Gemini Surfactant CMP Slurry for Self-Stopping Planarization
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Solution Overview
Problem
Chemical mechanical polishing (CMP) processes face challenges in achieving high planarity and reducing surface defects during the polishing of semiconductor devices with ultrafine linewidths, particularly due to differences in polishing rates between convex and concave surfaces, and issues with storage stability of polishing slurries.
Innovation Solution
A polishing slurry composition incorporating abrasive particles, a pH-adjusting agent, and a surfactant with two or more ionic moieties and two or more lipophilic groups, known as a 'gemini surfactant', which controls the polishing rate and enhances dispersion stability, allowing for self-stopping of the polishing process and reducing surface defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional polishing slurries are used, then the polishing process can be carried out, but the polishing rate difference between convex and concave surfaces is slight making self-stopping difficult
Solution Approach 1:
The patent modifies the chemical composition parameters of the polishing slurry by incorporating specific surfactants (anionic, cationic, or nonionic types) and pH-adjusting agents to create a slurry system that exhibits differential polishing rates. This parameter change enables the polishing process to automatically stop when the desired planarity is achieved, as the convex surfaces are polished at a higher rate than concave surfaces.
Solution Approach 2:
The patent introduces surfactants as intermediary substances that mediate between the abrasive particles and the semiconductor surface. These surfactants modify the interfacial properties and enhance the chemical mechanical polishing action, creating a system where convex surfaces are preferentially polished compared to concave surfaces, thereby enabling self-stopping capability.
2Reliability
If conventional polishing slurries are used, then polishing can proceed, but surface defects occur and storage stability is poor
Solution Approach 1:
The patent introduces surfactants as intermediary substances that mediate between the abrasive particles and the semiconductor surface. These surfactants modify the interfacial properties and enhance the chemical mechanical polishing action, creating a system where convex surfaces are preferentially polished compared to concave surfaces, thereby enabling self-stopping capability.
Solution Approach 2:
The patent modifies the chemical composition parameters of the polishing slurry by incorporating specific surfactants (anionic, cationic, or nonionic types) and pH-adjusting agents to create a slurry system that exhibits differential polishing rates. This parameter change enables the polishing process to automatically stop when the desired planarity is achieved, as the convex surfaces are polished at a higher rate than concave surfaces.
3Productivity
If high integration and miniaturization are pursued, then semiconductor device performance improves, but CMP process requirements become more stringent
Solution Approach 1:
The patent modifies the chemical composition parameters of the polishing slurry by incorporating specific surfactants (anionic, cationic, or nonionic types) and pH-adjusting agents to create a slurry system that exhibits differential polishing rates. This parameter change enables the polishing process to automatically stop when the desired planarity is achieved, as the convex surfaces are polished at a higher rate than concave surfaces.
Solution Approach 2:
The patent introduces surfactants as intermediary substances that mediate between the abrasive particles and the semiconductor surface. These surfactants modify the interfacial properties and enhance the chemical mechanical polishing action, creating a system where convex surfaces are preferentially polished compared to concave surfaces, thereby enabling self-stopping capability.
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 planarity and self-stopping of the polishing process, reduces surface defects, and improves storage stability by controlling the relative polishing rates between convex and concave surfaces, while maintaining good dispersion stability.
Implementation Method 1
a surfactant with two or more ionic moieties (i.e. hydrophilic moieties) and two or more lipophilic groups
Implementation Method 2
the polishing pad is moved relative to the material to physically planarize irregularities of the material
Implementation Method 3
the polishing pad is moved relative to the material to physically planarize irregularities
Implementation Method 4
the polishing slurry is chemically reacted with the surface of the material
Data Source
AI summary
Disclosed are a slurry composition for chemical mechanical polishing and a precursor composition thereof. The polishing slurry composition includes deionized water, abrasive particles, a pH-adjusting agent and a surfactant, wherein the surfactant includes two or more ionic moieties and two or more lipophilic groups. The polishing slurry composition can polish convex surfaces of a semiconductor having a step height at a higher rate than the polishing rate for concave surfaces acting as polishing stop layers of the semiconductor so that the polishing can be self-stopped, reduces the occurrence of surface defects after the polishing process, and has a high degree of polishing planarization and good dispersion stability.