Zinc oxide (ZnO) has drawn much attention due to its excellent optical and electrical properties. In this study, ZnO film was prepared by a high-deposition-rate spatial atomic layer deposition (ALD) and subjected to a post-annealing process to suppress the intrinsic defects and improve the crystallinity and film properties. The results show that the film thickness increases with annealing temperature owing to the increment of oxide layer caused by the suppression of oxygen vacancy defects as indicated by the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) spectra. The film transmittance is seldom influenced by annealing. The refractive index increases with annealing temperature at 300–700 °C, possibly due to higher density and crystallinity of the film. The band gap decreases after annealing, which should be ascribed to the decrease in carrier concentration according to Burstein–Moss model. The carrier concentration decreases with increasing annealing temperature at 300–700 °C since the oxygen vacancy defects are suppressed, then it increases at 800 °C possibly due to the out-diffusion of oxygen atoms from the film. Meanwhile, the carrier mobility increases with temperature due to higher crystallinity and larger crystallite size. The film resistivity increases at 300–700 °C then decreases at 800 °C, which should be ascribed primarily to the variation of carrier concentration.

In this study, silicon oxide (SiO₂) films were deposited by remote plasma atomic layer deposition with Bis(diethylamino)silane (BDEAS) and an oxygen/argon mixture as the precursors. Oxygen plasma powers play a key role in the quality of SiO₂ films. Post-annealing was performed in the air at different temperatures for 1 h. The effects of oxygen plasma powers from 1000 W to 3000 W on the properties of the SiO₂ thin films were investigated. The experimental results demonstrated that the SiO₂ thin film growth per cycle was greatly affected by the O₂ plasma power. Atomic force microscope (AFM) and conductive AFM tests show that the surface of the SiO₂ thin films, with different O₂ plasma powers, is relatively smooth and the films all present favorable insulation properties. The water contact angle (WCA) of the SiO₂ thin film deposited at the power of 1500 W is higher than that of other WCAs of SiO₂ films deposited at other plasma powers, indicating that it is less hydrophilic. This phenomenon is more likely to be associated with a smaller bonding energy, which is consistent with the result obtained by Fourier transformation infrared spectroscopy. In addition, the influence of post-annealing temperature on the quality of the SiO₂ thin films was also investigated. As the annealing temperature increases, the SiO₂ thin film becomes denser, leading to a higher refractive index and a lower etch rate.

In this study, the effect of radical intensity on the deposition mechanism, optical, and electrical properties of tin oxide (SnO₂) thin films is investigated. The SnO₂ thin films are prepared by plasma-enhanced atomic layer deposition with different plasma power from 1000 to 3000 W. The experimental results show that plasma contains different amount of argon radicals (Ar*) and oxygen radicals (O*) with the increased power. The three deposition mechanisms are indicated by the variation of Ar* and O* intensities evidenced by optical emission spectroscopy. The adequate intensities of Ar* and O* are obtained by the power of 1500 W, inducing the highest oxygen vacancies (O_V) ratio, the narrowest band gap, and the densest film structure. The refractive index and optical loss increase with the plasma power, possibly owing to the increased film density. According to the Hall effect measurement results, the improved plasma power from 1000 to 1500 W enhances the carrier concentration due to the enlargement of O_V ratio, while the plasma powers higher than 1500 W further cause the removal of O_V and the significant bombardment from Ar*, leading to the increase of resistivity.

Indium oxide (In₂O₃) film has excellent optical and electrical properties, which makes it useful for a multitude of applications. The preparation of In₂O₃ film via atomic layer deposition (ALD) method remains an issue as most of the available In-precursors are inactive and thermally unstable. In this work, In₂O₃ film was prepared by ALD using a remote O₂ plasma as oxidant, which provides highly reactive oxygen radicals, and hence significantly enhancing the film growth. The substrate temperature that determines the adsorption state on the substrate and reaction energy of the precursor was investigated. At low substrate temperature (100–150 °C), the ratio of chemically adsorbed precursors is low, leading to a low growth rate and amorphous structure of the films. An amorphous-to-crystalline transition was observed at 150–200 °C. An ALD window with self-limiting reaction and a reasonable film growth rate was observed in the intermediate temperature range of 225–275 °C. At high substrate temperature (300–350 °C), the film growth rate further increases due to the decomposition of the precursors. The resulting film exhibits a rough surface which consists of coarse grains and obvious grain boundaries. The growth mode and properties of the In₂O₃ films prepared by plasma-enhanced ALD can be efficiently tuned by varying the substrate temperature.

The promising functional tin oxide (SnO_x) has attracted tremendous attention due to its transparent and conductive properties. The stoichiometric composition of SnO_x can be described as common n-type SnO₂ and p-type Sn₃O₄. In this study, the functional SnO_x films were prepared successfully by plasma-enhanced atomic layer deposition (PEALD) at different substrate temperatures from 100 to 400 °C. The experimental results involving optical, structural, chemical, and electrical properties and morphologies are discussed. The SnO₂ and oxygen-deficient Sn₃O₄ phases coexisting in PEALD SnO_x films were found. The PEALD SnO_x films are composed of intrinsic oxygen vacancies with O-Sn⁴⁺ bonds and then transformed into a crystalline SnO₂ phase with increased substrate temperature, revealing a direct 3.5–4.0 eV band gap and 1.9–2.1 refractive index. Lower (300 °C) substrate temperatures can cause precursor condensation and desorption, respectively, resulting in reduced film qualities. The proper composition ratio of O to Sn in PEALD SnO_x films near an estimated 1.74 suggests the highest mobility of 12.89 cm² V⁻¹ s⁻¹ at 300 °C.