Nanometer-scale pores in low-k dielectric films probed by positron annihilation lifetime spectroscopy

The mean pore size, open, and closed porosities in mesoporous low-k deielctric films were measured using positron annihilation lifetime spectroscopy. The ortho-positronium lifetime parameters were also obtained using both the maximum entropy and discrete lifetime analysis. The results indicate that total porosity increases linearly with porogen load, consistent with the porosity obtained from density measurements.