Branched nozzle oblique angle flow for initiated chemical vapor deposition

Abstract

Monomer precursor flow was introduced at an oblique angle to the substrate at two locations during the initiated chemical vapor deposition (iCVD) process using a branched nozzle inlet extension. The polymerization of methacrylic acid was systematically studied as a function of the nozzle length and the monomer flow rate. Our experimental data showed the evolution of two distinct symmetrical thickness profiles as the flow rate and nozzle length increased. The maximum thickness moved downstream along the axes of both nozzles as the flow rate and nozzle length increased. Computational models were used to study the effects of the nozzle length and the monomer flow rate on the velocity profile within the reactor. Increasing the monomer flow rate and the nozzle length resulted in increases in the velocity profile ranges and the movement of the location of the maximum velocity and local minimum velocity associated with the stagnation point. These velocity data provided insight for explaining the trends found in the experimental results. The data demonstrate the ability to use a branched nozzle inlet extension to control the location of polymer deposition during the iCVD process.