Multimodal CMP Composition for Silicon Oxide Planarization
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Solution Overview
Problem
Current chemical-mechanical polishing (CMP) methods for silicon oxide-containing substrates face challenges in achieving high removal rates without excessive erosion of silicon oxide within trenches, which is crucial for maintaining device performance and throughput in shallow trench isolation processes.
Innovation Solution
A CMP composition comprising ceria particles with specific size ranges, surface-modified silica or organic particles, and a polymer additive, along with a pH-adjusting agent, is used to create a multimodal particle size distribution, optimizing the polishing process to achieve efficient planarization with controlled removal rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high removal rates are used to increase device throughput, then productivity is improved, but trench erosion increases causing increased device defectivity
Solution Approach 1:
The patent applies parameter changes by using a multimodal particle size distribution with specific weight percentages of different particle sizes (0.03-0.3 μm particles at 5-20 wt%, 0.3-1.0 μm particles at 30-70 wt%, and 1.0-3.0 μm particles at 5-20 wt%). This distribution optimizes the balance between removal rate and selectivity, allowing high throughput while minimizing trench erosion and device defectivity.
Solution Approach 2:
The patent uses a composite abrasive system combining three different particle size ranges in specific proportions. This composite approach creates synergistic effects where larger particles provide aggressive material removal for high productivity, while smaller particles provide precision control and selectivity to prevent trench erosion and maintain device reliability.
2Productivity
If rapid blanket removal is achieved, then productivity is improved, but selectivity is worsened resulting in excessive trench erosion
Solution Approach 1:
The patent optimizes the particle size distribution parameters to achieve rapid blanket removal while maintaining selectivity. The specific weight percentages of different particle sizes (0.03-0.3 μm at 5-20 wt%, 0.3-1.0 μm at 30-70 wt%, 1.0-3.0 μm at 5-20 wt%) create a balanced system that provides both high removal rate and controlled selectivity, preventing excessive trench erosion.
Solution Approach 2:
The multimodal particle size distribution provides local quality differentiation where smaller particles (0.03-0.3 μm) provide precision and selectivity for trench areas, while larger particles (1.0-3.0 μm) provide aggressive removal for blanket oxide areas. This spatial differentiation of particle functions enables simultaneous high productivity and maintained selectivity.
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 composition effectively enhances removal rates and planarization efficiency while minimizing trench erosion, thereby improving device throughput and reducing defectivity.
Implementation Method 1
The polishing of the substrate typically is further aided by the chemical activity of the polishing composition and/or the mechanical activity of an abrasive suspended in the polishing composition
Implementation Method 2
The polishing of the substrate typically is further aided by the chemical activity of the polishing composition and/or the mechanical activity of an abrasive suspended in the polishing composition
Implementation Method 3
The polishing of the substrate typically is further aided by the chemical activity of the polishing composition
Data Source
AI summary
The invention provides chemical-mechanical polishing compositions and methods of chemically-mechanically polishing a substrate with the chemical-mechanical polishing compositions. The polishing compositions comprise first abrasive particles, wherein the first abrasive particles are ceria particles, second abrasive particles, wherein the second abrasive particles are ceria particles, surface-modified silica particles, or organic particles, a pH-adjusting agent, and an aqueous carrier. The polishing compositions also exhibit multimodal particle size distributions.