Resistance-Variable Memory Device with Series Electrode Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Resistance-variable memory devices face challenges in suppressing leak current in cross-point memory structures during write, read, and erase operations, which increases power consumption and hinders normal operations, and integrating rectifying elements to address this issue complicates device scaling for large-capacity storage.
Innovation Solution
The implementation of a resistance-variable memory device with a specific electrode structure, where two resistance-variable elements are connected in series, one with good data retention and the other with poor data retention, utilizing metal oxides as variable resistance layers, and specific electrode materials to suppress sneak current and maintain stable resistance states, thereby reducing leak current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If rectifying elements are connected to resistance-variable elements in series to suppress leak current, then leak current is reduced, but device size increases
Solution Approach 1:
The patent combines the rectifying function and resistance-variable function into a single integrated element. The resistance-variable element inherently provides rectification capability through its asymmetric current-voltage characteristics, eliminating the need for separate rectifying elements. This merging approach suppresses leak current while avoiding the device size increase that would result from adding separate rectifying components in series.
2Quantity of substance
If cross point type memory structure is used to achieve large capacity, then storage capacity increases, but sneak current increases power consumption
Solution Approach 1:
The patent converts the potentially harmful sneak current into a beneficial mechanism by utilizing the rectifying characteristics of the resistance-variable element. The asymmetric I-V characteristics allow the element to block reverse current while maintaining forward conduction, thereby suppressing sneak current paths in the cross-point architecture and reducing power consumption without sacrificing storage capacity.
3Device complexity
If resistance-variable elements with poor data retention are used, then device complexity is reduced, but data retention deteriorates
Solution Approach 1:
The patent applies local quality by using different resistance-variable elements with different retention characteristics in different positions within the memory array. Elements requiring long-term data retention are placed in specific locations, while elements with shorter retention are used in other positions. This spatial differentiation allows the system to achieve acceptable overall performance without uniformly increasing device complexity across all elements.
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 effectively suppresses leak current in cross-point structures, enabling stable memory operations and maintaining distinct resistance states for '0' and '1' conditions, thereby enhancing the scalability and efficiency of resistance-variable memory devices.
Implementation Method 1
a variable resistance layer that is arranged between the first electrode and the third electrode and formed of a metal oxide; and a second variable resistance layer that is arranged between the second electrode and the third electrode and formed of a metal oxide
Data Source
AI summary
A memory device includes a first electrode, a second electrode, a third electrode, a first variable resistance layer between the first electrode and the third electrode, and a second variable resistance layer between the second electrode and the third electrode. The first, second, and third electrodes, and the first and second variable resistance layers are formed of materials that cause the first variable resistance layer to transition from a high resistance state to a low resistance state when a voltage is applied across the first and second electrodes and maintain the high resistance state when the voltage is cut off, and cause the second variable resistance layer to transition from a high resistance state to a low resistance state when the voltage is applied across the first and second electrodes and transition from the high resistance state to the low resistance state when the voltage is cut off.