From Chips to Chassis: The Role of Semiconductors in Modern Automotive Engineering — Part2
Welcome to second part of our four-part series on the pivotal role of semiconductor technology in the automotive industry. This comprehensive exploration delves into how advanced semiconductor solutions are shaping the evolving demands of modern vehicles. Here’s an overview of what each part covers:
· Part 1: Introduction and Overview
Begin your journey with an in-depth look at the essential role of automotive nodes. This section compares automotive nodes to general-purpose nodes and discusses their key technical parameters, setting the foundation by emphasizing the specialized requirements of semiconductors in automotive applications.
· Part 2: Automotive Node Definition and Comparison
Delve into the specifics of what defines an automotive node, how it contrasts with general-purpose nodes, and the critical technical parameters that distinguish it. This part focuses on the unique challenges and standards that automotive semiconductors need to meet.
· Part 3: Automotive IP and Design Infrastructure
This part explores the extensive infrastructure surrounding automotive semiconductors, including intellectual property (IP) and design frameworks. It also covers the rigorous compliance and safety standards essential for automotive applications.
· Part 4: Future Trends and Strategic Importance
Conclude the series with a forward-looking perspective on the strategic importance of a resilient supply chain and the emerging trends in automotive semiconductors. This final installment reflects on how ongoing innovations and collaborations are poised to transform the automotive landscape.
Part 2: Automotive Node Definition and Comparison
Introduction: This part focuses on the core aspects of automotive semiconductors, defining what constitutes an automotive node and how it differs from general-purpose nodes. This section also delves into the key technical parameters that underscore these differences and their implications for automotive applications. It offers an in-depth analysis emphasizing aspects such as reliability, durability, operating conditions, and compliance with safety standards.
Automotive Node Definition and Comparison
Definition of an Automotive Process Node
Automotive node is a specialized semiconductor technology platform designed to meet the rigorous demands of automotive applications. Unlike general-purpose nodes in consumer electronics, automotive nodes are engineered to ensure high reliability and durability, withstanding extreme environmental conditions and stringent safety standards. These nodes are integral to systems that require long life spans and fault-free operation under the harsh conditions typical of automotive environments.
Comparison with General Purpose Nodes
Automotive nodes differ from general-purpose nodes in several key aspects:
1. Reliability and Durability: Automotive nodes are built to last and operate reliably over the vehicle’s lifespan, which can be over 15 years or 150,000 miles. In contrast, general-purpose nodes might be designed for shorter operational lifespans, as in consumer electronics.
2. Operating Conditions: These nodes are designed to function in a broader range of temperatures and under more significant mechanical stress than their general-purpose counterparts, usually operated in more controlled environments.
3. Safety and Compliance: Automotive nodes must comply with specific automotive safety standards such as ISO 26262 for functional safety, which are not typically required for general consumer electronics.
Key Technical Parameters:
The following table summarizes key technical parameters & differences between general-purpose and automotive nodes:
Key Differences: General vs Automotive Nodes
+------------------------+----------------+------------------------------------------------------+
| Parameter | General Node | Automotive Node |
+------------------------+----------------+------------------------------------------------------+
| Process Qualification | Standard | AEC-Q100 Grade 1/2/3/4 |
| Reliability | Standard | Enhanced with aging models, thermal-aware analysis |
| Functional Safety | Not required | ISO 26262 ASIL B/D assessment |
| Temperature Resilience | Up to 85°C | Up to 150°C or higher |
| Design for Test (DFT) | Standard | Zero DPPM, cell-aware fault models, BIST/POST |
| Quality Management | Standard | IATF 16949 certified for automotive quality |
| Security | Standard | Configurable IPs for security levels |
| Power Management | Standard | BCD Power ICs, eFlash support |
| Transistor Type | FinFET, GAA | FinFET, GAA |
| HTOL | Standard | See below |
| Cost Considerations | Cost-Effective | Higher due to rigorous testing and certification |
| Node Availability | Leading nodes | Leading nodes and historically it been Mature nodes |
| | | |
+------------------------+----------------+------------------------------------------------------+
+---------+----------------------+---------------------------------------------------------+----------------------------------------------------+
| Grade | HTOL Test Conditions | Mission Profile | Reliability Model |
+---------+----------------------+---------------------------------------------------------+----------------------------------------------------+
| Grade 0 | 1000 hours at 150°C | 12000 hours at an average junction temperature of 105°C | Arrhenius equation with activation energy of 0.7eV |
| Grade 1 | 1000 hours at 125°C | 12000 hours at an average junction temperature of 95°C | Arrhenius equation with activation energy of 0.7eV |
| Grade 2 | 1000 hours at 105°C | 12000 hours at an average junction temperature of 87°C | Arrhenius equation with activation energy of 0.7eV |
| Grade 3 | 1000 hours at 85°C | 12000 hours at an average junction temperature of 70°C | Arrhenius equation with activation energy of 0.7eV |
+---------+----------------------+---------------------------------------------------------+----------------------------------------------------+his comparison underscores the specialized nature of automotive nodes, tailored to meet the exacting requirements of automotive applications where failure can have critical safety implications.Several factors influence the High-Temperature Operating Life (HTOL) requirements for automotive semiconductors.
