Commercial-scale sources for the evaporation of elemental Cu, Ga, and In: Modeling, design, and validation

A methodology for the design of commercial-scale sources for the evaporation of Cu, Ga, and In is described. Semi-empirical flow equations are utilized in predicting the internal pressure profile, and compared against temperature profiles generated by finite element modeling. This approach allows for the prediction of condensation within the source, and subsequent droplet ejection towards the substrate. Using this methodology, a commercial-scale prototype source was designed, fabricated, and validated for Cu, Ga, and In evaporation. Deposition profiles were determined, and rates sufficient for commercial-scale manufacturing were achieved.