Study on the Fabrication of Nickel/Nickel-Silicide Nanocrystals Embedded in SiO2 for Nonvolatile Memory

• Main Authors: Yen-Ya Hsu, 許雁雅
• Other Authors: Jen-Chung Lou
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/42847110010404157777

碩士 === 國立交通大學 === 電子工程系所 === 94 === We have studied experimentally and theoretically two kinds of nonvolatile metal nanocrystal memories: nickel nanocrystal memories and nickel-silicide nanocrystal memories. The metal nanocrystals memories come into notice as so many advantages. The advantages of metal nanocrystals over their semiconductor counterparts include low power consumption, higher density of states, smaller energy perturbation due to carrier confinement, stronger coupling with the channel, better size scalability, and the design freedom of engineering the work functions to optimize device characteristics. The reasons why nickel/nickel-silicide is chosen as the materials for the nanocrystals are the compatibility with current manufacturing technology of semiconductor industry and thermal stability of the nickel silicide. In our experiments, we would discuss some mechanisms about the nickel nanocrystals as memory storage medium. We obtained some conclusions to explain the memory effects for the different annealing temperatures. The two important mechanisms were nickel diffusion problem and the reaction between nickel and silicon dioxide. So these would be become the terrible problems as the high temperature processes. At the same time, we observed the nickel-silicide nanocrystal memories to improve the disadvantages of the nickel nanocrystal memories. The nickel film was only prepared to silicidation, so the high temperature processes were suitable for nickel silicide formation. The thin nickel/silicon film was exact to be controlled the dot size and observed good uniformity at the same time. However, another good result was obtained the one cell two bit memory from the silicon/nickel/silicon structure at 800℃ annealing.