Wafer Holder Edge Cleaning for TTV-Stable Back Grinding
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Solution Overview
Problem
In semiconductor wafer grinding processes, grinding debris deposited on the substrate holding surface can lead to Total Thickness Variation (TTV) deterioration due to incomplete removal, as existing technologies do not effectively address debris accumulation at the edge portions and notches of the wafer, affecting the uniformity of the ground substrate thickness.
Innovation Solution
A processing apparatus equipped with dedicated edge cleaning devices, including first and second edge cleaning units that supply dual-fluid cleaning liquids or pure water to remove grinding debris from the substrate holding surface, ensuring thorough cleaning and preventing debris accumulation, especially at the notch positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If water seal portion is formed to suppress processing water reaching the substrate, then substrate contamination is reduced, but cleaning effectiveness at edge portions deteriorates
Solution Approach 1:
The cleaning device is divided into multiple independent cleaning units (first cleaning unit, second cleaning unit, third cleaning unit) that can be positioned at different locations. Each unit has its own cleaning liquid supply mechanism, allowing targeted cleaning of specific areas including edge portions and notches without compromising the water seal function elsewhere.
Solution Approach 2:
The invention applies cleaning functions specifically at locations where debris accumulates (edge portions and notches) rather than uniformly across the entire substrate holding surface. The cleaning liquid is supplied locally to these critical areas through positioned nozzles, ensuring effective debris removal while maintaining the water seal barrier in other regions.
2Manufacturing precision
If edge cleaning device is added to clean substrate holding surface, then cleaning effectiveness improves, but device complexity increases
Solution Approach 1:
The cleaning device integrates multiple functions into a single system: debris removal from edge portions, notch cleaning, and coordination with the water seal mechanism. The control unit manages multiple cleaning units and coordinates their operation with the water seal portion, creating a multi-functional system that addresses various cleaning needs without requiring separate independent devices.
Solution Approach 2:
The invention merges the cleaning liquid supply mechanisms and positioning systems into a unified edge cleaning device structure. Multiple cleaning units share common support structures and control systems, reducing overall device complexity compared to having completely separate cleaning systems for each function.
3Manufacturing precision
If multiple cleaning units are used to clean edge portions, then debris removal effectiveness improves, but processing time increases
Solution Approach 1:
The cleaning units operate in a coordinated sequence rather than simultaneously. The control unit controls the periodic operation of each cleaning unit, activating them in succession at different locations. This periodic action ensures thorough debris removal from all critical areas while minimizing total processing time compared to sequential manual cleaning or less optimized automated systems.
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 effectively removes grinding debris from the substrate holding surface, improving the in-surface uniformity of the ground substrate thickness by preventing debris-induced TTV deterioration, ensuring accurate and consistent processing results.
Implementation Method 1
an edge cleaning device configured to clean an edge portion of the substrate holding surface
Data Source
AI summary
A processing apparatus configured to process a substrate includes a substrate holder having a substrate holding surface configured to attract and hold the substrate thereon; and an edge cleaning device configured to clean an edge portion of the substrate holding surface. Further, a processing method of processing a rear surface of the substrate by using the processing apparatus includes processing the rear surface of the substrate while a front surface of the substrate is attracted to and held by a substrate holding surface of a substrate holder; and cleaning an edge portion of the substrate holding surface.