CH4/H2 inductively coupled plasma (ICP) etching for high performance GaInAsP buried heterostructure lasers

We have successfully demonstrated CH₄/H₂ ICP etching for high performance GaInAsP buried heterostructure laser for the first time. CH₄/H₂ ICP etching characteristics have been investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Auger electron spectroscopy (AES). A vertical mesa structure with smooth surface was obtained under low bias voltage and low CH₄/H₂ ratio with sufficient etching rate. The laser showed good characteristics such as low threshold current of 4.4 mA, slope efficiency of 0.65 W/A at 20°C and high reliability at high temperature. From aging test results, estimated lifetime was over 10⁵ hours. CH₄/H₂ ICP etching can become a promising technique for the fabrication of lasers and photonic integrated circuits