High gain x bandwidth product over 140-GHz planar junction AlInAs avalanche photodiodes

This letter demonstrates a planar junction GaInAs-AlInAs avalanche photodiode using back-side illumination through thinned InP substrate covered with chemical vapor deposition SiNx antireflection coating. The combined properties of very low dark current (I-dark(M = 10) = 17 nA), low excess noise factor (f (M = 10) = 3.5), and high gain x bandwidth product over 140 GHz were simultaneously achieved with a high primary responsivity of 0.95 A/W at 1.55 mu m.