Semiconductor Evaluation Substrate for Mirror Electron Inspection Sensitivity
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Solution Overview
Problem
The challenge lies in ensuring consistent defect detection sensitivity of mirror electron microscopes for semiconductor wafers, as defects such as latent scratches and crystal defects within the wafer surface are difficult to quantify due to their random size and location, affecting the reliability of inspection devices.
Innovation Solution
A semiconductor substrate with artificially formed indentations of varying sizes, created using an indenter with specific hardness and shape, is used to evaluate defect detection sensitivity. The substrate is mounted on a wafer holder, and a negative voltage is applied to enhance contrast in mirror electron images, allowing for the calculation of defect detection rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If defects are formed incidentally on the wafer surface, then the mirror electron microscope can detect them with high sensitivity, but it becomes difficult to quantitatively evaluate the defect detection sensitivity and assure device performance
Solution Approach 1:
The patent applies preliminary action by forming test indentations on the wafer surface before inspection. These indentations are created by pressing an indenter with specific hardness and shape at controlled positions and depths. By preparing these known defects in advance, the inspection device's detection sensitivity can be quantitatively evaluated using a defect detection rate, thus assuring device performance.
Solution Approach 2:
The patent utilizes parameter changes by varying the pressing load when forming indentations with an indenter. By controlling parameters such as indenter hardness, shape, and pressing load, test defects with different characteristics can be created. This allows systematic evaluation of the inspection device's ability to detect defects across different severity levels.
2Reliability
If artificial test patterns are used to evaluate inspection sensitivity, then quantitative evaluation becomes possible, but the evaluation may not reflect real defect detection capabilities
Solution Approach 1:
The patent applies local quality by creating indentations with specific local characteristics on the wafer surface. The indentations have controlled depth, shape, and position, mimicking real defect characteristics. This localized defect creation allows the evaluation to closely reflect real defect detection capabilities while maintaining quantitative measurability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables quantitative evaluation of defect inspection sensitivity, serving as a performance indicator for mirror electron microscopes, ensuring consistent detection capabilities.
Implementation Method 1
a plurality of first indentations formed by pressing an indenter having prescribed hardness and shape with a first pressing load
Implementation Method 2
an inspection device detecting a defect of a semiconductor substrate by a mirror electron image
Implementation Method 3
since an electron beam is used for image forming, the resolution of the optical system is several tens nanometers
Implementation Method 4
magnitude of negative voltage applied to a wafer holder is adjusted so as to be capable of observing contrast of the first indentation in a mirror electron image
Data Source
AI summary
It is necessary to guarantee performance by quantitatively evaluating the defect detection sensitivity of an inspection device for using the mirror electron image to detect defect in a semiconductor substrate. The size and position of accidentally formed defects are random, however, and this type of quantitative evaluation has been difficult. This semiconductor substrate 101 for evaluation is for evaluating the defect detection sensitivity of an inspection device and comprises a plurality of first indentations 104 that are formed through the pressing, with a first pressing load, of an indenter having a prescribed hardness and shape into the semiconductor substrate for evaluation. Further, a mirror electron image of the plurality of first indentations of the semiconductor substrate for evaluation is acquired, and the defect detection sensitivity of an inspection device is evaluated through the calculation of the defect detection rate of the plurality of first indentations in the acquired mirror electron image.