Micromachining of GaAs structures with an acidic hydrogen peroxide solution

A study was made on the micromachining of various GaAs substrates in a H2SO4:H2O2:H2O solution with composition 1:8:1. In the first part the anisotropy etching behaviour was studied. Etch rates and morphologies produced by the acidic solution were evaluated. The second part was devoted to the determination of a database (dissolution constants) for the GaAs crystal. Theoretical 3D etching shapes were derived from the simulator TENSOSIM using this database. Comparison of theoretical 3D etching shapes with experimental shapes supports the validity of the proposed database. So this study opens up new applications in the field of GaAs micromechanical devices.