| AVS 54th International Symposium | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS2-WeM |
| Session: | Plasma-Surface Interactions I |
| Presenter: | G.S. Upadhyaya, University of Wisconsin-Madison |
| Authors: | G.S. Upadhyaya, University of Wisconsin-Madison J.L. Shohet, University of Wisconsin-Madison |
| Correspondent: | Click to Email |
Vacuum-ultraviolet (VUV) radiation emitted from processing plasmas can damage dielectric materials by creating electron-hole pairs. However, the resulting increased dielectric conductivity during VUV irradiation can also be beneficial in either partially or completely depleting previously deposited plasma charge. The underlying mechanisms that can be responsible for VUV-induced charge depletion are determined by exposing plasma-charged SiO2/Si samples to monochromatic-synchrotron radiation with photon energies in the range from 8 to 18 eV. Charge depletion was observed only for photon energies smaller than 13 eV. For photon energies between 8 and 11 eV, photoinjection of electrons from the Si into SiO2 conduction band is identified as the process responsible for charge depletion. For photon energies between 11-13 eV, field emission of electrons from Si into the oxide due to electric-field enhancement at the Si-SiO2 interface is believed to be the charge-depletion mechanism. Qualitative photoinjection and field-emission models convincingly explain all experimental measurements.
This work was supported by the National Science Foundation under grant No. DMR-0306582. The SRC is a national facility, funded by NSF under grant No. DMR-0084402.