Wafer Scribe-Area Test Structures for Pre-Singulation Leakage Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in assessing the quality of process steps and dice quality due to the inability to effectively analyze voltage leakage in test structures before singulation, which can lead to defects in the final semiconductor devices.
Innovation Solution
Incorporating test structures in the scribe area of a semiconductor wafer with p-type and n-type diffusion regions and contacts, where electron-beam testing can detect voltage leakage by measuring reflectivity differences, allowing for the evaluation of process step quality and dice quality before singulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If test structures are analyzed after singulation, then dice quality can be assessed, but voltage leakage cannot be detected before singulation leading to potential defects
Solution Approach 1:
The patent places test structures in the scribe area that can be analyzed before singulation occurs. This preliminary analysis allows voltage leakage to be detected early in the manufacturing process, enabling defect identification before the wafer is cut into individual dice, thus resolving the timing issue while maintaining reliability assessment
2Productivity
If traditional testing methods are used after singulation, then manufacturing process can continue efficiently, but voltage leakage detection is not possible
Solution Approach 1:
The patent introduces test structures as intermediary elements placed in the scribe area between functional dice. These test structures serve as mediators that enable voltage leakage detection through electron-beam analysis without interfering with the normal singulation process or dice functionality, thus maintaining productivity while enabling detection capability
3Measurement precision
If test structures are placed in scribe area, then voltage leakage can be detected before singulation, but additional structures increase wafer complexity
Solution Approach 1:
The patent applies local quality by placing test structures only in the scribe area between dice, rather than throughout the entire wafer or within functional dice. This localized approach enables voltage leakage detection precision while minimizing the added structural complexity to only the necessary regions, preserving the overall simplicity of the wafer design
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 the detection of voltage leakage and subsequent evaluation of process step quality and dice quality, facilitating early identification of defects and improving the overall manufacturing process by using electron-beam testing to assess the performance and quality of semiconductor wafers.
Implementation Method 1
electron-beam testing can detect voltage leakage by measuring reflectivity differences
Data Source
AI summary
Test structures for wafers are disclosed. A device may include a silicon wafer including a number of die and a scribe area between two die of the number of die. The scribe area may include one or more test structures. The test structures may include a p-doped region and an n-doped region adjacent to the p-doped region. The test structures may also include a first contact electrically coupled to the p-doped region and a second contact electrically coupled to the n-doped region. The second contact may be proximate to the first contact. Associated devices, systems, and methods are also disclosed.