Tungsten CMP Slurry with Polyaminosilane for Low Etch Rates
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Solution Overview
Problem
Existing CMP compositions for polishing tungsten on semiconductor substrates face challenges in achieving a high polishing rate while minimizing etch rates and surface irregularities, particularly in patterned wafers.
Innovation Solution
A CMP slurry composition comprising a solvent, abrasive agent, and a corrosion inhibitor, where the corrosion inhibitor is a polyaminosilane with a weight average molecular weight of 500 g/mol to 5,000 g/mol, which includes silicon-bonded hydroxyl groups and free amino groups, is used to enhance polishing efficiency and reduce etch rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional CMP compositions are used to increase polishing rate, then tungsten polishing efficiency improves, but etch rate of patterned wafers increases and surface irregularities worsen
Solution Approach 1:
The patent changes the molecular weight parameter of the corrosion inhibitor to a specific range (500-5000 g/mol) to optimize the chemical interaction with tungsten. This parameter adjustment allows the composition to achieve high polishing rates while controlling etch rates and minimizing surface irregularities on patterned wafers
Solution Approach 2:
The patent uses a composite corrosion inhibitor system combining polyaminosilane with specific molecular weight characteristics and functional groups. This composite approach enables simultaneous achievement of high polishing rate and low etch rate by creating a balanced chemical mechanism that protects patterned wafer surfaces while maintaining polishing efficiency
2Productivity
If stronger corrosive agents are used to increase polishing rate, then material removal speed improves, but etch rate of patterned wafers increases
Solution Approach 1:
The patent adjusts the molecular weight parameter of the corrosion inhibitor to a specific range (500-5000 g/mol) to optimize the chemical interaction with tungsten. This parameter adjustment allows the composition to achieve high polishing rates while controlling etch rates and minimizing surface irregularities on patterned wafers
Solution Approach 2:
The patent converts the potentially harmful corrosive action into a beneficial polishing mechanism by using polyaminosilane with specific molecular weight and functional groups. The corrosion inhibitor creates a controlled chemical reaction that removes tungsten at high rates while simultaneously protecting patterned wafer surfaces from excessive etching
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 achieves a high polishing rate for tungsten, reduces etch rates of patterned wafers, and improves the removal of surface irregularities, maintaining stability and effectiveness across a range of pH conditions.
Implementation Method 1
the corrosion inhibitor includes a polyaminosilane having a weight average molecular weight of 500 g/mol to 5,000 g/mol, or a salt thereof
Implementation Method 2
an abrasive agent
Implementation Method 3
chemical accelerators such as oxidizing agents, catalysts, or the like
Data Source
AI summary
A CMP slurry composition for polishing tungsten and a method of polishing tungsten using the composition, the composition includes a solvent, the solvent comprising a polar solvent or a nonpolar solvent; an abrasive agent; and a corrosion inhibitor, wherein the corrosion inhibitor includes a polyaminosilane having a weight average molecular weight of 500 g/mol to 5,000 g/mol, or a salt thereof.