Silicate Composite Polishing Pad for CMP Scratching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Chemical mechanical polishing (CMP) operations face issues such as wafer scratching due to foreign materials in polishing pads, leading to defects and variability in pad performance, which affect the planarization and removal rate of semiconductor, magnetic, and optical substrates.
Innovation Solution
A polishing pad with a polymeric matrix and fluid-filled polymeric microelements containing silicate-containing regions, where silicate particles are distributed to coat less than 50% of the outer surface, and air classification is used to minimize excessive scratching by separating silicate particles with specific structures, resulting in a consistent and uniform polishing surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If glass spheres or ceramic particles are used as polishing media, then high removal rate is achieved, but wafer scratching and gouging occur
Solution Approach 1:
The patent uses composite materials by combining polymeric microelements with embedded silicate particles. The polymeric matrix provides softness and compliance to prevent scratching, while the silicate particles provide the abrasive action for high removal rate. This composite structure resolves the contradiction between removal rate and scratching by integrating both hard and soft properties in a unified polishing media.
Solution Approach 2:
The patent applies local quality by having different regions of the polishing pad have different properties. The polymeric microelements provide a soft base material that prevents scratching, while the embedded silicate particles provide localized abrasive zones that enable high removal rate. This spatial distribution of different material qualities allows simultaneous achievement of both goals.
2Reliability
If careful casting techniques with controlled curing cycles are used, then pad-to-pad variability is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-forming the polymeric microelements with embedded silicate particles before incorporating them into the polishing pad matrix. This preliminary preparation of the polishing media ensures consistent properties throughout the pad, reducing pad-to-pad variability without requiring complex multi-step curing processes. The microelements are prepared in advance with controlled silicate embedding, simplifying the overall manufacturing process.
3Object-affected harmful factors
If silicate particles are embedded in polymeric microelements, then scratching is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent utilizes porous materials by employing polymeric microelements with controlled porosity and void spaces. The porous structure allows for uniform distribution of silicate particles throughout the microelement matrix while maintaining manufacturing feasibility. The porous nature of the polymeric microelements provides a framework that naturally disperses silicate particles, reducing the need for extremely precise manufacturing controls while still achieving consistent scratching resistance.
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 solution reduces scratching and gouging defects, enhances planarization, and minimizes pad-to-pad variability, improving the removal rate and consistency of polishing pads for advanced CMP applications.
Implementation Method 1
the polymeric microelements having an outer surface and being fluid-filled for creating texture at the polishing surface
Implementation Method 2
silicate-containing regions being spaced to coat less than 50 percent of the outer surface of the polymeric microelements
Implementation Method 3
air classification is used to minimize excessive scratching by separating silicate particles with specific structures
Data Source
AI summary
The invention provides a polishing pad useful for polishing at least one of semiconductor, magnetic and optical substrates. It includes a polymeric matrix having a polishing surface. Polymeric microelements are distributed within the polymeric matrix and at the polishing surface of the polymeric matrix. Silicate-containing regions distributed within each of the polymeric microelements coat less than 50 percent of the outer surface of the polymeric microelements. Less than 0.1 weight percent total of the polymeric microelements are associated with i) silicate particles having a particle size of greater than 5 μm; ii) silicate-containing regions covering greater than 50 percent of the outer surface of the polymeric microelements; and iii) polymeric microelements agglomerated with silicate particles to an average cluster size of greater than 120 μm.