Silicon nitride (SiN) films were deposited by a pulsed plasma enhanced chemical vapor deposition system in a SiH4-NH3 chemistry. Surface morphology of SiN films at room temperature is first reported. Scanning electron microscope and atomic force microscopy were used for characterization. Radio frequency source power was varied from 200-800 W with an increment of 200 W. For each power, duty cycle was controlled as 40, 50, 70, 90%. Particularly, surface roughness was detailed in terms of a distribution of maximum pixel size or major pixel density, and a nonuniformity of pixel density. A consistent decrease in surface roughness with reducing duty cycle was observed in the ranges of 40-70% and 40-90% at 200 and 600 W, respectively. In contrast, surface roughness increased with reducing duty cycle at 800 W. Meanwhile, both maximum pixel size and distribution of major pixel density were highly correlated to surface roughness as a function of duty cycle at all powers. These two metrics are expected to effectively characterize the degree of surface densification as well as to support surface roughness variations.
Silicon nitride films were deposited at room temperature in a plasma-enhanced chemical vapor deposition system. Ion energy and ion energy flux were measured with an ion energy analysis system. The effects of the radio frequency bias power on the ion energy distribution, deposition rate, refractive index, and surface roughness were examined along with the correlations between the ion energy diagnostics and film properties. The bias power varied from 30 W to 90 W. The surface roughness measured by atomic force microscopy was detailed in terms of the mean surface roughness and major pixel density. The deposition rate increased from 271 Å/min to 308 Å/min, increasing the bias power and correlation with the ion energy. Particularly, the refractive index increased with a decrease in the bias power. This is a unique feature resulting from the room-temperature deposition of silicon nitride film controlled in terms of the bias power. Moreover, the large variation from 1.94 to 2.49 facilitates the control of the refractive index as a function of the bias power. Strong dependency of the refractive index on the ion energy flux was also identified.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.