Cooled Substrate Support Assembly for Cryogenic RF Arcing Control
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Solution Overview
Problem
Existing substrate support assemblies for cryogenic temperature processing in semiconductor manufacturing face challenges such as charge buildup leading to arcing and coolant leakage due to thermal expansion and contraction, which can cause processing errors and device damage.
Innovation Solution
The substrate support assembly incorporates fluid conduits configured to reduce arcing, featuring a facility plate, ground plate, and a connector with a biasing assembly and fastener in a pocket, along with a sliding seal to maintain vacuum and prevent refrigerant leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulative conduits are used to route coolant through grounded and powered portions of the substrate support assembly, then electrical shorting is prevented, but charge buildup occurs over time causing arcing between the conduit and grounded portions
Solution Approach 1:
A biased connector assembly acts as an intermediary between the insulative conduit and the substrate support assembly. The connector includes a biased member that maintains electrical isolation while providing a controlled path for charge dissipation, preventing charge buildup on the conduit surface that would otherwise lead to arcing.
Solution Approach 2:
The patent replaces the simple insulative conduit with a more complex connector assembly that includes biased members and multiple contact points. This mechanical substitution allows for active management of electrical charges through controlled contact and separation mechanisms, replacing the passive insulation approach.
2Temperature
If coolant flow is increased to improve cooling efficiency, then substrate temperature control is enhanced, but charge buildup accelerates causing more frequent arcing
Solution Approach 1:
The biased connector assembly serves as an intermediary that decouples the relationship between coolant flow and charge buildup. By providing a controlled electrical interface separate from the fluid conduit, it allows high-velocity coolant flow for improved temperature control while simultaneously managing electrical charges to prevent arcing.
3Manufacturing precision
If the substrate support assembly is cooled to cryogenic temperatures for improved etching selectivity, then manufacturing precision is improved, but thermal expansion and contraction cause leakage at the conduits
Solution Approach 1:
The patent employs materials and design features that accommodate parameter changes during cryogenic cycling. The biased connector assembly and sealing elements are designed to maintain their functional properties across the temperature range from room temperature to cryogenic conditions, allowing thermal expansion and contraction without compromising seal integrity.
Solution Approach 2:
The biased member in the connector assembly provides dynamic adjustment capability. As the assembly undergoes thermal expansion and contraction during cryogenic operation, the biased member can move and adjust to maintain proper contact and sealing, preventing leakage that would occur in rigid fixed-geometry designs.
4Force
If RF power is applied to the substrate support assembly for electrostatic chucking, then substrate holding force is improved, but arcing between conduits and grounded portions increases
Solution Approach 1:
The biased connector assembly acts as an intermediary electrical interface that manages the interaction between RF-powered components and grounded portions. It provides controlled electrical contact that allows RF power transmission for electrostatic chucking while preventing uncontrolled discharge and arcing through its biased contact mechanism.
Solution Approach 2:
The biased connector assembly provides beforehand cushioning against electrical discharge by maintaining controlled electrical potential differences. The biased members are pre-positioned to manage charge distribution before RF power is applied, cushioning against the development of conditions that would lead to arcing during high-power operation.
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 effectively maintains substrates at cryogenic temperatures while preventing arcing and coolant leakage, ensuring reliable and efficient processing of semiconductor devices.
Implementation Method 1
A sliding seal surrounds a body of the connector
Implementation Method 2
coolant circulated through the substrate support assembly
Implementation Method 3
processing at cryogenic temperatures
Implementation Method 4
The connector comprises a biasing assembly and a fastener disposed in a pocket formed in the ground plate
Data Source
AI summary
A substrate support assembly is described herein that includes a facility plate, a ground plate coupled to the facility plate, a fluid conduit disposed within the substrate support assembly disposed through the facility plate and the ground plate, and a connector coupled to the ground plate that houses a portion of the fluid conduit. The connector includes a biasing assembly and a fastener disposed in a pocket formed in the ground plate.