Leakage defect detection method

Abstract

The invention provides a leakage defect detection method. According to the method, a first voltage contrast image with high-definition BVC is obtained by means of voltage contrast detection in a positive mode, a potential leakage defect position in a semiconductor sample is captured, then a second voltage contrast image is obtained by scanning the position of the BVC again by means of voltage contrast detection in a negative mode, the BVC is screened by means of the DVC of the second voltage contrast image so that accurate BVC classification can be achieved, and a high-purity high-risk leakage defect is obtained.

Description

technical field [0001] The invention relates to a semiconductor reliability analysis method, in particular to a leakage defect detection method. Background technique [0002] At present, there are various reliability analysis methods for semiconductor devices, among which the voltage contrast (Voltage Contrast, VC) detection method has been widely used. The voltage contrast detection method usually uses a scanning electron microscope (Scanning Electron Microscopy, SEM) to perform voltage contrast detection on samples of semiconductor devices. The principle is to excite secondary electrons by bombarding the surface of the sample with a focused electron beam (E-beam). The material properties of the sample determine the number of secondary electrons generated, so the material of the bombarded sample is different, and the number of secondary electrons collected is also different, and the number of secondary electrons is expressed as image brightness , so as to determine whether...

AI Technical Summary

Problems solved by technology

The voltage contrast detection of a single negative charge mode requires a higher LE in order to obtain a stable image brightness

Experiments have proved that although the voltage contrast detection in the negative charge mode can accurately detect high-risk leakage defects, the long-term high voltage and high current will cause a large amount of interference charges to accumulate on the sample surface of the semiconductor device, which will eventually cause a large blur in the image brightness. noise disturbance

[0004] The problem with the voltage contrast detection using the positive charge mode is that because the leakage defect itself has different mechanisms, there are many influencing factors, such as: piping (piping) and short circuit (short), etc., and its severity cannot be quantified in detail. The BVC detected by the voltage contrast of the positive charge mode can only be roughly judged that a leakage defect may have occurred at the BVC position. Because the voltage contrast detection of the positive charge mode can judge the leakage defect is vague, and even some BVCs are not real leakage defects. , so it is necessary to use other reliability analysis methods of semiconductor devices, for example, further judgment of failure analysis (FA data confirm) to obtain the authenticity and severity of leakage defects

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