Theta-doped 4HSiC avalanche ultraviolet photoelectric detector and its production

Abstract

The invention is concerned with delta-doped 4H-SiC ultraviolet avalanche photodetector and its production, involved with a kind of ultraviolet photodetector. Thedelta-doped 4H-SiC ultraviolet avalanche photodetector and production can enhance the capability of device, eliminate the restrict of quantum yield and respond time to avalanche device, control the thickness of elevated area, the concentration of surface charge and the length of absorbing area. The table-board owns n+ type of 4H-SiC under lay, and there is n+ type buffer layer, super-low-doped n- type layer, delta-doped n type layer, low-doped n- type layer and high-doped p+ type layer on the table-board one by one. The super-low-doped n- type layer, delta-doped n type layer, low-doped n- type layer form active layer. It has at least three table-boards, the lowest one sets on the n+ type buffer layer to isolation of device, the other table-boards set on active layer of device, while the surface of device owns compact Silica passivation film with p type and n type poles.

Description

technical field [0001] The invention relates to an ultraviolet photodetector, in particular to an avalanche structure (APD) ultraviolet photodetector with delta-doped 4H-SiC (silicon carbide) separating an absorption region, a charge region and a multiplication region and a preparation method thereof. Background technique [0002] At present, the detection of ultraviolet light mainly uses silicon-based ultraviolet photodetectors, but since the bandgap width of silicon is 1.1eV, its absorption of light is mainly concentrated in the visible and near-infrared bands, so silicon-based ultraviolet photodetectors require an expensive filtering system. In recent years, the development of the third generation of advanced semiconductor materials represented by SiC has opened up new fields for the research of semiconductor ultraviolet photodetectors. The third-generation advanced semiconductor material has a wide band gap, and the ultraviolet photodetector prepared by it is not sensit...

AI Technical Summary

Problems solved by technology

A good optimal value cannot be reached among the response time, quantum efficiency and breakdown voltage of the device

The present invention adopts the avalanche photodetector structure that separates the absorption region, the charge region and the multiplication region. The detector of this structure has been relatively mature in InGaAs infrared photodetectors (Photonics Technology Letters, 1998, 10: 409-411), but in SiC-based UV photodetectors have not yet been used

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