Method for measuring depth of deep trench

Abstract

The invention discloses a method for measuring the depth of a deep trench, and relates to the field of semiconductor manufacturing. The method comprises the steps of placing a wafer with a deep trenchin water; irradiating the wafer through a measurement light source; obtaining first reflected light, second reflected light, third reflected light and fourth reflected light, wherein the first reflected light comes from the bottom of the deep trench, the second reflected light comes from the water surface above the deep trench, the third reflected light comes from the surface of the wafer, and the fourth reflected light comes from the water surface above the surface of the wafer; obtaining the water depth of the deep trench according to the first reflected light and the second reflected light, and obtaining the water depth at the surface of the wafer according to the third reflected light and the fourth reflected light; and determining the depth of the deep trench according to the water depth at the deep trench and the water depth at the surface of the wafer. The problems of poor real-time performance and high cost of the existing method for measuring the depth of the deep trench aresolved; and the effects of improving the compatibility of deep trench depth measurement and a wafer processing technology, realizing online measurement and enhancing timeliness are achieved.

Description

technical field [0001] The present application relates to the field of semiconductor manufacturing, 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, is more and more widely used, such as: in the production of DRAM (Dynamic Random Access Memory, 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 deep trenches inside it reaches 40 microns. [0003] When measuring the depth of grooves, groove depth measurement techniques such as profilometers or atomic force microscopes are routinely used. However, conventional methods are difficult to meet the measurement requirements when measuring the depth of deep grooves. At present, the depth of the groove is mainly detected by SEM (scanning electron microscope, scanning electron ...

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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