Electrostatic Chuck Electrode Zoning for Wafer Etch Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrostatic chucks in plasma processing apparatuses cause process non-uniformities due to side-to-side etch rate variations resulting from the layout of electrodes, leading to deficiencies in temperature control and uniformity during semiconductor wafer processing.
Innovation Solution
The electrostatic chuck assembly features a radial layout of clamping electrodes divided into four thermally isolated zones with electrical connections across gaps, a thermal control system with radially arranged release apertures, and a sealing band with a specific width to enhance temperature control and durability, thereby improving process uniformity and reducing leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electrode layout is used in electrostatic chuck, then the chucking function is achieved, but side-to-side etch rate non-uniformity occurs
Solution Approach 1:
The electrode is divided into multiple independent electrode segments arranged in a radial pattern, allowing each segment to be independently controlled. This segmentation enables compensation for side-to-side etch rate non-uniformity by adjusting the voltage applied to different segments, thereby improving etch rate uniformity across the wafer surface.
Solution Approach 2:
Different electrode segments are assigned different voltages based on their radial positions to create localized electric field adjustments. This local quality approach allows targeted compensation for etch rate variations in different regions of the wafer, improving overall process uniformity while maintaining effective chucking.
2Temperature
If thermal control system is added to electrostatic chuck, then temperature control is improved, but device complexity increases
Solution Approach 1:
The thermal control system is merged with the electrostatic chuck structure by integrating heating elements and thermal management components directly into the chuck body. This combination allows temperature control functionality to be added without requiring separate independent systems, thereby improving temperature control while minimizing the increase in device complexity.
Solution Approach 2:
The electrostatic chuck is designed to perform multiple functions: electrostatic chucking, thermal control, and plasma generation. By making the chuck multi-functional, the patent avoids the need for separate dedicated systems for each function, thereby improving temperature control capability while keeping the overall system complexity manageable.
3Reliability
If sealing band with specific width is used, then heat exchange gas leakage is prevented, but manufacturing complexity increases
Solution Approach 1:
The sealing band width is optimized to specific parameter ranges (e.g., 0.5-2.0 mm) to achieve effective sealing of heat exchange gas. By defining specific width parameters, the patent ensures reliable sealing performance while maintaining manufacturability within standard manufacturing tolerances, balancing reliability with ease of manufacture.
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 effectively controls etch rate and chemical deposition uniformity, enhances temperature control in radial and azimuthal directions, and ensures the sealing band's durability to prevent heat exchange gas leakage, resulting in improved processing outcomes.
Implementation Method 1
The clamping electrodes are connected to a voltage source and are configured to generate electrostatic forces
Implementation Method 2
The heating electrodes are connected to a power source and are configured to generate resistive heating
Data Source
AI summary
An electrostatic chuck including a clamping layer having a first clamping electrode and a second clamping electrode is disclosed. A first clamping electrode defining a first clamping zone and a second clamping zone is provided. The first clamping zone and the second clamping zone are separated by a first gap and are electrically connected by at least one electrical connection extending across the first gap. A second clamping electrode disposed radially outward from the first clamping electrode. The second clamping electrode defining a third clamping zone and a fourth clamping zone that are separated by a second gap. The third clamping zone and the fourth clamping zone are electrically connected by at least one electrical connection extending across the second gap. Plasma processing apparatuses and systems incorporating the electrostatic chuck are also provided.