Large-scale metalorganic chemical vapor deposition growth of highly reliable 780 nm AlGaAs multiple quantum well high-power lasers

Abstract

Successful large-scale (twelve 2 inch diamter wafers/run) metalorganic chemical vapor deposition (MOCVD) growth of AlGaAs multiple quantum well (MQW) structure for 780 nm high-power lasers using a barrel-shaped reactor is demonstrated. Excellent uniformity of growth rate (∓3.5%) and Al content (∓0.3%) for an Al 0.48Ga 0.52As layer within a 2 inch diameter wafer has been obtained. Very accurate layer thickness control down to 1 nm has also been realized for AlGaAs well layer. Application of this technique to 780 nm AlGaAs MQW high power laser diodes realized excellent uniformity of the laser characteristics. The uniformity of the beam divergency to the junction plane (θ ⊥), lasing wavelength and threshold current were 27∓1°, 785∓3 nm and 48∓7 mA, respectively. In addition, it is shown that the reduction of the oxygen concentration in the laser crystal below 1x10 17 cm -3 is essential to obtain low threshold current with good reproducibility. Stable operation of the laser diodes for more than 1000 h has been also confirmed even at accelarating condition of 60°C, 50 mW.