Deposition parameter studies and surface acoustic wavecharacterization of PECVD silicon nitride films on lithium niobate

摘要

Silicon nitride films were deposited by a plasma enhanced chemicalnvapor deposition technique using silane-ammonia as the reactant gasnmixture. The influence of the process parameters such as flow ratio ofnthe reactant gases, pressure, substrate temperature, RF power, time ofndeposition and electrode spacing on the deposition and etch rates wereninvestigated. From the matrix of deposition conditions, the depositionnparameters for high quality films applicable to surface acoustic waven(SAW) technology were found. Experimental results on the acoustic loss,nreflectivity and velocity dispersion for the fabricated devices arenpresented