Cerium CMP Polishing Liquid for Stopper Defect Control
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Solution Overview
Problem
In semiconductor manufacturing, existing CMP polishing liquids struggle to achieve a high polishing rate ratio of insulating materials to stopper materials while preventing scratches and holes in the stopper, which affects the reliability of semiconductor elements.
Innovation Solution
A CMP polishing liquid with cerium abrasive grains, a nonionic water-soluble compound, and a polymer compound containing carboxylic acid or carboxylate groups, where the basic pH adjusting agent content is less than 1.3×10−2 mol/kg, optimizing the pH and polymer compound content to suppress recessed defects in the stopper.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a polishing liquid with high polishing rate ratio R is used to increase insulating material removal efficiency, then the polishing rate ratio R is improved, but recessed defects occur in the stopper
Solution Approach 1:
The patent applies parameter changes by precisely controlling the pH of the polishing liquid within 3.0-5.0 and limiting the basic pH adjusting agent content to less than 1.3×10^-2 mol/kg. This parameter optimization enables the polishing liquid to achieve a high polishing rate ratio for insulating materials while preventing recessed defects in the stopper, resolving the contradiction between productivity and reliability
Solution Approach 2:
The patent uses a composite formulation combining cerium oxide abrasive grains with specific polymer compounds (having carboxylic acid or carboxylate groups) and nonionic water-soluble compounds. This composite material approach creates a synergistic effect that selectively removes insulating materials while protecting the stopper from recessed defects, simultaneously improving polishing rate ratio and stopper integrity
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 an excellent polishing rate ratio and reduces the occurrence of recessed defects in the stopper, enhancing the reliability and surface flatness of semiconductor elements.
Implementation Method 1
a ceria-based polishing liquid containing cerium oxide (ceria) particles as abrasive grains
Implementation Method 2
a polymer compound B having at least one selected from the group consisting of carboxylic acid groups and carboxylate groups
Data Source
AI summary
Provided is a CMP polishing liquid used for removing a part of an insulating portion of a base substrate, which includes a substrate, a stopper provided on one surface of the substrate, and the insulating portion provided on a surface of the stopper opposite to the substrate, by CMP to expose the stopper, the polishing liquid containing: abrasive grains containing cerium; a nonionic water-soluble compound A; a polymer compound B having at least one selected from the group consisting of carboxylic acid groups and carboxylate groups; a basic pH adjusting agent which is optionally contained; and water, in which a content of the basic pH adjusting agent is less than 1.3×10−2 mol/kg based on the total mass of the polishing liquid.