Wafer back alignment method, wafer back alignment equipment and photoetching machine

Abstract

The invention provides a wafer back alignment method, wafer back alignment equipment and a photoetching machine. The wafer back alignment method comprises the following steps that a wafer is provided; a first laser beam is emitted to the wafer to etch a front face alignment mark at a first preset position on the front face of the wafer, a second laser beam is emitted to the wafer to etch a back face alignment mark at a second preset position on the back face of the wafer, and the first preset position and the second preset position are located in the same wafer coordinate system; the front alignment mark is set as a front reference for wafer processing, and the back alignment mark is set as a back reference for wafer processing. The method is advantaged in that the front alignment mark and the back alignment mark are etched through the first laser beam and the second laser beam respectively, so the etched front alignment mark and back alignment mark are located in the same wafer coordinate system, operation steps are reduced, calculation of the corresponding relation of multiple coordinate systems is reduced, alignment efficiency and alignment accuracy are improved, and calculation precision is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a wafer crystal back alignment method, wafer crystal back alignment equipment and a photolithography machine. Background technique [0002] Wafer crystal back alignment is a process required for the production of products such as CIS (CMOS Image Sensor, metal oxide semiconductor field effect transistor image sensor) and IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor). [0003] At present, there are many crystal back alignment methods, and each of these crystal back alignment methods has its own disadvantages, as follows: [0004] 1. CCD (Charge-coupled Device, charge-coupled device) imaging alignment, this alignment method is prone to errors. [0005] 2. Alignment of visible light (or infrared light) after crystal back thinning: [0006] In order to achieve alignment, the thickness of the polished wafer should be less than 5 micro...

AI Technical Summary

Problems solved by technology

[0020] The technical problem to be solved by the present invention is to overcome the defects in the prior art that the front and back of the wafer need to be aligned separately, and there are common errors, the alignment efficiency and accuracy are low, and the calculation accuracy is low, and a wafer is provided. Wafer crystal back alignment method, wafer crystal back alignment equipment and lithography machine

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