Planar GaAs And GaAs/A1 0.3 Ga 0.7 As Schottky Barrier Photodiodes With High-Speed And High-Sensitivity

Planar GaAs and GaAs/A103Ga0.7As Schottky barrier photodiodes with high-speed and high-sensitivity have been fabricated and characterized. In order to improves the sensitivity of photo-diodes, surface passivation and antireflection coatings have been performed using various dielectric films, such as Si02, Si3N4, and polyimide. The internal quantum efficiency of 60% to 77% and the responsivity of 0.47 A/W to 0.6 A/W were measured for the wavelength range of 0.5 μm to 0.84 μm. A rise time of 8.5 ps and a 3-dB cutoff frequency of 42 GHz were measured for the GaAs/A10.3Ga0.7As photodiode, whereas 15 ps and 24 GHz were measured for the GaAs photodiode.