Dielectric CMP Composition for Silicon Oxide Selectivity and Low Dishing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ceria abrasive-based chemical mechanical polishing (CMP) compositions for silicon-containing substrates face challenges in achieving improved removal rates, selectivity between different silicon materials, and minimizing erosion and dishing during the polishing process.
Innovation Solution
A CMP composition comprising cubiform ceria abrasive particles dispersed in a liquid carrier, along with a cationic polymer of low charge density, is used to enhance the polishing efficiency and selectivity for silicon oxide materials, reducing erosion and dishing while improving removal rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional ceria abrasive compositions are used, then polishing capability is provided, but removal rates are insufficient and selectivity between silicon materials is poor
Solution Approach 1:
The patent changes the chemical composition parameters by introducing a specific organic acid (picolinic acid) and controlling pH levels to optimize the removal rate of silicon oxide while maintaining selectivity. This chemical parameter modification enables the polishing composition to achieve both high productivity and material selectivity simultaneously
Solution Approach 2:
The patent creates a composite polishing composition by combining ceria abrasives with organic acids (picolinic acid and acetic acid) in specific concentrations. This composite formulation enhances the chemical mechanical polishing action, improving removal rates while maintaining control over selectivity between different silicon materials
2Productivity
If aggressive polishing is applied to improve removal rates, then throughput increases, but erosion and dishing increase
Solution Approach 1:
The patent modifies the chemical parameters by controlling pH within a specific range (2-6) and using buffered solutions to maintain stable polishing conditions. This prevents excessive mechanical action that causes erosion and dishing, allowing high throughput to be achieved while preserving surface quality and manufacturing precision
Solution Approach 2:
The organic acids (picolinic acid and acetic acid) act as intermediaries that facilitate the chemical reaction between the abrasive and silicon oxide, enabling material removal through a controlled chemical mechanism rather than aggressive mechanical action. This intermediary chemical action reduces erosion and dishing while maintaining high removal rates
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 achieves significantly improved silicon oxide removal rates, enhanced selectivity between silicon oxide and polysilicon, and reduced dishing and erosion, leading to improved throughput and cost-effectiveness in CMP processes.
Implementation Method 1
a cationic polymer having a charge density of less than about 6 milliequivalents per gram (meq/g)
Implementation Method 2
Chemical mechanical polishing is a key enabling technology in integrated circuit (IC) and micro-electro-mechanical systems (MEMS) fabrication
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A chemical mechanical polishing composition for polishing a substrate having a silicon oxygen material comprises, consists of, or consists essentially of a liquid carrier, cubiform ceria abrasive particles dispersed in the liquid carrier, and a cationic polymer having a charge density of less than about 6 meq/g.