Selective MOMBE growth behaviour at the lateral interface of waveguide/laser butt-joints

Selective MOMBE growth of InP-GaInAsP optical waveguide structures by MOMBE was studied for butt coupling with a double heterostructure (DH) laser. Selective deposition was accomplished at a growth temperature of 485 degrees C using SiNx for masking the laser mesa on top and partially on the side walls. The influence of the native oxide desorption process, the growth conditions (V/III-ratio) and undercut etching of the vertical part of the mask was investigated. Uniform waveguide deposition even at the mesa edges of the laser, a low lateral growth rate of approximately 20 percent of the vertical rate and reduced excessive growth near the edge of the vertical mask were successfully achieved.