Semiconductor Aging Damage Simulation via BTI and HCI Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor device design processes fail to accurately account for aging-related damage, particularly bias temperature instability (BTI) and hot carrier injection (HCI), which can lead to performance degradation over time, as they often categorize damage by single modes or assume simultaneous occurrence, leading to inaccurate assessments.
Innovation Solution
A method and system that measure and apply aging effects in transistors by generating a damage metric considering both BTI and HCI, incorporating voltage, temperature, and channel length and width, and simulating their impact on performance parameters like threshold voltage shift and drive current degradation, allowing for more realistic performance predictions throughout a transistor's lifecycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If aging effects are categorized by single modes or assumed simultaneous occurrence, then the design process is simplified, but the accuracy of performance prediction deteriorates
Solution Approach 1:
The patent segments the aging damage calculation by dividing the transistor operation time into discrete time slices and separating BTI and HCI damage calculations into distinct evaluation paths. For each time slice, the method determines whether BTI or HCI is the dominant damage mechanism and calculates damage separately, then sums the results. This segmentation enables accurate prediction of transistor performance degradation over time while maintaining computational feasibility through structured breakdown of complex aging effects.
2Measurement precision
If multiple sources of damage are accounted for with their interactions, then the performance prediction accuracy is improved, but the computational complexity increases
Solution Approach 1:
The patent implements a dynamic damage evaluation method that adapts the calculation approach based on operating conditions. The system continuously evaluates voltage and current parameters during simulation, dynamically determining whether BTI or HCI dominates at each time slice, and adjusts the damage calculation methodology accordingly. This dynamic approach accurately captures the interacting effects of multiple damage mechanisms while optimizing computational resources by applying the appropriate damage model only when relevant conditions are met.
Solution Approach 2:
The method changes calculation parameters based on operating conditions by monitoring voltage thresholds and current levels to determine dominant damage mechanisms. When VGS exceeds VTH, HCI damage parameters are activated; when VGS is below VTH but significant, BTI parameters are applied. This parameter-based conditional logic enables accurate modeling of multiple damage sources with their interactions while maintaining computational efficiency through selective parameter application.
3Measurement precision
If detailed voltage, temperature, and dimensional parameters are incorporated, then the aging effect measurement precision is improved, but the data processing requirements increase
Solution Approach 1:
The patent applies partial action by selectively incorporating detailed parameters only when necessary for accurate damage calculation. The method evaluates voltage, temperature, and dimensional parameters conditionally based on the dominant damage mechanism identified for each time slice. For example, HCI damage calculations require detailed voltage and current parameters only when VGS > VTH conditions are met, while BTI damage uses different parameter sets. This selective parameter incorporation achieves high measurement precision while minimizing unnecessary data processing.
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 a more accurate simulation of transistor aging effects, enabling designers to assess and mitigate performance degradation, ensuring the circuit meets performance criteria over its expected lifetime by accounting for multiple sources of damage and their interactions.
Implementation Method 1
A high VGS creates a high vertical electric field across the gate channel, which leads to carriers (electrons or holes) in the transistor channel being pulled into the gate dielectric
Implementation Method 2
The high electric field at the drain causes impact ionization of current carriers
Data Source
AI summary
A method includes generating a circuit design and executing a simulation of the circuit design at a plurality of time slices. Type 1 damage and type 2 damage are determined for each time slice. A total type 1 damage is provided as a sum of the type 1 damage for all of the slices in which type 1 damage is greater than type 2 damage. A total type 2 damage is similarly added for the slices where the type 2 damage is dominant. A type 1 aging effect is determined based on the total type 1 damage. A type 2 aging effect is determined based on the total type 2 damage. The type 1 aging effect is added to the type 2 aging effect to obtain a total aging effect. The circuit design is tested using the total aging effect to determine if the circuit design provides adequate lifetime performance.