Tree-based control software for multilevel sequencing in thin film deposition applications

A simple, extensible control software scheme for sequential deposition applications including atomic layer deposition, molecular beam epitaxy, and layer-by-layer deposition is presented. While single-component loops are easily programmed, nested loop architectures needed for complex multilayer thin films or compositionally graded structures are cumbersome to implement with only "For-loop" coding. Software code based on a generic tree architecture is introduced to achieve multilevel or compound sequencing. This architecture makes it possible to write many different deposition sequences without modifying the underlying software. The tree can be easily traversed using recursive techniques, simplifying the programmer's task and opening up novel material combinations and sequences to thin film researchers. A LABVIEW software implementation consisting of a few simple functions is presented, as well as a sampling of the potential complex deposition schemes facilitated by this architecture. (C) 2015 American Vacuum Society.