Automatic process control for artificially layered structures.
01 January 1987
A laboratory or small system controller is described that combines a miniature UHV compatible, specie selective deposition sensor with a software program that runs on a personal computer. It integrates composition control to 0.1angstroms/sec with the analog control of substrate temperatures, doping levels and simpler functions such as shutters. This system has been running for a year and a half and has produced not only complex superlattice structures, but also novel non-linear profiles such as parabolic composition grading in Ge-Si strained-layer heterostructures in a reproducible, operator-independent mode.