New chemical solutions for the etching of (011) oriented V-grooves in InP(001) for CSBH laser diodes

Abstract

We have developed two new etchant systems by adding H2O2 and HBr into the conventional HCI–H3PO4 etchant for the fabrication of InP-based channeled substrate heterostructure (CSBH) lasers. These etchants do not erode photoresists and they provide high quality etched side walls. The etch factors for the new etchant systems based on HBr and H2O7 are 17% and 12% higher than that of the: conventional 5HCI–H3PO4 etchant, respectively. These high etch factors give a narrow V-groove in InP and they lead to a lower magnitude and a better control of the threshold current of CSBH lasers.