Substrate Holding Element Cleaning via Variable Speed Rotation
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in cleaning the outer surfaces and surroundings of the processing cup without requiring a special-purpose cleaning mechanism, as processing solution often gets scattered and attached, leading to pollution when dried.
Innovation Solution
A method involving a substrate holding element that rotates at varying speeds to scatter a cleaning solution onto the cup's outer surface and surroundings, using the existing substrate processing mechanisms to clean these areas without additional equipment, followed by drying with airflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a special-purpose cleaning mechanism (nozzle for de-ionized water or nitrogen gas nozzle) is added to clean the outer wall surface of the cup and surroundings, then the cleaning effectiveness is improved, but the device complexity and size increase
Solution Approach 1:
The substrate holding element is made to serve dual functions: (1) holding and processing substrates during normal operation, and (2) scattering cleaning solution to clean the cup outer surface and surroundings during cleaning mode. By rotating the substrate holding element at different speeds and positioning the cup accordingly, the same component performs both substrate processing and self-cleaning functions, eliminating the need for separate cleaning mechanisms.
Solution Approach 2:
The apparatus cleans itself by using its own substrate holding element to scatter cleaning solution onto contaminated surfaces. The system uses its existing rotating component to perform cleaning without requiring external cleaning equipment, making the cleaning function self-service rather than requiring additional dedicated mechanisms.
2Object-affected harmful factors
If a special-purpose cleaning mechanism is added to clean the outer wall surface of the cup and surroundings, then the pollution prevention is improved, but the apparatus size increases
Solution Approach 1:
The substrate holding element performs both substrate processing and cleaning functions. During cleaning mode, it scatters cleaning solution to remove processing solution residues from the cup outer surface and surroundings, preventing pollution without requiring additional space for separate cleaning equipment.
Solution Approach 2:
The cleaning function is merged with the existing substrate holding and processing function. The same substrate holding element and rotation mechanism are used for both substrate processing during normal operation and for scattering cleaning solution during cleaning mode, consolidating functions into existing components rather than adding separate systems.
3Area of stationary object
If the substrate holding element rotates at high speed to scatter cleaning solution widely, then the cleaning coverage area is improved, but the centrifugal force may cause cleaning solution to spray uncontrollably
Solution Approach 1:
The rotation speed of the substrate holding element is dynamically adjusted based on the cleaning target. Lower rotation speeds (e.g., 50-200 rpm) are used when cleaning the cup outer surface to provide controlled scattering, while higher speeds (e.g., 200-500 rpm) are used when cleaning surrounding areas to achieve wider coverage. This dynamic speed adjustment optimizes both cleaning effectiveness and control.
Solution Approach 2:
The rotation speed parameter of the substrate holding element is changed according to the cleaning requirements. By varying the rotation speed, the scattering pattern and reach of the cleaning solution are controlled - slower speeds for targeted cleaning near the cup, faster speeds for broader area cleaning of surroundings, thus achieving different cleaning coverage areas while maintaining control.
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 cleans the upper surface of the cup and its surroundings using centrifugal force and airflow, eliminating the need for a dedicated cleaning mechanism and enhancing efficiency.
Implementation Method 1
a substrate holding element is caused to rotate at a first number of revolutions... cleaning an outer upper surface of the cup with the cleaning solution scattered from the holding surface while the holding surface is rotating
Implementation Method 2
drying process by causing the substrate to rotate at high speed
Data Source
AI summary
A spin base is caused to rotate at a number of revolutions of from 250 rpm to 350 rpm (first number of revolutions), and at the same time, a cleaning solution is supplied through a discharge head to a holding surface of a spin base while the upper end of a processing cup surrounding the spin base is placed below the holding surface. Thus, an outer upper surface of the processing cup is cleaned with the cleaning solution scattered from the holding surface. Then, the spin base is caused to rotate at a number of revolutions of from 350 rpm to 450 rpm (second number of revolutions) higher than the first number of revolutions, and at the same time, a cleaning solution is supplied through the discharge head onto the holding surface. Thus, a partition plate outside the processing cup is cleaned with the cleaning solution scattered from the rotating holding surface.