Wafer Back Surface Cleaning with Rinse Transfer to Prevent Re-Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wafer back surface cleaning devices face issues with foreign matter re-adhering to the front and back surfaces of wafers during and after cleaning, particularly in scrub cleaning using sponge pads, and air drying can reintroduce contaminants.
Innovation Solution
A wafer back surface cleaning device with a first hand for receiving cleaned wafers, a second hand for conveying and transferring, a rotating cleaning pad for scrub cleaning, and oblique cleaning water supply nozzles for rinse cleaning, along with a cylindrical cover to prevent splash, ensuring continuous operation without re-adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a rotation plate with a non-rotation liquid discharge plate and continuous liquid supply is used to clean the wafer back surface, then cleaning coverage is improved, but foreign matter can be sandwiched between the rotation plate and wafer back surface affecting processing finish
Solution Approach 1:
Instead of rotating the liquid discharge plate, the patent rotates the wafer support plate with the wafer while keeping the liquid discharge plate stationary. This inversion of the rotating component eliminates the risk of sandwiching foreign matter between the rotating plate and wafer back surface, while still achieving effective cleaning through the relative motion between the liquid film and wafer surface.
2Productivity
If automated cleaning with rotation plate and cleaning pad is used, then productivity is improved, but dirt from the sponge cleaning pad can remain on the wafer back surface
Solution Approach 1:
The patent removes the cleaning pad component entirely from the system, replacing mechanical sponge cleaning with a liquid film cleaning method. The cleaning function is achieved through a liquid film supplied from the stationary liquid discharge plate that flows over the rotating wafer back surface, extracting the problematic sponge element that leaves dirt residue while maintaining automated cleaning capability.
3Productivity
If air blow is applied to dry the wafer back surface after cleaning, then drying efficiency is improved, but foreign matter can re-adhere to the wafer surfaces
Solution Approach 1:
The patent replaces the mechanical air blow drying system with a liquid film-based drying approach. The liquid film supplied to the rotating wafer back surface serves multiple functions including cleaning and drying, eliminating the need for separate air blow drying that causes foreign matter re-adhesion. The liquid film physically removes moisture and contaminants simultaneously.
4Productivity
If the same hand conveys the wafer through all cleaning operations without grip changes, then operation continuity is improved, but the hand must accommodate multiple functions
Solution Approach 1:
The patent designs the hand as a multi-functional component that performs gripping, conveying, and positioning functions throughout the entire cleaning process without changing grips. The hand accommodates multiple roles including holding the wafer during liquid film application, supporting the wafer during rotation, and transferring the cleaned wafer, thereby achieving operational continuity through universal functionality.
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 device effectively removes residual dirt through scrub and rinse cleaning, prevents re-adhesion of contaminants, and enhances productivity by allowing continuous operation without changing grips, thus improving wafer quality and processing efficiency.
Implementation Method 1
a treatment liquid and a rinse liquid are supplied between the wafer and the rotation plate from the liquid discharge nozzle continuously provided below the liquid discharge port to clean the back surface of the wafer with a liquid film formed
Implementation Method 2
Drying air is blown to the back surface of the wafer W and the wafer suction pad 106, respectively, from the air blow 107 and an air blow 108, and foreign matter or water remaining on the back surface of the wafer W is removed
Data Source
AI summary
A wafer back surface cleaning device preventing foreign matter from re-adhering to a wafer during and after cleaning. A hand H1 receives a wafer that has been cleaned at a cleaning position and conveys the wafer to a subsequent process, a hand H2 conveys the wafer before grinding to the cleaning position and transfers the wafer that has been cleaned to hand H1 with a front surface of the wafer directed upward. A cleaning pad and a cleaning water supply nozzle discharges the cleaning water to a back surface of the wafer, at the cleaning position, the hand H2 brings the back surface of the wafer to the cleaning position into contact with the cleaning pad to scrub, and receives the cleaning water on the back surface of the wafer after scrub cleaning to perform rinse cleaning, and then transfers the wafer to the hand H1.