Mechanism of low-stress and high-density SiO2 dielectric film deposition in TEOS/O2 PECVD: A multiscale simulation study

With the development of microelectronic devices toward higher integration and reliability, plasma-enhanced chemical vapor deposition (PECVD) SiO2 dielectric films play an important role in device insulation and surface passivation. However, the coupling and trade-off mechanism between film densification and residual stress remain unclear, which limits further improvement of their comprehensive performance. To address this issue, this study establishes a multiscale framework for SiO2 film deposition in a tetraethyl orthosilicate (TEOS)/O2 system. At the reactor scale, a comsol-based plasma discharge and deposition model is developed to analyze the coupling among electron-impact dissociation, active-oxygen oxidation, and surface deposition. At the atomic scale, a Large-scale Atomic/Molecular Massively Parallel Simulator-based deposition model is constructed to investigate the effects of deposition conditions on film densification and residual-stress evolution. By converting the macroscopic deposition rate and particle energy into atomic-scale inputs, a cross-scale relationship among process parameters, deposition behavior, and film structural properties is established. The results show that the TEOS flow rate is the dominant factor affecting film performance. Temperature and pressure regulate film growth by altering active-species transport and effective deposition flux, whereas high-frequency power mainly affects plasma reaction activity and low-frequency power controls structural rearrangement and stress state through particle bombardment energy. An optimized process solution was further obtained by constructing a comprehensive evaluation function, leading to a 36.4% improvement in overall performance. This study reveals the intrinsic relationship between densification and compressive-stress accumulation in PECVD SiO2 films, providing theoretical guidance for optimizing the deposition process of low-stress and high-density dielectric films.