Substrate Support Thermal Uniformity via Layer Thickness Variation
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Solution Overview
Problem
Substrate processing systems face challenges in achieving uniform substrate temperatures due to non-uniform heat dissipation, leading to temperature variations across the substrate, which can affect processing outcomes.
Innovation Solution
The substrate support system is designed with a baseplate, spray coat layer, bond layer, and ceramic layer, where the thickness and thermal conductivity of these components vary in radial and azimuthal directions to optimize thermal conductivity and introduce intentional thermal non-uniformities, complemented by coolant channels and heat transfer gas management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If uniform thickness and thermal conductivity are used in the substrate support layers, then the structure is simple and easy to manufacture, but temperature uniformity across the substrate deteriorates due to non-uniform heat dissipation
Solution Approach 1:
The patent applies local quality by making the spray coat layer and bond layer have spatially varying thicknesses. The spray coat layer has a first thickness in a first region and a second thickness in a second region, while the bond layer has a third thickness in the first region and a fourth thickness in the second region. This non-uniform thickness distribution creates intentional thermal non-uniformities that compensate for non-uniform heat dissipation, achieving uniform substrate temperature across different operational conditions.
Solution Approach 2:
The patent changes physical parameters (thickness and thermal conductivity) of the spray coat and bond layers to optimize thermal performance. By varying the thickness parameters of these layers in different regions, the system achieves uniform temperature distribution across the substrate while maintaining structural integrity and manufacturability.
2Ease of manufacture
If the substrate support structure is simplified, then manufacturing is easier, but the ability to control temperature uniformity deteriorates
Solution Approach 1:
The patent maintains relative manufacturing simplicity while achieving temperature uniformity through local quality variations. The spray coat and bond layers are applied with different thicknesses in different regions, but this can be accomplished through conventional manufacturing techniques such as selective deposition or lamination, avoiding the need for completely complex multi-component structures.
Solution Approach 2:
The patent uses a composite structure consisting of multiple layers (spray coat layer and bond layer) with different thermal properties. This composite approach allows each layer to contribute differently to the overall thermal management, with the spray coat layer providing one thermal pathway and the bond layer providing another, enabling temperature uniformity control while maintaining manufacturability.
3Stability of the object's composition
If intentional thermal non-uniformities are introduced in the support layers, then temperature uniformity across the substrate is improved, but the device complexity increases
Solution Approach 1:
The patent introduces intentional thermal non-uniformities through local quality variations in the spray coat and bond layers. By controlling the thickness of these layers in different regions (first region vs. second region), the system creates specific thermal pathways that compensate for non-uniform heat dissipation from the substrate, achieving uniform temperature distribution without requiring complex active control systems.
Solution Approach 2:
The patent converts the harmful effect of non-uniform heat dissipation into a benefit by intentionally designing non-uniform thermal conductance in the support layers. The non-uniform thickness distribution of the spray coat and bond layers creates thermal non-uniformities that exactly compensate for the non-uniform heat generation, transforming a potential problem into a solution.
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
This configuration achieves desired temperature uniformities across the substrate, reducing variations to less than 1°C, thereby improving processing consistency and reducing thermal non-uniformities caused by plasma and ion flux.
Implementation Method 1
The spray coat layer has a first thickness and a first thermal conductivity. A bond layer is arranged on the spray coat layer. The bond layer has a second thickness and a second thermal conductivity.
Implementation Method 2
The substrate support may include a plurality of channels to provide a heat transfer gas (e.g., helium) to a backside of the substrate arranged on the ceramic layer. The heat transfer gas facilitates cooling of the substrate and/or the ceramic layer.
Data Source
AI summary
A substrate support for a substrate processing system includes a baseplate and a spray coat layer arranged on the baseplate. The spray coat layer has a first thickness and a first thermal conductivity. A bond layer is arranged on the spray coat layer. The bond layer has a second thickness and a second thermal conductivity. A ceramic layer is arranged on the bond layer. At least one of the first thickness and the second thickness varies in at least one of a radial direction and an azimuthal direction such that a third thermal conductivity between the ceramic layer and the baseplate varies in the at least one of the radial direction and the azimuthal direction.