A UV detector with a double-doped Al composition graded separation layer

Abstract

The invention relates to an ultraviolet detector with a double-doped Al composition graded separation layer, comprising a substrate, an AlN intermediate layer, and a non-doped i-Al layer arranged in sequence from bottom to top. x1 Ga 1‑x1 N-buffer layer, n-type n-Al x2 Ga 1‑x2 N-layer, undoped i-Al x3 Ga 1‑x3 N absorption layer, double-doped Al composition graded p-Al x4 Ga 1‑x4 N / i‑Al x5 Ga 1‑x5 N / n‑Al x6 Ga 1‑x6 N separation layer, non-doped i-Al x7 Ga 1‑x7 N multiplication layer, p-type p-Al x8 Ga 1‑x8 N layer and p-type GaN layer; in n-type n‑Al x1 Ga 1‑x1 The n-type ohmic electrode is drawn out on the N layer, and the p-type ohmic electrode is drawn out on the p-type GaN layer, where x1>x2=x3=x4>x5>x6=x7>x8. The p-type doping and n-type doping can use the polarization induction effect accompanied by the composition gradient to increase the carrier concentration and further enhance the polarization electric field.

Description

technical field [0001] The invention relates to an ultraviolet detector with a double-doped Al component graded separation layer, which belongs to the field of semiconductor optoelectronic devices. Background technique [0002] Al as a direct bandgap semiconductor material x Ga 1-x N, the forbidden band width is continuously adjustable from 3.42 eV to 6.8 eV with different Al components, and its emission spectrum ranges from 200-365 nm, which just covers the solar spectrum blind zone (240-280 nm) caused by the ozone layer absorbing ultraviolet light. ), and the AlGaN material is small in size, light in weight, long in life, and good in shock resistance; high temperature resistance, corrosion resistance, and radiation resistance, suitable for harsh environments; low working voltage, no high-voltage power supply, etc. One of the ideal materials for appliances. [0003] The detection of weak light signals is an important application in the field of ultraviolet detection, esp...

AI Technical Summary

Problems solved by technology

However, increasing the Al composition also increases the lattice mismatch of the material

In addition, for UV detectors with p-i-n structure with absorption layer, separation layer and multiplication layer, due to the large difference in Al composition between layers, it will lead to large lattice mismatch, which is easy to cause high position The wrong density seriously affects the crystal quality of the device, resulting in a large dark current

In addition, the large difference in Al composition will also enhance the piezoelectric polarization effect and reduce the electron-hole ionization energy, which in turn affects the detection of weak signals, resulting in a decrease in responsivity.

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