Copper CMP Formulation for Low Dishing and High Removal
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Solution Overview
Problem
Current chemical mechanical planarization (CMP) formulations for copper substrates fail to achieve high removal rates while minimizing metal dishing and selectivity to barrier materials, especially as technology nodes advance, leading to increased challenges in achieving low dishing and high removal rates.
Innovation Solution
A CMP formulation comprising particulate materials, specific amino acids, oxidizers, corrosion inhibitors, and surfactants, optimized to provide improved dishing performance and removal rates, including the use of colloidal silica, aminoacetic acid, and 1,2,4-triazole, with a balanced concentration of components to enhance copper polishing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional CMP formulations are used for copper substrates, then copper removal can be achieved, but metal dishing increases and removal rates decrease at advanced technology nodes
Solution Approach 1:
The patent changes the chemical composition parameters of the CMP formulation by incorporating specific amino acids (glycine, alanine, bicine, sarcosine) in optimized concentrations (0.01-16 wt%), along with specific oxidizers (0.25-5 wt%), corrosion inhibitors (0.1 ppm-2 wt%), and particulate materials (0.001-0.25 wt%). This parameter optimization resolves the contradiction by achieving both low dishing and high removal rates simultaneously through enhanced chemical selectivity and controlled mechanical removal.
Solution Approach 2:
The patent creates a composite CMP formulation system that combines multiple functional components: amino acids for selective chemical reaction with copper, oxidizers for controlled oxidation, corrosion inhibitors for metal protection, and particulate materials for mechanical polishing. This composite approach resolves the technical contradiction by synergistically combining chemical and mechanical actions to achieve low dishing with high removal rates.
2Productivity
If CMP formulations increase removal rates, then productivity improves, but metal loss and dishing increase
Solution Approach 1:
The patent optimizes the concentration parameters of amino acids (0.01-16 wt%) and corrosion inhibitors (0.1 ppm-2 wt%) to control the chemical reaction rate and metal dissolution. This parameter control enables high removal rates while minimizing unwanted metal loss through selective chemical action and inhibited non-productive dissolution.
Solution Approach 2:
The amino acids act as intermediary compounds that mediate the chemical reaction between the CMP formulation and copper substrate. They provide selective chemical etching of copper while the corrosion inhibitors simultaneously protect against excessive metal loss, enabling controlled high-rate removal with minimal waste.
3Manufacturing precision
If CMP formulations achieve high selectivity to barrier material, then manufacturing precision improves, but removal rate decreases
Solution Approach 1:
The patent adjusts the chemical composition parameters including amino acid types and concentrations (0.01-16 wt%), oxidizer levels (0.25-5 wt%), and pH conditions to optimize selectivity. These parameter changes enable the formulation to preferentially react with copper while sparing barrier materials, maintaining high removal rates through enhanced chemical specificity rather than reduced polishing intensity.
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 formulation achieves significant reductions in dishing and maintains high removal rates, demonstrating improved performance in advanced technology nodes by effectively polishing copper substrates with low metal loss and high selectivity to barrier layers.
Implementation Method 1
0.25 to 5 wt% oxidizer
Implementation Method 2
0.1 ppm to 2 wt % corrosion inhibitor
Implementation Method 3
0.001 to 0.25 wt % particulate materials selected from the group consisting of fumed silica, colloidal silica, fumed alumina, colloidal alumina
Data Source
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AI summary
Copper chemical mechanical polishing (CMP) formulation, method and system are disclosed. The CMP formulation comprises particulate materials, at least two or more amino acids, oxidizer, corrosion inhibitor, and rest being water.