Resistive RAM using Nanomaterials

Resistive RAMs are non-volatile RAMs and with the help of Nanomaterials we can make them faster in switching speed,smaller in size and store information in "Terabit" scale or more.In a nutshell "a revolution in the market of memory devices".

1. BY : DEBDUT SENGUPTA 41 Joyabrata bhattacharjee 54 UNDER THE GUIDANCE OF: PROF.SOURAV GHOSH Resistive RAM using Nanomaterials

2. What is RAM? Random access memory (RAM) is a type of data storage used in computers that is generally located on the motherboard. This type of memory is volatile. It is made up of transistors and capacitors .

3. Different types of RAM

4. What is Resistive RAM? Resistive random-access memory  ( RRAM  or  ReRAM ) is a type of  nonvolatile   memory(NV). It is computer memory that works by changing the resistance across a  dielectric  solid-state material often referred to as a  memristor . It is a passive two-terminal electronic device.

5. How does RRAM work? Bipolar Resistive switching mechanism. There is a change in the resistance of the dielectric due to the applied voltage. Memristors , which are considered to be a sub-category of  resistive RAM.

6. What are Nanomaterials ? Materials of which a single unit is sized between 1 and 1000 nm (10^-9 m). They have unique optical, electronic, or mechanical properties. TYPES:- 1. Natural nanomaterials 2.Fullerenes. 3.Graphene nanostructures. 4.Nanoparticles.

7. Advantage of using Nanomaterials in RRAM Increase in storage capacity. Faster execution. Low power consumption. Increase in scalability and facile integration.

8. There are mainly two types of Nanomaterial based RRAMs

9. Structural details of the two types of RRAMs Another device structure has a single layer sandwiched between two metal electrodes The layer contains Au-DT NPs, 8HQ, PS. One has a triple-layer structure,sandwiched between two aluminum (Al) electrodes. Upper and lower layer has organic semiconductors and the middle layer has metal NPs .

10. ELECTRICAL CHARACTERISTICS of the nanoparticle devices I – V  curve of an Al/Au-DT NPs+8HQ+PS/Al device 

11. MEMORY APPLICATIONS OF NP BASED RRAM The top and bottom curves are the applied voltage and the corresponding current, respectively. W, R, and E in the top figure mean write, read and erase, respectively. The labels ‘1’ and ‘0’ in the bottom figure indicate the device in the ON and OFF state. THE CYCLE DEMONSTRATES THAT THE DEVICE CAN BE USED AS A MEMORY DEVICE.

12. ADVANTAGES The transition time from ON to OFF is less than 25ns. The resistive switches can be repeated number of times and can be driven by short voltage pulses. Since this is a non volatile memory device so there is a better stability in the two states. These devices have a faster response to external electric fields and can have extremely high density due to the nanometer size of the materials.

13. DISADVANTAGES The nanomaterial lithographic and fabrication process is quite expensive because of the high cost of nanoparticles synthesis. Compared to basic semiconductor materials, some of the nanomaterials may get corroded more easily.

14. Future Scope: Nanomaterial based RRAM is scalable below 30nm.So the size of future memory devices can be highly reduced. As RRAM has high response speed, is non-volatile, so it can replace DRAMs and Flash memories. Due to high density of nanomaterial based RRAM,it can store informations in “terabit” scale or higher.