Fabrication and characteristics of nonvolatile memory with CoSi2 nanocrystals embedded in high-k dielectrics structure
| Autor: | Ching-Che Huang, 黃敬哲 |
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| Rok vydání: | 2009 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 97 Current requirements of nonvolatile memory (NVM) are the high density cells, low-power consumption, high-speed operation and good reliability for the scaling down devices. However, all of the charges stored in the floating gate will leak into the substrate if the tunnel oxide has a leakage path in the conventional NVM during endurance test. Therefore, the tunnel oxide thickness is difficult to scale down in terms of charge retention and endurance characteristics. The nonvolatile nanocrystal memories are one of promising candidates to substitute for conventional floating gate memory, because the discrete storage nodes as the charge storage media have been effectively improve data retention under endurance test for the scaling down device. Many methods have been developed recently for the formation of nanocrystal. Generally, most methods need thermal treatment with high temperature and long duration. This procedure will influence thermal budget and throughput in current manufacture technology of semiconductor industry. In this thesis, we used the three kind of high-k dielectric structure as the tunnel oxide (Al2O3, HfO2/Al2O3/HfO2, Al2O3/HfO2/Al2O3) to overcome the limitation of conventional NVMs during the scaling down process. First, we used Al2O3 as tunnel oxide. It observed that device of Al2O3 as tunnel oxide reduce equivalent thickness without lost retention too much. Then, we used HfO2/Al2O3/HfO2 as tunnel oxide. It observed the device of HfO2/Al2O3/HfO2 as tunnel oxide which had bigger window than the device used thermal oxide as tunnel oxide. Moreover it had better retention characteristics than the device used thermal oxide as tunnel oxide with a small charge lose rate. And it reduced equivalent thickness of SiO2.Final, we used Al2O3/HfO2/Al2O3 as tunnel oxide. It observed the device of Al2O3/HfO2/Al2O3 as tunnel oxide which had better retention characteristics than the device used HfO2/Al2O3/HfO2 as tunnel oxide without decrease the electron and hole injection. And we reduce equivalent thickness of SiO2 . |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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