Capacitor Dielectric Structure With Amorphous Layer for Low Leakage
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Solution Overview
Problem
Capacitor structures in DRAMs experience large leakage currents due to the high dielectric materials like hafnium oxide or zirconium oxide when in contact with metal electrodes, which affects their insulating properties and performance.
Innovation Solution
A capacitor structure is designed with a dielectric layer comprising a first amorphous layer that maintains an amorphous structure after annealing, inhibiting electron migration, and a high dielectric constant layer formed by crystallizing an initial dielectric layer, reducing leakage current and enhancing dielectric properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high dielectric constant materials (hafnium oxide, zirconium oxide) are used in the dielectric layer, then the dielectric properties are improved, but large leakage current is generated when in contact with metal electrodes
Solution Approach 1:
An amorphous layer is introduced as an intermediary between the metal electrode and the high dielectric constant material. This amorphous layer acts as a buffer that prevents direct contact between the electrode and the crystalline dielectric material, thereby suppressing leakage current while preserving the high dielectric constant properties of the underlying layer.
Solution Approach 2:
The dielectric layer is constructed as a composite structure combining an amorphous layer with a high dielectric constant material layer. This composite approach allows the system to simultaneously achieve the low leakage current characteristics of amorphous materials and the high dielectric constant properties of crystalline materials like hafnium oxide or zirconium oxide.
2Ease of manufacture
If a simple single-layer dielectric structure is used, then the manufacturing process is simple, but the leakage current cannot be effectively controlled
Solution Approach 1:
The dielectric layer is segmented into multiple functional sub-layers: an amorphous layer for leakage suppression and a high dielectric constant material layer for enhanced dielectric properties. This segmentation allows each layer to perform its specific function optimally while maintaining overall manufacturing feasibility through sequential deposition processes.
3Reliability
If the dielectric layer is made thicker to reduce leakage, then the insulating property is improved, but the capacitor density and integration are reduced
Solution Approach 1:
Instead of increasing the overall thickness of the dielectric layer, the invention changes the material composition and structural parameters by introducing an amorphous layer with specific properties. This allows achieving superior insulating performance through material parameter optimization rather than geometric scaling, thereby maintaining high capacitor density and integration 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 solution effectively reduces leakage current and improves the performance of the capacitor structure by maintaining an amorphous structure in the first amorphous layer and increasing the dielectric constant of the high dielectric constant layer, resulting in better insulating properties.
Implementation Method 1
The first amorphous layer maintains an amorphous structure after annealing, and electron migration is unlikely to occur in an amorphous structure
Implementation Method 2
electron migration is unlikely to occur in an amorphous structure, thereby the first amorphous layer can inhibit electron transport
Implementation Method 3
the high dielectric constant layer is formed by crystallizing an initial dielectric constant layer after annealing
Implementation Method 4
The high dielectric constant layer is formed by crystallizing an initial dielectric constant layer after annealing
Data Source
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AI summary
This application relates to the technical field of semiconductor technology, and specifically relates to a preparation method for a capacitor structure, a capacitor structure, and a memory, which are used to solve the technical problem of large leakage current of the capacitor structure. The preparation method for the capacitor structure includes: forming a dielectric layer on a first electrode, wherein, the dielectric layer includes a first amorphous layer and a high dielectric constant layer which are stacked, the first amorphous layer maintaining an amorphous structure after annealing, and the high dielectric constant layer being formed by crystallizing an initial dielectric constant layer after annealing; and forming a second electrode on the dielectric layer. Since the first amorphous layer remains an amorphous structure after annealing, electron transport can be suppressed, thereby reducing the leakage current of the capacitor structure.