Charge trapping and charge compensation during Auger electron spectroscopyon SiO2

It is well known that radiolysis, induced by the electron bombardment, lead s to different defects in SiO2, but little is known about the trapping beha vior of these defects. In this article, the charging behavior and the depth profiles of the irradiation damage introduced by electron bombardment are studied with Auger electron spectroscopy (AES). For charge reduction an env ironmental AES using O-2 (up to 8 x 10(-8) Torr) and specimen heating are a pplied. In environmental AES, a strong charge reduction is observed, and th e importance of the environment for charge compensation reveals a correlati on with electron stimulated desorption. By heating the sample, a strong cha rge reduction takes place above 500 degrees C; complete charge compensation can be expected by heating the sample above 700 degrees C in an O-2 enviro nment of 5 x 10(-8) Torr. We suggest that E-' centers, nonbridging oxygen h ole centers, and peroxy radicals, are responsible for the efficient trappin g of electrons. The observed discharging is believed to be related to the a nnealing of the defects. (C) 1999 American Institute of Physics. [S0021-897 9(99)01016-3].