Study of Etching for Mesa-isolated InP/InGaAs Avalanche Photo Diode

The difference of the side wall and surface morphology about mesa-isolated InP/InGaAs avalanche photodiodes (APD), which were manufactured by ICP etching and wet etching respectively, was compared. And the influence of the dark current and breakdown voltage between ICP etching and wet etching was compared too. Under the conditions of Cl2/Ar2/CH4, the surface of InP with inductively coupled plasma (ICP) etching turned to be rough, and the cause of this formation was investigated. This paper mainly improved the surface morphology by optimizing the ICP etching time and power, which raised the temperature of the etched surface to ensure the stability of the etching and confirmed the stable conditions to manufacture In/InGaAs APD. And the mesa-isolated APD with good performance was finally manufactured.