Atomic Force Microscope and Pulsed Ti-Sapphire Laser to Pursue Device Research at Virginia Microelectronic Center

摘要

A Digital Nanoscan III Atomic Force Microscope (AFM) and a roughing station have been purchased and installed. The latter was made possible by a discount negotiated with Digital Inc. The AFM acquired is of high resolution type with a maximum of 15 by 15 micron scan area and equipped with Electric Force Microscopy (EFM), Magnetic Force Microscopy (MFM) features and atmospheric scanning tunneling microscopy as well. Moreover, the instrument has been outfitted with optional equipment facilitating imaging of biological samples (liquid cell) and a sample holder for cross-sectional AFM. The scope has been in operation for more than a year, and has been and is heavily used by graduate and undergraduate students in Electrical Engineering and Physics. The scope was also used for a graduate class in laboratory techniques in the Physics Department. The scope has been primarily used for investigating surface features of GaN. As grown surfaces as well as etched surfaces for defect analysis have been imaged. We have already obtained crucial defect information on HVPE, MBE and MOCVD samples. We are currently making good progress toward developing samples for EFM development as well as using EFM on unknown samples for checking the polarity of the films. The scope gets used for quick imaging of Si (5 5 12) surfaces for Prof. Baski's research in Physics. The roughing station is a BOC Edwards (EXP combined Outfit Pumping Station) which sports a dry mechanical pump and a turbo pump. This system eliminated the use of time consuming liquid nitrogen traps in six vacuum systems as well as speeding up the process of roughing the systems down to low enough pressure before the resident pumps take over. We are already saving on nitrogen use while benefiting from reduced turn around time and better vacuum to be obtained.