Spectroscopic Analysis of Effects of Additive Nitrogen on Atmospheric Pressure Ar/HMDS Plasma

Hexamethyldisilazane (HMDS) is a cost-effective and stable compound used to synthesize thin films for applications such as silicon nitride thin-film deposition. Plasma-enhanced chemical vapor deposition is commonly used to deposit thin films from HMDS because plasma offers sufficient energy to effectively decompose HMDS and facilitates the formation of films. Various gases are added to the plasma to modulate its characteristics. This study investigated the effect of N-2 addition to atmospheric-pressure Ar/HMDS plasma. Optical emission spectroscopy measurements provided valuable insights into the characteristics of the plasma under different N-2 gas flow rates, and the importance of N-2 as a deposition parameter was discussed. The introduction of N-2 in the Ar/HMDS plasma decreased the excitation, vibrational, and rotational temperatures, significantly changing the composition of reactive species in the plasma.