Back Surface Substrate Cleaning via Combined Scrub and Two-Fluid Nozzle
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Solution Overview
Problem
Conventional cleaning techniques struggle to effectively remove foreign matter, such as polishing debris, from the back surface of substrates like wafers, leading to potential patterning deviations and contamination issues during wafer processing.
Innovation Solution
A substrate processing apparatus and method that combines scrub cleaning and two-fluid cleaning processes in a single cleaning chamber, utilizing a scrub cleaning tool and a two-fluid nozzle to efficiently remove particles from the back surface of wafers, preventing debris from remaining on the wafer after cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional scrub cleaning with pen-type brush or roll sponge is used, then the cleaning process is simple, but foreign matter covered with deposited film cannot be removed effectively
Solution Approach 1:
The patent combines polishing and cleaning operations into a single integrated process. The polishing tool simultaneously performs both polishing and cleaning functions, eliminating the need for separate cleaning steps while achieving high removal efficiency of foreign matter including those covered with deposited film.
Solution Approach 2:
The polishing tool is designed to perform multiple functions: it polishes the back surface of the substrate and simultaneously cleans foreign matter from the surface. This multi-functional approach increases cleaning effectiveness without adding separate cleaning devices or processes.
2Reliability
If polishing is performed on the back surface, then foreign matter removal efficiency is improved, but polishing debris remains on the back surface after cleaning
Solution Approach 1:
The patent converts the harmful polishing debris into removable particles by continuing the polishing process. The sustained polishing action transforms adhered debris into loose particles that can be easily removed, thereby eliminating contamination while maintaining high foreign matter removal efficiency.
Solution Approach 2:
The polishing process is extended beyond traditional endpoints to perform a preliminary cleaning action. By continuing polishing after the primary polishing function is complete, the system prepares the surface by loosening debris before final removal, ensuring no contamination remains.
3Reliability
If the cleaning process is extended to ensure complete particle removal, then cleaning effectiveness is improved, but processing time increases
Solution Approach 1:
The patent merges polishing and cleaning into one simultaneous operation. The polishing tool performs both functions concurrently, achieving complete particle removal without requiring extended processing time, as the same mechanical action accomplishes both goals.
Solution Approach 2:
The polishing process continues uninterrupted to simultaneously achieve polishing and cleaning objectives. This continuous action ensures complete particle removal while maintaining efficient processing time, as the useful polishing action persists throughout the entire operation without idle cleaning steps.
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 combined scrub and two-fluid cleaning process achieves high removal efficiency of particles from the back surface of wafers, ensuring effective cleaning in a short period and preventing debris from falling onto other wafers, thus enhancing processing reliability and preventing contamination.
Implementation Method 1
a two-fluid nozzle configured to deliver a two-fluid jet to the back surface of the substrate
Implementation Method 2
delivering a two-fluid jet to the back surface of the substrate
Implementation Method 3
a scrub cleaning tool configured to scrub the back surface of the substrate
Implementation Method 4
scrub cleaning tool configured to be rotatable
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
An apparatus which can remove particles, such as polishing debris, from a back surface with high removal efficiency is provided. The apparatus includes: a substrate holder configured to rotate the substrate while holding the substrate with the back surface facing upward; a scrub cleaning tool configured to be rotatable; a two-fluid nozzle disposed above the substrate holder; and a housing defining a cleaning chamber in which the substrate holder, the scrub cleaning tool, and the two-fluid nozzle are located.