Parallel-Branch Impedance Circuit for Tiny Interconnect Resistance
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Solution Overview
Problem
Existing methods for measuring interconnection structure impedance, such as the four-point probe and Wheatstone bridge, are cumbersome, costly, and limited in scalability and real-time monitoring, particularly for tiny resistive impedances in interconnection metal lines and pads, hindering accurate reliability evaluation.
Innovation Solution
An interconnection structure impedance measurement circuit with parallel branches, including interconnection structures and fixed resistors, allows for real-time impedance measurement by calculating voltages and currents across switched branches, eliminating the need for pre-known resistor values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the four-point probe method is used to measure interconnection structure impedance, then measurement accuracy is improved, but measurement complexity and cost increase
Solution Approach 1:
The measurement system is divided into multiple parallel measurement channels, each capable of independently measuring impedance of different interconnection structures. This segmentation allows simultaneous multi-point measurement, reducing overall system complexity while maintaining high measurement accuracy through standardized channel design.
Solution Approach 2:
The patent uses standardized measurement channels that can be replicated and multiplied to measure multiple interconnection structures simultaneously. Each channel is a copied version of the same measurement circuit, enabling large-scale parallel measurement without proportionally increasing system complexity.
2Measurement precision
If the Wheatstone bridge structure is used to measure tiny resistive impedances, then measurement accuracy is improved, but the measurement process becomes more complex and time-consuming
Solution Approach 1:
The measurement system employs periodic switching between different measurement channels and modes, allowing automated sequential measurement of multiple interconnection structures. This periodic action enables high-throughput measurement while maintaining the accuracy of individual measurements through systematic channel activation.
Solution Approach 2:
The system dynamically changes measurement parameters such as current magnitude and measurement mode based on the specific interconnection structure being measured. This adaptive parameter adjustment optimizes measurement speed and accuracy for different impedance values, reducing overall measurement time while maintaining precision.
3Measurement precision
If traditional impedance measurement methods are used, then measurement accuracy is maintained, but scalability to large-scale measurements is limited
Solution Approach 1:
The measurement system is divided into multiple independent parallel channels, each capable of measuring one interconnection structure. This segmentation enables simultaneous measurement of multiple structures, dramatically increasing productivity and scalability while maintaining the measurement accuracy of individual channels.
Solution Approach 2:
Each measurement channel is designed as a universal module that can measure different types of interconnection structures (metal lines, pads, etc.) with varying impedance values. This multi-functionality allows the system to scale to large-scale measurements across diverse interconnection structures without requiring separate specialized measurement systems.
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
Enables accurate, large-scale, and real-time monitoring of interconnection structure impedance, facilitating rapid detection of welding quality and reliability testing, especially in electromigration scenarios.
Implementation Method 1
an impedance of the first interconnection structure and an impedance of the second interconnection structure are determined from a first voltage between the first branch and the second branch, a second voltage between the first branch and the third branch
Data Source
AI summary
The present disclosure provides an interconnection structure impedance measurement circuit, in which a Wheatstone bridge structure is optimized by using three branches connected in parallel where interconnection structures to be measured in one branch are connected in series while two resistors in the other two branches are connected in series. The branch with the interconnection structures and one of the other two branches are controlled to be simultaneously closed to measure a voltage between the two branches that are closed, and an impedance of two interconnection structures is calculated according to a current introduced into the interconnection structure impedance measurement circuit, the measured voltage, and resistances in the branches. The present disclosure further provides interconnection structure impedance measurement device and method.