A broadband photodiode for visible to infrared light detection

Abstract

The photodiode involved in the present invention can expand the absorption band of light, and complete the detection from visible light to infrared light band (400nm~1350nm), and has high performance in two important bands of 0.8μm~0.9μm and 1.1μm~1.35μm. Responsiveness. Its structure includes: a heavily doped N-type Si substrate with an opening, on which a lightly doped N-type Si epitaxial layer, heavily doped P-type Si, and an intrinsic Ge buffer layer and The mesa structure is formed of heavily doped P-type Ge above it, and a silicon dioxide dielectric layer and a passivation layer are sequentially stacked on the mesa. A metal contact cathode VR is provided on the back of the N-type Si substrate, a first metal contact anode VAF is provided on the heavily doped P-type Si, a second metal contact anode VAS is provided on the heavily doped P-type Ge, lightly doped An anti-reflection layer is arranged on the back of the hetero-N-type Si epitaxial layer.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a photodiode. Background technique [0002] In optical fiber communication systems, photodetectors are one of the essential key components. 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, avalanche photodetectors and silicon preamplifiers. . The 1.06μm-1.55μm band optical fiber communication network usually uses Ge single crystal substrate or InP-based PIN photodetector, avalanche photodetector and silicon preamplifier mixed integrated optical receiver. [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, PIN silicon photoelectric planar d...

AI Technical Summary

Problems solved by technology

However, due to the inherent characteristics of the energy band structure, Si single crystal materials have problems such as low absorption coefficient, long absorption length, and no response to the band above 1.1 μm for near-infrared light.

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