Method and device for measuring thickness of wafer

Abstract

The invention provides a method and a device for measuring thickness of a wafer. The method is characterized in that the wafer is kept in a vertical state during measurement and a vacuum chuck is also arranged vertically, so that the gravity of each point on the surface of the wafer is parallel to the surface of the wafer under the condition that the wafer is adsorbed. According to the invention, the problems of the surface damage and the surface fracture of the wafer easily caused by adopting a contact probe in the existing wafer for the vertical measurement, as well as the problems that the measurement accuracy of the non-contact measurement for transparent materials and surface high-brightness materials cannot meet market requirements and the like, are solved.

Description

technical field [0001] The invention relates to the technical field of precision measurement, in particular to a wafer thickness measurement method and device. Background technique [0002] As the core product in the solar energy field, the quality of wafers determines the rise and fall of the industry, and the processing and manufacturing technology and quality control standards around wafers are developing rapidly to meet the increasingly high performance requirements of the market. [0003] The wafer is a brittle sheet-like plate, generally composed of 4 layers of materials, the first layer is the wafer layer, the second layer is the adhesive, the third layer is the glass, and the fourth layer is the adhesive tape. The process is made into finished wafers, and then the next process is scribing, grooving and other processing. The thickness uniformity of the finished wafer will determine the processing quality of the subsequent process, and ultimately affect the performanc...

AI Technical Summary

Problems solved by technology

In this measurement method, each point of the wafer will be subjected to gravity during the measurement process. For example, if the contact measurement method is used, the probe acts vertically downward on the surface of the wafer, just in the same direction as the gravity of each point on the surface, resulting in Downward force becomes greater, more likely to cause wafer fragmentation

As for the non-contact measurement method, due to the laser irradiation method for measurement, it will be difficult to unify the measurement data of each layer due to the different reflection effects of different measurement materials, especially for the measurement of the glass layer and the high-brightness surface after the finished product, due to the transparency of the material or It is the high brightness of the surface that affects the measurement accuracy, resulting in distortion of the measurement data, and the measurement accuracy is difficult to meet the wafer quality control requirements

In addition, in the previous measurement method, the probe is moved downwards driven by the Z axis. Due to the influence of the linearity error of the Z axis’s up and down motion, it is difficult to ensure the perpendicularity of the probe or laser beam to the wafer surface at each measurement point, thereby affecting the Accuracy has some influence

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