Stress in the Cat-CVD mu c-Si:H films is of concern for the performance of the flexible solar cells and MEMS devices. We report the results of our initial studies on stress determination of the HWCVD deposited mu c-Si:H films and its variation with thermal treatment. From the analysis of the stress values of the intrinsic pc-Si:H films it is seen (at least in the preliminary results obtained) that films deposited around 250 degrees C show a lower stress which could be due to the better network and optimum hydrogen content in the films. Secondly the doped films show an order of magnitude larger internal stress compared to the intrinsic films while the grain size is comparable. However upon annealing the stress minimizes and we get films with very low stress. (c) 2005 Elsevier B.V. All rights reserved.