"IN-SITU DIAGNOSTICS FOR PROCESS MONITORING AND CONTROL OF THE PLASMA DEPOSITION OF A-SI:H"

THIS PROPOSAL WILL APPLY FOURIER TRANSFORM INFRARED (FT-IR) SPECTROSCOPY AS AN IN-SITU DIAGNOSTIC FOR THE DEPOSITION OF AMORPHOUS HYDROGENATED SILICON (A-SI:H). SUCCESSFUL PLASMA DEPOSITION OF A-SI:H ON A COMMERCIAL SCALE WILL REQUIRE SIMULTANEOUS KNOWLEDGE OF MANY PROCESS VARIABLES WITHIN THE PLASMA REACTOR. THESE VARIABLES INCLUDE 1) FILM THICKNESS, COMPOSITION (INCLUDING DOPING LEVEL), AND INDEX OF REFRACTION, 2) SUBSTRATE TEMPERATURE, 3) GAS TEMPERATURE ANDCOMPOSITION, AND 4) ADSORBED SPECIES. THERE ARE CURRENTLY NO TECHNIQUES THAT CAN MONITOR MORE THAN ONE OF THESE VARIABLES AT A TIME. FT-IR SPECTROSCOPY HAS THE POTENTIAL TO MONITOR MOST OF THE ABOVE PROCESS VARIABLES SIMULTANEOUSLY AND IN-SITU. GOOD SPATIAL RESOLUTION IS ALSO POSSIBLE. PHASE I WILL DEVELOP MODIFICATIONS OF STATE-OF-THE-ART FT-IR TECHNIQUES USED IN HYDROCARBON ANALYSIS AND DEMONSTRATE THEIR CAPABILITIES ON A SIMPLE PLASMA REACTOR. NEW METHODS FOR IMPROVED SENSITIVITY WILL ALSO BE EXPLORED. PHASE II OF THIS PROPOSAL WILL EXTEND THESE NEW TECHNIQUES TO DEVELOP A RUGGED SPECTROMETER FOR USE ON COMMERCIAL REACTORS.