Precision Chemical Etching of GaP(NAs) Epitaxial Layers for the Formation of Monolithic Optoelectronic Devices

The results of studying the applicability of various etchants for the precision wet etching of structures of monolithic optoelectronic devices containing GaPNAs layers are presented. It is shown that an etchant based on potassium iodide and hydrochloric acid is best suited for this purpose. The presence of nitrogen (up to 4%) and arsenic in the semiconductor composition does not greatly affect the etchant action but requires additional calibration experiments to refine the etching rate in each particular case. Examples of the practical application of precision etching to measure the characteristics of GaPNAs-based solar cells are presented.