This study uses atomic force microscopy (AFM) to investigate the oxygen etching behavior of the following silicon surface orientations: (001), (111), (113), (5 5 12) and (112). Most etching was performed at sample temperatures between 650 °C and 800 °C, at pressures of 3.3×10-7 and 1.5×10-7 Torr, and at an exposure of 200 L. Surface orientation strongly influences the morphology resulting from extended etching. The surface orientations that are stable against etching and remain flat include Si(001), Si(111), and Si(113). Such surfaces also include island structures, which result from etching around oxide-induced pinning sites. The density of these islands increases at lower temperatures and higher pressures. The surface orientations that are unstable against oxygen etching and facet to other orientations include Si(5 5 12) and Si(112). These surfaces form sawtooth facets that are primarily composed of more stable (111) and (113) planes. By controlling the temperature and exposure during oxygen etching, it is therefore possible to form a variety of surface morphologies.
| Identifer | oai:union.ndltd.org:vcu.edu/oai:scholarscompass.vcu.edu:etd-2007 |
| Date | 01 January 2005 |
| Creators | Willis, Mary L. |
| Publisher | VCU Scholars Compass |
| Source Sets | Virginia Commonwealth University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
| Rights | © The Author |
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