Method for detecting wafer edge cleaning width of wafer

Abstract

The invention relates to a method for detecting wafer edge cleaning width of a wafer in semiconductor photoetching. The method comprises the following steps: coating a photoresistance film on a wafer and cleaning the wafer edge; defining a plurality of detecting sections on the wafer edge of the wafer; defining a plurality of thickness measuring points in each detecting section; sequentially and repeatedly measuring the thickness of the photoresistance films of all the measuring points in different detecting sections; comparing the thickness difference of the photoresistance films of all measuring points in each detecting section by using the average thickness of the photoresistance films as a reference value, finding out the cleaning boundary of the wafer edge and obtaining the wafer edge cleaning width of all the detecting sections by the coordinate calculation of the measuring points. After being applied and implemented, the method can effectively monitor the wafer edge cleaning width, effectively adjust the parameter of a photoresistance coating machine according to a measuring result, enabling the wafer edge cleaning width and position of the wafer to meet the process requirement, and improve the yield of products.

Description

technical field [0001] The invention relates to a detection method for a semiconductor manufacturing process, in particular to a method for detecting the cleaning width of a wafer edge in semiconductor photolithography. Background technique [0002] In the semiconductor process, lithography has become a crucial intermediate link. The general photolithography process mainly includes three steps: photoresist coating, exposure and development, in which the quality of photoresist coating directly affects the yield of subsequent processes. For the photoresist liquid coating process, the photoresist coated on the wafer must have a certain uniform thickness. [0003] The prior art is generally implemented by spin coating, that is, the wafer is fixed on the rotary chuck of the spin coating machine, and the photoresist is coated by centrifugal force while the wafer is rotating. So that the photoresist liquid can be evenly coated on the surface of the wafer. Although the photoresis...

AI Technical Summary

Problems solved by technology

The width of the edge cleaning can be set on the machine according to the process requirements. However, due to possible errors in the control system of the robot arm of the machine, the width of the edge cleaning may not be consistent with the set value of the machine.

The edge cleaning is too wide, too narrow, and the asymmetrical offset of the edge cleaning area will cause a decrease in the edge yield. This is a situation that should be avoided in the photolithography process. Specifically: the edge cleaning is too wide, The internal effective lattice is reduced, which ultimately affects the product yield; if the crystal edge cleaning is too narrow, the photoresist film layer remaining in the crystal edge area is likely to cause defects in the subsequent process

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