HBr-Based Gas Cluster Ion Beam Smoothing as a Final Polish for the Production of MBE-Epi-Ready GaSb Wafers

S.R. Vangala1, L.P. Allen2, V. DiFilippo3, C. Santeufemio1, J.Li1, X. Qian1, Y. Park4, K. Krishnaswam1, B. Zhu1, G. Dallas2, D. Bliss5, H. Dauplaise5, K.S. Jones6 and W.D. Goodhue1 

1 Photonics Center, University of Massachusetts, Lowell, MA  01854, USA 
Email: ssrvangala@yahoo.com Phone: +1-978-934-3982 and William_Goodhue@uml.edu Phone: +1-978-934-3785

2 Galaxy Compound Semiconductors, Inc. Spokane, WA  99206, USA
Email: lisapallen@adelphia.net  Phone: +1-603-878-2332

3 Epion Corporation, 37 Manning Park, Billerica, MA  01821, USA

4 Institute for Nanotechnology Applications, Inje University, Gimhae, South Korea

5 Air Force Research Laboratory/SNHC, Hanscom AFB, USA

6 Department of Materials Science, University of florida, Gainesville, FL 32611, USA

For the first time, as gas cluster ion beam (GCIB) process incorporating Br gas was successfully used on GaSb (100) as a surface preparation technique for molecular beam Epitaxy (MBE).  Thermal X-ray photoelectron spectroscopy (TXPS) revealed that the surface oxide layer contained bonded bromine which as liberated at ~400oC and Sb-oxides that were liberated at ~500oC, leaving mostly Ga-oxides.  Reflection high energy electron diffraction (RHEED) analysis within the MBE growth chamber showed a standard 1 x 3 reconstruction pattern in a Sb overpressure, confirming that Ga-oxides were desorbed by 530oC, leaving a smooth single crystal surface fo epitaxial growth.  In addition, the episurfaces of the Br-GCIB finished surfaces showed uniform step-terrace formations as compared to the swirled step terrace episurfaces grown on chemical mechanical polishing (CMP) finished surfaces. 

Keywords:  GaSb, Gas-Cluster-Ion-Beam-Polishing, Hydrogen Bromide, Epi-Ready, MBE

                                                14.24 pdf                     Return to TOC