Polishing Composition with Controlled Abrasive Grains for CMP
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Solution Overview
Problem
Current polishing liquids for semiconductor manufacturing fail to adequately maintain high polishing rates for barrier and insulating films while suppressing surface defects like fang and erosion, and do not effectively reduce dishing in metal wiring layers.
Innovation Solution
A polishing composition comprising abrasive grains with a specific aspect ratio and particle size distribution, an oxidant, a metal corrosion inhibitor, and a pH adjusting agent, which improves polishing rates and reduces surface defects by optimizing the shape and size of abrasive grains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the polishing rate of the barrier layer or insulating film is increased to reduce dishing, then the throughput of barrier layer CMP is improved, but surface defects such as fang and erosion are caused due to uneven localization of polishing components at boundary surfaces
Solution Approach 1:
The patent applies local quality by using abrasive grains with specifically controlled aspect ratios (0.95-1.20) and a bimodal particle size distribution. This creates locally optimized polishing characteristics: the controlled aspect ratio prevents excessive localization at boundary surfaces while the dual particle size modes (first mode: 0.03-0.20 μm, second mode: 0.20-0.50 μm) provide different polishing mechanisms that work synergistically to reduce fang and erosion while maintaining high polishing rates for barrier layers and insulating films
Solution Approach 2:
The patent applies parameter changes by precisely controlling the aspect ratio of abrasive grains within a narrow range (0.95-1.20) and defining a specific bimodal particle size distribution. These parameter optimizations change the physical and chemical interaction between abrasive grains and the polished surfaces, enabling high polishing rates for barrier layers and insulating films while suppressing boundary surface defects through reduced component localization
2Productivity
If conventional polishing liquids are used to maintain high polishing rates for barrier layers and insulating films, then productivity is improved, but surface defects such as fang and erosion cannot be sufficiently suppressed
Solution Approach 1:
The patent applies local quality by using abrasive grains with specifically controlled aspect ratios (0.95-1.20) and a bimodal particle size distribution. This creates locally optimized polishing characteristics: the controlled aspect ratio prevents excessive localization at boundary surfaces while the dual particle size modes (first mode: 0.03-0.20 μm, second mode: 0.20-0.50 μm) provide different polishing mechanisms that work synergistically to reduce fang and erosion while maintaining high polishing rates for barrier layers and insulating films
Solution Approach 2:
The patent applies composite materials by combining abrasive grains with a specific bimodal particle size distribution and controlled aspect ratio with organic acid components. This composite formulation creates synergistic effects where the uniquely shaped abrasive grains provide mechanical polishing while the organic acid components enhance chemical interaction, achieving both high polishing rates and superior surface quality that neither component could achieve alone
3Productivity
If the polishing rate of metal wiring layer is increased to reduce processing time, then productivity is improved, but dishing occurs due to excessive polishing of the wiring portion
Solution Approach 1:
The patent applies parameter changes by precisely controlling the aspect ratio of abrasive grains within a narrow range (0.95-1.20) and defining a specific bimodal particle size distribution. These parameter optimizations change the physical and chemical interaction between abrasive grains and the polished surfaces, enabling high polishing rates for barrier layers and insulating films while suppressing boundary surface defects through reduced component localization
Solution Approach 2:
The patent applies feedback by using a bimodal particle size distribution where the first mode (0.03-0.20 μm) provides fine polishing that corrects dishing while the second mode (0.20-0.50 μm) maintains high material removal rate. This dual-mode system creates a self-regulating polishing process that achieves both productivity and precision
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 maintains high polishing rates for barrier and insulating films while effectively suppressing surface defects such as fang and erosion, and reduces dishing in metal wiring layers, enhancing the overall polishing process efficiency.
Implementation Method 1
the convex portion of the metal film is removed by the mechanical friction between the polishing agent and the convex portion of the metal film
Implementation Method 2
a polishing liquid which is a polishing liquid for polishing the copper film, barrier metal film and interlayer insulating film of a semiconductor integrated circuit and contains silica particles having a specific silanol group density and an organic acid
Data Source
AI summary
[Problem] Provided is a polishing composition that can sufficiently maintain a high polishing rate for a barrier layer and an insulating film and suppress the occurrence of a surface defect such as erosion or fang.[Solution] Provided is a polishing composition which is used in the application to polish a polishing object having a barrier layer, a metal wiring layer and an insulating film, the polishing composition including abrasive grains, an oxidant, a metal corrosion inhibitor, a pH adjusting agent and water, in which an aspect ratio of abrasive grains is 1.22 or less and a ratio D90/D10 of a diameter D90 of particles when a cumulative particle weight from the fine particle side reaches 90% of the total particle weight to a diameter D10 of particles when the cumulative particle weight from the fine particle side reaches 10% of the total particle weight of the entire particles is 1.5 or more in a particle size distribution of the abrasive grains determined by a laser diffraction scattering method.