ESC Gasket Design for High Power Plasma Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electrostatic chuck (ESC) designs fail to withstand high power and high bias voltages used in high aspect ratio plasma etching processes, leading to bond failures and plasma ignition due to dielectric breakdown and excessive surface temperature changes.
Innovation Solution
The ESC design incorporates a side wall bonding layer protection O-ring or metal gasket that fills over 90% of the pocket with a 12% compression, reducing gas discharge and preventing corrosion, while also conducting accumulated charge away from the bonding layer, thus enhancing the seal and reducing arcing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high power and high bias voltage are applied to achieve high aspect ratio plasma etching, then etching performance is improved, but dielectric breakdown and bond failures occur
Solution Approach 1:
A bonding layer is introduced as an intermediary between the electrostatic chuck and the dielectric puck. This bonding layer acts as a protective mediator that prevents direct exposure of the adhesive bond to high power plasma, thereby preventing bond failures while maintaining the high power etching process
Solution Approach 2:
The bonding layer is designed as a sacrificial protective element that can be replaced. It absorbs the damage from plasma exposure and high power conditions, protecting the more critical and expensive components (electrostatic chuck and dielectric puck) from degradation
2Productivity
If high power plasma is applied to achieve high aspect ratio etching, then etching capability is improved, but plasma ignition in holes and openings occurs
Solution Approach 1:
Holes and openings are removed from the electrostatic chuck design. The electrostatic chuck is designed without holes or openings that could trap plasma, thereby eliminating the source of plasma ignition problems while maintaining the ability to apply high power plasma for etching
Solution Approach 2:
The design converts the potential harm of plasma trapping by eliminating holes and openings. By creating a solid, hole-free surface, the design prevents plasma ignition issues that would otherwise occur in cavities, turning a design constraint into a solution
3Productivity
If high bias power is applied to support high aspect ratio plasma etching, then etching performance is improved, but ESC surface temperature changes at higher rate
Solution Approach 1:
The system is segmented into distinct functional layers: the electrostatic chuck, the bonding layer, and the dielectric puck. This segmentation allows the dielectric puck to serve as a thermal buffer that absorbs and distributes heat, reducing surface temperature fluctuations while maintaining high bias power for plasma etching
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
The design effectively protects the bonding layer from plasma damage, reduces arcing, and maintains a secure seal, enabling the ESC to operate reliably under high power and high bias conditions.
Implementation Method 1
a gasket between the mounting ring and the plate, the gasket configured to protect the adhesive
Implementation Method 2
Common processes use an ESC to hold a wafer with 2 MHz 6.5 KW plasma power applied to the wafer for etching applications
Implementation Method 3
In these manufacturing processes, plasma may be used for depositing or etching various material layers
Implementation Method 4
the pedestal may include an embedded heater adapted to control the temperature of the substrate and/or provide elevated temperatures
Data Source
AI summary
A workpiece carrier suitable for high power processes is described. It may include a puck to carry the workpiece, a plate bonded to the puck by an adhesive, a mounting ring surrounding the puck and the cooling plate, and a gasket between the mounting ring and the plate, the gasket configured to protect the adhesive.