Multi-Dielectric Storage Capacitor for Higher DRAM Charge Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dynamic random-access memory capacitors face limitations in capacitance due to the relatively low dielectric constant of traditional dielectric materials, which restricts the storage capacity of semiconductor storage devices.
Innovation Solution
A storage capacitor design featuring multiple dielectric layers, where the first and third layers can be made of the same metallic oxide materials like hafnium, zirconium, niobium, aluminum, or titanium, and the second layer can be of different materials, with specific thickness ratios and dimensions to enhance the effective dielectric constant, allowing for increased electrical charge storage within a given footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional dielectric materials with low dielectric constant are used, then the capacitor structure is simple, but the storage capacity is limited
Solution Approach 1:
The capacitor dielectric is segmented into three distinct 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, enabling increased storage capacity while maintaining a manageable structural complexity through systematic layering
Solution Approach 2:
The patent employs composite dielectric structures where the first and third dielectric layers use one material (e.g., silicon oxide) and the second dielectric layer uses a different material (e.g., silicon nitride). This composite approach leverages the complementary properties of different materials to achieve superior overall capacitance compared to single-material dielectrics
2Quantity of substance
If the dielectric constant is increased to hold more electrical charge, then the capacitance increases, but the manufacturing precision requirements increase
Solution Approach 1:
Different dielectric layers are assigned different materials and thicknesses based on their local functional requirements. The second dielectric layer, positioned between the first and third layers, uses a material with higher dielectric constant and greater thickness to provide the primary capacitance contribution, while the first and third layers provide structural support and interface quality, optimizing both charge storage and manufacturability
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 multi-layer dielectric structure effectively increases the dielectric constant, enabling semiconductor storage devices to hold greater electrical charges within a smaller footprint, thereby enhancing storage capacity.
Implementation Method 1
The ability of the capacitor to hold electrical charges (i.e., capacitance) is a function of the surface area of the electrodes, a distance between the electrodes, and a (relative) dielectric constant or k-value of the dielectric material, wherein the capacitance is proportional to the dielectric constant or k-value of the dielectric material
Data Source
AI summary
The present application provides a storage capacitor with multiple dielectrics. The storage capacitor includes a lower electrode, an upper electrode, a first dielectric layer, a second dielectric layer and a third dielectric layer. The first dielectric layer covers the lower electrode, the second dielectric layer is disposed on the first dielectric layer, and the third dielectric layer is disposed on the second dielectric layer. The upper electrode is disposed on the third dielectric layer.