ADVANCED DIELECTRIC CAP FOR III-V ION IMPLANTATION

ION IMPLANTATION HAS BEEN DEMONSTRATED TO BE THE LEADING FABRICATION TECHNOLOGY FOR HIGHLY UNIFORM DOPING OF SEMICONDUCTORS. HOWEVER, SEVERAL PROBLEMS ASSOCIATED WITH ION IMPLANTATION NOW HINDERS THE PROGRESS OF GAAS ICS, AFFECTING KEY AREAS OF PERFORMANCE, RELIABILITY AND YIELD. THESE DIFFICULTIES ARE LARGELY DUE TO LACK OF A RELIABLE, REPRODUCIBLE SURFACE ENCAPSULATION TECHNIQUE AND A MORE FUNDAMENTAL UNDERSTANDING OF GAAS SURFACE CHEMISTRY. THE PROPOSED RESEARCH PROGRAM WILL BE CONCENTRATED ON A BASIC STUDY USING A NEW APPROACH TO STABILIZE THE INTERFACE BETWEEN THE GAAS SUBSTRATE AND THE SI3N4 ENCAPSULANT. IN PRESENT APPLICATION, THE NATIVE OXIDE (GA2O3. AS2O3) UNDERGOES A HIGH TEMPERATURE REACTION WITH GAAS PRODUCING A CONDUCTIVE AS INTERFACE LAYER DETRIMENTAL TO INTEGRATED CIRCUIT PERFORMANCE. IN THIS STUDY, A PLASMA REDUCTION METHOD WILL BE UTILIZED TO REMOVE THE AS2O3 LAYER AND STABILIZE THE INTERFACE WITH A HIGH BANDGAP GAN LAYER FOLLOWED BY SUBSEQUENT GROWTH OF A HIGH PURITY SI3N4 LAYER, ALL PERFORMED IN-SITU BY PLASMA CVD. DETAILED CHARACTERIZATION TECHNIQUES WILL BE USED TO DOCUMENT PROPERTIES OF THIS METHOD AND TO CORRELATE WITH SUBSEQUENT ION IMPLANTATION DOPING MEASUREMENTS. RESULTS OF THIS RESEARCH WILL BENEFIT UNDERSTANDING OF THE BASIC SURFACE CHEMISTRY OF GAAS AND IMPACT BADLY NEEDED IMPROVEMENTS IN DEVICE AND CIRCUIT FABRICATION METHODS.