Rf‐sputtering growth of stoichiometric amorphous TeO₂ thin films

Abstract

Amorphous stoichiometric thin films of TeO 2 have been successfully grown by reactive rf-sputtering deposition. The proper choice of deposition parameters such as the rf power, the Ar/O 2 composition and pressure of the sputtering gas, the substrate temperature, enabled us to obtain TeO x films of different thickness (up to 2.4 µm) with constant and reproducible optical and structural characteristics. The x value was calculated from RBS measurements to be equal to 2.04 ± 0.08 and all films showed good optical transparency in the visible and near infrared range. The structure of the films was studied by XRD, TEM and SAD, and it was found to be amorphous with the presence of rare and small Te crystallites.

Properties of crystalline γ-TeO2 thin film

“…It has been reported that g-TeO 2 phase appears as the first crystalline structure during the temperature-induced crystallization of TeO 2 glass [11]. Thin films always have advantage over the bulk counterpart and few attempts have been made to fabricate the TeO 2 thin film using various techniques such as sputtering, thermal evaporation, sol gel, etc [4,[12][13][14][15][16][17]. Surprisingly, most of the films were found to be amorphous in nature and little efforts have been made to obtain the crystalline film despite the fact that crystalline material have high opto-acoustic figure of merit.…”

TeO2: A Prospective High‐k Dielectric

“…[16] Both amorphous and crystalline forms of TeO 2 display a dielectric constant in the range of 19-25; however, until now it has not been considerably harnessed for high-k applications. [17] Dielectric is an essential functional layer in the field effect devices and the primary criteria for high-k materials are to have a dielectric constant greater than 10 (preferably in the range of [20][21][22][23][24][25][26][27][28][29][30] and bandgap over 4 eV (considering 1 eV offset between semiconductor and dielectric with respect to valence and conduction bands). [18] Binary oxides turn out to be the prime choice due to their simplicity and completry metal oxide semiconductor (CMOS) compatibility; however, low processing temperature and ease of fabrication are also to be considered.…”

“…have reported compromised properties relative to the bulk samples. [21][22][23] In this study, nanocrystalline and highly transparent TeO 2 films are fabricated by pulsed laser deposition (PLD) and reliable figures of high permittivity along with low leakage current are obtained in metal-insulator-metal (MIM) configuration with indium tin oxide (ITO) and gold as electrodes…”

“…have reported compromised properties relative to the bulk samples. [ 21–23 ] In this study, nanocrystalline and highly transparent TeO 2 films are fabricated by pulsed laser deposition (PLD) and reliable figures of high permittivity along with low leakage current are obtained in metal–insulator–metal (MIM) configuration with indium tin oxide (ITO) and gold as electrodes (Au/TeO 2 /ITO). The field‐effect behavior is confirmed by integrating the TeO 2 dielectric layer with tellurium (as a semiconductor) in the metal–oxide–semiconductor (MOS) configuration (Au/Te/TeO 2 /ITO).…”

Improvement of a novel anode material TeO2 by chlorine doping

“…So it may be used as lithium-inserting electrode material. Until now, great attention has been drawn to prepare amorphous TeO 2 film/nanoparticles [9][10][11][12][13] and tellurium oxides by various methods [14].…”