Focused ion beam sample preparation method for precisely positioning front-layer defects

Abstract

The invention provides a focused ion beam sample preparation method for precisely positioning front-layer defects. The method comprises the following steps: carrying out online defect detection on a wafer to find out the defects and observing the specific features of the defects by using a scanning electron microscope or an optical microscope; if the scanning electron microscope cannot observe the defects or judge the reasons of the defects and the reasons of the defects cannot be judged according to the observation result of the optical microscope, firstly obtaining the microscopic observation result by using the optical microscope and then carrying our defect positioning by means of the microscopic observation result and the information of different layers of photo masks, obtained a wafer product design process.

Description

technical field [0001] The invention relates to the field of focused ion beam machines, and more specifically, the invention relates to a focused ion beam sample preparation method for precisely locating defects in the front layer. Background technique [0002] The Focused Ion Beam (FIB) system is a microdissection instrument that uses an electric lens to focus the ion beam into a very small size. The existing focused ion beam machines use ions as the electron microscope inspection function, such as figure 1 As shown, it includes a cavity 21, an ion source 22, an electron detector 23, and a sample seat 24. The ion source 22 emits an ion beam that bombards the surface of a sample 25 on the sample seat to generate electrons, and the bombarded secondary electrons and backscattered electrons Then the electronic detector 23 collects the signal for imaging, which is the so-called electron microscopic image. [0003] However, the current FIB machine uses ions as the electron micro...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that because FIB is a destructive inspection, a large number of particles caused by cutting will be suspended in the entire cavity, and these suspended particles will cause huge pollution to the optical lens, and also have a huge impact on the observation quality of the optical lens. It will not be clear whether it is a defect in the front layer of the sample or a defect in the cavity, which will affect the final positioning

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