Semiconductor Test Device for Diagnosing Shared Contact Bridges
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Solution Overview
Problem
The challenge in semiconductor integrated circuits is accurately determining the cause of current flow between adjacent shared contacts, which can be due to bridges or short-circuits, making it difficult to diagnose and address contact failures effectively.
Innovation Solution
The solution involves defining specific test regions on a semiconductor substrate with distinct configurations, including primary and secondary test regions, gate lines, shared contacts, and nodes, allowing for the application of voltage and measurement of current to diagnose short-circuits and determine the source of current flow between adjacent shared contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current flow detection is performed between nodes connected to adjacent shared contacts, then bridge occurrence can be detected, but it becomes difficult to accurately determine the cause of current flow (bridge vs. other short-circuits)
Solution Approach 1:
The test structure is segmented into multiple independent test regions (first test region with both first and second conductive type active regions, second test region with only first conductive type active regions). Each region can be tested independently to isolate and identify the specific cause of current flow. By segmenting the test areas, the patent enables precise localization of defects without requiring complex overall test structures.
Solution Approach 2:
Different test regions are designed with different configurations tailored to specific test purposes. The first test region includes both first and second conductive type active regions to test for bridges between adjacent shared contacts, while the second test region includes only first conductive type active regions to test for other types of short-circuits. This local differentiation allows accurate determination of current flow causes.
2Reliability
If multiple test regions with different configurations are defined, then accurate diagnosis of current flow cause is enabled, but device structure becomes more complex
Solution Approach 1:
The semiconductor substrate is divided into distinct test regions with specific configurations. The first test region contains both first and second conductive type active regions arranged to detect bridges, while the second test region contains only first conductive type active regions. This segmentation allows reliable diagnosis by comparing test results across regions without requiring overly complex structures.
Solution Approach 2:
The second test region serves as a simplified copy or reference version of the first test region, lacking only the second conductive type active regions. This copying approach provides a baseline for comparison, enabling reliable diagnosis by contrasting test results between the complete first test region and the simplified second test region, thereby identifying the specific cause of current flow.
3Measurement precision
If adjacent shared contacts are electrically connected (bridge), then current flows between nodes, but other parameters may also cause current flow making accurate determination difficult
Solution Approach 1:
The test structure segments different failure modes into separate testable regions. Bridges between adjacent shared contacts are tested in the first test region with both conductive type active regions, while other short-circuit types are tested in the second test region with only first conductive type active regions. This segmentation eliminates false positives by isolating specific failure causes to specific regions.
Solution Approach 2:
Each test region is designed with local structural characteristics optimized for detecting specific failure types. The first test region's configuration with both conductive type active regions creates a local structure sensitive to bridges, while the second test region's configuration creates a local structure sensitive to other short-circuits. This local quality differentiation enables precise identification of current flow causes without false positives.
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 approach enables precise detection of short-circuits and bridges, improving the accuracy of diagnosing defects in static memory cells, thereby enhancing the manufacturability and reliability of semiconductor integrated circuits.
Implementation Method 1
determined whether current flows between the nodes or not. If current flows between the nodes, it may be determined that a bridge has occurred between the adjacent shared contacts
Data Source
AI summary
A test device and a semiconductor integrated circuit are provided. The test device may include a first test region and a second test region defined on a semiconductor substrate. The first test region may include a first test element and the second region may include a second test element. The first test element may include a pair of first secondary test regions in the semiconductor substrate extending in a first direction. The second test element may include structures corresponding to the first test element except the second test element does not include structures corresponding to the pair of first secondary test regions.