Depth profile of mechanical properties of plasma-polymerized tetravinylsilane films evaluated by cyclic nanoindentation

Plasma-polymerized tetravinylsilane films deposited on silicon wafers by PECVD at different powers using pulsed plasma were analyzed by both typical conventional depth sensing and by cyclic nanoindentation. A comparative study of the two methods was carried out under reduced system drift. It was found that cyclic nanoindentation is a reproducible technique enabling reliable construction of the depth profile of mechanical properties to the same degree of accuracy as conventional nanoindentation but considerably faster. The Young's modulus (7.9–17GPa) and hardness (0.69–3.0GPa) of films were controlled by the effective power (0.1–10W). Conditions for appropriate depth analysis of mechanical properties at shallow depth and the limited applicability of the 10% rule are also discussed.