Substrate Holder Edge Cleaning for Wafer Grinding Debris Control
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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 substrate holder.
Innovation Solution
A processing apparatus equipped with dedicated edge cleaning devices, such as the first and second edge cleaning units, which utilize dual-fluid nozzles and rotating mechanisms to remove grinding debris from the substrate holding surface, ensuring thorough cleaning and preventing debris accumulation during and after grinding processes.
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 debris accumulates at the edge portions of the substrate holding surface
Solution Approach 1:
The invention extracts the cleaning function from the water seal structure by adding a separate edge cleaning device. This device includes a cleaning liquid supply unit that delivers cleaning liquid to the edge portions of the substrate holding surface, and a suction unit that removes debris through suction holes. This separation allows the water seal to focus on preventing substrate contamination while the dedicated cleaning system handles debris removal.
Solution Approach 2:
The invention introduces cleaning liquid as an intermediary substance between the debris accumulation problem and the solution. The cleaning liquid supply unit delivers cleaning liquid to the edge portions where debris accumulates, and the suction unit removes the mixture of debris and cleaning liquid. This intermediary cleaning liquid facilitates effective debris removal without compromising the water seal's function of preventing processing water from reaching the substrate.
2Manufacturing precision
If edge cleaning device is added to remove debris, then TTV deterioration is prevented, but device complexity increases
Solution Approach 1:
The edge cleaning device is designed with multi-functionality to reduce overall system complexity. The suction unit serves dual purposes: it removes debris from the edge portions during processing and can also clean the substrate holding surface when the substrate is not present. The cleaning liquid supply unit provides both cooling and cleaning functions. This multi-functionality justifies the added complexity by consolidating multiple functions into integrated components rather than separate systems.
Solution Approach 2:
The edge cleaning device operates autonomously during the substrate processing cycle. The suction unit automatically activates to remove debris as it accumulates at the edge portions, and the cleaning liquid supply unit continuously provides cleaning liquid without manual intervention. This self-service capability reduces the need for additional control systems and manual cleaning operations, thereby minimizing the increase in device complexity.
3Object-generated harmful factors
If cleaning liquid is supplied to edge portions, then debris is removed effectively, but processing time increases
Solution Approach 1:
The edge cleaning device operates continuously during the substrate processing cycle rather than requiring separate cleaning steps. The cleaning liquid supply unit continuously delivers cleaning liquid to the edge portions, and the suction unit continuously removes debris throughout the processing time. This continuous operation ensures debris is removed as it accumulates without interrupting the main processing cycle, thereby maintaining high debris removal efficiency while minimizing additional processing time.
Solution Approach 2:
The cleaning liquid is supplied preliminarily to the edge portions before debris accumulation becomes problematic. The continuous supply of cleaning liquid prevents debris from adhering strongly to the substrate holding surface, making removal more efficient. This preliminary cleaning action reduces the time required for debris removal compared to cleaning after significant accumulation occurs.
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.