Multi-level cell (MLC) approach of RRAM devices

Defenitions:

Single-level cell (SLC) means that the device can only store one-bit per cell, and MLC memories can store multiple bits in a single cell. As an example: 4 bit/cell is corresponding to 16 resistance levels.

Resistive switching refers to the reversible change of the resistance of a nanometer-sized media by the application of electrical pulses.One siginificant property of the RRAM devices are stable multi resistance states which can be modulated under two approaches, either by change of curent compliance (CC) or RESET Stop Voltage (RSV) method.

                         DOI:10.1038/s41598-017-11657-4

Retention data and cycle of endurance (at least 100 cycles for DC I-V sweep) is required for all the resistance states.

Another approach to MLC explicitly for 2D or 3D based memristor is increasing the range of voltages @ both SET and RESET side:

DOI: 10.1038/ncomms4473 |www.nature.com/naturecommunications