CMP Slurry with Accelerators for Silicon Nitride and Polysilicon Removal
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Solution Overview
Problem
Current chemical mechanical polishing slurries for silicon nitride and polysilicon in semiconductor manufacturing often lack selectivity, particularly in emerging technologies that require non-selective high removal rates for both materials, which are scarce in the market.
Innovation Solution
An acid chemical mechanical polishing slurry containing low concentration abrasive particles and specific compounds such as pyridine, piperidine, pyrrolidine, pyrrole, and pyrimidine derivatives with carboxyl or amino groups, along with silica abrasive particles and accelerating agents, to enhance the removal rates of silicon nitride and polysilicon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional polishing slurry is used to achieve high removal rate of silicon nitride, then the removal rate of polysilicon also increases, but selectivity is lost
Solution Approach 1:
The patent changes the chemical parameters of the polishing slurry by introducing specific accelerators (pyridine, piperidine, pyrrolidine, pyrrole compounds with carboxyl groups and pyrimidine compounds with amino groups) and adjusting pH to 2-6. These parameter changes enable high removal rates of silicon nitride while maintaining selectivity against polysilicon, resolving the contradiction between productivity and manufacturing precision.
2Manufacturing precision
If selective polishing slurry is used for silicon dioxide with low silicon nitride removal, then silicon nitride barrier layer is preserved, but high removal rate of silicon nitride is not achieved
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition with specific accelerators and pH adjustment to achieve non-selective high removal rates for both silicon nitride and polysilicon, which was previously scarce in the market.
Solution Approach 2:
The patent uses composite material approach by combining silica abrasive particles with organic accelerators (pyridine, piperidine, pyrrolidine, pyrrole, pyrimidine compounds) to create a polishing slurry that achieves high removal rates for multiple materials simultaneously.
3Productivity
If high concentration abrasive particles are used to increase removal rate, then polishing speed increases, but slurry viscosity and complexity increase
Solution Approach 1:
The patent changes the concentration parameter of abrasive particles to low levels (1-15% mass percent) while introducing organic accelerators to maintain high removal rates. This resolves the contradiction by achieving high productivity without increasing slurry complexity or viscosity.
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 significantly increases the removal rates of both silicon nitride and polysilicon, achieving improved polishing performance across various semiconductor processes by adjusting the concentration of these compounds and maintaining a pH range of 2-6.
Implementation Method 1
silica abrasive particles
Implementation Method 2
one or more compounds selected from pyridine compound, piperidine compound, pyrrolidine compound or pyrrole compound and their derivatives, which have one or more carboxyl groups, and pyrimidine compound having one or more amino groups
Data Source
AI summary
The present invention discloses a chemical mechanical polishing slurry, and the chemical mechanical polishing slurry comprises silica abrasive particles and accelerating agents, wherein the accelerating agents are selected from pyridine compound, piperidine compound, pyrrolidine compound or pyrrole compound and their derivatives, which have one or more carboxyl groups, and pyrimidine compound and its derivatives, which have one or more amino groups. The chemical mechanical polishing slurry can simultaneously increase the removal rate of both silicon nitride and polysilicon.