tailieunhanh - Báo cáo hóa học: "Scanned Probe Oxidation on p-GaAs(100) Surface with an Atomic Force Microscopy"

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: Scanned Probe Oxidation on p-GaAs(100) Surface with an Atomic Force Microscopy | Nanoscale Res Lett 2008 3 249-254 DOI S11671-008-9144-2 NANO EXPRESS Scanned Probe Oxidation on p-GaAs 100 Surface with an Atomic Force Microscopy Sheng-Rui Jian Jenh-Yih Juang Received 9 April 2008 Accepted 23 June 2008 Published online 3 July 2008 to the authors 2008 Abstract Locally anodic oxidation has been performed to fabricate the nanoscale oxide structures on p-GaAs 100 surface by using an atomic force microscopy AFM with the conventional and carbon nanotube CNT -attached probes. The results can be utilized to fabricate the oxide nanodots under ambient conditions in noncontact mode. To investigate the conversion of GaAs to oxides micro-Auger analysis was employed to analyze the chemical compositions. The growth kinetics and the associated mechanism of the oxide nanodots were studied under DC voltages. With the CNT-attached probe the initial growth rate of oxide nanodots is in the order of 300 nm s which is 15 times larger than that obtained by using the conventional one. The oxide nanodots cease to grow practically as the electric field strength is reduced to the threshold value of 2 X 107 V cm-1. In addition results indicate that the height of oxide nanodots is significantly enhanced with an AC voltage for both types of probes. The influence of the AC voltages on controlling the dynamics of the AFM-induced nanooxidation is discussed. Keywords Atomic force microscopy p-GaAs 100 Nanooxidation Multi-walled carbon nanotube Auger electron spectroscopy . Jian H Department of Materials Science and Engineering I-Shou University Kaohsiung 840 Taiwan ROC e-mail srjian@ . Juang Department of Electrophysics National Chiao Tung University Hsinchu 300 Taiwan ROC Introduction Scanning probe microscopes SPM techniques have demonstrated potential in the creation and characterization of structures patterns and devices at the nanometer scale. In particular atomic force microscopy AFM local anodic oxidation 1 is one of the most versatile methods for .