Monolithic Porous Pad Cast on Rotatable Base
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in planarizing dielectric materials and removing residual slurry and contaminants from wafers, leading to variations in surface topography and contamination issues that affect device yield and reliability.
Innovation Solution
A porous brush or pad is cast or molded directly onto a rotatable base with interlocking channels, allowing for uniform fluid distribution and material removal, which maintains node alignment and prevents twisting, thereby ensuring consistent contact and efficient cleaning of substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a brush sleeve is slid over a core support for cleaning wafers, then the brush can be replaced, but the alignment of brush protrusions becomes asymmetric and distorted, requiring breaking in and flushing procedures that reduce productivity
Solution Approach 1:
The brush protrusions are integrally formed with the brush sleeve as a single monolithic structure, eliminating the alignment issues that occur when separate components are assembled. This merging of the brush elements into one piece allows for quick replacement without requiring breaking in or flushing procedures.
Solution Approach 2:
The brush protrusions are pre-aligned and pre-formed in the correct positions during manufacturing of the monolithic brush sleeve. This preliminary alignment eliminates the need for post-installation breaking in and flushing procedures, directly improving productivity by reducing downtime.
2Ease of operation
If cleaning fluids are delivered through brush core holes, then fluid distribution is intended to be uniform, but holes near the chemical receiving end flow chemicals faster than holes at the opposite side, causing uneven cleaning
Solution Approach 1:
The brush sleeve is designed with varying pore densities in different regions to compensate for the pressure gradient in fluid flow. Areas with higher flow rates have higher pore densities to distribute the excess fluid, while areas with lower flow rates have lower pore densities, achieving uniform overall fluid distribution across the brush surface.
Solution Approach 2:
The pore size, pore shape, or pore density of the porous material is varied as a parameter along the length of the brush sleeve to compensate for non-uniform fluid pressure distribution. This parameter change ensures that fluid flows uniformly through all regions of the brush despite the pressure gradient.
3Reliability
If dummy wafers are used to ensure brush cleanliness and operational stability, then alignment and contact can be verified, but this non-value added step increases cost in time and dummy wafers
Solution Approach 1:
The monolithic brush design with pre-aligned protrusions and controlled pore distribution ensures consistent performance from the first use. This preliminary design optimization eliminates the need for preliminary breaking in and flushing procedures that currently require dummy wafers, directly reducing time loss and costs.
Solution Approach 2:
The uniform pore distribution and monolithic structure of the brush enable it to self-regulate fluid flow and maintain consistent contact with the wafer surface from initial installation. This self-service capability eliminates the need for external verification using dummy wafers, reducing both time and material costs.
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
This solution enhances the uniformity of material removal and cleaning, reduces downtime, and improves the efficiency of semiconductor wafer processing by maintaining node alignment and preventing twisting, leading to higher device yields and reduced costs.
Implementation Method 1
The porous pad material has a monolithic structure and can fill one or more of the channels in the base thereby interlocking the porous pad material with the base
Implementation Method 2
Chemical-mechanical polishing (CMP) operations are performed to remove the excess metal. After any such CMP operation, it is necessary that the planarized wafer be cleaned to remove particulates and contaminants
Implementation Method 3
The combination of rotational movement of the brush and force or pressure placed on the brush against the wafer as well as the application of cleaning fluids or deionized water causes residual slurry materials to be removed from the surface of the wafer
Data Source
AI summary
The present invention includes methods and materials for making a brush or pad for removing materials, particles, or chemicals from a substrate. The brush or pad includes a rotatable base for supporting a porous pad material. The base include an inner surface and an outer surface and a plurality of channels in the base for interlocking the porous pad material with the base. A porous pad material covers at least a portion of the outer surface of the base and is used for removing material from various substrates. The porous pad material fills one or more of the channels in the base and interlocks the porous pad material with the base. Preferably the channels fluidly connect said inner surface with the outer surface of the base and aid in the alignment of porous pad nodes and the distribution of fluid within the porous pad.