Voltage-Controlled Magnetic Anisotropy Memory for Low-Energy Writing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing magnetic memories face challenges in reducing energy consumption due to high access frequencies and large writing charges required for write operations, leading to an 'energy dilemma' where energy saved in standby mode is consumed in active mode, and no existing solution effectively addresses this issue.
Innovation Solution
A magnetic memory design with a specific configuration of conductive layers, magnetoresistive elements, and control circuits that reduce write current and writing charge by controlling the flow of spin current and applying voltages to manage magnetic anisotropy, allowing for efficient data writing and reading with lower energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If nonvolatile memories are used to replace SRAMs and DRAMs, then energy consumption during standby state is reduced, but energy consumption during active state increases due to large writing charge required
Solution Approach 1:
The patent applies parameter changes by utilizing voltage-controlled magnetic anisotropy to dynamically adjust the magnetic properties of the storage layer. By applying a control voltage to the tunnel barrier layer, the magnetic anisotropy energy is modified, which directly changes the threshold current required for magnetization switching. This enables the memory to operate with lower writing charge during active state while maintaining nonvolatile characteristics during standby state, thus resolving the energy consumption contradiction.
Solution Approach 2:
The patent implements dynamics by making the magnetic anisotropy可调 (tunable) through voltage control. The magnetic properties of the storage layer are not fixed but can be dynamically adjusted by applying different voltages to the tunnel barrier layer. This dynamic control allows the system to optimize its operating parameters in real-time, reducing the writing charge requirement during active operations while preserving data retention during standby, thereby addressing the energy dilemma.
2Productivity
If access frequency of cache memory is increased to handle higher frequency access, then productivity is improved, but energy consumption increases considerably
Solution Approach 1:
The patent reduces energy consumption per access operation by changing the magnetic anisotropy parameter through voltage control. This parameter change lowers the threshold current for magnetization switching, enabling high-speed write operations with reduced energy expenditure. Consequently, the memory can sustain high access frequencies without proportionally increasing energy consumption, resolving the contradiction between productivity and energy use.
3Loss of energy
If writing charge is reduced to lower energy consumption, then reliability of data retention may be compromised
Solution Approach 1:
The patent applies preliminary action by pre-conditioning the magnetic storage layer through voltage-controlled magnetic anisotropy adjustment before the write operation. By applying a control voltage to the tunnel barrier layer, the magnetic anisotropy energy is modified in advance, which facilitates easier magnetization switching with lower threshold current. This preliminary preparation ensures that even with reduced writing charge, the magnetization switching remains reliable and data retention is maintained, thus resolving the contradiction between energy reduction and reliability.
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 proposed solution enables reduced energy consumption and high-speed write and read operations in magnetic memories by minimizing write current and charge, effectively addressing the energy consumption challenges faced by existing technologies.
Implementation Method 1
a first magnetoresistive element disposed corresponding to the second region, the first magnetoresistive element including a first magnetic layer, a second magnetic layer disposed between the second region and the first magnetic layer
Implementation Method 2
STT (spin transfer torque)-MRAM (Magnetic Random Access Memory)
Data Source
AI summary
A magnetic memory includes: first to third terminals; a conductive layer including first to fifth regions, the first region being electrically connected to the first terminal, the fifth region being electrically connected to the second terminal, and the third region being electrically connected to the third terminal; a first magnetoresistive element including a first magnetic layer, a second magnetic layer disposed between the second region and the first magnetic layer, and a first nonmagnetic layer disposed between the first and the second magnetic layer; a second magnetoresistive element including a third magnetic layer, a fourth magnetic layer disposed between the fourth region and the third magnetic layer, and a second nonmagnetic layer disposed between the third and the fourth magnetic layer; and a circuit flowing a write current between the first and the second terminal and between the second and the third terminal in a write operation.