High-speed photoelectric detector structure and manufacturing method thereof

Abstract

The invention discloses a high-speed photoelectric detector structure. An epitaxial wafer of the high-speed photoelectric detector structure comprises an InP substrate, a lower ohmic contact layer, a lower window layer, an absorption layer, an upper window layer and an upper ohmic contact layer, the lower ohmic contact layer, the lower window layer, the absorption layer, the upper window layer and the upper ohmic contact layer sequentially grow on the InP substrate from bottom to top, the epitaxial wafer is a mesa structure, and one side surface of the mesa structure is a light incident surface. The incident surface is provided with an antireflection film, the other side surface far away from the antireflection film is a light reflection surface, and the light reflection surface is provided with a high reflection film. A light incident direction of a photodetector is perpendicular to the direction of a drift electric field, the absorption layer is 0.1-3 mu m, the drift of carriers is fast, and a bandwidth is high. While the internal quantum efficiency is improved, the size of the device is further reduced, the bandwidth of the device is improved, the uniform distribution of a photocurrent of the whole absorption layer is balanced, and the problem of nonlinear distortion of signals caused by uneven light absorption of the absorption layer and local photocurrent saturation is avoided.

Description

technical field [0001] The invention relates to the technical field of photodetectors, in particular to a high-speed photodetector and a manufacturing method thereof. Background technique [0002] Optical detectors are widely used in optical communication systems, imaging systems and military fields, and are key optical receiving devices in high-speed optical communication systems. Photodetectors are developing towards high performance and high integration. Optical detectors used in optical fiber communication systems can generally be classified into two types: photodiodes (PDs) and avalanche photodiodes (APDs). The frequency response bandwidth and quantum efficiency of traditional photodetectors restrict each other. Generally, the quantum efficiency of the device can be increased by increasing the absorbing layer of the device, but the transit time of the carriers becomes longer and the response rate decreases. In photodetectors, the absorption of photons occurs in the a...

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Problems solved by technology

However, the resonator-enhanced (RCE) photodetector has the characteristics of high-speed response due to the thin thickness of the absorbing layer. However, due to the small difference in refractive index between the two materials in the epitaxially grown DBR, it is necessary to achieve a higher reflectivity. , the logarithm of DBR is more, and the thickness of DBR is very thick by epitaxial growth, which increases the difficulty and cost of the process, and also leads to a large parasitic resistance of the device, which affects the bandwidth of the device.

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