RADIATION STUDY ON MOS STRUCTURES,
Abstract
Two effects of ionizing radiation on oxidized silicon surfaces have previously been reported: the formation of a space charge in the oxide and the creation of surface states at the oxide-silicon interface. In this report, the effects of processing variables -- including substrate type, oxidation conditions, gettering and annealing steps, and the use of silicon nitride in place of silicon dioxide -- on the above two phenomena are described. It is found that all oxide devices are very sensitive to ionizing radiation. Nitride devices are relatively unaffected by ionizing radiation, but they possess a high field trapping instability which makes them unacceptable for the gate dielectric of an MOS transistor. Experiments with nuclear reactor irradiation show that in a reactor environment bulk damage due to fast neutrons dominates in the degradation of bipolar transistors, junction field-effect transistors, and p-n junction diodes, whereas, surface effects due to ionizing radiation also present in the reactor are most important in the case of MOS transistors. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1968
- Accession Number
- AD0666435
Entities
People
- D. J. Fitzgerald
- E. H. Snow