| AVS 62nd International Symposium & Exhibition | |
| Surface Science | Thursday Sessions |
| Session SS+AS+EM+EN-ThM |
| Session: | Semiconductor Surfaces and Interfaces - I |
| Presenter: | Jonghan Park, University of Texas at Dallas |
| Authors: | W.N. Peng, University of Texas at Dallas J.H. Park, University of Texas at Dallas L.-H. Liu, University of Texas at Dallas R.C. Longo, University of Texas at Dallas D.J. Michalak, Intel Corporation D.M. Pak, University of Texas at Dallas Y.J. Lee, University of Texas at Dallas J.X. Hsu, University of Texas at Dallas K.J. Cho, University of Texas at Dallas Y.J. Chabal, University of Texas at Dallas |
| Correspondent: | Click to Email |
Recently, oxide-free and partially methoxy-terminated Si surfaces1 have been developed as a novel platform for surface reactions because of their superior reactivity compared to hydrogen termination2. As a result, strong polar bonds such as Si-F could be stabilized on these surfaces. Since the electrical quality is critical for many applications (i.e. surface defects can degrade the device performance), we performed contactless surface recombination velocity measurements to examine the electronic quality of partially covered surfaces. Interestingly, we found that the carrier lifetime is significantly increased after fluorine termination, with the carrier lifetime 10 times higher than that of hydrogen terminated Si surfaces, approaching 1.5 ms. This anomalously long carrier lifetime can be explained either by a better surface passivation or by surface band bending effects. We therefore performed UPS and kelvin probe measurements to investigate the band structure of these surfaces after fluorine termination and found evidence for band bending. A potential model of a surface dipole layer induced band bending is supported by DFT calculations. Regardless of the mechanism controlling the recombination time, this method is well suited to explore the fluorination mechanism of H-terminated surfaces.
[1] D. Michalak, S. Amy, D. Aureau, M. Dai, A. Esteve, and Y. J. Chabal, Nature Materials, 9, (2010)
[2] P. Thissen, T. Peixoto, R. Longo, W. Peng, W. Schmidt, K. Cho, and Y.J. Chabal, JACS, 134 (2012)