THE STRUCTURE OF SIO2, ITS DEFECTS AND RADIATION HARDNESS

We review our understanding of the structure of amorphous SiO2 and the role of processing in inducing defect precursors. Five potential sources of positive trapped oxide charge and two of negative trapped charge are described. The most studied of these is the positively charged oxygen-vacancy center. Ionizing radiation is found to be approximately 1000 times less efficient than particle radiation in creating this defect. Various processing induced precursors of the defect and their transformation by radiation are discussed in detail. Macroscopic structural modifications induced by very large radiation doses (10(9) rad) are also discussed. Ionizing radiation is also found to be approximately 1000 times less efficient than particle radiation in inducing these modifications.