Temperature Grade: The automotive temperature grade (0, 1, 2, or 3) directly impacts HTOL requirements. Higher grades (0 and 1) for harsh environments like under-hood applications require more stringent HTOL testing at higher temperatures.
- Application Domain: The specific automotive domain (e.g., powertrain, body electronics, safety systems, infotainment) influences HTOL requirements due to varying operating conditions and reliability expectations.
- Mission Profile: The semiconductor’s expected lifetime and operating conditions in its intended application affect HTOL requirements. Typical factors include:
* Average junction temperature
* Expected operating hours
* Duty cycle
* Environmental conditions (humidity, vibration, etc.) - Safety Criticality: Components used in safety-critical systems (e.g., braking, steering) may have more stringent HTOL requirements due to their importance in vehicle safety.
- Reliability Models: The use of reliability models, such as the Arrhenius equation with a specific activation energy (e.g., 0.7eV), influences how HTOL test conditions are determined to predict long-term reliability.
- Industry Standards: Compliance with standards like AEC-Q100 sets baseline HTOL requirements for automotive qualification.
- Semiconductor Technology: The specific process node, transistor type (e.g., FinFET, GAA), and materials used can affect a component’s susceptibility to high-temperature degradation, influencing HTOL requirements.
- Power Dissipation: Components with higher power dissipation may require more rigorous HTOL testing due to increased self-heating effects.
- Failure Mechanisms: Understanding specific failure mechanisms relevant to the semiconductor technology and application can influence HTOL test conditions.
- Customer Requirements: Automotive OEMs or Tier 1 suppliers may have additional HTOL requirements beyond industry standards based on their specific needs or experiences.
Challenges of Compliance
While these standards and technologies provide a framework for safety and efficiency, complying with them presents significant challenges. The cost and complexity of developing semiconductors that meet these rigorous standards can be substantial. However, these investments are critical to ensuring the safety and reliability of automotive systems consumers increasingly depend on.
Advanced Technologies in Automotive Semiconductors
Innovations in Semiconductor Technologies: FinFETs and GAA
FinFETs are 3D transistors that control electrical current via a gate wrapped around a raised channel. They are crucial for enhancing performance and reducing the power consumption of chips at nodes up to 3nm. Their design helps minimize leakage current, a critical advantage as devices become smaller and more densely packed.
Gate-All-Around (GAA) Technology: GAA technology, particularly relevant for nodes smaller than 3nm, represents a significant advancement in transistor architecture. Unlike FinFETs, GAA transistors feature a gate that encircles the channel completely, offering superior control and significantly reducing leakage currents even further. This design is crucial for pushing the scaling limits while maintaining efficiency and reliability, making it ideal for high-performance automotive applications where power efficiency and space constraints are critical.
Process Specifications for Automotive Nodes:
GAA (Gate-All-Around) transistor technology promises significant improvements in power consumption for automotive chips compared to the previous FinFET architecture. Here’s how GAA impacts power consumption:
Reduced Leakage Current: GAA transistors provide superior electrostatic control over the channel because the gate is wrapped around all four sides, suppressing leakage currents more effectively than FinFET’s. This allows GAA chips to operate at lower supply voltages while maintaining performance, directly translating to lower static power consumption.
Improved Drive Current: GAA’s horizontally stacked nanosheet/nanowire channel structure enables higher drive currents than vertical FinFET fins. Higher drive currents mean chips can perform similarly at lower operating voltages, reducing dynamic power consumption.
Capacitance Scaling: GAA’s multi-bridge channel architecture allows better scaling of gate capacitance compared to FinFETs, reducing charging & discharging losses. Lower capacitance directly improves both dynamic and static power efficiency.
Process Optimization
GAA nodes (e.g., 3nm and below) leverage novel materials and engineering techniques to boost transistor performance and energy efficiency further. Optimized threshold voltages, work functions, and channel materials in GAA can minimize power consumption.
· Channel Length and Thickness: These are optimized for low power consumption while maintaining performance under high-temperature conditions typical in automotive environments. In automotive applications, shorter channel lengths are often optimized for faster switching times and reduced gate delay, which are crucial in safety-critical applications. However, adjustments must ensure that this does not compromise the device’s ability to withstand higher temperatures and electrical stresses.
