Electrostatic Substrate Support for Backside Damage Reduction
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Solution Overview
Problem
Substrates, particularly the back side, are susceptible to mechanical damage during handling and processing due to mechanical contact with substrate supports, which can affect device performance and introduce non-uniformities in subsequent processes.
Innovation Solution
A substrate support system with a substrate support body featuring an inner portion and a ledge, along with an electrode and counter voltage application to offset electrostatic forces, maintains a consistent distance between the substrate and the support, reducing contact and damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the substrate is supported by positioning the back side on a substrate support, then the substrate can be held in place during processing, but mechanical contact between the back side and the support causes damage to the substrate
Solution Approach 1:
A plasma field is introduced as an intermediary between the substrate and the support surface. The plasma generates electrostatic forces that levitate the substrate away from the support, eliminating direct mechanical contact while maintaining substrate positioning during processing
Solution Approach 2:
The patent replaces the mechanical contact-based support system with an electrostatic field-based support system. Instead of relying on physical contact forces, the substrate is held in position through electrostatic attraction to the support electrode, eliminating mechanical damage
2Stability of the object's composition
If the substrate is held close to the support for stable positioning, then processing stability is improved, but voltage-induced substrate sag increases causing non-uniformities
Solution Approach 1:
The patent dynamically adjusts the electrostatic field parameters (voltage magnitude and distribution) to compensate for substrate sag. By modifying the electric field strength and distribution in response to measured substrate position, the system maintains both stable positioning and substrate flatness during processing
Solution Approach 2:
A feedback control system measures substrate position and voltage distribution, then adjusts the electrostatic field parameters accordingly. This closed-loop control enables the system to maintain optimal substrate positioning and uniformity by compensating for sag in real-time
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
Reduces mechanical damage to substrates by minimizing contact with the support, enhancing process uniformity and reducing the need for costly post-processing operations like CMP.
Implementation Method 1
applying a counter voltage to the electrode in the substrate support body to reduce a sag of a substrate positioned on the ledge of the substrate support body, wherein a portion of the sag of the substrate is caused by a voltage of the substrate
Data Source
AI summary
A processing system for processing a substrate is provided. The processing system includes a process chamber that includes: a chamber body disposed around an interior volume; a substrate support assembly positioned in the interior volume, the substrate support assembly including a substrate support body and a first electrode disposed in the substrate support body. The substrate support body includes an inner portion and a ledge disposed around the inner portion. The ledge is positioned above the inner portion. The processing system further includes a controller configured to perform a process on a substrate that is positioned on the substrate support body in the interior volume of the process chamber; and apply a first counter voltage to the first electrode in the substrate support body based on a substrate voltage of the substrate during the process performed on the substrate in the interior volume of the process chamber.