Silicon Oxide: A Non-innocent Surface for Molecular Electronics and Nanoelectronics Studies

Abstract

Silicon oxide (SiO(x)) has been widely used in many electronic systems as a supportive and insulating medium. Here, we demonstrate various electrical phenomena such as resistive switching and related nonlinear conduction, current hysteresis, and negative differential resistance intrinsic to a thin layer of SiO(x). These behaviors can largely mimic numerous electrical phenomena observed in molecules and other nanomaterials, suggesting that substantial caution should be paid when studying conduction in electronic systems with SiO(x) as a component. The actual electrical phenomena can be the result of conduction from SiO(x) at a post soft-breakdown state and not the presumed molecular or nanomaterial component. These electrical properties and the underlying mechanisms are discussed in detail.

Highly transparent nonvolatile resistive memory devices from silicon oxide and graphene

“…S2). In the characteristic I-V curve (black curve), starting from a high-resistance (OFF) state, the current level suddenly increases at ~4 V to a low-resistance (ON) state and then decreases at ~10 V. The current or conductance increase and decrease define the set and reset values, respectively 17,20 , indicating unipolar resistive switching behaviour. The resistance or memory state can be read at a low-voltage bias ( < 3 V) without altering its value, featuring the nonvolatile property.…”

“…The switching properties obtained in this planar nanogap configuration are similar to those from vertical structures, confirming the same switching mechanism intrinsic to SiO x 18 . Note that more detailed discussions about this intrinsic SiO x switching mechanism are covered in our previous studies [17][18][19][20] .…”

“…This material-assisted local-field enhancement offers another route to bring down the electroforming voltage apart from thermal annealing 17 . As a result, a thin layer of conducting molecules or carbon materials could be coated over the SiO x surface region to induce local-field enhancement for reduction of the electroforming voltage 20 . The switching properties obtained in this planar nanogap configuration are similar to those from vertical structures, confirming the same switching mechanism intrinsic to SiO x 18 .…”

“…Instead of merely serving as a passive solid electrolyte in metallic programmable cells 15 , an active role of SiO x in constructing resistive switching memory was recently revealed: SiO x itself can serve as the source of the formation of metallic-phase silicon filaments as well as the surrounding supportive matrix 17,18 . The result is a memory effect that is intrinsic to SiO x and largely electrode independent 19,20 . This intrinsic memory effect in SiO x relaxes the restriction on the choice of electrode materials, making high-transparency memory devices feasible.…”

Semiconductor-Free Nonvolatile Resistive Switching Memory Devices Based on Metal Nanogaps Fabricated on Flexible Substrates via Adhesion Lithography

“…To this end there is significant evidence that the reported nanogap switching behaviour is due to tunnelling current and a change in gap size, namely the temperature independence of the current, multilevel switching, [53] dependence of switching on the electrode material, [41] and independence of the switching behaviour on substrate material [54]. However, there is also significant evidence that switching can be due to a breakdown in the dielectric substrate (often SiO2), such as an independence of switching on electrode material [33], evidence of damage to the substrate [55], and direct imaging of filamentation taking place [28].…”