AlGaN/SiC double-color ultraviolet detector

Abstract

The invention discloses an AlGaN / SiC double-color ultraviolet detector. The detector comprises an N-type SiC substrate layer, an N-type heavily-doped SiC ohmic layer, an unintentionally-doped SiC absorption layer, a P-type SiC ohmic contact layer, an unintentionally-doped AlGaN absorption layer, an ohmic contact back electrode, a semitransparent Schottky electrode, a first contact electrode, a second contact electrode and a transparent medium passivation layer. The advantages of an AlGaN material system and an SiC material system are combined. The detector is based on low lattice defects of aSiC material, high visible light blind ultraviolet responsivity and small lattice mismatch and thermal mismatch with an AlGaN material, and the AlGaN layer is adopted as an absorption layer for solarblind detection and a filtering layer for visible light blind detection, thereby achieving the detection of two wavebands of one device, and greatly improving the resolution capability of the detectorfor a target object. The detector has the characteristics that the structure is simple, the manufacturing process is compatible with the current LED process, the detection wave band is variable, andthe ultraviolet spectrum analysis is facilitated.

Description

technical field [0001] The invention relates to the field of semiconductor optoelectronic devices, in particular to an AlGaN / SiC two-color ultraviolet detector. Background technique [0002] The emergence of a new generation of wide-bandgap semiconductor materials (bandgap>2.5eV), such as GaN, ZnO, diamond and SiC, has injected new vitality into the research and application development of high-performance ultraviolet detectors. In the field of ultraviolet detection applications, the absorption of ultraviolet light by wide-bandgap semiconductors is determined by their forbidden band widths, so they have natural frequency band selectivity without the need for additional filters. At the same time, wide-bandgap semiconductor materials usually have good thermal conductivity , high electron drift saturation speed and good chemical stability, it is an ideal material for making ultraviolet detection devices. [0003] Among them, the AlGaN material is currently the most researche...

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Problems solved by technology

[0003] Among them, the AlGaN material is currently the most researched, and there have been corresponding commercial applications. Its advantage is that it can work in the sun-blind band when the Al composition is ≥ 0.4. AlGaN / GaN-based two-color ultraviolet detectors have been reported. However, sapphire lining The AlGaN material at the bottom has a large lattice mismatch and thermal mismatch, resulting in low spectral responsivity and high dark current. Due to the insulation of sapphire, only planar structures can be made, and the turn-on voltage is usually high.

Due to its low lattice defect density and wide bandgap, SiC materials can meet the response range of visible light-blind ultraviolet detectors. There have been reports of ultraviolet detectors with corresponding high avalanche gain factors. However, SiC-based devices are used to achieve solar-blind deep Ultraviolet detection also requires the installation of expensive filtering systems

Therefore, it is difficult for a single material system to realize the detection of two wave bands at the same time.

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