Shield Line for Semiconductor Leakage Current Detection
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Solution Overview
Problem
Semiconductor manufacturing faces challenges in product yield and reliability, particularly in high voltage applications, where defects in metal line isolation can lead to failures during operation, and existing testing methods fail to identify these defects effectively.
Innovation Solution
The introduction of a shield line between metal lines carrying different voltages, which is not part of any functional circuit, allows for the application of a stress voltage to detect leakage currents indicative of potential failures, thereby identifying susceptible regions without affecting the operational circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing testing methods are used, then manufacturing process is simple, but defects in metal line isolation cannot be detected effectively
Solution Approach 1:
A shield line is introduced as an intermediary element between adjacent metal lines carrying different voltages. This shield line serves as a mediator to detect leakage currents that indicate isolation defects, enabling precise defect detection without directly modifying the functional metal lines while maintaining structural simplicity.
2Reliability
If shield line is added between metal lines, then leakage current detection is improved, but device area increases
Solution Approach 1:
The shield line is strategically placed only in critical regions where metal lines carrying different voltages are adjacent and isolation defects are most likely to occur. This localized approach provides targeted defect detection capability while minimizing the additional area consumed, rather than adding shield lines throughout the entire device.
3Measurement precision
If stress voltage is applied to detect leakage currents, then defect identification is improved, but risk of damaging functional circuitry increases
Solution Approach 1:
The shield line acts as a protective intermediary that allows stress voltage to be applied safely. By measuring leakage currents through the shield line rather than through functional metal lines, the testing method achieves high detection accuracy while isolating the functional circuitry from damaging stress conditions.
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 the detection of small leakage currents, significantly improving the identification of weak regions in metal lines, reducing the risk of failures and enhancing the reliability of semiconductor devices without increasing area consumption or test time.
Implementation Method 1
measuring a current through the shield line in response to the stress voltage
Data Source
AI summary
In accordance with an embodiment of the present invention, a method of testing a plurality of semiconductor devices includes applying a stress voltage having a peak voltage on a shield line disposed over a substrate. The substrate has functional circuitry of a semiconductor device. A fixed voltage is applied to a first metal line disposed above the substrate adjacent the shield line. The first metal line is coupled to the functional circuitry and is configured to be coupled to a high voltage node during operation. The peak voltage is greater than a maximum fixed voltage. The shield line separates the first metal line from an adjacent second metal line configured to be coupled to a low voltage node during operation. The method further includes measuring a current through the shield line in response to the stress voltage, determining the current through the shield line of the semiconductor device, and based on the determination, identifying the semiconductor device as passing the test.