Substrate Support Feedback Control for Wafer Clamping Stress
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Solution Overview
Problem
In semiconductor manufacturing, conventional substrate supports often apply excessive clamping forces due to manufacturing variances, leading to workpiece damage, inconsistent yields, and quality issues, as they struggle to maintain a consistent and predictable clamping force.
Innovation Solution
A substrate support with a sensor assembly that detects workpiece deflection and adjusts the clamping force in real-time, using a sensor housed within a gas hole or lift pin to ensure minimal excess deflection and prevent over-chucking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional substrate supports increase clamping force to provide a factor of safety against manufacturing variances, then reliability of workpiece holding is improved, but workpiece damage and film stress increase
Solution Approach 1:
The patent employs a sensor assembly that provides real-time feedback on workpiece deflection during clamping. This feedback loop enables the system to monitor actual workpiece conditions and adjust clamping force dynamically, replacing the conventional open-loop approach that relies on predetermined safety factors. The sensor assembly measures deflection metrics and communicates this information to a control system that modulates the clamping force accordingly, ensuring reliable workpiece holding without excessive force that causes damage.
Solution Approach 2:
The patent transitions from a static clamping force approach to a dynamic adjustment mechanism. The clamping force is no longer fixed but varies in real-time based on sensor feedback regarding workpiece deflection. This dynamic system allows the substrate support to adapt to manufacturing variances and workpiece-specific conditions, applying only the necessary force to maintain reliability without causing damage through excessive static clamping.
2Stability of the object's composition
If conventional substrate supports apply higher clamping force to counter manufacturing variances, then workpiece holding stability is improved, but manufacturing precision deteriorates due to over-chucking
Solution Approach 1:
The sensor assembly provides continuous feedback on workpiece deflection, enabling the control system to maintain optimal clamping force that ensures holding stability without exceeding thresholds that would compromise manufacturing precision. This closed-loop control prevents over-chucking by dynamically adjusting force based on actual workpiece response rather than relying on conservative over-clamping.
Solution Approach 2:
The system dynamically changes the clamping force parameter based on real-time sensor data regarding workpiece deflection. Rather than maintaining a fixed high clamping force to ensure stability, the system adjusts the force parameter within an optimal range that maintains holding stability while preventing the excessive force conditions that lead to manufacturing defects such as craters, embedded parts, and particulate generation.
3Manufacturing precision
If substrate support uses sensor assembly to detect workpiece deflection, then manufacturing precision is improved by preventing over-chucking, but device complexity increases
Solution Approach 1:
The sensor assembly is integrated into the existing substrate support structure, allowing it to serve multiple functions: detecting workpiece deflection, providing feedback for clamping force control, and potentially monitoring other process parameters. This multi-functionality approach minimizes the addition of separate dedicated components, thereby reducing the overall complexity increase while achieving improved clamping force consistency and manufacturing precision.
4Measurement precision
If conventional substrate supports use electrical potential measurement to compensate for workpiece effects, then clamping force prediction is improved, but reliability deteriorates due to persistent over-chucking
Solution Approach 1:
The patent implements a feedback-based control system that uses real-time deflection measurements from the sensor assembly to actively adjust clamping force. This replaces the conventional open-loop electrical potential measurement approach that attempted to predict and compensate for workpiece effects through algorithms. The feedback mechanism directly monitors actual workpiece response and dynamically adjusts force, providing reliable workpiece protection by preventing over-chucking rather than merely predicting it.
Solution Approach 2:
The system replaces the conventional electrical potential measurement and algorithmic compensation approach with a direct mechanical deflection measurement using the sensor assembly. This substitution provides more direct and reliable information about actual workpiece conditions, enabling more effective protection against over-chucking by basing control decisions on direct mechanical response rather than electrical potential inference.
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 solution effectively reduces workpiece damage and film stress by maintaining a consistent clamping force, improving yield consistency and reducing defects in semiconductor manufacturing.
Implementation Method 1
A sensor assembly is disposed in the gas hole and configured to detect a metric indicative of a deflection of a workpiece disposed on the workpiece support surface
Data Source
AI summary
Embodiments disclosed herein include a substrate support having a sensor assembly, and processing chamber having the same. In one embodiment, a substrate support assembly has a puck having a workpiece support surface, a gas hole formed through the workpiece support surface, and a sensor assembly disposed in the gas hole. The substrate support assembly further has a transition conduit fluidly coupled to the gas hole, and a connection coupled to the transition conduit. The connection has a first opening fluidly coupled to the transition conduit and a second opening coupled to a control system, where the control system is coupled to the sensor assembly.