 2011 6 444 http content 6 1 444 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Fabrication of ultrahigh-density nanowires by electrochemical nanolithography Feng Chen1 2 Hongquan Jiang 2 Arnold M Kiefer2 Anna M Clausen2 Yuk-Hong Ting2 Amy E Wendt2 Bingjun Ding1 and Max G Lagally2 Abstract An approach has been developed to produce silver nanoparticles AgNPs rapidly on semiconductor wafers using electrochemical deposition. The closely packed AgNPs have a density of up to X 1011 cm-2 with good size uniformity. AgNPs retain their shape and position on the substrate when used as nanomasks for producing ultrahigh-density vertical nanowire arrays with controllable size making it a one-step nanolithography technique. We demonstrate this method on Si SiGe multilayer superlattices using electrochemical nanopatterning and plasma etching to obtain high-density Si SiGe multilayer superlattice nanowires. Introduction Low-dimensional systems are of high interest because their unique properties can improve device performance in a range of applications including optics 1 2 mechanics 3 microelectronics 4 and magnetics 5 . These systems have enhanced surface and quantum confinement effects caused by the large surface-to-volume ratio and small size making them dramatically different from their bulk counterparts. Superlattice nanowires have the potential to improve the performance of thermoelectronics 6-9 small sizes have lower thermal conductivity 8 9 and they can be made at a high density thus providing improved performance. Generally there are two major approaches in the fabrication of nanostructures bottom-up 10 and top-down 11 . Among the various bottom-up methods vaporliquid-solid VLS growth is one of the most popular and is used to grow nanostructures such as nanowires 12-14 . VLS growth uses a catalytic liquid-alloy phase that can rapidly adsorb a vapor to supersaturation levels in