DRAM Capacitor Dielectric Layer Segmentation
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Solution Overview
Problem
Capacitors in DRAM devices face a challenge in achieving high capacitance without increasing leakage currents, which is a limitation in maintaining reliable data storage due to the trade-off between capacitance and dielectric layer thickness.
Innovation Solution
A capacitor structure is developed with a dielectric layer structure comprising a first, second, and third dielectric layer, where the second dielectric layer includes hafnium oxide or zirconium oxide with mixed tetragonal and orthorhombic crystal phases, and has a thickness less than 50% of the total dielectric layer structure, optimizing capacitance while minimizing leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the dielectric layer thickness is increased to achieve higher capacitance, then the capacitance increases, but the leakage current also increases
Solution Approach 1:
The dielectric layer is divided into three separate dielectric layers (first, second, and third dielectric layers) with different materials and thicknesses. This segmentation allows each layer to contribute differently to the overall capacitance while controlling leakage current through the specific configuration of materials and their interfaces.
Solution Approach 2:
The patent uses composite dielectric structures combining different materials (e.g., hafnium oxide, zirconium oxide, silicon oxide, titanium oxide) in specific layers. The second dielectric layer contains materials with at least two different crystal phases, creating a composite structure that optimizes both capacitance and leakage current characteristics through material property combinations.
2Object-generated harmful factors
If the dielectric layer thickness is reduced to decrease leakage current, then the leakage current decreases, but the capacitance also decreases
Solution Approach 1:
By segmenting the dielectric layer into three layers, the patent achieves a total thickness that limits leakage current while individual layers contribute to high capacitance. The thin second dielectric layer (less than 50% of total thickness) specifically controls leakage, while the combined structure maintains high capacitance.
Solution Approach 2:
The patent changes material parameters (dielectric constant, crystal phase composition) and thickness parameters of each layer to optimize performance. The second dielectric layer uses materials with specific crystal phases and controlled thickness to achieve the right balance between capacitance and leakage current suppression.
3Quantity of substance
If materials with high dielectric constant are used to increase capacitance, then the capacitance increases, but the manufacturing complexity increases
Solution Approach 1:
Different regions of the dielectric structure use different materials optimized for specific functions. The second dielectric layer uses materials with high dielectric constant and specific crystal phases for capacitance enhancement, while other layers use materials optimized for leakage control and interface quality, reducing overall manufacturing complexity through functional specialization.
Solution Approach 2:
The composite dielectric structure combines materials that can be deposited using standard semiconductor manufacturing techniques. By selecting materials like hafnium oxide, zirconium oxide, silicon oxide, and titanium oxide that are compatible with existing ALD and CVD processes, the patent achieves high capacitance without excessive manufacturing complexity.
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
This configuration enhances capacitance while maintaining low leakage currents, ensuring reliable data storage and performance in DRAM devices by effectively utilizing ferroelectric or antiferroelectric properties of the dielectric layers.
Implementation Method 1
the second dielectric layer includes an oxide having ferroelectric or antiferroelectric properties
Implementation Method 2
the second dielectric layer includes an oxide having ferroelectric or antiferroelectric properties
Implementation Method 3
the second dielectric layer includes a material with at least two different crystal phases
Data Source
AI summary
A capacitor is described. The capacitor includes a lower electrode, a dielectric layer structure disposed on the lower electrode, and an upper electrode disposed on the dielectric layer structure. The dielectric layer structure includes a first dielectric layer, a second dielectric layer contacting the first dielectric layer, and a third dielectric layer contacting the second dielectric layer. Each of the first to third dielectric layers includes a material with a crystalline structure. The second dielectric layer includes an oxide having ferroelectric or antiferroelectric properties, and the second dielectric layer includes a material in which at least two different crystal phases are mixed.