Metal Nitride Capacitor Electrodes With Low-Impurity ALD Interface Control
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Solution Overview
Problem
The degradation of electrode materials during high-temperature processes in capacitor manufacturing leads to performance deterioration, particularly in capacitors with high dielectric constants, which is exacerbated by the inclusion of carbon impurities and the formation of depletion layers in the interfacial layers.
Innovation Solution
The use of metal nitrides, represented by MM′N, as electrode materials with minimal carbon impurities, along with a manufacturing method involving atomic layer deposition (ALD) to form a metal nitride film, which includes purging steps to remove organic ligands and halogen compounds, followed by heat treatment to minimize impurities and stabilize capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-temperature process is used for thin film deposition to achieve high dielectric constant, then capacitor capacitance is improved, but electrode material degrades and performance deteriorates
Solution Approach 1:
A protective capping layer is formed on the electrode material before the high-temperature deposition process. This preliminary protective action prevents direct exposure and degradation of the electrode material during subsequent high-temperature processing, allowing the dielectric layer to be deposited at elevated temperatures without compromising electrode integrity
Solution Approach 2:
The capping layer acts as an intermediary barrier between the electrode material and the high-temperature environment. It mediates the thermal stress and chemical interactions, protecting the electrode while enabling the formation of high-dielectric-constant materials in the capacitor structure
2Ease of manufacture
If conventional deposition methods are used to simplify manufacturing, then process complexity is reduced, but carbon impurities and depletion layers form in interfacial regions
Solution Approach 1:
The deposition process is segmented into distinct sequential steps: forming the electrode material, depositing the capping layer, removing organic contaminants, and forming the dielectric layer. This segmentation allows each step to be optimized independently, ensuring high interfacial purity while maintaining manufacturing feasibility through standardized process modules
Solution Approach 2:
Organic ligands and carbon-containing contaminants are removed through purging and heat treatment steps before dielectric layer formation. This preliminary cleaning action prevents carbon impurity incorporation in the interfacial region, ensuring high manufacturing precision without requiring complex in-situ purification systems
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 resulting capacitors exhibit stable electrical performance with reduced capacitance variation under bias voltage, enhancing the integration and performance of integrated circuit devices by minimizing carbon impurities and depletion layer formation.
Implementation Method 1
performing a first purging of removing an organic ligand not being adsorbed on the substrate, among the first source
Implementation Method 2
supplying a second source including a halogen compound into the reaction chamber; performing a second purging of removing an organic ligand not reacted with the second source
Implementation Method 3
supplying a nitridant into the reaction chamber
Implementation Method 4
performing heat treatment for removing a halogen element remaining as a reaction by-product from the halogen compound
Data Source
AI summary
A capacitor includes: a lower electrode including a metal nitride represented by MM′N, wherein M is a metal element, M′ is an element different from M, and N is nitrogen; a dielectric layer on the lower electrode; an interfacial layer between the lower electrode and the dielectric layer and including a metal nitrate represented by MM′ON, wherein M is a metal element, M′ is an element different from M, N is nitrogen, and O is oxygen; and an upper electrode on the dielectric layer.