Preparation of silicon oxide with bubble layer by helium plasma irradiation followed by oxidation

Silicon oxide bubble layer on silicon wafer was produced by helium ion irradiation followed by oxygen plasma irradiation or thermal oxidation. By the helium ion irradiation, a bubble layer was formed. The thickness and porosity of bubble layer depended on the irradiation condition. By the oxygen plasma irradiation to the bubble layer, only the surface of the bubble layer was oxidized. By the thermal oxidation, an entire region of the bubble layer was oxidized. In the latter case, the thickness of the silicon oxide bubble layer was as high as approximately 200 nm in the present experiment. Estimated dielectric constant of this layer was approximately 3. (C) 2002 Elsevier Science Ltd. All rights reserved.