Wafer Load-Lock Level Stream Gas Flow for Uniform Cooling
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Solution Overview
Problem
In semiconductor manufacturing, existing wafer cooling and heating systems face inefficiencies due to temperature gradients across wafers during the cooling or heating process, leading to increased cycle times and reduced throughput, particularly in load-lock designs with downstream gas flow configurations.
Innovation Solution
A wafer cooling/heating system incorporating a level stream design with a side-mounted diffuser and thermoelectric modules, where gas flows parallel to the wafers through adjustable nozzles, and exhaust lines control gas removal, optimizing temperature uniformity and throughput by reducing cooling/heating time by 82% and improving wafer throughput by 45%.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If downstream gas flow configuration is used in load-lock, then system simplicity is maintained, but temperature gradients across wafers increase and cooling/heating time increases
Solution Approach 1:
The patent inverts the conventional downstream gas flow configuration by implementing a level stream flow pattern where gas enters horizontally and flows parallel to the wafer surface. This reversal of the flow direction eliminates temperature gradients that plague downstream configurations, achieving uniform temperature distribution across all wafers while reducing cooling/heating time by 82%.
Solution Approach 2:
The patent applies local quality by positioning gas inlets at specific locations that deliver cooling gas directly to regions requiring it most. The level stream configuration ensures each wafer receives uniform gas flow at its specific location, creating locally optimized temperature control that collectively achieves uniform cooling across the entire load-lock.
2Device complexity
If downstream gas flow configuration is used in load-lock, then system simplicity is maintained, but temperature uniformity across wafers deteriorates
Solution Approach 1:
The patent inverts the conventional downstream gas flow configuration by implementing a level stream flow pattern where gas enters horizontally and flows parallel to the wafer surface. This reversal of the flow direction eliminates temperature gradients that plague downstream configurations, achieving uniform temperature distribution across all wafers while reducing cooling/heating time by 82%.
Solution Approach 2:
The level stream flow configuration creates equipotential temperature distribution across the load-lock by ensuring all wafers are exposed to gas at the same pressure and temperature conditions. This eliminates the temperature potential differences that cause non-uniform cooling in downstream configurations, achieving manufacturing precision of within 1°C across all wafers.
3Reliability
If conventional cooling systems are used, then basic cooling function is provided, but cooling efficiency and throughput remain low
Solution Approach 1:
The patent fundamentally changes the flow parameters from vertical downstream flow to horizontal level stream flow. This parameter change in flow direction and velocity distribution increases gas-wafer interaction efficiency, reducing cooling time by 82% and increasing wafer throughput by 45% while maintaining reliable cooling function.
Solution Approach 2:
The level stream configuration enables continuous, uniform gas flow across all wafers simultaneously, eliminating the sequential or non-uniform cooling patterns of conventional systems. This continuous useful action across the entire wafer stack maximizes cooling efficiency and throughput.
4Speed
If gas flow rate is increased to reduce cooling time, then cooling speed improves, but temperature uniformity deteriorates due to turbulence and gradients
Solution Approach 1:
The patent inverts the conventional approach by using horizontal level stream flow instead of vertical downstream flow. This inversion allows high gas flow rates to be used while maintaining laminar flow conditions and temperature uniformity, because the horizontal flow pattern distributes gas evenly across all wafers without creating the turbulence and gradients that occur in vertical configurations.
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 achieves improved temperature uniformity and accelerated wafer cooling/heating, enhancing overall processing efficiency and throughput by maintaining a wide range of gas temperatures from -50°C to 50°C and detecting potential nozzle malfunctions.
Implementation Method 1
a thermoelectric module having a top surface and a bottom surface, the top surface configured to be heated or cooled by the application of an electric current
Implementation Method 2
a diffuser configured to direct the gas flow in a direction parallel to the one or more wafers
Data Source
AI summary
The present disclosure describes a wafer cooling/heating system that includes a load-lock and a thermo module. The load-lock uses a level stream design to improve temperature uniformity across one or more wafers during a cooling/heating process. The load-lock can include (i) a wafer holder configured to receive wafers at a front side of the load-lock; (ii) a gas diffuser with one or more nozzles along a back side of the load-lock, a side surface of the load-lock, or a combination thereof; and (iii) one or more exhaust lines. Further, the thermo module can be configured to control a temperature of a gas provided to the load-lock.