Evaluation of Silicon Nitride Film Formed by Atomic Layer Deposition on the Silicon Substrate with Trench Structure Using Angle-Resolved Hard X-ray Photoelectron Spectroscopy

We evaluated the silicon nitride (SiN) films fabricated by plasma enhanced atomic layer deposition (PEALD) on the trench Si substrate. The transmission electron microscopy (TEM) observation showed that the SiN film was conformally deposited along the trench. However, from the angle-resolved hard X-ray photoelectron spectroscopy (HAXPES) measurements, the chemical bonding states in the SiN film on the trench sidewall from top to the bottom were different. On the sidewall of the trench, we found that N deficiency was generated in the SiN film, resulting in the non-stoichiometric SiN film formation. The precursor energy might not be sufficient and deactivated in the deep trench. The stoichiometric SiN film was deposited on the sidewall of the deep trench by increasing the deposition temperature.