Wafer Cleaning Nozzle and Optical Heating for Wet Processing
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Solution Overview
Problem
Current wet processing systems for small wafers, such as those in minimal fab systems, face inefficiencies in cleaning and heating processes, particularly in using minimal amounts of cleaning agents and preventing agent spillage during rotation, and in efficiently heating the wafer interface with processing liquids.
Innovation Solution
A wet processing apparatus that includes a stage for the wafer, a rotary driving unit to rotate the stage, a supply nozzle to deliver a predetermined amount of cleaning agent that fills the space between the nozzle and the wafer, and a control unit to manage the rotation speed and nozzle positioning, ensuring efficient cleaning with minimal agent usage and preventing spillage through centrifugal force, while also incorporating a heating mechanism to heat the wafer interface with the processing liquid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a spin cleaning apparatus supplies a small amount of cleaning liquid to clean a small wafer, then cleaning agent consumption is reduced, but the cleaning liquid may spill during wafer rotation
Solution Approach 1:
The supply nozzle supplies the cleaning liquid to the wafer surface before the spin rotation begins, allowing the liquid to be properly positioned and distributed on the wafer surface in advance. This preliminary action ensures that the cleaning liquid remains on the wafer during rotation without spilling, while still using a minimal amount of cleaning agent.
Solution Approach 2:
The patent replaces the conventional spin coating method with a drop-based cleaning method where a small droplet of cleaning liquid is supplied to the wafer surface. This mechanical substitution allows for precise control of cleaning agent quantity and position, preventing spillage during rotation while minimizing consumption.
2Productivity
If the wafer rotation speed is increased to improve cleaning efficiency, then cleaning speed increases, but cleaning liquid spillage risk increases
Solution Approach 1:
The cleaning liquid is supplied to the wafer surface before rotation begins, establishing a stable liquid position that can withstand higher rotation speeds without spilling. This preliminary positioning allows the system to achieve both high cleaning speed and spillage prevention.
3Temperature
If conventional heating methods are used to heat the wafer and cleaning liquid, then heating capability is provided, but heating efficiency and energy consumption are poor
Solution Approach 1:
The patent replaces conventional thermal heating methods with optical heating using a light source. The light irradiates the wafer and cleaning liquid interface, providing efficient and localized heating with minimal energy consumption. This substitution of mechanical/thermal heating with optical heating achieves the desired temperature control while significantly improving energy efficiency.
Solution Approach 2:
The heating is applied locally at the interface between the wafer and cleaning liquid where it is most needed for the cleaning process. This localized heating approach, achieved through optical irradiation, improves heating efficiency and reduces overall energy consumption compared to bulk heating methods.
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 apparatus enables efficient cleaning of small wafers with reduced cleaning agent consumption, prevents spillage during rotation, and effectively heats the wafer interface with the processing liquid, optimizing resource usage and cleaning efficiency.
Implementation Method 1
a predetermined amount of the cleaning agent to fill the space between the supply nozzle and the object to be cleaned
Implementation Method 2
rotating the object to be cleaned in a state where the cleaning agent fills the space between the object to be cleaned and the supply nozzle prevents the cleaning agent from spilling down by a centrifugal force
Implementation Method 3
a heating mechanism to heat the wafer interface with the processing liquid
Data Source
AI summary
A wafer cleaner and a method therefor that efficiently cleans a wafer with a little amount of a cleaning liquid and efficiently performs a heating wet cleaning processing. The present invention includes a stage where a wafer is placed, a rotary driving unit that rotates the stage in a circumferential direction, a liquid discharge nozzle disposed facing the wafer placed on the stage and supplies a cleaning liquid on the wafer placed on the stage, and a control unit that causes the liquid discharge nozzle to supply a space between the wafer placed on the stage and the liquid discharge nozzle with a predetermined amount of the cleaning liquid to fill the space. The present invention also includes a lamp disposed on a position facing the wafer placed on the stage to heat at least an interface portion of the wafer and a cleaning liquid.