RRAM Resetting Method Reducing Complementary Switching
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Solution Overview
Problem
Resistive random access memory (RRAM) experiences a complementary switching phenomenon when subjected to excessively high voltage during resetting, leading to difficulty in distinguishing between high and low resistance states, resulting in memory loss and reduced endurance.
Innovation Solution
A resetting method involving a first and second verifying operation to determine the need for a healing resetting operation, with an oxygen supplying layer between the oxygen gettering layer and the upper electrode to continuously supply oxygen ions, and a healing resetting operation with increased voltage to reduce the complementary switching phenomenon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If an excessively high voltage is used for the resetting operation, then the resetting speed is improved, but the complementary switching phenomenon occurs causing the resistive memory cell to increase current instead of maintaining low current state
Solution Approach 1:
The patent applies preliminary action by performing a first resetting operation at a first voltage to initially reset the resistive memory cell, then performing a second resetting operation at a second voltage (higher than the first) only if needed. This staged approach allows the system to achieve resetting without immediately applying excessively high voltage that would cause complementary switching, thus resolving the contradiction between resetting speed and reliability.
Solution Approach 2:
The patent implements dynamics by making the resetting voltage adaptive rather than fixed. The resetting voltage dynamically adjusts based on the state of the resistive memory cell - starting at a lower voltage and increasing to a higher voltage only when necessary. This dynamic voltage adjustment allows the system to achieve fast resetting when needed while avoiding the complementary switching phenomenon when the cell is already properly reset, resolving the speed-reliability contradiction.
2Manufacturing precision
If multiple resetting operations are performed on the resistive memory cell, then the resetting completeness is improved, but the probability of complementary switching phenomenon increases
Solution Approach 1:
The patent applies feedback by performing verifying operations between resetting operations to check the state of the resistive memory cell. The system uses the verifying results to determine whether additional resetting operations are necessary. This feedback mechanism ensures resetting completeness while avoiding unnecessary multiple resetting operations that would increase the probability of complementary switching phenomenon, thus resolving the contradiction between resetting completeness and reliability.
3Reliability
If a higher resetting voltage is applied to ensure proper resetting, then the resetting effectiveness is improved, but the endurance of RRAM is reduced due to increased complementary switching phenomenon
Solution Approach 1:
The patent applies preliminary action by performing initial resetting operations at lower voltages before applying higher voltages. This staged approach ensures that the resistive memory cell is properly reset using minimal necessary voltage, reducing stress on the cell and preserving endurance. The higher voltage is applied only as a preliminary step when lower voltages are insufficient, balancing resetting effectiveness with endurance preservation.
Solution Approach 2:
The patent implements parameter changes by dynamically adjusting the resetting voltage parameter based on the actual state of the resistive memory cell. Instead of always using a high resetting voltage, the system changes the voltage parameter to match the needed resetting level, ensuring effective resetting while minimizing voltage-induced degradation and preserving RRAM endurance over time.
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 method effectively reduces the complementary switching phenomenon, thereby extending the endurance of RRAM by ensuring accurate resistance state distinction and preventing memory loss.
Implementation Method 1
the oxygen supplying layer is disposed between the oxygen gettering layer and the upper electrode and/or between the oxygen gettering layer and the first barrier layer to continuously supply oxygen ions or oxygen atoms to the data storage layer during the resetting operation
Data Source
AI summary
Provided is a resetting method of a resistive random access memory (RRAM) including the following steps. A first resetting operation and a first verifying operation on the at least one resistive memory cell are performed. Whether to perform a second resetting operation according to a verifying result of the first verifying operation is determined. A second verifying operation is performed after the second resetting operation is determined to be performed and is finished. To determine whether to perform a healing resetting operation according to a verifying result of the second verifying operation, which comprises: performing the healing resetting operation when a verifying current of the second verifying operation is greater than a predetermined current, wherein a resetting voltage of the healing resetting operation is greater than a resetting voltage of the second resetting operation.