Electrostatic Chuck Inner Plate Segmentation for Etch Uniformity
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Solution Overview
Problem
Current semiconductor fabrication processes face challenges in achieving uniform etch quality due to variations in electric field intensity across the substrate during plasma etching, leading to inconsistent substrate processing.
Innovation Solution
An electrostatic chuck design featuring a chuck base, an upper plate, and an inner plate with specific diameter and thickness configurations, along with dielectric rings, is used to control the electric field intensity uniformly across the substrate, enhancing etch uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional electrostatic chuck without an inner plate is used, then the structure is simple, but the electric field intensity varies across the substrate leading to poor etch uniformity
Solution Approach 1:
The electrostatic chuck is segmented into multiple functional plates: an upper plate, an inner plate with smaller diameter, and a chuck base. This segmentation allows different regions to serve different purposes - the inner plate specifically addresses the electric field uniformity problem in the central region while the overall structure maintains electrostatic clamping functionality.
Solution Approach 2:
The inner plate is strategically positioned in the central region where electric field uniformity is most critical for etch quality. By adding this localized component with specific diameter and thickness parameters, the patent improves electric field distribution in the problematic area without unnecessarily complicating the entire chuck structure.
2Manufacturing precision
If the inner plate diameter is increased to cover more substrate area, then electric field uniformity improves, but the risk of arcing between the inner plate and upper plate increases
Solution Approach 1:
The patent optimizes the inner plate diameter to be smaller than the upper plate diameter, creating a specific geometric parameter relationship. This parameter configuration ensures that the inner plate provides sufficient electric field uniformity improvement while maintaining safe clearance to prevent arcing between the inner plate and upper plate during plasma processing.
3Manufacturing precision
If a thicker inner plate is used to improve electric field control, then etch uniformity increases, but the overall chuck height and complexity increase
Solution Approach 1:
The patent specifies optimal thickness parameters for the inner plate that balance electric field control capability with compact overall dimensions. The thickness is sufficient to provide the necessary electric field uniformity improvement but constrained to avoid excessive chuck height increase that would complicate the overall apparatus design.
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 controlled electric field intensity results in improved etch uniformity and increased substrate processing consistency, optimizing the plasma processing apparatus for semiconductor fabrication.
Implementation Method 1
The electrostatic chuck may generate an electrostatic force between the substrate and an electrode based on a voltage applied to the electrode to support the substrate
Implementation Method 2
the etching process may include a dry etching process in which a plasma reaction is used
Data Source
AI summary
Electrostatic chucks, plasma processing apparatuses, and methods of fabricating semiconductor devices using the same are provided. The electrostatic chuck includes a chuck base, an upper plate provided on the chuck base, and an inner plate provided between the chuck base and the upper plate. A first diameter of the inner plate is less than a second diameter of the upper plate.