Investigating the Impact of Hydrogen Bonding on Silicon Nitride (SiNx) Film

Abstract

The deposition of amorphous hydrogenated silicon nitride (a‐SiNx:H) via plasma‐enhanced chemical vapor deposition is critical for optimizing the performance of crystalline silicon (c‐Si) solar cells. This study investigates the impact of varying gas ratios (GR = NH3/SiH4) on the optical and physical properties of deposited SiNx films. Results show that the refractive index (RI) ranges from 1.8 to 2.3 with changing gas compositions. Fourier transform infrared Spectroscopy reveals shifts in [SiNH] and [SiH] stretching modes, indicating changes in hydrogen passivation and nitrogen incorporation. Hydrogen bonding densities of [SiH] and [SiNH] correlate positively with the RI. For example, the hydrogen bonding density [NH] ranges from 4.53 × 1023 to 6.32 × 1023 cm−3 for [SiNH] bonds while [Si‐H] varies from 6.93 × 1023 to 1.06 × 1024 cm−3. Secondary ion mass spectrometry (SIMS) analysis shows stable hydrogen intensity, contrasting with a decrease in nitrogenhydrogen bonds. These findings highlight the key role of hydrogen bonding in determining SiNx film properties, with significant implications for semiconductor and photovoltaic applications.