자외선 조사에 따른 SiOC(-H) 박막의 전기적 특성

Abstract

The research work is focused on exploring the bonding structure and the electrical property of the SiOC(-H) thin films. These films were deposited by plasma-enhanced chemical-vapor deposition (PECVD) using the TriMethylSilan (TMS: H-Si-(CH3)3) and oxygen gas with various deposition conditions. The SiOC(-H) films were characterized with ultraviolet (UV) treatment effect in terms of the treatment time and annealing temperature. Film thickness is measured by field emission scanning electron microscopy (FESEM). Bonding configurations of Si-O-Si, Si-O-C, Si-CH3 and OH-related bonds in the SiOC(-H) films were investigated by Fourier transform infrared (FTIR) spectroscopy. The electric properties including the capacitance-voltage (C-V) characteristics were investigated using the Al/SiOC(-H)/p-Si(100) metal-insulator-semiconductor (MIS) structure. The deposition rates of the SiOC(-H) films were increased as the flow rate ratio increased. The relative absorption areas of the Si-O-Si network and Si-O-C open-linked mode were decreased as the UV treatment time and annealing temperature increased. On the other hand, the Si-O-C cage-linked and Si-O-C ring-linked modes were increased as the UV treatment time and annealing temperature increased. The dielectric constant of SiOC(-H) films decreased with increasing the UV treatment time and the annealing temperature. For the UV treatment time of 5 min, the dielectric constant was varied from 2.49 to 2.29 as the annealing temperature increased from room temperature (RT) to 400 ℃. At annealing temperature 400 ℃, the dielectric constant varied from 2.50 to 2.05 as the UV treatment time increased from 0 to 8 min.