A Nonpolar Algan-based Schottky UV Detector

Abstract

The present invention provides a non -polar Algan Krutki UV detector. From bottom to top to set up substrate, low -temperature aln nuclear layer, high temperature Aln buffer layer, Aln / Al x GA 1‑x N -ultra -crystal structure, N -type doped N‑al y GA 1‑y N layer, N -type doped n 、al z GA 1‑z N absorbing layer, ALN potential barrier enhancement layer, metal film layer, in N‑al y GA 1‑y The n layer leads the Ohm electrode, where 0 <y <z <x <1.Due to non -polar N‑al y GA 1‑y There is a horizontal polarized electric field that points to cathode in the n layer, so it will speed up the photochemical carrier in N‑al y GA 1‑y The N layer migrates to the EME, thereby greatly improving the production efficiency of the optical current, thereby improving the optoelectronic conversion efficiency and response of the device.Insert aln / al x GA 1‑x N -ultra -crystal structure, while increasing the height of the buffer layer, improve the crystal quality of the Algan extension layer.In N‑al z GA 1‑z N The enhanced layer of the ALN Blood of the absorbing layer and the metal film layer can effectively increase the height and thickness of the Schartki Blood.Therefore, aln / al x GA 1‑x The insertion of the N -ultra -lattice structure and the ALN potential barrier enhanced layer is conducive to reducing the dark current of the device and improving the signal -to -noise ratio and stability of the detector.

Description

technical field [0001] The invention relates to the field of semiconductor optoelectronic devices, in particular to a non-polar AlGaN-based Schottky ultraviolet detector. Background technique [0002] With the vigorous development of third-generation semiconductor materials such as GaN, diamond and SiC, it will lay the foundation for the development of high-performance ultraviolet detectors. Especially AlGaN material, because its forbidden band width can be adjusted between 3.4-6.2 eV by controlling the aluminum composition, and the corresponding spectral wavelength covers the ultraviolet region of 365-200 nm, so it has significant advantages in ultraviolet detection. It is an ideal material for making ultraviolet photodetection devices. [0003] At present, most of the ultraviolet detectors used in the market are such as figure 2 The p-n junction or pin structure shown is usually back-illuminated. Compared with these traditional UV detectors, Schottky UV detectors have u...

AI Technical Summary

Problems solved by technology

[0004] However, if image 3 In the traditional polar AlGaN-based Schottky UV detector shown, due to the presence of a polarized electric field with an intensity as high as MV / cm in the direction parallel to the incident light, the photogenerated carriers in the ohmic contact layer are perpendicular to The lateral movement of the polarization electric field to the corresponding electrode will be strongly hindered by the polarization electric field, so that the photoelectric conversion efficiency of the detector is not high

In addition, during the growth process of high Al composition AlGaN materials, the large lattice mismatch and thermal mismatch with the substrate material will also introduce a large number of dislocations and defects that usually serve as conductive channels

Moreover, defects existing at the metal-semiconductor interface can easily lead to the formation of tunneling current

The above-mentioned problems cause the dark current of the existing Schottky UV detector to be large, and the signal-to-noise ratio and stability are poor, which seriously limits the performance and development of the Schottky UV detector.

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