Reentrant Flow Path Valve Manifold for Deadleg Elimination
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Solution Overview
Problem
Substrate processing systems face issues with film residue buildup and condensation in dead-leg volumes, leading to defects during deposition processes, as stagnant precursor gas can condense and contaminate the substrate.
Innovation Solution
A gas delivery system with a cylinder and annular purge channel configuration that supplies purge gas to eliminate precursor and remote plasma gas diffusion, reducing condensation by maintaining a temperature above the condensation point and using computational modeling to optimize flow rates, thereby minimizing particle formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional gas delivery system with valve manifolds is used, then gas flow control is achieved, but dead-leg volumes form where precursor gas stagnates and condenses, creating particles that contaminate the substrate
Solution Approach 1:
The patent extracts and eliminates the dead-leg volume from the gas delivery system by redesigning the flow path. The reentrant flow path configuration removes the stagnant region where precursor gas would otherwise accumulate and condense, directly addressing the particle formation problem while maintaining gas flow control functionality
Solution Approach 2:
The patent applies inversion by reversing the conventional linear flow path through the valve manifold. Instead of gas flowing straight through, the reentrant path causes gas to flow back through previously occupied regions, preventing stagnation and ensuring continuous movement of precursor gas to eliminate condensation zones
2Reliability
If purge gas is supplied to eliminate precursor diffusion, then condensation is reduced, but system complexity increases with additional gas channels and flow control mechanisms
Solution Approach 1:
The reentrant flow path serves multiple functions simultaneously: it controls gas flow distribution, eliminates dead-leg volumes, prevents precursor stagnation, and maintains continuous gas movement without requiring separate purge channels. This multi-functionality reduces overall system complexity while achieving condensation prevention
Solution Approach 2:
The patent merges the flow control function and the dead-leg elimination function into a single reentrant flow path design. By combining these functions, the system achieves condensation prevention without adding separate purge gas infrastructure, thereby avoiding increased system complexity
3Productivity
If vaporized precursor is supplied through gas channels, then deposition process is enabled, but stagnant precursor in dead-leg volumes condenses and falls onto the substrate causing defects
Solution Approach 1:
The reentrant flow path ensures continuous movement of vaporized precursor gas through the valve manifold without stagnation. The continuous flow prevents precursor accumulation and condensation in dead-leg volumes, eliminating the source of substrate defects while maintaining efficient deposition process
Solution Approach 2:
By inverting the conventional linear flow path into a reentrant configuration, the system ensures that precursor gas continuously recirculates through the valve manifold regions. This inversion prevents stagnant zones from forming, eliminating condensation and associated substrate defects while preserving deposition efficiency
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 system effectively reduces or eliminates on-wafer particles by preventing precursor condensation in dead-leg volumes, improving particle performance and maintaining clean conditions for over 100 remote plasma clean hours.
Implementation Method 1
supplies purge gas to eliminate precursor and remote plasma gas diffusion
Implementation Method 2
reducing condensation by maintaining a temperature above the condensation point
Implementation Method 3
The flow channel is heated to a temperature above a condensation temperature of the vaporized precursor
Data Source
AI summary
A gas delivery system for a substrate processing system includes first and second valves, a first gas channel, and a cylinder. The first valve includes a first inlet and a first outlet. The first outlet is in fluid communication with a processing chamber of the substrate processing system. The second valve includes a second inlet and a second outlet. The cylinder defines a second gas channel having a first end and a second end. The cylinder is at least partially disposed within the first gas channel such that the cylinder and the first gas channel collectively define a flow channel. The flow channel is in fluid communication with the first end of the second gas channel and with the first inlet. A third gas channel is in fluid communication with the second end of the second gas channel and with the second inlet.