Electrostatic Chuck Dielectric Embedding for Gap Spacing Control
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Solution Overview
Problem
Conventional electrostatic holding apparatuses for semiconductor wafers face challenges such as variations in gap spacing, mechanical weakness due to soft dielectric materials, and complex manufacturing processes, leading to inconsistent clamping pressure and reduced durability.
Innovation Solution
An electrostatic holding apparatus with a base body of ceramic material and an electrode device featuring a dielectric layer made of inorganic dielectric materials, where the dielectric layer is partially embedded into the insulating layer to set a precise gap spacing, and a curable plastic insulating layer for enhanced mechanical strength and chemical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a dielectric layer made of soft material (e.g., glass) is used, then the manufacturing process is simpler, but the mechanical strength and wear resistance of the burls are reduced
Solution Approach 1:
The patent applies composite materials by combining a hard base body material (e.g., SiSiC ceramic) with a softer dielectric layer material (e.g., glass). The base body provides mechanical strength and wear resistance, while the dielectric layer provides the necessary electrical insulation and electrostatic clamping function. This composite structure resolves the contradiction by allowing each material to contribute its superior properties to the overall system.
2Ease of manufacture
If adhesive is used to bond the dielectric layer to the base body, then the manufacturing process is simplified, but the position stability of the burls and evenness of the clamp support surface deteriorate due to adhesive shrinkage or ageing
Solution Approach 1:
The patent extracts and eliminates the adhesive bonding step from the manufacturing process. Instead of using adhesive to bond the dielectric layer to the base body, the dielectric layer is directly formed on the base body surface through deposition or other bonding methods that do not involve shrinkable adhesive materials. This removal of the adhesive layer prevents the shrinkage and ageing problems that would otherwise compromise burl position stability and support surface evenness.
3Reliability
If a complex multi-layer construction is used, then the electrostatic clamping pressure can be optimized, but the manufacturing time and costs increase significantly
Solution Approach 1:
The patent segments the electrostatic clamping apparatus into functionally independent components: a base body with burls, a dielectric layer, and an electrode layer. Each component can be manufactured separately with optimized processes and then assembled. This segmentation allows for parallel manufacturing of components, reducing overall manufacturing time while maintaining the necessary functional complexity for optimized electrostatic clamping pressure.
4Stress or pressure
If the gap spacing is reduced to achieve high clamping pressure, then the electrostatic clamping pressure increases, but the manufacturing precision requirements and susceptibility to variations increase
Solution Approach 1:
The patent applies preliminary action by pre-forming the dielectric layer with a controlled thickness that establishes the gap spacing before the electrode layer is applied. The dielectric layer thickness is precisely controlled during its formation process (e.g., through deposition techniques), and this pre-established thickness determines the final gap spacing. This preliminary formation of the dielectric layer with controlled thickness allows for high clamping pressure while managing manufacturing precision requirements through controlled material deposition rather than post-assembly adjustments.
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 provides a stable and homogeneous clamping pressure, improved durability, and simplified production with reduced manufacturing costs and time, while preventing fluctuations in gap spacing and enhancing chemical and physical resistance.
Implementation Method 1
an electrode device to generate an electrostatic holding force
Implementation Method 2
the dielectric properties of the material composition in this spacing
Data Source
AI summary
Holding apparatus 100 for electrostatic holding of component 1, in particular a silicon wafer, includes plate-type base body 10 with plurality of projecting burls 11, the front surfaces 12 of which span a burl support plane for component 1, and electrode device 20 arranged in layered form in spacings between burls 11 and has plastic insulating layer 21 connected with base body 10, electrode layer 22 and dielectric layer 23, whereby electrode layer 22 is arranged between insulating layer 21 and dielectric layer 23, whereby a predetermined gap spacing A is set between the burl support plane and a top side of dielectric layer 23, and dielectric layer 23 includes an inorganic dielectric and is embedded at least in part into insulating layer 21. Methods for producing holding apparatus 100 for electrostatic holding of component 1, in particular a silicon wafer, are also described.