TSV Via Cleaning with Heated Atomized Inert-Gas Spray
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Solution Overview
Problem
Conventional semiconductor cleaning methods struggle to effectively clean high-aspect-ratio TSV vias due to difficulties in liquid infiltration and residue removal, especially when the hole diameter is small, leading to incomplete filling and defects.
Innovation Solution
A method involving a cleaning liquid and inert gas mixture is heated and atomized using an atomizer, with adjustable flow rates and pulse mode delivery, to efficiently wet and clean the inner walls and bottoms of TSV vias, followed by passivation and rinsing with atomized solutions to form a silicon oxide layer and remove residues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional cleaning methods (slot ultrasonic cleaning, monolithic megasonic cleaning, monolithic high-pressure water jet cleaning) are used, then the cleaning process can be performed on wafer surfaces, but the cleaning liquid cannot effectively infiltrate high-aspect-ratio TSV vias due to surface tension, resulting in incomplete residue removal
Solution Approach 1:
The patent changes the physical state of the cleaning liquid from bulk liquid to aerosol by controlling parameters such as liquid particle size (1-10 μm), gas-to-liquid ratio, and injection pressure. This parameter transformation enables the cleaning liquid to overcome surface tension effects and effectively infiltrate high-aspect-ratio TSV vias, resolving the contradiction between cleaning quality and surface tension barriers
Solution Approach 2:
The cleaning liquid undergoes a phase transition from liquid to aerosol (liquid-gas mixture) through atomization. This phase change reduces the effective surface tension impact on the cleaning liquid, allowing it to penetrate deep into narrow TSV vias while maintaining cleaning effectiveness, thus solving the infiltration problem caused by surface tension
2Productivity
If the hole diameter of TSV blind hole is small and aspect ratio is large, then the TSV via density and integration level are improved, but the liquid exchange in the TSV blind hole becomes difficult due to surface tension
Solution Approach 1:
The patent uses pneumatic atomization where compressed gas (pneumatic force) breaks up the cleaning liquid into fine aerosol particles. This pneumatic approach enables the cleaning liquid to be delivered into small-diameter, high-aspect-ratio TSV vias where conventional liquid delivery fails, thus maintaining ease of operation while achieving high TSV via density
Solution Approach 2:
The patent transforms the cleaning liquid delivery from a bulk liquid phase to an aerosol phase, effectively adding a gaseous dimension to the liquid. This dimensional change allows the cleaning medium to access narrow TSV vias that would be inaccessible to conventional liquid cleaning, enabling both high via density and effective liquid exchange
3Productivity
If conventional cleaning methods are used, then the equipment structure is relatively simple, but the cleaning efficiency and residue removal capability are insufficient for high-aspect-ratio TSV vias
Solution Approach 1:
The patent introduces an intermediary aerosolization system that converts cleaning liquid into fine particles using compressed gas. This intermediary mechanism bridges the gap between conventional simple equipment and the need for high cleaning efficiency in complex high-aspect-ratio TSV vias, achieving improved productivity with moderate equipment complexity
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 method enhances cleaning efficiency by ensuring thorough wetting and removal of residues within TSV vias, improving the quality of TSV via cleaning and passivation, and reducing the thickness of surface adsorption layers, thus addressing the limitations of conventional methods.
Implementation Method 1
atomizing the cleaning liquid in an atomizer, to spray on a wafer surface and to wet an inner wall and a bottom of the through via
Implementation Method 2
the liquid in the through via is difficult to infiltrate due to the surface tension of the cleaning liquid
Implementation Method 3
heating a cleaning liquid to a predetermined temperature
Implementation Method 4
mixing the cleaning liquid with an inert gas and entering into a cleaning chamber
Data Source
AI summary
A method for cleaning a through via including the following steps is provided: heating a cleaning fluid to a predetermined temperature; mixing the cleaning liquid with an inert gas and entering into a cleaning cavity; atomizing the cleaning liquid in an atomizer to spray on a wafer surface and to wet an inner wall and a bottom of the through via; and closing a cleaning liquid valve.