STI CMP Slurry With Ceria-Coated Abrasives for Faster Oxide Removal
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Solution Overview
Problem
Current Shallow Trench Isolation (STI) chemical mechanical planarization (CMP) processes face challenges in achieving high oxide film removal rates with low abrasive concentrations and require effective chemical additives to boost removal rates for high throughput device fabrication.
Innovation Solution
The use of ceria-coated inorganic oxide abrasive particles combined with a gelatin molecule possessing both negative and positive charges, made from natural or synthetic sources, as a chemical additive in the CMP polishing composition to enhance oxide film removal rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional CMP processes are used, then oxide film removal is achieved, but removal rate is insufficient for high throughput fabrication
Solution Approach 1:
The patent modifies the chemical composition parameters of the CMP slurry by incorporating gelatin molecules with specific charge characteristics and controlling pH levels (maintained between 2-12), which fundamentally changes the removal mechanism from purely mechanical to chemically-enhanced mechanical, achieving up to 246% improvement in TEOS removal rate and 500% improvement in SiN removal rate
Solution Approach 2:
The invention creates a composite polishing system combining ceria-coated inorganic oxide abrasive particles with gelatin molecules, where the gelatin acts as a chemical additive that interacts with the oxide films during polishing. This composite approach synergistically combines the mechanical removal capability of abrasives with the chemical etching effect of gelatin, enabling dramatically enhanced removal rates while maintaining process control
2Productivity
If high abrasive concentration is used to increase removal rate, then productivity improves, but cost and potential damage to underlying structures increases
Solution Approach 1:
The gelatin molecules serve as a chemical intermediary that facilitates oxide film removal through chemical interaction rather than purely mechanical abrasion. The gelatin with its amphoteric nature (containing both positive and negative charges) chemically interacts with the oxide surfaces, enabling removal at lower abrasive concentrations and reducing mechanical damage to the substrate while maintaining high productivity
3Productivity
If conventional polishing compositions are used, then process simplicity is maintained, but removal rate enhancement is insufficient
Solution Approach 1:
The patent systematically optimizes key parameters including pH (maintained between 2-12), gelatin concentration, and abrasive particle size to achieve maximum removal rates. By controlling these parameters, the formulation achieves enhanced performance without requiring excessively complex multi-component systems, balancing simplicity with effectiveness
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 ceria-coated inorganic oxide particles with gelatin as a chemical additive significantly increase oxide film removal rates, demonstrating up to 246% improvement in TEOS and 500% improvement in SiN film removal rates, making the process more efficient for STI CMP applications.
Implementation Method 1
a gelatin molecule possessing both negative and positive charges, made from natural or synthetic sources, as a chemical additive in the CMP polishing composition to enhance oxide film removal rates
Implementation Method 2
ceria-coated inorganic oxide abrasive particles
Data Source
AI summary
High oxide film removal rate Shallow Trench Isolation (STI) chemical mechanical planarization (CMP) polishing compositions, methods, and systems of use therefore are provided. The CMP polishing composition comprises abrasives of ceria coated inorganic oxide particles, such as ceria-coated silica; and a chemical additive for providing a high oxide film removal rate. The chemical additive is a gelatin molecule possessing negative and positive charges on the same molecule.