In-situ Electrostatic Chuck Replacement Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrostatic chucks in semiconductor processing require removal from the processing chamber to replace, exposing the chamber to the external atmosphere and causing lengthy maintenance and downtime, due to mechanical latching mechanisms and thermal expansion issues.
Innovation Solution
An in-situ replaceable electrostatic chuck system using an attractive electrostatic force to detach and reattach the chuck, allowing for robotic replacement without exposing the chamber to the atmosphere, reducing mechanical complexity and downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical latching mechanism is used to hold the electrostatic chuck to the base, then the chuck can be securely fixed during processing, but the replacement process requires opening the chamber to external atmosphere causing lengthy maintenance downtime
Solution Approach 1:
The patent replaces the mechanical latching mechanism with an electrostatic attraction system. A lower electrode on the base and a corresponding electrode on the chuck create electrostatic forces that securely hold the chuck during processing. For replacement, the electrostatic attraction is simply turned off, allowing the chuck to be removed without mechanical manipulation and without requiring chamber opening, thus eliminating maintenance downtime while maintaining secure fixation during operation.
Solution Approach 2:
The electrostatic chuck system uses the electrostatic field itself to both secure the chuck during processing and enable its easy removal for replacement. By controlling the electrostatic attraction through electrode activation/deactivation, the system serves both functions (fixation and release) without requiring external mechanical intervention or chamber opening, making the replacement process self-contained within the vacuum environment.
2Reliability
If the electrostatic chuck is adhered to the base during processing, then secure holding is achieved, but thermal expansion differences cause warping during cool down requiring detachment
Solution Approach 1:
The patent implements a dynamic adherence system where the electrostatic attraction is activated during processing to secure the chuck, and deactivated during cool down to allow detachment. This dynamic control of the electrostatic field between the lower electrode and chuck electrode enables the system to adapt to different operational phases: firmly held during plasma processing, and freely detachable during thermal cooling to prevent warping from differential thermal expansion.
3Reliability
If mechanical pressing members are used to hold the electrostatic chuck, then the chuck can be prevented from floating, but the mechanical latching complexity increases and requires chamber opening for replacement
Solution Approach 1:
The patent eliminates mechanical pressing members and latching mechanisms entirely, replacing them with an electrostatic field-based holding system. The electrostatic attraction between the lower electrode on the base and the corresponding electrode on the chuck provides sufficient holding force to prevent floating during processing, while requiring no mechanical complexity for release or replacement. The system is controlled simply by activating or deactivating the electrostatic field through electrode power control.
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 rapid and reliable replacement of electrostatic chucks, minimizing process downtime and increasing operational reliability by using an electrostatic force for adherence, reducing mechanical interference and maintenance needs.
Implementation Method 1
a direct current (DC) voltage is applied to the first electrode, and an electrostatic attractive force is generated between the chuck main body and the substrate so as to hold the substrate in place during processing
Implementation Method 2
the chuck's main body and the base cool down at different rates so as to avoid warping the chuck when adhered to base during a cool down cycle
Data Source
AI summary
A substrate support for use in a reaction chamber includes a base, and an in-situ electrostatic chuck. The chuck includes a first electrode in an upper portion of the chuck that is configured to hold a wafer to an upper surface of the upper portion by a first electrostatic attractive force under a condition of a first voltage is applied to the first electrode, and a second electrode that opposes an upper surface of the base and is configured to hold the chuck to the base by a second electrostatic attractive force under a condition that a second voltage is applied to the second electrode. Under a condition that the second voltage is not supplied to the second electrode, the second electrostatic attractive force is not present and the chuck is freed to be replaced in-situ without also removing the base and without exposing the reaction chamber to external atmosphere.