Large-area uniform OMVPE growth for GaAs/AIGaAs quantum-well diode lasers with controlled emission wavelength

Abstract

The properties of GaAs and AlGaAs epilayers grown in a vertical rotating-disk OMVPE reactor operated at reduced pressure (0.2 atm) are extremely uniform. For substrate rotation at 500 rpm, the thickness uniformity is ±1% for thick epilayers and ±2% for quantum wells 3−10 nm thick. The coefficient of variation in aluminum composition is 1.8 × 10−3 or less. For broad-area GRIN-SCH diode lasers containing a single-quantumwell active layer, the threshold current density and differential quantum efficiency are highly uniform. The laser emission wavelength is precisely controlled by adjusting the active layer thickness and composition. For 175 devices distributed over a 16-cm2 wafer containing a 10-nm-thick Al0.07Ga0.93As active layer, the total variation in emission wavelength is 3.0 nm. For all of these devices and for test devices from nine additional wafers, the wavelengths range from 803.5 to 807.4 nm.