III-nitride semiconductor avalanche photodetector

Abstract

The invention discloses an III-nitride semiconductor avalanche photodetector which comprises a substrate and an epitaxial layer that grows above the substrate. According to a sequence from bottom to top, the epitaxial layer is successively provided with an unintentional adulteration nitride buffer layer, an unintentional adulteration nitride transition layer, a heavy adulteration n-type nitride ohmic electrode contact layer, a heterogeneous light adulteration p-type nitride active layer, a p-type adulteration nitride layer and a heavy adulteration p-type nitride ohmic electrode contact layer. Simultaneously, the invention discloses a device manufacturing method, the method comprises the steps of taking advantage of multiple times of photoetching and dry etching to make steps on the periphery of a device, respectively carrying out vapor deposition of p-type and n-type metal electrodes on the p-type ohmic contact layer and the n-type ohmic contact layer, and forming ohmic contact with a semiconductor through an alloy. According to the device structure, the electric field intensity of an avalanche photodiode active area can be enhanced, and the properties of low dark current, high gain and high detection responsivity of the nitride avalanche photodetector can be realized by effectively increasing the field intensity of the active area and reducing the marginal leakage current of the device.

Description

technical field [0001] The invention relates to a detector, in particular to a low-current, avalanche photodetector based on Group III nitride semiconductor materials and a preparation method thereof. [0002] technical background [0003] With the rapid development of information technology, semiconductor-based solid-state photodetection technology plays an increasingly important role in the field of modern photoelectric information detection. Group III nitride semiconductors represented by GaN-based materials (including their binary compounds GaN, InN, and AlN, ternary compounds InGaN, AlGaN, and AlInN, and quaternary compounds AlInGaN) have wide band gap adjustment ranges, direct band gaps, High electron mobility, high breakdown electric field, high electron saturation drift velocity, high thermal conductivity, small dielectric constant, high temperature resistance, strong radiation resistance, high chemical stability, etc., can be adjusted by ternary or quaternary The co...

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Problems solved by technology

In other words, the method of tilting the mesa structure also has the disadvantages of difficult manufacturing process and reduced device fill factor.

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