| Autor: |
Gerald Lucovsky, Evan J. Katz, Harold L. Hughes, Leonard J. Brillson, Z. Zhang, Kwun-Bum Chung |
| Rok vydání: |
2009 |
| Předmět: |
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| Zdroj: |
2009 International Semiconductor Device Research Symposium. |
| Popis: |
We have combined nanoscale depth-resolved cathodoluminescence spectroscopy (DRCLS) and spectroscopic ellipsometry (SE) to measure the energies and depth distribution of charge traps in SiO 2 /SiO x /SiO 2 gate dielectrics for radiation-tolerant electronics. It is now known that suboxide layers within silicon-on-oxide (SOI) structures result in Si nanoclusters that can reduce the shift of the flatband voltage by trapping protons formed during hole injection [1]. Previous studies based on ion implantation showed that positive charge trapping is due to proton trapping at network oxygen atoms having large Si-O-Si bond angles. Such traps can be used to reduce the net positive charge during exposure to ionizing radiation that result in negative flatband voltage shifts and pathways for charge leakage. We used thermal oxidation to prepare SiO 2 /SiO x /SiO 2 gate dielectrics with reduced oxide concentrations and monitored their optical absorption and emission features with annealing and irradiation. These nanoscale film structures are known to phase segregate with annealing from amorphous Si (a-Si) into nanocrystalline surrounded by a SiO 2 shell [2]. The use of cathodoluminescence and UV SE enables us to measure optical transitions at energies involving not only intra- but also interphase transitions due to their intimate contact and high area. Understanding the physical nature of such traps may enable control of radiation-induced holes in higher-K dielectric SOI structures. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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