Magnetic Memory Two-Stage Programming Write Error Reduction
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Solution Overview
Problem
Magnetic memory technologies face challenges in efficiently writing data into magnetoresistive effect elements due to fluctuations in write current, which can lead to errors and reduced reliability.
Innovation Solution
The magnetic memory employs a voltage control spintronic memory (VoCSM) approach, using a two-stage programming method with controlled write current sequences and pulse widths to manage magnetization switching thresholds, ensuring accurate data writing by adjusting the control voltage applied to magnetoresistive effect elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-stage programming method is used with fixed write current, then the device complexity is reduced, but write errors increase due to current fluctuations
Solution Approach 1:
The programming method is divided into two distinct stages: a first programming step that sets an initial magnetization state, and a second programming step that finalizes the desired data state. This segmentation allows each stage to be optimized independently, with the first step preparing the magnetic tunnel junction in a known state and the second step writing the actual data, thereby reducing write errors caused by current fluctuations while maintaining manageable device complexity.
Solution Approach 2:
The first programming step performs a preliminary action by setting the magnetization state of the magnetic tunnel junction to a predetermined initial state before the actual data writing occurs in the second step. This preliminary magnetization state establishment ensures that subsequent write operations start from a known, stable condition, reducing the impact of write current fluctuations on final write accuracy.
2Productivity
If write current is increased to improve writing speed, then productivity is improved, but write errors increase due to exceeded magnetization switching thresholds
Solution Approach 1:
The write current is made dynamic rather than fixed, with the current value being adjusted based on the specific operation being performed. The first programming step uses a first write current value optimized for initial magnetization state setting, while the second programming step uses a second write current value optimized for final data writing. This dynamic current adjustment allows the system to achieve high writing speeds when appropriate while preventing write errors by using lower currents when the magnetic tunnel junction is more sensitive to current variations.
Solution Approach 2:
The patent changes the parameter of write current value between different programming steps. By using different current magnitudes optimized for different stages of the programming process, the system can achieve fast writing when high current is appropriate while avoiding write errors by using lower currents during sensitive operations. This parameter change approach directly addresses the contradiction between speed and accuracy by making current a variable rather than a constant.
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 method effectively reduces write errors and enhances the reliability of data storage by stabilizing the write current and maintaining the integrity of magnetization states in magnetoresistive effect elements.
Implementation Method 1
Magnetic memories using magnetoresistive effect elements as memory elements are under development and study
Implementation Method 2
a common electrode 20 made of a material having a spin Hall effect
Data Source
AI summary
According to one embodiment, a magnetic memory includes: magnetoresistive effect elements arranged on an conductive layer; and a first circuit which passes a write current through the conductive layer and applies a control voltage to the magnetoresistive effect elements, to write data including a first value and a second value into the magnetoresistive effect elements. The first circuit adjusts at least one of a write sequence of the first value and the second value, a current value of the write current, and a pulse width of the write current, on the basis of an arrangement of the first value and the second value in the data.