Chemical etching of InGaAsP/InP using HBr-H/sub 3/PO/sub 4/-K/sub 2/Cr/sub 2/O/sub 7/ and its application to microlens array

InP/InGaAsP etching properties of HBr-H/sub 3/PO/sub 4/-(0.5M)K/sub 2/Cr/sub 2/O/sub 7/ etchant such as masking material, etching rate, etching profile, etched side wall shape and etc are studied. Using these characteristics, we made InP microlens array. SEM pictures and AFM measurement confirm that formed microlens array has high uniformity and good surface quality. The height of microlens can be controlled by changing of the radius of photoresist mask pattern.