EM Temperature Evaluation With Self-Heating and Thermal Coupling
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Solution Overview
Problem
Current electromigration (EM) evaluation methodologies in semiconductor devices do not accurately account for self-heating effects (SHE), leading to underestimated conductive line operating temperatures and increased risks of premature failures in FinFET integrated circuit designs.
Innovation Solution
A self-heating aware EM evaluation methodology that uses equation-based device temperature calculations and pseudo-3D thermal models to adjust conductive line temperatures, considering FinFET, high-resistance, and conductive line self-heating effects, to improve the accuracy of EM evaluations and reduce the risk of premature failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional EM evaluation methodologies are used, then the evaluation process is simple, but the temperature calculation accuracy is insufficient leading to underestimated conductive line operating temperatures
Solution Approach 1:
The patent segments the thermal analysis into distinct components: self-heating effects (SHE) from active regions, thermal coupling effects from neighboring structures, and heat sink effects. This segmentation allows each thermal mechanism to be calculated and combined separately, improving accuracy while maintaining a systematic evaluation process that doesn't require complete thermal simulation complexity.
Solution Approach 2:
The patent transitions from conventional 2D cross-sectional thermal analysis to a pseudo-3D thermal model that incorporates horizontal thermal coupling effects. This dimensional enhancement captures heat flow in the lateral direction between neighboring active regions and conductive lines, significantly improving temperature calculation accuracy without requiring full 3D thermal simulation complexity.
2Measurement precision
If self-heating effects are considered in EM evaluation, then temperature accuracy improves, but the risk of premature failures increases due to higher temperatures
Solution Approach 1:
The patent applies preliminary thermal analysis during the design phase to identify conductive lines that will experience elevated temperatures due to self-heating and thermal coupling effects. By calculating adjusted temperatures before manufacturing, designers can proactively modify layouts, spacing, or materials to prevent premature failures, rather than discovering reliability issues after device fabrication.
Solution Approach 2:
The patent modifies the temperature parameter used in EM evaluation from nominal or junction temperature to an adjusted temperature that incorporates self-heating and thermal coupling effects. This parameter change reflects the actual operating conditions of conductive lines more accurately, allowing for proper reliability assessment and design optimization to prevent premature failures.
3Measurement precision
If pseudo-3D thermal models are used for temperature calculation, then local temperature accuracy improves, but the simulation runtime increases
Solution Approach 1:
The patent applies partial thermal analysis by focusing computational resources only on regions where thermal effects are significant - specifically areas with high current density, closely spaced active regions, and conductive lines adjacent to heat-generating structures. This selective approach captures the most critical thermal interactions without performing exhaustive thermal simulation across the entire device, thereby reducing simulation runtime while maintaining local temperature accuracy where it matters most.
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 provides more accurate local temperature calculations and thermal-aware EM evaluation results, reducing the risk of premature product failure and simulation runtime, while ensuring semiconductor devices meet performance and lifetime expectations.
Implementation Method 1
the movement of the metal atoms resulting from momentum transfer between the electrons passing through the conductive lines and the metal atoms comprising the conductive lines
Implementation Method 2
self-heating effects (SHE), leading to underestimated conductive line operating temperatures
Data Source
AI summary
An electromigration (EM) sign-off methodology that utilizes a system for analyzing an integrated circuit design layout to identify heat sensitive structures, self-heating effects, heat generating structures, and heat dissipating structures. The EM sign-off methodology includes a memory and a processor configured for calculating adjustments of an evaluation temperature for a heat sensitive structure by calculating the effects of self-heating within the temperature sensitive structure as well as additional heating and/or cooling as a function of thermal coupling to surrounding heat generating structures and/or heat dissipating elements located within a defined thermal coupling volume or range of the heat sensitive structures.