Electrostatic Chuck Electrode Layout for Etch Uniformity
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Solution Overview
Problem
Existing electrostatic chucks in plasma processing apparatuses cause process non-uniformities due to the layout of electrodes, leading to side-to-side etch rate non-uniformity patterns.
Innovation Solution
A unique radial layout for the chucking electrodes with thermally isolated and electrically connected zones, along with a thermal control system and a sealing band, to improve process uniformity and temperature control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electrode layout is used in electrostatic chuck, then device complexity is reduced, but process uniformity deteriorates due to side-to-side etch rate non-uniformity patterns
Solution Approach 1:
The electrostatic chuck is divided into multiple independently controllable electrode zones (e.g., first, second, third, and fourth zones) arranged in a specific pattern. Each zone can be controlled separately to compensate for non-uniformities, thereby improving process uniformity without requiring complete redesign of the entire electrode system.
Solution Approach 2:
Different electrode zones are assigned different control parameters and potentials to address local non-uniformities in specific regions of the workpiece. This allows tailored control of etch rates in different zones, improving overall process uniformity while maintaining manageable device complexity through localized adjustments.
2Temperature
If thermally isolated zones are implemented, then temperature control is improved, but device complexity increases
Solution Approach 1:
The thermal control system is segmented into multiple thermally isolated zones that correspond to the electrode zones. Each thermal zone can be independently controlled to maintain uniform temperature distribution across the workpiece, preventing thermal non-uniformities that would otherwise degrade process quality.
Solution Approach 2:
The thermal control zones are merged with the electrode zones in a coordinated manner, where each electrode zone has its corresponding thermal control zone. This integration allows simultaneous control of both electrical and thermal parameters in each region, improving overall process uniformity while utilizing shared structural elements.
3Reliability
If sealing band with sufficient width is used, then reliability is improved by preventing gas leakage, but device complexity increases
Solution Approach 1:
The sealing band is designed with specific width requirements (e.g., at least 0.05 inches) to ensure adequate sealing effectiveness in critical regions. This localized specification ensures reliability where needed while avoiding unnecessary complexity in non-critical areas, balancing sealing performance with device simplicity.
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 solution achieves improved process uniformity by allowing independent control of each thermally isolated zone, enhancing temperature control in both radial and azimuthal directions, and ensuring the sealing band's durability to prevent gas leakage.
Implementation Method 1
an electrostatic chuck including a workpiece support surface configured to support a workpiece during processing of the workpiece
Implementation Method 2
a thermal control system
Data Source
AI summary
An electrostatic chuck including a workpiece support surface, clamping layer, heating layer, thermal control system, and sealing band is disclosed. The sealing band surrounds an outer perimeter of the electrostatic chuck including at least a portion of the workpiece surface. The sealing band has a width greater than about 3 millimeters (mm) up to about 10 mm. Plasma processing apparatuses and systems incorporating the electrostatic chuck are also provided.