IN-SITU INVESTIGATION OF ION DRIFT PROCESSES IN GLASS DURING ANODIC BONDING

By means of in situ high-energy ion-beam analysis, which allows a quan titative multielement depth profiling, the formation of an anodic alka li-depleted polarization layer and of an oxygen-enriched interface lay er has been investigated. Drift rates and depletion-layer thicknesses are determined as a function of the process temperature, bias and drif t time. The drift behaviour of cations including potassium, calcium, a luminium and hydrogen has been examined. Finally, the drift of oxygen ions towards the compound interface is observed. The absence of non-br idging oxygen in TEMPAX, which has been proved by NMR investigations, gives rise to the conclusion that the drift behaviour of oxygen ions d epends mainly on the composition of the 'leached' glass surface layer. The results confirm anodic oxidation as the main mechanism responsibl e for the actual interface chemistry. (C) 1998 Elsevier Science S.A. A ll rights reserved.