Variable Dielectric Capacitors for NAND Memory Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional NAND memory devices face reliability issues due to dielectric breakdown as the thickness of the dielectric material is scaled down to increase memory density, leading to decreased stress tolerance and reliability concerns in high-voltage circuits.
Innovation Solution
The development of capacitors with conductive structures spaced by a variable dielectric material, allowing for increased capacitance efficiency per unit area and the ability to withstand higher voltages, achieved by adjusting the spacing and thickness of the dielectric material based on its dielectric constant and the applied voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the thickness of the dielectric material is scaled down to increase memory density, then device density is improved, but reliability deteriorates due to dielectric breakdown
Solution Approach 1:
The patent applies local quality by using different dielectric materials with different dielectric constants in different regions of the capacitor structure. Specifically, a first dielectric material with a first dielectric constant is used in a first region, and a second dielectric material with a second dielectric constant is used in a second region. This allows the capacitor to achieve higher capacitance in specific areas while maintaining overall reliability by distributing stress across regions with different dielectric properties.
Solution Approach 2:
The patent employs composite materials by combining multiple dielectric materials with different dielectric constants within the same capacitor structure. This composite approach enables the structure to simultaneously achieve high capacitance (through high-k materials) and high reliability (through low-stress materials), resolving the contradiction between density and reliability.
2Productivity
If the area of the capacitor is reduced to increase device density, then productivity is improved, but the stress voltage tolerance deteriorates
Solution Approach 1:
The patent changes the dielectric parameter (dielectric constant) by using materials with different k-values in different regions. This allows the capacitor to maintain higher capacitance per unit area, effectively increasing the electrical capacity without proportionally increasing the physical area, thus improving device density while maintaining stress voltage tolerance.
3Ease of manufacture
If conventional planar capacitors are used with fixed size, then manufacturing is simplified, but capacitance efficiency per unit area is limited
Solution Approach 1:
The patent divides the capacitor structure into different regions with different dielectric materials, allowing each region to contribute differently to the overall capacitance. This regional differentiation increases capacitance efficiency per unit area while maintaining a structure that can be manufactured using standard semiconductor fabrication processes.
Solution Approach 2:
By combining multiple dielectric materials in a composite structure, the patent achieves higher capacitance efficiency per unit area compared to conventional single-material planar capacitors, while the overall fabrication process remains compatible with existing manufacturing 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
These capacitors provide enhanced capacitance efficiency and reliability by maintaining or increasing capacitance in a smaller space, reducing the risk of dielectric breakdown and enabling operation at higher voltages, thus addressing the reliability concerns in NAND memory devices.
Implementation Method 1
capacitors with conductive structures spaced by a variable dielectric material
Implementation Method 2
increased capacitance efficiency per unit area
Implementation Method 3
withstand higher voltages, achieved by adjusting the spacing and thickness of the dielectric material based on its dielectric constant and the applied voltage
Data Source
AI summary
Semiconductor structures including a plurality of conductive structures having a dielectric material therebetween are disclosed. The thickness of the dielectric material spacing apart the conductive structures may be adjusted to provide optimization of capacitance and voltage threshold. The semiconductor structures may be used as capacitors, for example, in memory devices. Various methods may be used to form such semiconductor structures and capacitors including such semiconductor structures. Memory devices including such capacitors are also disclosed.