A Photodetector Containing Buried Oxygen Layer Structure

Abstract

The invention relates to the field of semiconductor devices, in particular to a photodetector with a buried oxygen layer structure, which can detect visible light to infrared light. Among them, the Ge PIN photodiode and the Si PIN photodiode are connected back to back through the heavily doped N-type Si layer containing the buried oxide layer, and the Si PIN photodiode and the Ge PIN photodiode have relatively high responses to short and long wavelengths, respectively. Features, realize the detection of visible light to infrared light band; the passivation layer not only has the function of passivating the device, but also has the function of reducing short-wave reflection; the buried oxide layer and the N-type silicon layer form a Bragg reflector, which can reflect light in the band around 0.85μm Short-wave photons, strengthen the absorption of Si PIN photodiodes to short-waves in the band around 0.85 μm; the first metal anode contact acts as an electrode and a metal mirror at the same time, playing the role of applying voltage and reflecting long-wave photons, and strengthening Ge PIN photodiodes to long-wave photons absorption; and the photodiode involved in the present invention has a low working voltage, and is easy to mix and integrate with the preamplifier.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a photodetector with a buried oxide layer structure. Background technique [0002] Photodetectors are essential key components in optical fiber communication systems. Short-distance, high-density optical fiber communication systems and data transmission systems in the 0.8μm-0.9μm band often use Si single crystal substrates or GaAs-based PIN photodetectors and avalanche photodetectors for detection. The 1.06μm-1.55μm band optical fiber communication network is usually detected by Ge single crystal substrate or InP-based PIN photodetector or avalanche photodetector. [0003] As one of the important branches, silicon photodiodes are widely used in the field of visible light detection and imaging because of their good spectral response, low noise, long life and high compatibility with CMOS processes. Among them, silicon photodiodes, as one of the most commonly used photodetecto...

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Problems solved by technology

However, a buffer layer material of several microns is usually required, resulting in a relatively large surface roughness of the Ge film.

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