· Electrostatic Control: GAA’s architecture enhances electrostatic control, improving scalability and performance at advanced nodes. Utilizing GAA technology, automotive semiconductors achieve better electrostatic control by fully encompassing the conducting channel, minimizing short-channel effects and leakage currents even as device dimensions shrink.
· Width Quantization and Parasitic Extraction: Critical for maintaining signal integrity and reducing power loss in compact designs.
· Thermal Properties: Materials and design adjustments enhance heat dissipation capabilities, critical in environments where components are subjected to extreme thermal variation and stress.
By providing better electrostatic integrity, drive strength, and scaling potential, GAA transistors are projected to reduce total power consumption compared to scaled FinFET nodes for the same performance targets — a critical advantage for power-constrained automotive applications. However, achieving these power benefits in real automotive chips will depend on overcoming GAA’s manufacturing challenges related to patterning, thermal management, and achieving high yields.
Zero Defects Per Million (DPPM) Goals
Zero DPPM is a stringent quality standard aimed at ensuring no defects in a million units of semiconductor production, which is critical for automotive reliability and safety. Achieving Zero DPPM involves:
· Enhanced Quality Assurance Processes: These include more rigorous testing at various stages of the manufacturing process.
· Advanced Design and Manufacturing Techniques: These include improved layout designs, better material quality, and precision in fabrication to minimize the risk of failure.
Design Techniques and Power Efficiency
Enhancements in Power Consumption and Energy Efficiency
· Design Techniques to Reduce Power Consumption: Low-power design methodologies, such as multi-threshold CMOS (MTCMOS) technology, power gating, and dynamic voltage and frequency scaling (DVFS), are crucial in minimizing energy usage while maintaining performance.
· Impact on Reliability Aspects: Techniques that reduce power also impact reliability parameters like Bias Temperature Instability (BTI) and Hot Carrier Injection (HCI). For example, reducing operating voltages to save energy can exacerbate BTI effects, but careful design and material selection can mitigate these risks.
Cell-aware Fault Models and Thermal-aware Electromigration (EM) Analysis
· Cell-aware Fault Models: Used to identify potential faults at the transistor and cell level within integrated circuits, crucial for predicting failure rates and improving the reliability of automotive electronics.
· Thermal-aware EM Analysis is essential for assessing and managing the risks of electromigration, which can lead to circuit failure due to intense and localized heating in high-density chip areas.
Technological Complexity and Regulatory Challenges
Compliance and Qualification Processes
· Role of Semiconductor IP Companies: These companies play a vital role in ensuring that their products meet ASIL, Auto Grade, and AEC-Q100 compliance, addressing different aspects of safety and reliability required in the automotive sector.
· Cost and Qualification Impacts: A semiconductor’s grade influences its performance, manufacturing costs, and complexity, impacting the overall budget and design decisions in automotive applications.
Performance and Operational Conditions
Impact of Temperature on Performance
· Temperature Effects: High or varying temperatures can affect automotive-grade processors’ performance, efficiency, and longevity. Thermal management strategies are critical in maintaining operational integrity and reliability.
· Thermal Management Techniques include using heat sinks, thermal interface materials, and advanced cooling solutions to ensure that temperature variations do not impact the semiconductor’s functionality.
Impact on Power Consumption: GAA technology significantly reduces leakage and allows more densely packed circuits. This efficiency is pivotal in automotive applications where long-term reliability and energy efficiency are crucial.
Up Next: In Part 3, we explore the comprehensive infrastructure surrounding automotive semiconductors, including intellectual property (IP), design frameworks, and the critical standards ensuring functional safety and compliance.
References/Further Reading:
1. Application Service — Automotive | Samsung Semiconductor USA
2. A Technology Trifecta for Automotive | GlobalFoundries
3. How Are Process Nodes Defined? ExtremeTech
4. Logic Node — Process Technology — Samsung Semiconductor
5. Reimagining PVT Monitoring IP For Advanced Node GAA Process
6. Applied Materials Outlines Next-Gen Tools for 3nm and GAA
7. All you need to know about GAA chip manufacturing process — EDN
8. Impact Of GAA Transistors At 3/2nm — Semiconductor Engineering
9. GAA-FET architecture provides better SCE — Power Electronics News
10. Driving Semiconductor Performance with Gate-All- Around (GAA)
11. Power Management for Autonomous Driving Systems
12. Development of an Energy Efficient and Cost Effective Autonomous Vehicle Research Platform
13. Overall system power consumption vs. number of vehicles at different velocities
14. Need for Thermal Management in Automotive Electronics
15. Foundation IP for Automotive: so Stringent Quality Requirements!
16. Automotive Grade Quality Products (AEC-Q100 and Beyond)
17. Foundry perspective on the automotive semiconductors market
18. TSMC offers advice to automakers from a foundry’s perspective
19. Foundries Accelerate Auto Efforts — Semiconductor Engineering
