Electric-field-controlled interface dipole modulation for Si-based memory devices

Abstract

Various nonvolatile memory devices have been investigated to replace Si-based flash memories or emulate synaptic plasticity for next-generation neuromorphic computing. A crucial criterion to achieve low-cost high-density memory chips is material compatibility with conventional Si technologies. In this paper, we propose and demonstrate a new memory concept, interface dipole modulation (IDM) memory. IDM can be integrated as a Si field-effect transistor (FET) based memory device. The first demonstration of this concept employed a HfO2/Si MOS capacitor where the interface monolayer (ML) TiO2 functions as a dipole modulator. However, this configuration is unsuitable for Si-FET-based devices due to its large interface state density (Dit). Consequently, we propose, a multi-stacked amorphous HfO2/1-ML TiO2/SiO2 IDM structure to realize a low Dit and a wide memory window. Herein we describe the quasi-static and pulse response characteristics of multi-stacked IDM MOS capacitors and demonstrate flash-type and analog memory operations of an IDM FET device.

Interfacial Dipole Modulation Device With SiOX Switching Species

“…2(c) displays the optimal number of IDM stacks and Fig 2(d) shows the C-V curve for a 14-stack IDM structure. In the conventional IDM structure, the maximum MW was produced by 6-stack (≈ 1.5 V) [24]. However, in our new structure, the large quantities of interfacial dipoles enabled a wide MW at 14stack (≈ 8.05 V).…”

Improved Resistive Switching Observed in Ti/Zr3N2/p-Si Capacitor via Hydrogen Passivation

“…Meanwhile, according to the reported literature related to H 2 annealing [37], [38], it is well-known that hydrogen allows a different bonding energy depending on electronegativity of molecules such as N-H, N-O, N-Zr, and N-F, which are dipole-inducing forms. Especially, in the negative bias region, the current at LRS is lower than that at HRS because of the internal electric field induced by the formed dipole, which results in a negative shift in the I − V curve characteristics [39], [40]. Then, if we use V read = +0.1 V, currents at HRS and LRS are 0.125 nA and 3.696 nA, and the current ratio (CR) between HRS and HRS is about 29.6.…”

Electric‐Dipole Gated Two Terminal Phototransistor for Charge‐Coupled Device

“…The HfO 2 face is negatively charged due to the high density of interface traps (10 14 cm 2 eV −1 as addressed below) originating from the oxygen vacancies. [37][38][39][40] These oxygen vacancies are generated due to the diffusion of oxygen atoms from HfO 2 to the Si at the HfO 2 /Si interface during the growth of the HfO 2 layer. [37][38][39][40] When the device is illuminated under radiation, the photogenerated electron-hole pairs in the depletion region drift in opposite directions under the influence of the built-in potential (V BI ).…”

“…[37][38][39][40] These oxygen vacancies are generated due to the diffusion of oxygen atoms from HfO 2 to the Si at the HfO 2 /Si interface during the growth of the HfO 2 layer. [37][38][39][40] When the device is illuminated under radiation, the photogenerated electron-hole pairs in the depletion region drift in opposite directions under the influence of the built-in potential (V BI ). The holes move toward the HfO 2 at HfO 2 /Si interface.…”

“…[33][34] Furthermore, the HfO 2 thin film contains the additional character of strong interface dipole formation along with higher interface trap states on the Si. [35][36] This phenomenon occurs due to dangling bonds as well as the migration of oxygen atoms from the HfO 2 to Si at the interface [37][38][39][40] and generates very interesting characteristics of forming a depletion region in the semiconductor and a strong negative pole at the insulator interface. This combination can be applied to manipulate the field-effect without a gate electrode, where the depletion region provides the photovoltage and the high-k dielectric provides the strong field-effect.…”