CMP Cleaning Nozzles with Variable Outlet Velocity
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving effective planarization and cleaning of advanced semiconductor ICs, particularly with the increasing complexity and miniaturization of circuits, where existing CMP methods struggle to efficiently remove residues and ensure proper planarization of metal and dielectric layers.
Innovation Solution
A chemical mechanical polishing (CMP) system comprising a polishing unit, a cleaning unit with adjustable spray nozzles, and a drying unit, where the cleaning unit uses polyvinyl alcohol brushes and megasonic cleaners, and the spray nozzles are designed with varying outlet configurations to optimize the distribution and velocity of cleaning solutions for efficient residue removal and planarization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional CMP methods are used for planarization, then metal and dielectric layers can be removed, but residues remain on the wafer surface and cleaning effectiveness is insufficient
Solution Approach 1:
The patent introduces a multi-component cleaning system as an intermediary between CMP polishing and subsequent processing. This includes spray nozzles delivering cleaning solutions, megasonic cleaning modules, and brush assemblies that work together to remove residues without damaging the planarized surface. The cleaning solutions chemically interact with residues while the mechanical components physically remove them, solving the contradiction between effective removal and surface integrity.
Solution Approach 2:
The patent replaces conventional mechanical wiping or rinsing methods with megasonic cleaning technology. The megasonic module generates high-frequency sound waves that create cavitation bubbles, which collapse to produce micro-jets that dislodge residues. This non-contact mechanical substitution achieves superior cleaning effectiveness without the mechanical stress that could damage the planarized wafer surface.
2Object-generated harmful factors
If cleaning solutions are applied to remove residues, then cleaning effectiveness improves, but corrosion risk increases
Solution Approach 1:
The patent carefully controls multiple parameters of the cleaning process: pH levels of cleaning solutions, temperature, application time, and spray pressure. By optimizing these parameters, the cleaning solutions effectively remove residues while minimizing corrosive effects on the wafer. The system dynamically adjusts parameters based on process requirements to balance cleaning effectiveness with wafer protection.
Solution Approach 2:
The cleaning system uses composite cleaning solutions containing multiple chemical components that work synergistically. These composite formulations include chelating agents, surfactants, and mild acids or bases that collectively enhance residue removal while the buffering components prevent excessive corrosion. The multi-component approach allows the solution to address multiple contamination types without compromising wafer integrity.
3Object-generated harmful factors
If multiple cleaning modules are added to improve cleaning effectiveness, then residue removal improves, but system complexity increases
Solution Approach 1:
The patent combines multiple cleaning functions into an integrated cleaning unit that processes wafers through multiple modules in sequence. The spray cleaning section, megasonic cleaning module, and brush cleaning section are merged into a single coordinated system that handles wafers continuously. This merging approach achieves comprehensive cleaning effectiveness while avoiding the complexity of separate, standalone cleaning systems.
Solution Approach 2:
The cleaning unit is designed as a multi-functional module that can handle different wafer types and contamination levels using the same basic infrastructure. The spray nozzles, megasonic module, and brushes can be adjusted or configured for different cleaning requirements, providing universal cleaning capability across various semiconductor processing scenarios without requiring entirely separate systems.
4Area of stationary object
If spray nozzles are used to apply cleaning solutions, then cleaning coverage improves, but solution distribution uniformity decreases
Solution Approach 1:
The spray cleaning system divides the cleaning solution application into multiple discrete spray nozzles positioned at different locations and angles. Each nozzle covers a specific zone of the wafer surface, and the collective pattern of multiple segmented spray zones achieves comprehensive coverage. The segmentation allows each nozzle to maintain focused, uniform spray patterns while the overall system provides broad coverage.
Solution Approach 2:
The spray nozzle arrangement is designed to deliver locally optimized cleaning to different wafer regions. Nozzles are positioned and angled to provide appropriate solution delivery for specific areas, with variations in spray parameters tailored to local contamination patterns or surface characteristics. This local quality approach ensures uniform distribution across the entire wafer surface despite the complexity of comprehensive coverage.
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 system achieves improved planarization and cleaning of semiconductor wafers by effectively removing residues and preventing corrosion, ensuring a smooth surface for subsequent layers, thereby enhancing production efficiency and reducing defects.
Implementation Method 1
The cleaning unit uses polyvinyl alcohol brushes and megasonic cleaners
Implementation Method 2
The cleaning unit uses polyvinyl alcohol brushes and megasonic cleaners
Implementation Method 3
the spray nozzles are designed with varying outlet configurations to optimize the distribution and velocity of cleaning solutions for efficient residue removal
Implementation Method 4
Chemical mechanical polishing (CMP) has become a key technology driver to achieve local or global wafer planarization
Data Source
AI summary
Methods for cleaning integrated circuit (IC) wafers after undergoing planarization processes (for example, chemical mechanical polishing processes) and associated cleaning units and/or planarization units are disclosed herein. An exemplary method includes configuring outlet areas of spray nozzles to deliver a cleaning solution to optimal locations of the IC wafer and delivering the cleaning solution via the spray nozzles having the configured outlet areas to the IC wafer. Each of the outlet areas is configured to achieve a particular velocity of the cleaning solution exiting the outlet area, such that the cleaning solution reaches a particular location of the IC wafer depending on the particular velocity. In some implementations, the cleaning solution enters inlet areas of the spray nozzles at the same flow rate and the cleaning solution exits the outlet areas of the spray nozzles at different velocities.