SYNTHESIS OF ORIENTED FERROELECTRIC BISMUTH TITANATE BI4TI3O12 THIN FILMS ON SILICON SUBSTRATES

ADVANCED FERROELECTRIC MEMORY DEVICES COMBINE THE FAST ACCESS TIME OF SEMICONDUCTOR RAMS WITH THE NONVOLATILITY OF MAGNETIC STORAGE TO CREATE AN IDEAL STORAGE MEDIUM. RECENT ATTEMPS TO REALIZE SUCH DEVICES HAVE BEEN ONLY PARTIALLY SUCCESSFUL; LIMITED SWITCHING LIFETIMES CAUSED BY FATIGUE IN THE FERROELECTRIC MATERIALS IS STILL A SIGNIFICANT RELIABILITY CONCERN. TO REALIZE THE POTENTIAL OF FERROELETRIC MEMORIES FOR ADVANCED APPLICATIONS, SUPERIOR MATERIALS, AND PROCESSING TEHCNIQUES MUST BE APPLIED TO INCREASED PERFORMANCE RELIABILITY. THIS PROJECT WILL ASSESS THE FEASIBILITY OF A NOVEL APPROACH TO ACHIEVING DESIRED DEVICE PERFORMANCE BY UTILIZING THIN FILMS OF FERROELECTRIC BISMUTH TITANATE, BI4TI3O12. THE FERROELECTRIC PROPERTIES OF BISMUTH TITANATE, EXTREMELY LOW AGING EFFECT, FAST SWITCHING CAPABILITY AND LOW COERCIVE FIELD, MAKE IT A VERY ATTRACTIVE MATERIAL FOR MEMORY APPLICATIONS. ADDITIONALLY, THE METHOD PROPOSED CAN ACHIEVE LOW TEMPERATURE FORMATION OF ORIENTED THIN FILMS OF BISMUTH TITANATE AND CAN BE INTEGRATED INTO A STANDARD SEMICONDUCTOR PROCESS FLOW. THE PHASE I RESEARCH WILL DEPOSIT BISMUTH TITANATE FILMS AND EXPERIMENTALLY DETERMINE THE FILM'S FERROELECTRIC CHARACTERISTICS AND RELATE THEM TO THE OBSERVED MICROSTRUCTURE AND DEPOSITION PROCESS VARIABLES. THE PROCESS WILL BE OPTIMIZED AND SCALED UP IN PHASE II/ ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONS - THIS PROCESSING TECHNIQUE WILL ENABLE COMMERCIAL SCALE PRODUCTION OF IN ORIENTED FERROELECTRIC THIN FILMS ON SILICON FOR MICROELECTRONIC MEMORY APPLICATIONS. IT IS EXDPECTED TO BE A COST-EFFECTIVE METHOD FOR PRODUCING SUCH FILMS IN LARGE DIAMETER SIZES FOR USE IN HIGH PERFORMANCE DEVICES FOR STRATEGIC AND COMMERCIAL APPLICATIONS. KEY WORDS - NONVOLATILE FERROELECTRIC MEMORIES, THIN FILM, BISMUTH TITANATE