Calculation of intrinsic stress by creep deformation of an Si substrate on chemical vapor deposited diamond films

Abstract

Diamond films were deposited on a p-type Si substrate by a hot-filament chemical vapor deposition method. We observed intrinsic stress of the film by creep deformation of the Si substrate, and deduced intrinsic residual stresses of films using the power-law creep equation. Thermal strain and creep strain in the Si substrate were subtracted from the total ex situ measured strain. Thermal strain was removed by the numerical method, and creep strains in the substrate were examined by measuring the curvature of Si substrates which had been removed from the diamond films by the electron cyclotron resonance etching process using oxygen plasma. The results showed that creep deformation of the Si substrates must be considered when residual stresses are measured by the curvature method. This is especially true in cases where the film was thick, or when temperature or stress conditions were high. From this study, we propose a new approach to measuring intrinsic stress from the creep deformation of substrates. (C) 2000 Published by Elsevier Science S.A. All rights reserved.