The mechanism for the suppression of leakage current in high dielectric TiO2 thin films by adopting ultra-thin HfO2 films for memory application

Abstract

Low temperature crystallization of high permittivity Ta oxide using an Nb oxide thin film for metal/insulator/metal capacitors in dynamic random access memory applications

Novel Selector‐Induced Current‐Limiting Effect through Asymmetry Control for High‐Density One‐Selector–One‐Resistor Crossbar Arrays

“…In contrast, the current in the negative bias region, especially V = ≈−1 V showed almost no temperature dependency, suggesting that a tunneling mechanism works. Replotting the data according to the Fowler–Nordheim (F–N) tunneling formalism showed a qualitative coincidence (right panel of Figure a) with the model . A schematic diagram showing the current conduction mechanism under the positive and negative bias conditions can be drawn as shown in Figure b, where the F–N tunneling had a higher TiO 2 film thickness‐dependent current conduction property than the P–F conduction.…”

A comprehensive study on the leakage current mechanisms of Pt/SrTiO3/Pt capacitor

“…We show that this model demonstrates an improved agreement to experimental current density both as a function of voltage and temperature compared to previous published models. 16,18,20,23,25 The model also indicates the existence of fixed positive charges at the bottom electrode leading to the characteristic asymmetry observed in the current-densityÀvoltage (J À V) characteristics.…”

“…16 However, there are several discrepancies with the existing models in respect of the impact of dielectric film quality or interface on leakage current. The Poole-Frenkel model proposed previously [7][8][9][17][18][19] suggests that bulk controls the leakage current while the Schottky emission model 18,[20][21][22][23][24][25] indicates interface as a dominant factor.…”

Conduction and stability of holmium titanium oxide thin films grown by atomic layer deposition

“…Ho-doped TiO 2 and HoTiO 3 are also high permittivity (high-k) materials and possible candidates to replace SiO 2 in field-effect transistors [3]. Although TiO 2 is considered a good candidate as a dielectric layer in metal-insulator-metal (MIM) capacitors for dynamic random access memories (DRAM) [4] because of its high permittivity value, its major drawback is its small band gap/low barrier height and hence its large leakage current when biased. However, when combined with a larger band gap material, the leakage current reduces significantly: Al-doped TiO 2 MIM capacitors with an equivalent oxide thickness of 0.56 nm with leakage current of around 1 × 10 −8 A cm −2 have been fabricated [5].…”