Polishing composition for semiconductor process and method of manufacturing substrate using same
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Solution Overview
Problem
In semiconductor manufacturing, chemical mechanical polishing (CMP) processes face challenges in achieving sufficient polishing rate and speed while minimizing dishing or erosion, especially after metal wiring formation.
Innovation Solution
A polishing composition for semiconductor processing is developed, which includes abrasive particles with positive surface charges and specific metal ions, such as alkali metal ions and secondary metal ions like iron or copper, in controlled ratios to enhance dispersibility and polishing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional slurry compositions are used to achieve sufficient polishing rate, then polishing speed increases, but dishing and erosion worsen
Solution Approach 1:
The patent changes the chemical parameters of the slurry by introducing specific metal ions (Fe2+, Fe3+, Cu2+, Ni2+, Al3+, Ca2+, Zn2+) with controlled concentrations and ratios. These parameter changes modify the chemical reactivity of the slurry, enabling effective polishing at lower mechanical pressures, thus achieving high polishing rates while minimizing dishing and erosion.
Solution Approach 2:
The patent creates a composite slurry system combining multiple metal ions with abrasive particles. This composite composition synergistically enhances polishing performance: different metal ions contribute different chemical reactivities, while the abrasive particles provide mechanical removal, achieving both high polishing rate and surface uniformity simultaneously.
2Productivity
If higher polishing pressure is applied to increase polishing rate, then productivity improves, but dishing and erosion increase
Solution Approach 1:
The patent replaces purely mechanical polishing with a chemical-mechanical hybrid approach. The metal ions in the slurry provide chemical etching action that works synergistically with mild mechanical abrasion, enabling effective material removal at lower pressures, thus avoiding dishing and erosion while maintaining high polishing rates.
3Manufacturing precision
If abrasive particles with negative surface charges are used, then conventional polishing is achieved, but dispersibility and polishing efficiency are insufficient
Solution Approach 1:
The patent changes the surface charge parameter of abrasive particles from negative to positive through surface modification. This parameter change enables better electrostatic interaction with the chemically activated surface, improving both dispersibility and polishing efficiency, and allows the slurry to work effectively at lower concentrations.
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 effectively improves the dispersibility of abrasive particles and enhances polishing rates on silicon oxide and tungsten films, while minimizing defects and maintaining electrical properties of the semiconductor substrates.
Implementation Method 1
the abrasive particles have surface positive charges, and wherein an amount of the first metal ion is 15 ppm (by weight) to 100 ppm (by weight)
Implementation Method 2
a substrate is pressurized and rotated, while a slurry is applied to a polishing pad, and the surface thereof is polished
Implementation Method 3
the polishing composition for semiconductor processing includes abrasive particles and a first metal ion, which is an alkali metal ion
Data Source
AI summary
The polishing composition for semiconductor processing includes abrasive particles and a first metal ion, which is an alkali metal ion, wherein the abrasive particles have surface positive charges, and wherein an amount of the first metal ion is 15 ppm (by weight) to 100 ppm (by weight).