CMP Slurry Composition for Organic Layer Polishing
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Solution Overview
Problem
Conventional chemical mechanical polishing (CMP) slurries are ineffective in polishing organic layers, which are essential for advanced semiconductor device fabrication, particularly in V-NAND flash memory devices and double patterning technology, due to lack of etch selectivity with silicon-containing layers.
Innovation Solution
A CMP slurry composition comprising oxide-polishing particles, oxidants, polishing regulators, surfactants, pH regulators, and deionized water, optimized to achieve etch selectivity between organic and oxide layers, with specific concentrations and components such as silica, chlorate series oxidants, and carboxylic acid, enabling efficient polishing of organic layers with selectivity ranging from 6:1 to 430:1.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional CMP slurry is used for polishing organic layers, then the polishing process can be performed, but the etch selectivity between organic layer and silicon-containing layer is insufficient leading to ineffective polishing
Solution Approach 1:
The patent modifies the chemical composition parameters of the CMP slurry by incorporating specific oxidants (hydrogen peroxide, ammonium persulfate, potassium persulfate), polishing regulators (carboxylic acids, sulfonic acids, amino acids), and surfactants. These parameter changes enable the slurry to achieve high etch selectivity between organic layers and silicon-containing layers, effectively resolving the insufficient polishing effectiveness of conventional slurries.
Solution Approach 2:
The patent creates a composite CMP slurry system combining multiple functional components: oxide-polishing particles (silica, ceria, alumina) for mechanical removal, oxidants for chemical modification of organic materials, polishing regulators for controlling etch rates, and surfactants for improving slurry performance. This composite approach achieves both high etch selectivity and reliable polishing effectiveness.
2Reliability
If etch selectivity is increased to effectively polish organic layers, then polishing effectiveness improves, but process complexity increases due to multiple additives
Solution Approach 1:
The patent designs a multi-functional CMP slurry where each additive serves multiple purposes: oxidants not only enhance etch selectivity but also modify organic material properties; polishing regulators control both etch rate and surface quality; surfactants improve slurry stability and polishing uniformity. This multi-functionality reduces the need for separate process steps despite the complex composition.
3Productivity
If oxide-polishing particles are used for mechanical polishing, then polishing rate increases, but selectivity between organic and oxide layers decreases
Solution Approach 1:
The patent reduces reliance on purely mechanical polishing by oxide particles and introduces chemical mechanisms through oxidants that selectively react with organic materials. This chemically-assisted mechanical polishing allows the use of oxide-polishing particles while maintaining high etch selectivity, as the chemical action preferentially removes organic layers before mechanical polishing occurs.
Solution Approach 2:
The patent optimizes the concentration and size distribution of oxide-polishing particles in combination with chemical additives. By controlling particle parameters (size, concentration) and chemical parameters (oxidant concentration, pH), the system achieves both high polishing rate and high etch selectivity, resolving the trade-off between 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 CMP slurry composition effectively polishes organic layers with high selectivity, preventing process failures like peeling or delamination, and facilitates the fabrication of semiconductor devices without etch rate issues, ensuring efficient semiconductor device manufacturing.
Implementation Method 1
from about 0.1% to about 5% by weight of an oxidant
Implementation Method 2
from about 0.001% to about 5% by weight of oxide-polishing particles
Data Source
AI summary
A chemical mechanical polishing (CMP) slurry composition for polishing an organic layer and a method of forming a semiconductor device using the same are disclosed. The CMP slurry composition may include from 0.001% to 5% by weight of oxide-polishing particles; from 0.1% to 5% by weight of an oxidant; from 0% to 5% by weight of a polishing regulator; from 0% to 3% by weight of a surfactant; from 0% to 3% by weight of a pH regulator; and from 79% to 99.889% by weight of deionized water. The use of the CMP slurry composition makes it possible to allow a silicon-free organic layer to be polished with a selectivity higher than 6:1 with respect to an oxide layer.