Wafer Drying Heating Zones for Pattern Collapse Prevention
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Solution Overview
Problem
As semiconductor wafers with decreasing feature sizes and increasing diameter face pattern collapse during drying due to surface tension and high aspect ratios, existing techniques for preventing pattern collapse are ineffective.
Innovation Solution
A rotary chuck system with a heating assembly of individually controllable radiant heating elements and a liquid dispenser that rapidly heats the wafer surface, preventing meniscus formation by evaporating rinse liquids quickly, using a transparent plate and LED heating elements to control heating zones based on the liquid dispenser's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional drying techniques are used on wafers with high aspect ratio features, then the drying process is simple, but pattern collapse occurs due to surface tension
Solution Approach 1:
The heating assembly is divided into multiple independently controllable heating zones (at least five groups) that can be individually activated. This segmentation allows selective heating of specific wafer regions corresponding to the liquid dispenser position, enabling targeted evaporation without requiring complex system-wide control
Solution Approach 2:
Different regions of the wafer receive different heating intensities through the controllable heating zones. The heating power supplied to each zone is adjusted based on the liquid dispenser's radial position, creating localized thermal conditions that optimize evaporation exactly where needed while preventing pattern collapse
2Productivity
If the wafer diameter is increased to accommodate more device features, then device capacity increases, but pattern collapse becomes more problematic due to higher aspect ratios
Solution Approach 1:
The heating system transitions from static uniform heating to dynamic localized heating. The heating zones are activated and deactivated based on the real-time radial position of the liquid dispenser, allowing the system to adapt thermal processing to the specific drying requirements at different wafer locations
Solution Approach 2:
The controller receives information about the liquid dispenser's radial position and uses this feedback to adjust the power supplied to corresponding heating zones. This closed-loop control ensures that heating is precisely coordinated with liquid dispensing, optimizing evaporation effectiveness across the entire wafer surface
3Productivity
If rapid evaporation is achieved to prevent pattern collapse, then drying speed increases, but localized heating control is required to avoid damage
Solution Approach 1:
The heating assembly is divided into multiple independently controllable heating zones (at least five groups) that can be individually activated. This segmentation allows selective heating of specific wafer regions corresponding to the liquid dispenser position, enabling targeted evaporation without requiring complex system-wide control
Solution Approach 2:
The power supplied to each heating zone is dynamically adjusted based on the liquid dispenser's radial position. This parameter change enables the system to optimize evaporation rate in different regions, achieving rapid drying while preventing localized overheating or damage
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
Effectively prevents pattern collapse by ensuring rapid and localized evaporation of rinse liquids, maintaining wafer performance and structure integrity.
Implementation Method 1
The heating assembly comprises an array of radiant heating elements distributed among at least five individually controllable groups
Implementation Method 2
ensuring rapid and localized evaporation of rinse liquids
Data Source
AI summary
An apparatus for processing wafer-shaped articles comprises a rotary chuck and a heating assembly that faces a wafer-shaped article when positioned on the rotary chuck. A liquid dispenser positioned so as to dispense liquid onto a surface of a wafer-shaped article that faces away from the rotary chuck when positioned on the rotary chuck. The heating assembly comprises an array of radiant heating elements distributed among at least five individually controllable groups. The liquid dispenser comprises one or more dispensing orifices configured to move a discharge point from a more central region of the rotary chuck to a more peripheral region of the rotary chuck. A controller controls power supplied to each of the at least five individually controllable groups of radiant heating elements based on a position of the discharge point of the liquid dispenser.