Chemical etching of Gallium orthophosphate: Application to piezoelectric device manufacturing

This paper presents a study of the chemical etching of gallium orthophosphate in the way to design high frequency resonators. Four different orientations (X, Y, Z and AT-cuts) are used. The dissolution rate is of Arrhenius law type and depends of both the cut orientation and the concentration of the solvent. The study of the surface state evolution shows that there is no correlation between the surface state and the dissolution rate. Antimesa AT-plates with frequency up to 34MHz and QF factor of $2{\times}10^{11}$ are manufactured with this method