How to Enhance Precision and Yield with Automated Run-to-Run (R2R) Control

Semiconductor manufacturing is one of the most demanding industries when it comes to process precision. Even minor variations in equipment behavior, material properties, or environmental conditions can lead to defects that reduce yield and increase costs. Traditional manual tuning methods struggle to keep pace with the complexity and speed required to maintain optimal process control.

Automated Run-to-Run (R2R) control offers a way to address these challenges by continuously adjusting process parameters between production runs using real-time data and advanced algorithms. In this blog, we explore how semiconductor manufacturers can leverage automated R2R control, specifically SmartSPC solution, to improve precision and yield.

Key Challenges in Semiconductor Manufacturing

Semiconductor production faces unique challenges, including equipment variability, process drift, and the complexity of the dependencies and interactions of the various processing areas. Even slight deviations between runs can lead to significant defects and yield loss.

As processes become more sensitive, the ability to dynamically adjust parameters between runs is vital. Common sources of variation include:

• Equipment shifts caused by wear or calibration drift.
• Material inconsistencies such as photoresist sensitivity or gas flow variations.
• Process complexity where multiple parameters, such as exposure dose and focus, interact in non-linear ways.

These variations can cause increased defect rates, reduced process capability, and lower yield. Manual tuning, often performed sequentially and reactively, is rarely fast or precise enough to correct these deviations promptly.

Learn more challenges in semiconductor frontend and backend processes here.

What is Automated Run-to-Run Process Control?

Automated R2R control is a closed-loop feedforward and feedback system that collects process data after each production run, analyzes it, and then adjusts process parameters for the next run automatically.

Unlike manual methods, it continuously learns and adapts, enabling quicker and more accurate responses to changes on the fab floor.

The run-to-run (R2R) closed-loop with feedforward and feedback mechanisms used in semiconductor manufacturing.

What is the Goal of R2R Control in Semiconductor Manufacturing?

The goal of R2R control is to achieve reliable and repeatable process performance from one run to the next. Data from the analysis of the last run is used to modify the recipe for the next run to correct for drifts. This results in more stable processes and consistent wafer quality.

How Automated R2R Control Enhances Precision and Improves Yield

In semiconductor fabs, maintaining tight control over critical parameters like exposure dose, focus, temperature, and chemical concentrations is essential to ensure product quality.

Enhancing Precision Through Advanced Feedforward and Feedback Systems

Automated R2R control improves precision in several key ways:

• Simultaneous Multi-Parameter Management: Unlike manual methods that adjust parameters individually, R2R control optimizes multiple interacting variables at once, reflecting real-world process interdependencies.
• Proactive Drift Compensation: By predicting and compensating for known sources of process drift, the system maintains tighter control limits, reducing variability before it affects production outcomes.
• Dynamic Real-Time Adjustments: Continuous monitoring enables parameter tuning on the fly, ensuring processes stay within defined specifications throughout production runs.

Transforming Precision into Higher Yield

Better precision enables manufacturers to gain the following yield benefits:

• Lower Defect Rates: More consistent control reduces the frequency of out-of-spec products caused by process variation.
• Rapid Response to Changes: The system quickly adapts to shifts in equipment behavior or raw material quality, minimizing downtime and disruptions.
• Reduced Scrap and Rework: Early identification and correction of deviations prevent waste and costly reprocessing efforts.

While specific results vary across fabs and processes, many manufacturers experience noticeable improvements in yield and throughput following the adoption of automated R2R control. These improvements contribute to operational efficiency and product reliability over time.

Implementing Automated Process Tuning and R2R Control with SmartSPC

camLine SmartSPC automates process tuning by integrating several key components, including:

• LineWorks SPACE
• LineWorks RM
• Advanced Calculation Option (ACO)
• Recipe Objects (ROBs) 

It uses advanced real-time data calculations to adjust process parameters quickly and accurately in response to production changes.

SmartSPC components and how its R2R work.

This helps streamline operations, maintain consistent product quality, and protect process integrity. The overall result leads to improved production yield and greater operational efficiency.

Learn more about SmartSPC core components and advanced capabilities here.

Conclusion

Automated R2R control is an effective approach to the precision and yield challenges in semiconductor manufacturing. By leveraging real-time data and configurable control loops, SmartSPC helps manufacturers maintain tighter process control, reduce defects, and improve overall production efficiency.