HALOGEN ASSISTED DIAMOND DEPOSITION IN A MICROWAVE PLASMA REACTOR

MICROWAVE PLASMA ENHANCED CHEMICAL VAPOR DEPOSITION (PECVD) OF DIAMOND FILMS USING HALOGEN BASED CHEMISTRIES IS PROPOSED IN ORDER TO DEVELOP A LOW TEMPERATURE DIAMOND DEPOSITION PROCESS. THE UNIQUE PROPERTIES OF DIAMOND, AN INSULATOR WITH THE HIGHEST ROOM TEMPERATURE THERMAL CONDUCTIVITY, MAKE IT AN ATTRACTIVE MATERIAL TO BE USED FOR IMPROVING THE THERMAL DISSIPATION PROPERTIES OF HIGH POWER DENSITY MICROELECTRONIC DEVICES. RECENT REPORTS INDICATE THAT HALOGEN BASED CHEMISTRIES HAVE ALLOWED A SIGNIFICANT REDUCTION OF THE DEPOSITION TEMPERATURE REQUIRED FOR DIAMOND DEPOSITION IN THERMAL CVD REACTORS. SUCH A REDUCTION IN TEMPERATURE WOULD ALLOW THE DEPOSITION OF THE DIAMOND FILMS DIRECTLY OVER HIGH POWER MICROELECTRONICS CHIPS. IN THIS WORK, WE PROPOSE THE USE OF MICROWAVE PECVD SINCE IT HAS CONSISTENTLY GENERATED (IN HYDROGEN-METHANE CHEMISTRIES) DIAMOND FILMS OF THE HIGHEST QUALITY WITH THERMAL CONDUCTIVITIES WHICH APPROACH THAT OF NATURAL DIAMOND. OPERATION OF THE CHIP AFTER DIAMOND DEPOSITION WOULD PROVIDE A PROOF-OF-PRINCIPLE EXPERIMENT FOR THE FEASIBILITY OF THE PROPOSED APPROACH. HIGH THERMAL CONDUCTIVITY DIAMOND FILMS DEPOSITED AT LOW TEMPERATURES WOULD GREATLY ENHANCE THE KIND OF MATERIALS OVER WHICH THESE FILMS CAN BE DEPOSITED (MOSTLY CERAMICS AND REFRACTORY METALS). A SIGNIFICANT REDUCTION ON THE DEPOSITION TEMPERATURE WOULD ALLOW DEPOSITION ON E.G. ALUMINUM AND IN PRINCIPLE OVER PLASTICS. DIAMOND FILMS DIRECTLY DEPOSITED ON COMPLETED MICROELECTRONIC DEVICES COULD HAVE A SIGNIFICANT IMPACT ON THE LEVELS OF DEVICE INTEGRATION THAT CAN BE ATTAINED IN SI OR GAAS BASED DEVICES.