Anodic bonding of gallium arsenide to glass

Abstract

We describe a modified anodic bonding technique for hermetic sealing between GaAs and glass, the modification being called for by the formation of a nonadherent oxide layer during the bonding process. We show that this can be avoided by prebaking the glass and performing the bonding operation in a reducing atmosphere. With this technique, strong, hermetic seals can be produced. Parameter dependence has been studied theoretically by solving the continuity equation for a one-dimensional model of the experimental situation. Experimentally, the bonds were evaluated with a number of methods, giving support for a model consisting of a high-field, sodium-depleted zone in the interface region during bond formation. The described technique is of particular interest for optoelectronic devices requiring transparent and hermetic seals.