Image sensor wafer reverse side processing method

Abstract

The invention relates to an image sensor wafer reverse side processing method. The image sensor wafer reverse side processing method includes a first step of carrying out polishing treatment to the surface of a wafer and planarizing the surface of the wafer, a second step of carrying out bonding connection to the obverse side of the wafer and a ground slide, a third step of carrying out thinning treatment to the reverse side of the wafer, a fourth step of carrying out treatment to the surface of the reverse side of the wafer through adoption of ozone, wherein the ozone concentration is 20-80 milligrams per liter, the treatment time is 6-15 minutes, and after treatment a layer of oxide film is generated on the reverse side of the wafer and the thickness of the oxide film is 10-15 angstroms, a fifth step of depositing a layer of high medium layer on the oxide film generated on the reverse side of the wafer, and a sixth step of depositing a metal shielding layer on the high medium layer. Through utilization of high activity of the ozone and on the basis of not needing extra hot process, the oxide film with high quality is generated on the reverse side of a silicon substrate of the wafer of a device. The problem of surface defects caused in the process of thinning of the reverse side of the wafer of the device is solved. Crosstalk and other problems generated by an image sensor are avoided. The image sensor wafer reverse side processing method has the advantages that temperature is low, cost is low, and process is easy to control.

Description

technical field [0001] The invention relates to a method for processing the backside of an image sensor wafer. Background technique [0002] Back-illuminated image sensors need to thin the back of the device wafer to allow incident light to enter the photodiode area. Some substrate defects caused by the thinning process will affect the performance of the image sensor, such as crosstalk, which urgently needs to be solved. The existing solution is to deal with the method of water vapor oxidation, but due to the high process temperature and high cost, there is a lot of room for improvement in the performance of the sensor. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a method for processing the backside of an image sensor wafer. By utilizing the high activity of ozone, a high-quality oxide layer can be grown on the backside of the silicon substrate of the device wafer without additional thermal processes. object...

AI Technical Summary

Problems solved by technology

[0002] The back-illuminated image sensor needs to thin the back of the device wafer so that the incident light enters the photodiode area. Some substrate defects caused by the thinning process will affect the performance of the image sensor, such as crosstalk, etc., which urgently need to be solved

The existing solution is to deal with the method of water vapor oxide, but due to the high process temperature and high cost, the performance of the sensor has a lot of room for improvement

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