Photosensitive diode

Abstract

The invention relates to a photosensitive diode. An N-type well region is formed in a P-type substrate, the surface of the N-type well region is provided with a silicide layer, and the surface of the silicide layer is provided with a polycrystalline silicon layer. A first P-type active region and a second P-type active region are respectively arranged in positions, on the two sides of the silicide layer, of the N-type well region, the surfaces of the first P-type active region and the second P-type active region are respectively provided with a first contact hole and a second contact hole, and a photosensitive area is formed between the inner side of the first contact hole and the inner side of the second contact hole. A first N-type heavily-doped region is arranged in a position, on the left side of the first P-type active region, of the N-type well region, and a second N-type heavily-doped region is arranged in a position, on the right side of the second P-type active region, of the N-type well region. A third P-type heavily-doped region and a fourth P-type heavily-doped region are respectively arranged in positions, on the two sides of the first N-type heavily-doped region, of the P-type substrate. The first N-type heavily-doped region, the second N-type heavily-doped region, the third P-type heavily-doped region and the fourth P-type heavily-doped region are respectively provided with a third contact hole, a fourth contact hole, a fifth contact hole and a sixth contact hole.

Description

technical field [0001] The invention relates to a semiconductor device structure, in particular to a photosensitive diode structure. Background technique [0002] A photosensitive diode (that is, a photosensitive resistor) is a semiconductor device that is very sensitive to light changes. The die of the photosensitive diode is a PN junction with photosensitive characteristics, which has unidirectional conductivity. Therefore, the intensity of light can be used to change the current in the circuit. [0003] A photodiode is also called a photodiode, and its die is a PN junction with photosensitive characteristics. When there is no light, there is a small saturated reverse leakage current, that is, dark current, and the photodiode is cut off at this time. When illuminated, the saturated reverse leakage current increases greatly to form a photocurrent, which changes with the intensity of incident light. When light irradiates the PN junction, electron-hole pairs can be generat...

AI Technical Summary

Problems solved by technology

It can be seen from the figure that this photodiode layout structure is not conducive to large-scale integration due to its asymmetry.

[0005] In addition, since this structure is obviously different from other device structures, it is easy to be identified and used by people with ulterior motives during use, resulting in problems such as information leakage.

[0006] Chinese patent (CN101064351A) and Chinese patent (CN102544139A) both disclose the structure and device of photodiodes, but these two patents do not propose corresponding improvement measures for the above technical problems

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