Novel quantum well intermixing in InGaAs-InGaAsP laser structure using argon plasma exposure

Summary form only given. We report a novel quantum well intermixing (QWI) technique in InGaAs-InGaAsP laser structures using high-density Ar plasma exposure. Samples with single quantum well laser structure were exposed to Ar plasma generated by an ECR system at different process conditions and exposure times. During the plasma treatment the Ar flow rate and process pressure were fixed at 50 sccm and 30 mTorr, respectively. The RF power was set to 450 W, while the microwave power to 1400 W for a set of samples, and 800 W for another. After plasma exposure, the samples were subsequently annealed at 600/spl deg/C for 2 minutes using a rapid thermal processor. Photoluminescence measurements at 77 K were then performed to assess the degree of bandgap shift. The degree of intermixing gradually increases with increasing exposure time for samples exposed at 1400 W. The bandgap shift saturated at about 106 nm (72 meV) after 10 min of plasma treatment. The samples exposed to 800 W produced results of similar trend to that of 1400 W, but with lower degrees of blue shift. This could be attributed to the use of lower microwave power, and hence lower ionization of Ar plasma, producing lower defect density due to ion bombardment as well as radiation.