Manufacture method of PIN photodiode

Abstract

The embodiments of the present invention provide a manufacture method of a PIN photodiode. The method includes the following steps that: the upper surfaces of a third oxide layer, a first oxide layer, a contact hole and a second oxide layer are coated with first negative photoresist, exposure and development are performed on the exposure area of the first negative photoresist, the first negative photoresist in a non-exposure area is removed, and therefore, a plurality of sections of second negative photoresist which are separated from one another can be formed; and the lateral width of each section of second negative photoresist is within a preset width range, and the contact hole is located between two sections of second negative photoresist, and a distance between the two sections of second negative photoresists is greater than the aperture of the contact hole. According to the method provided by the embodiments of the present invention, a metal layer is removed through two steps; according to the first step, the second negative photoresist is removed through adopting a stripping solution, so that the metal layer can be removed; according to the second step, a mixed solution is adopted to etch an titanium layer, so that an aluminum silicon copper layer on the titanium layer can be removed; the second oxide layer, namely an oxide layer on a P- region, is intact after the treatment of the two steps is performed, and the light transmittance of the oxide layer of the P- region is good, and the performance of the PIN photodiode can be improved.

Description

technical field [0001] Embodiments of the present invention relate to the field of semiconductors, in particular to a method for manufacturing a PIN photodiode. Background technique [0002] In the prior art, the manufacturing process of the PIN photodiode includes the etching of the metal layer, the composition of the metal layer includes aluminum (98.5%), silicon (1%) and copper (0.5%), and the P-region is below the metal layer oxide layer. [0003] The etching of the metal layer includes dry etching and wet etching. If dry etching is used, it will cause etching damage to the P-region oxide layer; if wet etching is used, it will be damaged after etching. The residual silicon slag on the upper surface of the P-region oxide layer needs to be further removed. The residual silicon slag on the upper surface of the P-region oxide layer will be damaged during the removal process. If the removal is not clean, there will be Silicon dross remains on the surface of the P-region oxi...

AI Technical Summary

Problems solved by technology

[0004] During the etching process of the metal layer, no matter the damage to the P-region oxide layer or the residual silicon slag on the surface of the P-region oxide layer will affect the light transmittance of the P-region oxide layer, resulting in a decrease in the performance of the PIN photodiode

Images