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Title: Physical mechanisms for anisotropic plasma etching of cesium iodide

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.1803607· OSTI ID:20662134
;  [1]
  1. Electrical and Computer Engineering Department, Northeastern University, Boston, Massachusetts 02115 (United States)

The physical mechanisms for the interaction between a reactive plasma and a cesium iodide surface are investigated. Under conditions of ion bombardment and elevated substrate temperature, CsI is found to sputter etch slowly (15 nm/min). If atomic fluorine, fluorocarbon radicals, of SF{sub x} radicals are present in the discharge, however, CsI is reactively etched at substantially higher rates (up to 200 nm/min). The roles of plasma radicals and energetic ion bombardment are investigated by first exposing the surface to plasma radicals and then bombarding the surface with argon ions. The optical emission from Cs and I atoms is found to correlate with the etch rate of CsI and is used as an in situ monitor of radical-enhanced etching. Small surface exposures to CF{sub x}, SF{sub x}, and F radicals are shown to enhance the etch rate of CsI. If the exposure of the CsI surface is increased, however, these same radical species act as etch inhibitors. A simple model for reactive etching of CsI is proposed, and this model is shown to compare reasonably well with experimental etch rates.

OSTI ID:
20662134
Journal Information:
Journal of Applied Physics, Vol. 96, Issue 9; Other Information: DOI: 10.1063/1.1803607; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English