Vacuum Evaporation Source with Double-Wall Cylindrical Graphite Heater and Nozzle Outlet

Abstract

A resistance heated source is described which is capable of evaporating refractory materials in vacuo. Film thickness uniformity and deposition efficiency are improved through the use of a converging‐diverging nozzle at the crucible outlet. The source also features a double‐wall cylindrical graphite heater configuration which facilitates the reduction of heat losses and copper to graphite electrical connectors capable of operating over a large temperature range.