Photodiode, optical sensor device, and photodiode manufacturing method

摘要

A photodiode and the like capable of preventing the responsivity on the short wavelength side from deteriorating while totally improving the responsivity in a type II MQW structure, is provided. The photodiode is formed on a group III-V compound semiconductor substrate, and includes a pixel. The photodiode includes an absorption layer of a type II MQW structure, which is located on the substrate. The MQW structure includes fifty or more pairs of two different types of group III-V compound semiconductor layers. The thickness of one of the two different types of group III-V compound semiconductor layers, which layer has a higher potential of a valence band, is thinner than the thickness of the other layer.

主权项

1. A photodiode which is formed on a group III-V compound semiconductor substrate, and includes a pixel, the photodiode comprising:
an absorption layer which is located on the substrate, and has a type II multiple quantum well (MQW) structure, wherein the MQW structure includes fifty or more pairs of two different types of group III-V compound semiconductor layers, and a thickness of one of the two different types of group III-V compound semiconductor layers, which layer has a higher potential of a valence band than the other layer, is thinner than a thickness of the other layer, wherein the MQW structure is a type II MQW structure composed of pairs of InxGa1-xAs (0.38≦x≦0.68) and GaAsySb1-y (0.36≦y≦0.62), and the photodiode further comprising: a non-doped diffusive-concentration-distribution-adjusting layer located on the absorption layer, and a cap layer located on the non-doped diffusive-concentration-distribution-adjusting layer, wherein an oxygen concentration and a carbon concentration are both lower than 1×1017 cm−3 at an interface between the non-doped diffusive-concentration-distribution-adjusting layer and the cap layer.