Dielectric Multilayer Coating for Electrostatic Chuck Erosion Resistance
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Solution Overview
Problem
Electrostatic chucks in semiconductor manufacturing face issues with leakage current, variable electrostatic attraction force, and difficulty in de-chucking, as well as insufficient resistance to erosive and corrosive conditions such as plasma environments.
Innovation Solution
A dielectric multilayer comprising an undercoat metal oxide or nitride layer and a topcoat metal oxide layer with an aluminum oxide content of less than 1 weight percent, where the topcoat layer provides enhanced corrosion and plasma erosion resistance, and the undercoat layer has higher resistivity and porosity than the topcoat layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-layer dielectric coating is used on the electrostatic chuck, then the manufacturing process is simple, but the resistance to plasma erosion and corrosion is insufficient
Solution Approach 1:
The patent applies a two-layer composite dielectric coating structure where the first layer provides plasma erosion resistance and the second layer provides corrosion resistance. This composite structure resolves the contradiction by combining the benefits of multiple materials to simultaneously achieve high reliability against plasma erosion and corrosion while maintaining manufacturing feasibility through sequential coating processes.
2Ease of operation
If the dielectric layer has high porosity to allow charge migration, then Johnsen-Rahbek attraction is enabled, but current leakage through the body increases
Solution Approach 1:
The patent applies different dielectric layers with different properties at different locations/levels of the chuck structure. The first dielectric layer has higher porosity to enable charge migration for Johnsen-Rahbek attraction, while the second dielectric layer has lower porosity to reduce current leakage. This local differentiation of material properties resolves the contradiction between enabling electrostatic attraction and minimizing energy loss.
3Productivity
If the electrostatic chuck operates in plasma environment, then substrate processing is enabled, but current leakage through the chuck body increases due to plasma providing current path
Solution Approach 1:
The patent uses a two-layer dielectric coating where the first layer enables plasma interaction for substrate processing while the second layer acts as a barrier to prevent current leakage through the chuck body. This composite structure allows the chuck to operate effectively in plasma environments by separating the functions of plasma interaction and current blocking.
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 minimizes current leakage, stabilizes electrostatic attraction force, facilitates de-chucking, and enhances resistance to corrosive and erosive conditions, reducing substrate damage and improving processing reliability in harsh environments.
Implementation Method 1
the undercoat dielectric layer has a resistivity greater than the resistivity of the topcoat dielectric layer
Implementation Method 2
the topcoat dielectric layer has a corrosion resistance and/or plasma erosion resistance greater than the corrosion resistance and/or plasma erosion resistance of the undercoat dielectric layer
Implementation Method 3
The attractive force is commonly generated through either a Coulombic or a Johnsen-Rahbek effect
Implementation Method 4
The insulating properties of the body maintain a capacitive circuit (i.e., charge separation) between the electrodes and the substrate
Implementation Method 5
Electrostatic chucks utilizing Johnsen-Rahbek attraction have electrodes disposed in bodies having lower resistivities which allow charge migration through the body when power is applied to the electrodes
Data Source
AI summary
This invention relates to substrate supports, e.g., coated electrostatic chucks, having a dielectric multilayer formed thereon; dielectric multilayers that provide erosive and corrosive barrier protection in harsh environments such as plasma treating vessels used in semiconductor device manufacture; process chambers, e.g., deposition chambers, for processing substrates; methods for protecting substrate supports; and methods for producing substrate supports and electronic devices. The dielectric multilayer comprises (a) an undercoat dielectric layer comprising a metal oxide or metal nitride formed on a surface; and (b) a topcoat dielectric layer comprising a metal oxide formed on the undercoat dielectric layer. The topcoat dielectric layer has an aluminum oxide content of less than about 1 weight percent. The topcoat dielectric layer has a corrosion resistance and/or plasma erosion resistance greater than the corrosion resistance and/or plasma erosion resistance of the undercoat dielectric layer. The undercoat dielectric layer can have a resistivity greater than the resistivity of the topcoat dielectric layer. The topcoat dielectric layer can have a dielectric constant greater than the dielectric constant of the undercoat dielectric layer. The undercoat dielectric layer can have a porosity greater than the porosity of the topcoat dielectric layer. The invention is useful, for example, in the manufacture and protection of electrostatic chucks used in semiconductor device manufacture.