Low Temperature Silane-Based Silicon Oxides for MEMS and Packaging Applications

Silane-based silicon oxides with deposition temperatures ranging from 80°C to 300°C have been studied using Plasma Enhance Chemical Vapor Deposition (PECVD). The oxides were deposited using high frequency (HF, 13.56MHz) as well as low frequency (LF, 380KHz) Radio Frequency (RF) power sources in a capacitively-coupled plasma reactor. The high frequency and low frequency silicon oxides exhibited different film stresses and etch rates. The high frequency silicon oxide at 150°C was chosen for the encapsulation of Micro-Electro-Mechanical Systems (MEMS) devices due to its lower film stress and smoother surface roughness.