Method for measuring the depth of deep trenches

Abstract

The application discloses a method for measuring the depth of a deep groove, which relates to the field of semiconductor manufacturing. The method includes placing a wafer with a deep groove in water; irradiating the wafer with a measuring light source; The reflected light, the third reflected light and the fourth reflected light, the first reflected light originates from the bottom of the deep trench, the second reflected light originates from the water surface above the deep trench, the third reflected light originates from the surface of the wafer, and the third reflected light originates from the surface of the wafer. The four reflected lights come from the water surface above the wafer surface; the water depth at the deep groove is obtained according to the first reflected light and the second reflected light, and the water depth at the wafer surface is obtained according to the third reflected light and the fourth reflected light; according to the depth The water depth at the groove and the water depth at the surface of the wafer determine the depth of the deep groove; it solves the problem of poor real-time and high cost of measuring the depth of the deep groove by the existing method; it achieves the improvement of the depth measurement of the deep groove and the wafer processing. Process compatibility, realize online measurement, and enhance the effectiveness of timeliness.

Description

technical field [0001] The present application relates to the field of semiconductor manufacturing, and in particular, to a method for measuring the depth of a deep trench. Background technique [0002] With the development of chip technology, trench technology, especially deep trench technology, has become more and more widely used, for example, in the production of DRAM (Dynamic Random Access Memory), 3D flash memory, and power devices. There are applications. Taking the super junction MOSFET process (DT-SJ) as an example, the depth of the inner deep trench reaches 40 microns. [0003] When measuring the depth of grooves, groove depth measurement techniques such as step meter or atomic force microscope are conventionally used. However, conventional methods cannot meet the measurement requirements when measuring the depth of deep grooves. Currently, SEM (scanning electron microscope, scanning electron microscope) slicing is mainly used to detect the depth of the groove, b...

AI Technical Summary

Problems solved by technology

[0004] This application provides a method for measuring the depth of a deep groove, which can solve the problem of poor real-time performance and high cost of measuring the depth of a deep groove in the related art

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