Wafer Liquid Dispensing Nozzles for Temperature Uniformity
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Solution Overview
Problem
Conventional wafer processing devices face challenges in maintaining uniformity of process liquids across larger semiconductor wafers due to variations in temperature and viscosity, leading to inconsistent performance and increased susceptibility to 'pattern collapse' as wafer diameters increase, particularly with the transition from 200 mm to 300 mm and upcoming 450 mm wafers.
Innovation Solution
The apparatus employs a rotary chuck with at least two stationary liquid-dispensing nozzles positioned differently relative to the axis of rotation, with a liquid supply system that heats and controls the process liquid to maintain a temperature gradient across the wafer surface, ensuring consistent temperature and flow rates between central and peripheral regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional single-nozzle dispensing is used on larger wafers, then device coverage is achieved, but temperature and viscosity variations cause inconsistent process performance
Solution Approach 1:
The single dispensing nozzle is segmented into multiple nozzles (first and second nozzles) positioned at different radial locations. This segmentation allows independent temperature and flow rate control for different wafer regions, compensating for the temperature and viscosity variations that occur across larger wafer diameters.
Solution Approach 2:
Different nozzles are supplied with process liquid at different temperatures and flow rates tailored to their specific radial positions on the wafer. The first nozzle (closer to center) receives liquid at a different temperature than the second nozzle (closer to periphery), ensuring uniform process performance across the entire wafer surface despite variations in local conditions.
2Area of stationary object
If process liquid is dispensed across larger wafer diameters, then full wafer coverage is achieved, but temperature and viscosity variations increase
Solution Approach 1:
The system changes the temperature parameter of the process liquid differently for nozzles at different radial positions. The liquid supply system is configured to heat and supply process liquid such that the temperature of liquid from the first nozzle differs by a controlled amount from the temperature of liquid from the second nozzle, compensating for radial temperature gradients across the wafer.
Solution Approach 2:
The process liquid is pre-heated to different temperatures before reaching each nozzle based on the anticipated temperature variations across the wafer surface. This preliminary temperature adjustment ensures that when the liquid reaches different radial positions, the effective temperature remains uniform, preventing pattern collapse and ensuring consistent etching or cleaning performance.
3Productivity
If higher flow rates are used to cover larger areas, then processing speed increases, but temperature variations and pattern collapse risk increase
Solution Approach 1:
The total flow rate required for high-speed processing is segmented and distributed through multiple nozzles at different radial positions. Each nozzle delivers an optimized flow rate appropriate for its location, allowing overall high productivity while maintaining local flow conditions that prevent pattern collapse.
Solution Approach 2:
The system adjusts the flow rate parameter differently for each nozzle based on radial position and local process requirements. By optimizing flow rates at different locations rather than using a uniform high flow rate across the entire wafer, the system achieves high processing speed while maintaining the temperature and flow conditions necessary to prevent pattern collapse.
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
This approach ensures uniform process performance by maintaining temperature and flow rate differentials across the wafer, reducing material loss and improving cleaning efficiency, thereby enhancing the quality and yield of semiconductor devices.
Implementation Method 1
the liquid supply system comprising one or more heaters, and the liquid supply system being configured to heat and supply process liquid such that process liquid dispensed from the first liquid-dispensing nozzle has a temperature that differs by an amount within a predetermined range from a temperature of process liquid dispensed from the second liquid-dispensing nozzle
Data Source
AI summary
An apparatus and method for processing wafer-shaped articles utilizes at least first and second liquid-dispensing nozzles, wherein a first liquid-dispensing nozzle is positioned closer to an axis of rotation than the second liquid-dispensing nozzle. A liquid supply system supplies heated process liquid to the nozzles such that process liquid dispensed from the first nozzle has a temperature that differs by an amount within a predetermined range from a temperature of process liquid dispensed from the second liquid-dispensing nozzle.