Method of reducing roughness of a thick insulating layer

Abstract

A method for reducing roughness of an exposed surface of an insulator layer on a substrate, by depositing an insulator layer on a substrate wherein the insulator layer includes an exposed rough surface opposite the substrate, and then smoothing the exposed rough surface of the insulator layer by exposure to a gas plasma in a chamber. The chamber contains therein a gas at a pressure of greater than 0.25 Pa but less than 30 Pa, and the gas plasma is created using a radiofrequency generator applying to the insulator layer a power density greater than 0.6 W/cm2 but less than 10 W/cm2 for at least 10 seconds to less than 200 seconds. Substrate bonding and layer transfer may be carried out subsequently to transfer the thin layer of substrate and the insulator layer to a second substrate.

Dependencies are inferred from the claim text.