CMP Slurry Composition for TiN Oxidation and Selectivity Control
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Solution Overview
Problem
Existing chemical mechanical polishing (CMP) processes face challenges in maintaining polishing selectivity and preventing oxidation of layers like TiN, particularly in semiconductor manufacturing, where different materials have varying polishing rates and are susceptible to property changes.
Innovation Solution
A slurry composition comprising metal oxides, metal nitrides, metal oxynitrides, polyols, catalysts, and pH adjusting agents, which includes polyols with specific molecular weights and concentrations to enhance electrostatic repulsion and prevent oxidation, thereby improving polishing selectivity between materials like B—Si, TiN, and SiN.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional slurry compositions are used for CMP processing, then polishing can be performed, but oxidation of TiN layers occurs and polishing selectivity between different materials deteriorates
Solution Approach 1:
A polyol molecule serving as an intermediary is introduced into the slurry composition. This polyol simultaneously performs multiple functions: it prevents oxidation of TiN layers by forming a protective layer, maintains zeta potential for effective polishing, and preserves polishing selectivity between different materials. The polyol acts as a mediator that coordinates between oxidation prevention and selectivity maintenance without compromising either function.
Solution Approach 2:
The slurry composition utilizes parameter changes in the polyol concentration (0.01-500 mM range) and molecular weight (10-1000 g/mol range) to optimize both oxidation prevention and polishing selectivity. By adjusting these parameters, the composition achieves a balance where the polyol provides sufficient protection against oxidation while maintaining appropriate electrostatic repulsion for selective polishing of different materials.
2Reliability
If polyol concentration is increased to prevent oxidation, then oxidation resistance improves, but polishing rate may be affected
Solution Approach 1:
The patent optimizes the polyol concentration parameter within a specific range (0.01-500 mM) to achieve the desired balance between oxidation resistance and polishing rate. This parameter optimization ensures that sufficient polyol is present to prevent oxidation while maintaining adequate polishing efficiency for semiconductor manufacturing applications.
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 slurry composition achieves high polishing selectivity and reduces oxidation, maintaining zeta potential and controlling polishing speeds, resulting in improved polishing rates and reduced property changes of TiN and SiN layers.
Implementation Method 1
which includes polyols with specific molecular weights and concentrations to enhance electrostatic repulsion and prevent oxidation
Implementation Method 2
The polyol may have about 0.01 mM to about 500 mM of a concentration
Data Source
AI summary
A slurry composition may include an abrasive, a solvent, and polyol. The abrasive may include any one of metal oxide, metal nitride, metal oxynitride, and a combination thereof. The polyol may have about 0.01 mM to about 500 mM of a concentration. Thus, high polishing selectivities may be provided between a B—Si layer, a TiN layer and a SiN layer by controlling a polishing rate of the TiN layer.