Silver CMP Slurry Composition for Fast Polishing Without Scratches
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Solution Overview
Problem
Conventional copper wiring polishing slurries are inadequate for polishing silver due to its distinct properties, leading to silver residue, corrosion, and polishing scratches during semiconductor manufacturing.
Innovation Solution
A composition for chemical mechanical polishing comprising abrasive grains with a zeta potential of 10 mV or more, an oxidizing agent, and a nitrogen-containing heterocyclic compound, optimized with specific functional groups and pH, effectively polishes silver surfaces while reducing corrosion and scratches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional copper wiring polishing slurries are used for silver polishing, then polishing process can be maintained, but silver residue, corrosion, and polishing scratches occur on the silver surface
Solution Approach 1:
The invention changes the chemical composition parameters of the polishing slurry by introducing specific nitrogen-containing heterocyclic compounds and controlling the ratio of oxidizing agent to chelating agent within 10:1 to 50:1. This parameter optimization enables effective silver polishing without the harmful effects of conventional copper slurries, resolving the contradiction between maintaining polishing productivity and ensuring surface quality.
Solution Approach 2:
The nitrogen-containing heterocyclic compound acts as an intermediary substance that mediates between the oxidizing agent and silver surface. It enables controlled chemical reaction that removes silver uniformly while preventing corrosion and residue formation, thus achieving both high polishing speed and excellent surface quality simultaneously.
2Reliability
If silver is used as wiring material instead of copper, then device performance is enhanced with lower resistivity and higher electromigration stability, but conventional polishing techniques become ineffective causing silver residue and corrosion
Solution Approach 1:
The invention modifies the polishing slurry composition parameters specifically for silver materials, adjusting the oxidizing agent concentration, chelating agent type, and their ratio to achieve optimal polishing performance. This enables effective manufacturing process for silver-based wiring while maintaining the performance advantages of silver over copper.
Solution Approach 2:
The invention creates a new polishing slurry formulation that copies the successful functional structure of copper polishing slurries but adapts the chemical components specifically for silver. By transferring the conceptual framework while modifying the chemical parameters, it achieves ease of manufacture for silver wiring similar to established copper processes.
3Productivity
If high-speed polishing is performed on silver surfaces, then productivity is improved, but polishing scratches and surface defects increase
Solution Approach 1:
The invention optimizes multiple parameters including oxidizing agent concentration, chelating agent type, their ratio (10:1 to 50:1), and pH control to achieve the right balance between polishing speed and surface quality. This parameter optimization allows high-speed polishing while maintaining excellent surface finish with minimal scratches.
Solution Approach 2:
The polishing slurry maintains continuous effective action on the silver surface through the synergistic combination of oxidizing agent and chelating agent. This continuous controlled chemical-mechanical action enables sustained high-speed polishing without generating scratches or surface defects, maintaining manufacturing precision throughout the process.
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 enables high-speed polishing of silver surfaces with reduced corrosion and scratches, achieving a polished surface with excellent reflective properties.
Implementation Method 1
an oxidizing agent
Implementation Method 2
a nitrogen-containing heterocyclic compound
Data Source
AI summary
Provided are: a composition for chemical mechanical polishing; and a polishing method using the same. The composition allows rapid polishing of a polishing surface that contains a silver material for wiring, and makes it possible to obtain a polished surface having a high reflective property. This composition for chemical mechanical polishing comprises (A) abrasive grains, (B) a liquid medium, (C) an oxidizing agent, and (D) a nitrogen-containing hetrocyclic compound. The absolute value of the zeta potential of the (A) component of the composition for chemical mechanical polishing is 10 mV or more. When the content of the (C) component is noted as Mc (mass %) and the content of the (D) component is noted as Md (mass %), Mc/Md is 10 to 200.