Resistive Memory Cell With Series Transistor For Stable Recording
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current nonvolatile memory technologies, such as FeRAM, MRAM, phase change memory, and RRAM, face challenges in stable recording, high temperature sensitivity, limited rewrite cycles, and difficulty in miniaturization due to material properties and pulse voltage dependencies, leading to inefficient data recording and erasure processes.
Innovation Solution
A storage device with a memory cell featuring a storage element that changes resistance values based on threshold voltages and a MOS transistor in series, allowing for stable recording and erasure by controlling the resistance value to be higher than the minimum voltage required for erasure, ensuring consistent data storage and retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If voltage pulses are applied to change resistance value of the storage element, then recording and erasure operations can be performed, but the resistance value after recording varies depending on pulse width and magnitude, making stable recording difficult
Solution Approach 1:
The patent introduces a feedback mechanism where the resistance value of the storage element is measured after recording, and this measurement is used to adjust or verify the recording process. The control circuit monitors the resistance value and provides feedback to ensure stable recording by compensating for variations in pulse width and magnitude effects.
Solution Approach 2:
The patent changes the control parameter from direct voltage pulse application to resistance value-based control. By monitoring and controlling the resistance value as the primary parameter rather than focusing solely on voltage pulse characteristics, the system achieves more stable recording results that are less sensitive to pulse width and magnitude variations.
2Duration of action of stationary object
If the storage element is used for nonvolatile memory, then information can be retained without power, but the number of rewrite cycles is limited due to polarization inversion constraints
Solution Approach 1:
The patent introduces dynamic control of the storage element's resistance state through controlled voltage pulsing. By dynamically adjusting the timing and magnitude of voltage pulses based on real-time resistance measurements, the system extends the usable rewrite cycles while maintaining nonvolatile information retention.
Solution Approach 2:
The patent applies beforehand cushioning by measuring the resistance value after each recording operation and using this information to prevent excessive polarization inversion. The control circuit anticipates potential degradation by monitoring resistance changes and adjusting subsequent writing operations to stay within safe rewrite cycle limits.
3Duration of action of stationary object
If FeRAM is used for nonvolatile memory, then information can be retained without power, but reading speed is slow due to destructive readout requirements
Solution Approach 1:
The patent replaces the destructive readout mechanism with a non-destructive resistance measurement approach. Instead of using complex polarization inversion readout processes, the system uses simple electrical resistance measurement to read data, significantly improving read speed while maintaining nonvolatile storage capabilities.
4Duration of action of stationary object
If MRAM is used for nonvolatile memory, then information can be retained without power, but large current is required for recording due to magnetic field generation needs
Solution Approach 1:
The patent replaces the magnetic field-based recording mechanism with direct resistance change through controlled voltage pulsing. By using electrical resistance manipulation instead of magnetic field generation, the system eliminates the need for large currents while maintaining nonvolatile information retention.
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 solution enables stable and efficient recording and erasure operations, reducing the time required for data storage and allowing for high-speed data overwriting, while being resistant to temperature variations and pulse width dependencies.
Implementation Method 1
a storage element having a characteristic of changing from a state of a high resistance value to a state of a low resistance value by being supplied with a voltage equal to or higher than a first threshold voltage, and changing from a state of a low resistance value to a state of a high resistance value by being supplied with a voltage equal to or higher than a second threshold voltage different in polarity from the first threshold voltage
Data Source
AI summary
A storage device includes a memory cell having a storage element having a characteristic of changing from a state of a high resistance value to a state of a low resistance value by being supplied with a voltage equal to or higher than a first threshold voltage, and changing from a state of a low resistance value to a state of a high resistance value by being supplied with a voltage equal to or higher than a second threshold voltage different in polarity from the first threshold voltage, and a circuit element connected in series with the storage element, wherein letting R be a resistance value of the storage element after writing, V be the second threshold voltage, and I be a current that can be passed through the storage element at a time of erasure, R≧V/I.