A Study on Deposition Technology Utilizing Very High-Frequency (VHF) RF Systems

This study focuses on the development and optimization of a plasma-enhanced chemical vapor deposition system utilizing very high-frequency (VHF) plasma to enhance the deposition rate, film uniformity, and stress control in thin-film processes. A comparative analysis was conducted between conventional radio frequency (RF)-based (13.56 ㎒) and VHF-based (27.12 ㎒) systems using trisilicon tetranitride (Si₃N₄) single-layer deposition as the test case. The experimental results demonstrated that the VHF system achieved a deposition rate of 1,555 Å/min, which was approximately 2.1 times higher than that of the RF system. Furthermore, the film uniformity significantly improved from 1.48% to 0.90%, and the system exhibited stable tensile stress and refractive-index performance. These findings indicate that the VHF RF system offers superior plasma density and reactive gas dissociation efficiency, making it a promising solution for high-speed and high-precision thin-film deposition. This study systematically analyzed the VHF hardware architecture, impedance matching techniques, and bottom electrode control methods, thereby providing technical insights for future applications in advanced semiconductor manufacturing.