Preparation method of photodiode and photodiode

Abstract

The invention provides a method for preparing a photodiode, including S101: forming an oxide layer on a substrate; S102: forming two first grooves separated by an oxide layer, and forming a first implantation region at the bottom of the two first grooves; S103: Form a first opening, two second trenches, and a second opening between the two second trenches on the substrate, and implant ions into corresponding positions to form a second implantation region, a third implantation region, and a fourth implantation region area; S104: remove the oxide layer, and form a dielectric layer on the substrate; S105: etch the dielectric layer on the first implantation region and the third implantation region to form a contact hole, and then form a metal layer in the dielectric layer and the contact hole ; S106: firstly apply a photoresist layer on the upper surface of the metal layer and both sides of the metal layer, etch and remove the dielectric layer not covered by the photoresist layer, then remove the photoresist layer, and finally obtain a photodiode. The present invention also provides a photodiode with improved surface state and reliability.

Description

technical field [0001] The invention relates to the technical field of semiconductor chip manufacturing technology, in particular to a method for preparing a photodiode and the photodiode. Background technique [0002] Ordinary diodes are in a cut-off state when the reverse voltage is applied, and only a weak reverse current can flow. When designing and manufacturing photodiodes, try to make the area of ​​the PN junction relatively large in order to receive incident light. Photodiodes work under the action of reverse voltage. When there is no light, the reverse current is extremely weak, which is called dark current; when there is light, the reverse current rapidly increases to tens of microamperes, which is called photocurrent. The greater the intensity of the light, the greater the reverse current. The change of light causes the current change of the photodiode, which can convert the light signal into an electrical signal and become a photoelectric sensing device. [000...

AI Technical Summary

Problems solved by technology

[0003] At present, according to different performance parameters of photodiodes, they are applied to different fields. In the actual preparation process of photodiodes, mutual dissolution between metals and semiconductors often occurs when etching metals, resulting in contamination or damage to photodiodes. This greatly affects the surface state of the photodiode and reduces the reliability of the photodiode

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