Porous CMP Wafer Cleaning Brush for Nanoparticle Removal
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Solution Overview
Problem
Conventional post-CMP cleaning processes for semiconductor wafers suffer from particle defect issues due to slurry abrasives, polish wastes, and byproducts, particularly affecting advanced technology nodes with feature sizes down to 10-100 nm.
Innovation Solution
Development of brushes with PVA-copolymer or other polymers, including cellulose, lignin, nylon, or polytetrafluoroethylene backbones, and designed nanometer-scale pores, along with functional groups to enhance brush-particle affinity, improving the removal of particles up to 100 nm in size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional sponge brushes are used for post-CMP cleaning, then the cleaning process is simple and cost-effective, but particle defects increase due to inability to remove nanometer-scale particles
Solution Approach 1:
The brush is formed from a porous polymeric material with controlled pore sizes (50-1000 nm) that enable the brush to effectively capture and remove nanometer-scale particles from the wafer surface during post-CMP cleaning, directly addressing the particle removal efficiency requirement
Solution Approach 2:
The brush utilizes a composite structure combining a polymeric backbone material (cellulose, lignin, nylon, or PTFE) with functional groups and porous structures, creating a material that integrates mechanical cleaning capability with enhanced particle affinity and removal efficiency
2Manufacturing precision
If brush pore size is reduced to remove smaller particles, then particle removal efficiency improves, but brush manufacturing complexity increases
Solution Approach 1:
The patent specifies controlling the pore size parameter within a defined range (50-1000 nm) and controlling the degree of polymerization (500-20,000) to achieve the desired particle removal capability while maintaining manufacturability through established polymer processing techniques
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
Enhances post-CMP cleaning performance by reducing the amount of tiny particles remaining on wafers, thereby improving yield and productivity.
Implementation Method 1
the outer surface is formed by a porous polymeric material having pores... enhancing brush-particle affinity
Implementation Method 2
brushes are used to remove the residue on the polished wafers... relative movement of the polishing pad and the wafer surface
Data Source
AI summary
Tools and brushes for cleaning wafers after a Chemical Mechanical Polishing (CMP) process and methods for fabricating such brushes are provided. A brush for cleaning wafers after a Chemical Mechanical Polishing (CMP) process includes a sleeve member; and a plurality of spaced-apart nodules disposed to protrude from the sleeve member, and wherein an outer surface of the nodules is formed by a porous polymeric material having pores, and wherein the pores have a maximum pore dimension of 1000 nanometers (nm).