Copper Polishing Slurry for Display Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current copper polishing slurries for display devices face challenges in efficiently planarizing multi-layered wiring without increasing thickness and achieving excellent surface characteristics for low-resistance copper wiring, often requiring multiple polishing steps which are costly and inefficient.
Innovation Solution
A slurry comprising an abrasive, a catalyst with single molecule iron ions, a polishing suppressant, and an oxidizing agent, which reacts to generate hydroxyl radicals for enhanced copper oxidation and mechanical polishing, allowing for one-step polishing of copper layers on insulating layers without dishing or erosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional copper polishing slurries are used for multi-layered wiring planarization, then polishing speed may be improved, but surface non-uniformity transfers to next layers and process efficiency decreases due to multiple required steps
Solution Approach 1:
The invention combines copper polishing and insulating layer planarization into a single integrated CMP process. The slurry formulation with specific abrasive particles (0.5-5.0 wt% silica, 0.1-1.0 wt% alumina), catalyst (0.1-2.0 wt% iron citrate), polishing suppressant (0.1-2.0 wt% DTPMPA), and oxidizing agent (0.1-1.0 wt% hydrogen peroxide) enables simultaneous polishing of both copper wiring and insulating layer surfaces in one step, eliminating the need for separate polishing steps and improving overall process efficiency
2Manufacturing precision
If multiple polishing steps are used for planarization, then surface characteristics may be improved, but manufacturing cost increases and process complexity increases
Solution Approach 1:
The invention merges multiple polishing functions into a single slurry formulation that simultaneously achieves copper polishing and insulating layer planarization. The balanced composition of abrasives, catalyst, suppressant, and oxidizing agent provides uniform material removal rates for both copper and insulating materials, delivering excellent surface characteristics in one step and reducing manufacturing complexity
Solution Approach 2:
The invention optimizes slurry parameters including pH (maintained at 8-10 using ammonia or sodium hydroxide), abrasive particle size distribution, and chemical concentrations to achieve optimal polishing performance. The pH control and chemical composition are specifically tuned to provide different material removal rates for copper versus insulating materials, enabling simultaneous planarization with excellent surface finish in a single step
3Reliability
If copper wiring layer thickness is reduced for low resistance, then electrical performance is improved, but surface non-uniformity increases and polishing becomes more difficult
Solution Approach 1:
The invention adjusts slurry parameters including reducing abrasive concentration (0.5-5.0 wt% silica, 0.1-1.0 wt% alumina) and optimizing catalyst content (0.1-2.0 wt% iron citrate) to achieve gentler, more uniform material removal. The controlled oxidizing agent concentration (0.1-1.0 wt% hydrogen peroxide) prevents excessive oxidation of thin copper layers while maintaining adequate polishing action, ensuring surface uniformity for low-resistance copper wiring
4Manufacturing precision
If wiring layers are increased for high resolution, then display quality is improved, but device thickness increases and planarization complexity increases
Solution Approach 1:
The invention combines copper polishing and insulating layer planarization into one integrated CMP step, enabling efficient planarization of multi-layered wiring structures. This single-step process removes surface non-uniformities from multiple stacked layers simultaneously, maintaining device thickness control while supporting high-resolution multi-layer configurations
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
This approach enables efficient, single-step polishing of copper layers, preventing surface defects and improving process efficiency by maintaining low thickness and achieving high-resolution, high-step stacked structures with excellent surface characteristics for copper wiring.
Implementation Method 1
The catalyst and the oxidizing agent may react to generate hydroxyl radicals
Implementation Method 2
enhanced copper oxidation and mechanical polishing
Implementation Method 3
a chemical mechanical polishing (CMP) method may be used. CMP is a process that polishes the surface to be planarized by providing a slurry including abrasives
Data Source
AI summary
Embodiments provide a slurry for polishing copper, a manufacturing method of a display device which uses the slurry, and the display device. The slurry for polishing copper includes an abrasive, a catalyst including a single molecule having an iron ion, a polishing suppressant, and an oxidizing agent.