Electrostatic Chuck Leakage Current Reduction
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Solution Overview
Problem
Conventional substrate support systems in semiconductor manufacturing face challenges with high temperature operations and substrate-level plasma generation, leading to increased leakage currents and limited chucking windows, which can result in electric arcs and damage to substrates and chamber components.
Innovation Solution
The development of substrate support assemblies with an electrostatic chuck body featuring a heater and electrode, made from ceramic materials like aluminum nitride, which maintain low leakage currents and facilitate increased voltage chucking while supporting high-temperature operations and substrate-level plasma generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If substrate support systems operate at high temperatures and generate substrate-level plasma, then processing capabilities are improved, but leakage currents increase leading to electric arcs and damage
Solution Approach 1:
The substrate support system is divided into functionally independent segments: a plasma generation electrode, a heating element, and a substrate chucking surface. This segmentation allows each component to operate at optimized potentials and temperatures, reducing parasitic leakage currents while maintaining high-temperature plasma processing capabilities.
Solution Approach 2:
An intermediate insulating layer or coating is introduced between conductive components and the plasma environment. This intermediary layer acts as a barrier that reduces leakage current generation while allowing thermal energy and plasma to perform their processing functions, thereby preventing electric arcs and component damage.
2Force
If voltage is increased to extend chucking window, then substrate holding capability is improved, but leakage currents increase causing arcs and damage
Solution Approach 1:
The electrical parameters of the substrate support system are optimized by using materials with temperature-dependent resistivity characteristics. The system operates at elevated temperatures where the bulk material exhibits higher resistivity, naturally reducing leakage currents even at increased chucking voltages, thereby extending the usable chucking window without causing arcs.
Solution Approach 2:
The substrate support employs composite material construction combining conductive elements for chucking with high-resistivity ceramic or coated regions. This composite structure allows high voltage application for substrate holding while the high-resistivity portions minimize leakage current paths, preventing electric arcs and damage to substrates and chamber components.
3Ease of manufacture
If conventional materials are used in substrate support, then manufacturing is simpler, but high-temperature operations cause increased leakage currents
Solution Approach 1:
The material selection focuses on substances whose electrical resistivity increases with temperature in the operating range. This parameter change ensures that as the substrate support reaches high operating temperatures, the material naturally becomes more resistive, reducing leakage currents and improving reliability without complex manufacturing processes.
Solution Approach 2:
The substrate support uses composite material construction combining conductive elements for chucking with high-resistivity ceramic or coated regions. This composite structure allows high voltage application for substrate holding while the high-resistivity portions minimize leakage current paths, preventing electric arcs and damage to substrates and chamber components.
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
These assemblies reduce leakage currents and extend the voltage chucking window, preventing arcing and ensuring sustainable high-temperature operations, thereby improving the quality and uniformity of semiconductor device production.
Implementation Method 1
Internally located heating devices may generate heat within the support, and the heat may be transferred conductively to the substrate
Implementation Method 2
The assembly may include an electrostatic chuck body defining a substrate support surface... an electrode embedded within the electrostatic chuck body
Implementation Method 3
The ceramic material may be characterized by a volumetric resistivity of greater than or about 1×10^9 ohm-cm at a temperature of greater than or about 550° C.
Data Source
AI summary
Exemplary support assemblies may include an electrostatic chuck body defining a substrate support surface. The assemblies may include a support stem coupled with the electrostatic chuck body. The assemblies may include a heater embedded within the electrostatic chuck body. The assemblies may also include an electrode embedded within the electrostatic chuck body between the heater and the substrate support surface. The substrate support assemblies may be characterized by a leakage current through the electrostatic chuck body of less than or about 4 mA at a temperature of greater than or about 500° C. and a voltage of greater than or about 600 V.