3D Ferroelectric Memory Stack With Blocking Dielectric for Fatigue Control
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Solution Overview
Problem
Current semiconductor memory devices face challenges in efficiently storing and retrieving data due to limitations in the materials and structures used for memory elements.
Innovation Solution
A three-dimensional memory device is developed, featuring an alternating stack of insulating and conductive layers, with a memory opening fill structure that includes a vertical stack of charge storage elements, a semiconductor channel, a ferroelectric material layer, and a blocking dielectric layer, along with a tunneling dielectric layer between conductive layers and charge storage elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional memory materials and structures are used, then device simplicity is maintained, but data storage efficiency and durability are insufficient
Solution Approach 1:
The patent employs a composite memory element structure integrating multiple functional materials: ferroelectric material layer for polarization-based data storage, charge storage elements for enhanced retention, blocking dielectric layer for charge confinement, and tunneling dielectric layer for electron transport. This multi-material composite approach resolves the contradiction by achieving superior storage efficiency through material synergies while managing complexity through systematic integration.
Solution Approach 2:
The memory element is segmented into distinct functional layers: ferroelectric material layer, charge storage elements, blocking dielectric layer, and tunneling dielectric layer. Each segment performs a specific function, allowing optimization of individual components for storage efficiency while the overall segmented structure manages complexity through modular design and clear functional separation.
2Reliability
If ferroelectric material is used for data storage, then polarization and operational reliability are improved, but polarization fatigue occurs over time
Solution Approach 1:
The patent incorporates charge storage elements and blocking dielectric layers that act as protective buffers against polarization fatigue. These components preemptively mitigate degradation effects by confining charges and reducing stress on the ferroelectric material during repeated write/erase cycles, thereby extending the operational lifetime while maintaining high reliability.
Solution Approach 2:
The combination of ferroelectric material with charge storage elements and blocking dielectric creates a composite system where the ferroelectric layer provides high polarization and reliability, while the accompanying materials protect against polarization fatigue through charge confinement and stress distribution, resolving the durability contradiction.
3Quantity of substance
If alternating stack of insulating and conductive layers is used, then data storage capacity is enhanced, but manufacturing complexity increases
Solution Approach 1:
The alternating stack is segmented into repeating units of insulating layers and conductive layers, with each unit containing specific sub-layers (ferroelectric, charge storage, blocking dielectric, tunneling dielectric). This segmentation enables standardized fabrication processes for each layer type, enhancing storage capacity through vertical stacking while managing manufacturing complexity through repetitive, modular layer formation.
Solution Approach 2:
The patent transitions from two-dimensional planar memory structures to three-dimensional vertical stacking, increasing data storage capacity by utilizing the vertical dimension. The alternating layers are formed through sequential deposition processes that build complexity in the vertical direction while maintaining manufacturability through established thin-film fabrication techniques.
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 data storage efficiency and durability by utilizing ferroelectric material for improved polarization and reduced polarization fatigue, leading to enhanced operational reliability and longevity of the memory device.
Implementation Method 1
A ferroelectric material refers to a material that displays spontaneous polarization of electrical charges in the absence of an applied electric field. The net polarization P of electrical charges within the ferroelectric material is non-zero in the minimum energy state.
Implementation Method 2
Polarization P of a ferroelectric material as a function of an applied voltage V thereacross displays hysteresis.
Implementation Method 3
a tunneling dielectric layer is located between at least one of the electrically conductive layers and the vertical stack of charge storage elements
Implementation Method 4
a blocking dielectric layer located between the ferroelectric material layer and the vertical semiconductor channel
Data Source
AI summary
A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers, a memory opening vertically extending through the alternating stack, and a memory opening fill structure located in the memory opening and including a vertical stack of charge storage elements, a vertical semiconductor channel, a ferroelectric material layer located between the vertical stack of charge storage elements and the vertical semiconductor channel, and a blocking dielectric layer located between the ferroelectric material layer and the vertical semiconductor channel. A tunneling dielectric layer is located between at least one of the electrically conductive layers and the vertical stack of charge storage elements.