The behaviour of Zn diffusion in a GaInP/(Al0.5Ga0.5)0.5In0.5P multiple quantum-well layer was investigated as a function of the growth temperature and Zn/III ratio, using secondary ion mass spectroscopy. Then the diffusion length of Zn in the undoped (Al0.7Ga0.3)0.5In0.5P layer from the Zn-doped (Al0.7Ga0.3)0.5In0.5P (Zn: 1.0 x 1018 to 1.2 x 1018/cm3) cladding layer was evaluated to design a barrier layer for Zn diffusion into the GaInP/(Al0.5Ga0.5)0.5In0.5P multiple quantum-well active layer. As a result of incorporating a 130nm-thick diffusion barrier on top of the multiple quantum-well layers of the AlGaInP red laser, the full width at half maximum of the photoluminescence spectrum for the GaInP/(Al0.5Ga0.5)0.5In0.5P multiple quantum-well layers was reduced from 60 to 30meV at room temperature, and the threshold current was also greatly reduced from 110 to 75mA for a standard AlGaInP-based ridge laser as compared to a AlGaInP laser without a diffusion barrier.

Investigation of Zn Diffusion by SIMS and its Effects on the Performance of AlGaInP-Based Red Lasers. Y.C.Shin, B.J.Kim, D.H.Kang, Y.M.Kim, T.G.Kim: Semiconductor Science and Technology, 2006, 21, 35-9