Loading...

Investigation of The Effect of Morphology and Interface in Tri-Layer Tio2-Based and Multi-Layer Srtio3-Based Nanostructures on the Performance of Memory Resistor Component

Arab Bafrani, Hamid Reza | 2021

76 Viewed
  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 56090 (48)
  4. University: Sharif University of Technology
  5. Department: Institute for Nanoscience and Nanotechnology
  6. Advisor(s): Moshfegh, Alireza; Bagheri Shouraki, Saeed
  7. Abstract:
  8. Memristor is a modern circuit element that demonstrates resistance memory function and can have important applications in emerging memories and artificial synapses. Binary oxides and perovskite oxides are two major classes of materials that are promising for memory resistances. Among the binary oxides, TiO2, and among the perovskite oxides, SrTiO3 (STO), are particularly promising in research on electrical resistance switching. In this thesis, by using two deposition techniques of sputtering and pulsed laser deposition (PLD), we have constructed single-layer and multi-layer memristor devices based on these two materials. Two general mechanisms control the behavior of memristors: bulk-control and interface-controlled mechanisms. In this thesis, we aimed at determining conditions to control the effects of interface on the resulting memristor device. In an Au/TiO2/Au-based memristor device, we have demonstrated that the optimal conditions for the wet etching treatment could modify the surface roughness of the bottom gold electrode and led to an uneven electric field distribution that plays a vital role in reducing the energy consumption of the device. In particular, by increasing the interface roughness of the device from 4.2 to 13.1 nm, the set voltage (Vset) of this device decreases significantly from 2.26 to 1.93 V. Finally, we have introduced a multi-state multi-region strontium titanate (STO) memristor based on asymmetric heterostructure architectures of AuTi/STO/SNTO and AuTi/STO/SRO/STO/SNTO systems, where SRO denotes strontium ruthenate and SNTO denotes niobium-doped strontium titanate. In particular, we have showen that the AuTi/STO/SRO/STO/SNTO device shows memristive behavior at compliance current of 40 μA. The device has a initial resistance of 0.5 MΩ, and shows high resistance and low resistance states of 0.1 MΩ and 16 kΩ, respectively. Furthermore, we have shown that by controlling the compliance current passing the device, more than one operational region can be created in the device, and by engineering the bandgap, intermediate states can be created in addition to high-resistance and low-resistance states. This approach allows the construction of more than one operational region and new electrical states. Finally, we showed that a resistance switch based on the STO memristor with the proposed design is able to mimic the new functional properties of the human brain that can be used in the next generation of biodevices
  9. Keywords:
  10. Memristor ; Titanium Dioxide ; Multilayer Structure ; Interface Effect ; Strontium Titanate ; Resistive Memory ; Pulsed Laser Deposition (PLD)

 Digital Object List

 Bookmark

  • 6-2
  • correct-Arab PhD Thesis-29 August (1)