AVS 56th International Symposium & Exhibition
    Thin Film Wednesday Sessions
       Session TF-WeM

Paper TF-WeM11
Subsurface Oxidation for Micropatterning Silicon (SOMS)

Wednesday, November 11, 2009, 11:20 am, Room B4

Session: Nanostructuring Thin Films I
Presenter: F. Zhang, Brigham Young University
Authors: F. Zhang, Brigham Young University
K. Sautter, Yield Engineering Systems
R.C. Davis, Brigham Young University
M.R. Linford, Brigham Young University
Correspondent: Click to Email
We introduce a straightforward patterning technique for native oxide-capped silicon to produce features of both nanometer and micron dimensions: subsurface oxidation for micropatterning silicon (SOMS). In this method, a stencil mask with, for example, ca. 5 micron features is positioned over a silicon surface. RF plasma oxidation of the substrate creates a pattern of thicker oxide in the exposed regions. Etching with HF or KOH produces very shallow (few nanometer) or much higher aspect ratio features (hundreds of nanometers deep) on silicon, respectively, where patterning is confirmed by atomic force microscopy, scanning electron microscopy, and optical microscopy. The oxidation process itself is studied under a variety of reaction conditions, which have not been thoroughly explored in the literature, including higher and lower oxygen pressures (2 and 0.5 Torr), a variety of powers (50 – 400W), different treatment times, and as a function of reagent purity (99.5% or 99.994% oxygen). A mathematical model of the results is derived. The reagent purity, even at the high level studied, is shown to influence the process. SOMS can be easily performed in any normal chemistry lab with a plasma generator. Because of its simplicity, it may have industrial viability.