Characteristics of thin film deposition by photo‐CVD using a Xe2 excimer lamp

Abstract

AbstractRecently, a novel method of photochemical vapor deposition using vacuum ultraviolet (VUV) excimer lamps (VUV‐CVD) has been developed. We have been attempting to make thin films from organic precursors at room temperature by VUV‐CVD. We present the characteristics of VUV‐CVD films and the reaction properties of VUV‐CVD as a function of the addition of O2, the substrate temperature, and the illumination intensity, examining the growth rate, film quality, and gap‐filling properties when various organic siloxane gases are used as chemical precursors. VUV photons dissociate the organic precursor and produce radical reactants that consist of Si‐O and impurities such as C‐H and O‐H. They finally condense into deposition films including SiO2 and impurities. Therefore, the VUV‐CVD films are very similar in composition to the precursors. The reaction is altered by adding O2, which produces ozone and activated oxygen as a result of dissociation by VUV photons. The deposition efficiency is improved by both a low substrate temperature and the higher light intensity of the excimer lamp. Film deposition at room temperature in VUV‐CVD without thermal‐ or plasma‐induced damage constitutes an important innovation in thin film preparation. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(4): 43–50, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10325