Resistive Random Access Memory (RRAM): an Overview of Materials, Switching Mechanism, Performance, Multilevel Cell (mlc) Storage, Modeling, and Applications

Table 1 Comparison of emerging memory technologies

Memory technology	SRAM	DRAM	NAND Flash	NOR Flash	PCM	STT-MRAM	RRAM
Cell area	> 100F²	6F²	<4F²(3D)	10F²	4– 20F²	6– 20F²	<4F²(3D)
Cell element	6T	1T1C	1T	1T	1T(D)1R	1(2)T1R	1T(D)1R
Voltage	<1 V	<1 V	<10 V	<10 V	<3 V	<2 V	< 3 V
Read time	∼1 ns	∼10 ns	∼10 μs	∼50 ns	<10 ns	<10 ns	< 10 ns
Write time	∼1 ns	∼10 ns	100 μs–1 ms	10 μs–1 ms	∼50 ns	<5 ns	< 10 ns
Write energy (J/bit)	∼fJ	∼10 fJ	∼10 fJ	100 pJ	∼10 pJ	∼0.1 pJ	∼0.1 pJ
Retention	N/A	∼64 ms	>10 y	>10 y	>10 y	>10 y	> 10 y
Endurance	> 10¹⁶	>10¹⁶	>10⁴	>10⁵	>10⁹	>10¹⁵	∼10⁶– 10¹²
Multibit capacity	No	No	Yes	Yes	Yes	Yes	Yes
Non-volatility	No	No	Yes	Yes	Yes	Yes	Yes
Scalability	Yes	Yes	Yes	Yes	Yes	Yes	Yes
F: Feature size of lithography