4H-SiC ultraviolet photoelectric detector with spherical crown structure, and preparation method

Abstract

Disclosed are a 4H-SiC ultraviolet photoelectric detector with a spherical crown structure, and a preparation method. The ultraviolet photoelectric detector adopts a p-i-n structure; an N type bufferlayer and an i type absorption layer are grown on a highly-doped four-degree-off-axis double parabolic N+ type 4H-SiC substrate in sequence; an arc-shaped inclined table surface is formed on the i type absorption layer to form a spherical crown-shaped i type absorption layer surface; by adopting an injection and high-temperature annealing activation process, a P+ layer is formed on the upper surface of the spherical crown-shaped i type absorption layer; next, through a thermal oxidization method, a silicon dioxide passivation layer is grown on the surface of the P+ layer; through a photoetching process, an ICP etching process and a stripping process, a P type annular electrode window is etched in the silicon dioxide passivation layer of the P+ layer, and a P type electrode is formed by adopting a magnetron sputtering process; and the highly-doped four-degree-off-axis double parabolic N+ type 4H-SiC substrate on the back surface is etched, and an N type electrode is formed by adopting amagnetron sputtering process, so as to obtain the 4H-SiC ultraviolet photoelectric detector with the spherical crown structure.

Description

technical field [0001] The invention relates to a semiconductor photodetection device, in particular to a 4H-SiC ultraviolet photodetector with a spherical cap structure and a preparation method. Background technique [0002] Ultraviolet light is a strong electromagnetic wave in nature, which can have a strong impact on most organic and inorganic substances, so it is widely used in military, health, industry, agriculture, environmental protection and many other fields. Correspondingly, ultraviolet light detection devices and products have also attracted the attention of countries all over the world, and have huge market demand. For example, ultraviolet light detectors made into arrays can be used in the precise guidance of missiles, early warning of missiles, etc. Ultraviolet light detectors with high sensitivity also play an extremely important role in environmental monitoring, food disinfection, etc. . At present, the ultraviolet photomultiplier tube (PMT) has mature tec...

AI Technical Summary

Problems solved by technology

However, most of the 4H-SiC ultraviolet photodetectors now adopt a planar layered structure. This structure has the characteristics of directional detection, that is, it has a good detection effect for vertically incident ultraviolet light, but for obliquely incident ultraviolet light Light, the interface reflection caused by its tilt angle, the relative change of the thickness of the i-type absorbing layer and other accidents will inevitably affect its quantum efficiency.

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