Composite Ceramic Electrostatic Chuck for High-Temperature Resistivity
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Solution Overview
Problem
Conventional substrate support assemblies experience issues with resistivity reduction at high temperatures, leading to increased current leakage and arcing, which limits the chucking window and affects the quality of semiconductor processing, especially at temperatures above 650°C.
Innovation Solution
The use of composite ceramic materials with a base dielectric material and a second dielectric material having higher resistivity, evenly distributed to create a non-linear electrical conduction path, maintaining resistivity above 1×10^8 Ω-cm even at high temperatures, thereby reducing arcing and enabling stable chucking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dielectric materials are used in substrate support assemblies, then the assembly can provide basic electrostatic chucking function, but the resistivity degrades at high temperatures leading to increased current leakage and arcing
Solution Approach 1:
The patent applies composite materials by combining aluminum nitride (AlN) base dielectric material with boron nitride (BN) particles to create a composite ceramic material. This composite structure maintains high resistivity at elevated temperatures because the boron nitride particles distributed throughout the aluminum nitride matrix provide thermal stability and prevent the resistivity degradation that occurs in conventional single-material dielectrics when exposed to high temperatures during semiconductor processing
Solution Approach 2:
The patent applies parameter changes by modifying the electrical resistivity parameter of the dielectric material through composite formulation. By controlling the concentration of boron nitride particles (0.1 wt.% to 30 wt.% based upon the weight of base dielectric material and second dielectric material) and their distribution (greater than or about 50% of average concentration at any given point), the material achieves tunable resistivity that remains stable at high temperatures, directly addressing the resistivity degradation issue
2Reliability
If higher clamping pressures are applied to improve substrate contact, then chucking reliability improves, but voltage requirements increase and arcing risk increases
Solution Approach 1:
The patent applies parameter changes by utilizing the resistivity-stable composite material to enable operation at lower voltages. Because the aluminum nitride with boron nitride particles maintains consistent resistivity at high temperatures, the electrostatic chucking system can achieve reliable substrate contact and clamping without requiring high voltages that would increase arcing risk. The material's inherent electrical properties allow for optimized clamping pressure application
3Adaptability or versatility
If the substrate support is used for both heat generation and plasma generation, then operational versatility is improved, but interference effects and parasitic plasma formation occur
Solution Approach 1:
The patent applies composite materials to reduce parasitic plasma formation. The aluminum nitride with boron nitride particle composite provides controlled electrical properties that minimize unwanted plasma generation in the chamber. The specific composition and distribution of the composite material create more uniform electrical fields, reducing the interference effects and parasitic plasma that occur when the substrate support is used for both heating and plasma generation functions
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 composite ceramic materials provide stable resistivity and chucking capabilities at temperatures up to 700°C, allowing for higher clamping pressures and reduced arcing, thus improving the quality and reliability of semiconductor processing.
Implementation Method 1
the substrate support surface exhibits a resistivity of 1×10^8 Ω-cm to 1×10^11 Ω-cm at a temperature of greater than 600° C.
Implementation Method 2
maintains resistivity above 1×10^8 Ω-cm even at temperatures greater than 650°C
Implementation Method 3
The substrate support may also be utilized in some technologies to develop a substrate-level plasma
Implementation Method 4
Internally located heating devices may generate heat within the support, and the heat may be transferred conductively to the substrate
Data Source
AI summary
Substrate support assembly and methods of making such substrate support assemblies are provided. Substrate support assemblies include an electrostatic chuck body defining a substrate support surface, a support stem coupled with the electrostatic chuck body, and an electrode embedded within the electrostatic chuck body. Substrate support surfaces exhibit a resistivity of 1×108 Ω-cm to 1×1011 Ω-cm at a temperature of greater than 650° C. Substrate support surfaces can include a composite ceramic material having a base dielectric material and a second dielectric material having an electrical resistivity at least about two times higher than an electrical resistivity of the base dielectric material at a temperature of greater than 650° C.