In-line characterization of dielectric constant and leakage currents of low-k films with corona charge method

The use of corona charge method for monitoring the electrical properties of low-k dielectrics is investigated in this paper. First, the stability and reproducibility of k measurements are demonstrated on SiO 2 -based low-k materials. As mercury probe is the reference tool for k and leakage measurements, a comparison of the dielectric constants and leakage currents between both techniques is carried out on a set of different low-k films with various dielectric constants and thicknesses. Good correlations (over 95%) were obtained for the k values and breakdown voltages on all studied layers and an 82% correlation has been obtained for leakage densities at 1 MV/cm. As a consequence, corona charge method seems to be a good alternative for mercury probe to monitor in-line back-end low-k films.