THIN-FILM, HIGH DIELECTRIC CONSTANT, MICRON-SIZED CAPACITOR MATERIALS

WE PROPOSE AN EXTENSIVE STUDY OF MATERIALS AND DEPOSITION TECHNIQUES SUITABLE FOR FABRICATION OF HIGH-DIELECTRIC CONSTANT THIN-FILM DRAM (DYNAMIC RANDOM ACCESS MEMORY) CAPACITORS. THESE CAPACITORS WILL MINIMIZE THE NEED FOR TRENCH PROCESSING IN SUBMICRON, HIGH DENSITY MEMORIES. OUR RESEARCH FIRM HAS HAD CONSIDERABLE SUCCESS SINCE 1985 USING SPUTTERING AND SOL-GEL (SPIN-ON) DEPOSITION TECHNQIUES. RECENTLY, WE HAVE DEVLEOPED A PROTOTYPE U.V.-ASSISTED CVD MACHINE FOR FERROELECTRIC THIN FILM DEPOSITION AND RTA PROCESSING. WE ALSO HAVE EXPERIENCE WITH ELECTRON-BEAM EVAPORATION. THE MATERIALS WE ARE MOST EXPERIENCED WITH INCLUDE PBTIO3, PBZRO3, PZT, BAMGF4, YMNO3, BATIO3,AND SRTIO3. AT PRESENT, THE MOST FAVORED CAPACITOR MATERIAL FOR DRAM APPLICATION IN JAPAN IS SRXBA1XTIO3. THIS MATERIAL IS CURENTLY USED BYNEC. NEC DEPOSITS THIS MATERIAL USING SPUTTERING TECHNIQUES. WE PROPOSE TO CHARACTERIZE FILMS PROCESSED USING SOL-GEL AND CVD TECHNIQUES. AT THE CONCLUSION OF OUR PHASE I STUDIES, WE WILL DELIVER A LISTING OF MATERIALS, COMPATIBLE WITH EXISTING SILICON VLSI PROCESSING TECHNOLOGY, WHICH EXHIBIT HIGH DIELETRIC CONSTATN E(F) AT HIGH CLOCK RATES, NEGLIGIBLE AGING, AND GOOD TIME DEPENDENT D.C. BREAKDOWN CHARACTERISTICS. SYMETRIX ALSO PROPOSES TO PROVIDE A COMPARISON OF DEPOSITION TECHNIQUES FOR EACH MATERIAL AND AN INITIAL SAMPLING OF 2 SAFERS WITH CAPACITOR STRUCTURES USING THE MOST PROMISING MATERIAL. ANTICIPATED BENEFITS/POTENTIAL COMMERICIAL APPLICATIONS OF THE RESEARCH OR DEVELOPMENT. IT IS LIKELY THAT THE SIO2 CAPACITIVE LAYER IN DRAMS (DIELECTRIC CONSTANT OF 10) CAN BE REPLACED WITH A FERROELECTRIC OR NEAR-FERROELECTRIC MATERIAL WITH A DIELECTRIC CONSTANT OF GREATER THAN 1000. THIS MAY ELIMINATE TRENCH PROCESSING IN SUBMISSION, HIGH DENSITY DRAMS (GREATERTHAN 64 MB), A $10 BILLION/YEAR MARKET.