US Patent 7596160 Nitride semiconductor lasers and its manufacturing method

A nitride semiconductor laser which features low resistance and high reliability. A buried layer is formed by selective growth and the shape of a p-type cladding layer is inverted trapezoidal so that the resistance of the p-type cladding layer and that of a p-type contact layer are decreased. For long-term reliability of the laser, the buried layer is a high-resistance semi-insulating layer which suppresses increase in leak current.