Ferroelectric Capacitor Interface Oxide for Oxygen Vacancy Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ferroelectric capacitors face performance issues due to oxygen vacancies, particularly at the interface between the ferroelectric material and the upper electrode, which affects their operational characteristics and longevity, especially in applications like FeRAM.
Innovation Solution
A method involving the provision of reactive metal over ferroelectric material, followed by oxidation to reduce oxygen vacancies, with the oxidized metal forming a layer between the upper electrode and the ferroelectric material, thereby minimizing oxygen vacancies and enhancing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fabrication methods are used to form ferroelectric capacitors, then manufacturing simplicity is maintained, but oxygen vacancies form at the interface between ferroelectric material and upper electrode, degrading device performance and reliability
Solution Approach 1:
A reactive metal layer is deposited over the ferroelectric material before forming the upper electrode. This preliminary layer is then oxidized to create a metal oxide interface layer that prevents oxygen vacancy formation. The preliminary action of adding this protective layer eliminates the harmful effect of oxygen vacancies without complicating the overall fabrication process
Solution Approach 2:
A metal oxide layer is introduced as an intermediary between the upper electrode and the ferroelectric material. This intermediate layer serves as a buffer that prevents direct interaction between the electrode and ferroelectric material, thereby preventing oxygen vacancies from forming at the interface while maintaining electrical functionality
2Duration of action of stationary object
If the upper electrode is formed directly on the ferroelectric material, then device structure is simplified, but oxygen vacancies are created at the interface, reducing operational lifetime
Solution Approach 1:
A metal oxide layer is introduced as an intermediary between the upper electrode and the ferroelectric material. This intermediate layer serves as a buffer that prevents direct interaction between the electrode and ferroelectric material, thereby preventing oxygen vacancies from forming at the interface while maintaining electrical functionality
Solution Approach 2:
The interface composition is changed by oxidizing a reactive metal layer to form a metal oxide layer. This parameter change in the interface material composition transforms the interface from a direct metal-ferroelectric contact to a metal oxide-ferroelectric contact, which has beneficial properties of preventing oxygen vacancy formation
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 approach results in ferroelectric capacitors with improved endurance and potentially double the lifetime compared to conventional methods, by reducing oxygen vacancies and maintaining desired operating characteristics.
Implementation Method 1
reactive metal is provided across ferroelectric material and subsequently oxidized, with such oxidation including flow of oxygen into underlying ferroelectric material to decrease the number of oxygen vacancies within the ferroelectric material
Data Source
AI summary
Some embodiments include ferroelectric assemblies. Some embodiments include a capacitor which has ferroelectric insulative material between a first electrode and a second electrode. The capacitor also has a metal oxide between the second electrode and the ferroelectric insulative material. The metal oxide has a thickness of less than or equal to about 30 Å. Some embodiments include a method of forming an assembly. A first capacitor electrode is formed over a semiconductor-containing base. Ferroelectric insulative material is formed over the first electrode. A metal-containing material is formed over the ferroelectric insulative material. The metal-containing material is oxidized to form a metal oxide from the metal-containing material. A second electrode is formed over the metal oxide.