CMP Slurry Composition for Dielectric Auto-Stop Planarization
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Solution Overview
Problem
Existing chemical mechanical polishing (CMP) solutions struggle to balance polishing rate and planarization efficiency, particularly in achieving the auto-stop function for dielectric materials, leading to over-polishing and trench loss in micro-nano device manufacturing.
Innovation Solution
A CMP solution comprising cerium oxide, polyquaternium, carboxylic acid with a benzene ring, and polyvinylamine is formulated to form inhibiting films on particle surfaces, allowing controlled polishing rates based on step height, ensuring high rates at high step heights and low rates at low step heights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cerium oxide is used as polishing particles to improve polishing rate, then polishing rate is improved, but over-polishing occurs resulting in low planarization efficiency
Solution Approach 1:
The polishing solution creates different polishing rates at different locations based on step height. High step height areas maintain high polishing rates while low step height areas experience suppressed polishing rates, achieving localized quality control through the auto-stop function
Solution Approach 2:
The polishing rate parameter is dynamically changed based on step height conditions. The solution transitions from high polishing rate at high step heights to low polishing rate at low step heights, optimizing both productivity and precision through parameter adaptation
2Reliability
If negatively charged polymers are used to achieve auto stop function, then auto stop function is achieved, but step height lowering capacity is limited due to charge repulsion
Solution Approach 1:
Instead of using negatively charged polymers that repel from negatively charged silicon dioxide surfaces, this invention uses positively charged polyquaternium polymers that are attracted to and adsorb on the negatively charged surfaces, reversing the charge interaction mechanism to achieve better auto-stop performance
Solution Approach 2:
The invention combines cerium oxide polishing particles with polyquaternium polymers to create a composite polishing system that integrates both mechanical polishing and chemical inhibition mechanisms, achieving enhanced auto-stop function and step height lowering capacity
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 achieves a true auto-stop function, maintaining high polishing rates at high step heights and low rates at low step heights, reducing over-polishing and enhancing planarization efficiency with simplified processes.
Implementation Method 1
chemical mechanical polishing (CMP) has become the most effective and mature planarization technology
Implementation Method 2
the function of auto stop is achieved by using negatively charged polymers
Data Source
AI summary
Disclosed is a chemical mechanical polishing solution, which contains water, cerium oxide, polyquatemium, carboxylic acid containing a benzene ring and polyvinylamine. The function of auto stop in its true sense can only be achieved by using polyquatemium, carboxylic acid containing a benzene ring and polyvinylamine together. On the blanks, the polishing rates are low, while at the high step heights of patterned silicon chips, high polishing rates are kept. The lower is the step height, the better is the polishing rate inhibited, and thus the function of auto stop is achieved.