Mechanical property measurement of thin polymeric-low dielectric-constant films using bulge testing method

We report here the bulge testing results of both dense and porous poly-aryl ethers (PAE) polymeric low dielectric constant thin films. These films were prepared on a 4.7-mu m-thick Si membrane window of 1600x1600 mu m(2). The Si membrane was subsequently removed in a pulsed XeF2 etcher and the remain ing thin film became the bulge test sample. The biaxial moduli of both the dense and 40% porosity low-k PAE thin films were measured to be 6.40 +/- 0. 35 and 3.53 +/- 0.70 GPa, respectively. These biaxial moduli, when combined with the thermal stress data of these films, enabled us to estimate the th ermal expansion coefficients in the range of 26.8-32.6 and 56.1-72.5 ppm/de grees C for the dense and porous PAE films, respectively. (C) 2000 American Institute of Physics. [S0003-6951(00)01015-9].