Deposition of silicon oxynitride thin films by remote plasma enhanced chemical vapor deposition

We have deposited thin films of silicon oxynitride (SiO₂)_x(Si₃N₄)_(1−x) by remote plasma enhanced chemical vapor deposition by infrared (IR) absorption, Auger electron spectroscopy (AES), and ellipsometry. The dominant IR stretching band feature shifts approximately linearly with frequency between the frequencies of the end member compounds and as such is a very good secondary standard for the determination of alloy composition. This behavior is also indicative of a homogeneous alloy, rather than a two‐phase mixture. We have used AES to determine the O/N ratio and have combined this spectroscopy with the IR to confirm that the alloy films lie on the join line between SiO₂ and Si₃N₄. Changes in the Si LVV line shape with alloy composition in the derivative AES spectrum make it impossible to use this feature as a measure of the relative Si composition. Finally, the ellipsometry measurements are also characteristic of a homogeneous alloy material.