DEVELOPMENT OF A SUBSTITUTE FOR (HIGH TOXIC) ARSINE GAS FOR USE IN FABRICATION OF GALLIUM ARSENIDE

THE USE OF ARSINE FOR THE GROWTH OF GAAS EPITAXIAL LAYERS BY METALORGANIC CHEMICAL VAPOR DEPOSITION (MOCVD) IS COMING UNDER INCREASING SCRUTINY BY GOVERNMENT AGENCIES AND COMMUNITIES. THE EXTREME TOXICITY OF ARSINE GAS, WHICH MUST BE STORED IN HIGH-PRESSURE STEEL CYLINDERS, COULD LEAD TO CATASTROPHIC CONSEQUENCES IN CASE OF AN ACCIDENTAL RELEASE OF A LARGE QUANTITY OF ARSINE. IN THE FUTURE, USE OF ARSINE MAY BE SEVERLY RESTRICTED OR PROHIBITED, AND THE SUPPLY OF GAAS-BASED MILITARY DEVICES, INCLUDING MIMICS AND OPTOELECTRONIC COMPONENTS, COULD NOT BE GUARANTEED. LOW VAPOR PRESSURE LIQUID ARSINE DERIVATIVES, WHICH AVOID THE RISKS AND HAZARDS ASSOCIATED WITH THE USE OF ARSINE, HAVE BEEN UNDER INVESTIGATION OVER THE PAST SEVERAL YEARS. THE COMPOUNDS REPORTED IN THE LITERATURE INCLUDE TRIMETHYLARSINE, TRIETHYLARSINE DIMETHYLARSINE, MONOETHYLARSINE, DIETHYLARSINE, PHENYLARSINE AND TERTIARYBUTYLARSINE (TBA). THE FIRST THREE OF THESE MATERIALS WERE FOUND TO BE RESPONSIBLE FOR UNACCEPTABLY HIGH CARBON ACCEPTOR CONCENTRATIONS CAUSED BY AN INTRINSIC PYROLYSIS MECHANISM. FOR MONOETHYL, DIETHYL AND PHENYLARSINE, IT REMAINS TO BE DEMONSTRATED THAT ECONOMIC PURIFICATION TECHNIQUES CAN BE DEVELOPED, AND THAT THEIR INTRINSIC CHEMISTRY IS ADEQUATE TO ACHIEVE SEMICONDUCTOR GRADE PURITY. IN THE CASE OF TBA, SYNTHESIS AND PURIFICATION TECHNOLOGY HAS BEEN DEVELOPED WHICH CONSISTENTLY YIELDS A PRODUCT OF HIGH PURITY AND EXCELLENT MATERIALS RESULTS HAVE BEEN DEMONSTRATED MAKING IT THE LEADING CANDIDATE FOR AN ASH3-FREE COMPOUND SEMICONDUCTOR TECHNOLOGY. ANTICIPATED BENEFITS/POTENTIAL COMMUNICATION APPLICATIONS - THE DEVELOPMENT OF TBA AS AN ASH3 SUBSTITUTE SHOWS GREAT PROMISE AS THE BASIS OF A COMMERCIALLY VIABLE III/V EPITAXIAL TECHNOLOGY. DEVELOPMENT OF THE TBA OMVPE PROCESS AND TECHNIQUES FOR REPRODUCIBLY GROWING DEVICE-QUALITY HETEROSTRUCTURE WAFERS USING TBA HAS IMPLICATIONS FOR A BROAD RANGE OF APPLICATION AREAS INCLUDING