Christer Ovren

Anodic bonding of gallium arsenide to glass

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.

A fibre optic pressure sensor in silicon based on fluorescence decay

Abstract A multimode fibre optic pressure sensor based on decay-rate modulation in Nd:glass is presented. Silicon micromechanics are used in the fabrication of the pressure diaphragm and the sensor structure. Preliminary results are presented, together with a brief description of the fabrication.