Electrostatic Chuck Voltage Control Using Substrate Warpage Sensing
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Solution Overview
Problem
Existing methods fail to quantitatively measure the adsorption force of substrates in substrate processing apparatuses, which affects the efficiency and reliability of substrate handling.
Innovation Solution
A substrate processing apparatus equipped with a sensor on a transfer arm to measure distances to the substrate and a reference surface before and after adsorption, calculating differences in warpage amount to quantify the adsorption force and adjust the direct-current voltage accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensor measures distance to the substrate and reference surface before and after adsorption, then adsorption force can be quantified, but device complexity increases
Solution Approach 1:
The patent replaces direct mechanical force measurement with an optical measurement system. A sensor measures the distance between the substrate and reference surface before and after adsorption, and the control device calculates adsorption force based on the change in distance (warpage amount). This substitutes a complex mechanical force sensor with a simpler optical distance measurement system, achieving quantitative adsorption force measurement while managing device complexity.
2Stability of the object's composition
If direct-current voltage is adjusted based on warpage amount, then substrate handling stability improves, but control system complexity increases
Solution Approach 1:
The control device implements a feedback control mechanism where it continuously monitors the warpage amount (change in distance between substrate and reference surface) and adjusts the direct-current voltage applied to the electrostatic chuck accordingly. When warpage exceeds a threshold, the system increases voltage to improve adsorption force, thereby maintaining substrate handling stability through dynamic feedback adjustment.
3Duration of action of stationary object
If electrostatic chucking is optimized by monitoring warpage, then component lifespan extends, but measurement and control requirements increase
Solution Approach 1:
The patent introduces a reference surface as an intermediary element to facilitate warpage measurement. Instead of directly measuring substrate deformation, the sensor measures the distance between the substrate and the reference surface. The reference surface provides a stable measurement baseline, making it easier to detect and quantify warpage amount, thereby enabling optimized electrostatic chucking that extends component lifespan.
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
Enables precise quantification of adsorption force, ensuring stable substrate handling and extending the lifespan of consumable components by optimizing electrostatic chucking.
Implementation Method 1
a substrate support disposed in the chamber and including an electrostatic chuck that includes an electrostatic electrode and a substrate support surface, the substrate support being configured to electrostatically adsorb the substrate to the substrate support surface by applying a direct-current voltage to the electrostatic electrode
Data Source
AI summary
A substrate processing apparatus includes a substrate support including an electrostatic chuck, a transfer arm that transfers the substrate into the chamber, a sensor disposed at the transfer arm and measures a distance from the sensor to the substrate and a distance from the sensor to a reference surface set at the substrate support, and processing circuitry that acquires a first distance from the sensor to the substrate and a second distance from the sensor to the reference surface before adsorption and controls the direct-current voltage to be applied to the electrostatic electrode based on the amount of change in the warpage amount of the substrate.