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International audience; Surface activation of Carbon Fiber Reinforced Polymers (CFRP) using (Poly-EtherEtherKetone) (PEEK) matrices is required to achieve strong and long-term adherent painting on the composite. Among the different techniques, an industrial atmospheric pressure remote plasma has been used in this work to treat PEEK CFRP surfaces. The characterization of this device by means of electrical diagnostics related to the effect of such post-discharge on the surface modifications is discussed. Firstly, electrical characteristics of the discharge show fairly high currents associated to high voltages which suggest a nonestablished and cold arc. Power consumed by the electrical supply associated to post-discharge length and surface temperatures allowed a better understanding of the industrial device. Secondly, the effects of plasma on surface chemistry and topography are analyzed by water contact angle measurements, X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). Investigations showed that treated surfaces exhibited better hydrophilicity mainly due to an incorporation of oxygen containing groups (up to 8.4% more) under air plasma whereas an increase of the nanoroughness and specific surface is preponderant under nitrogen plasma. Different hydrophilic capabilities of the surface obtained in air and nitrogen gas plasmas highlight a potential optimization of activation performances according to industrial specification.

Anisotropic plasma-enhanced atomic layer etching (ALE) requires directional ions with a well-defined ion energy to remove materials in a highly selective and self-limiting fashion. In many plasma etching systems, the ion energy is controlled using radio-frequency (13.56 MHz) sinusoidal waveform biasing. However, this yields ions with a broad energy distribution, while also inducing electron heating mechanisms that can affect the ion flux. In this work, we report on precise ion energy control—independent of the ion flux—using low-frequency (LF: 100 kHz) tailored bias voltage waveforms in a commercial remote plasma reactor. A prototype LF bias generator has been used to apply tailored waveforms consisting of a positive voltage pulse and a negative linear voltage ramp. These waveforms yielded ions having narrow energy distributions (7 ± 1 eV full-width-at-half-maximum) measured on dielectric SiO2 substrates for ion energies up to 200 eV in collisionless Ar plasmas. The mono-energetic ions were used to etch SiO2 thin films by physical sputtering. In these sputter etch experiments, the ability to accurately control the ion energy in the

This paper presents design and implementation of remote-plasma-source (RPS) generator for semiconductor manufacturing chamber cleaning. The generator consists of a full-bridge resonant inverter, an inductive coupling transformer, and a chamber with low pressure gases. To design the power converter for generating plasma sources, the equivalent load of a plasma chamber is required. A traditional approach to acquire equivalent plasma load is measuring plasma density through Langmuir probe. But the intrusive characteristic and power stress limitation make Langmuir probe not a convenient method to be applied in some plasma source design. This study proposes an engineering approach to deriving equivalent plasma load which takes switching frequency and gas flow rate into account without special devices needed. The transformer and the chamber are modeled with an RLC load which is used for designing the resonant tanks of the inverter and the igniter. The system configuration and modeling processes are presented in detail, from which the inverter and igniter designs are presented correspondingly. Simulated and experimental results have verified the analyses, design approaches and discussions of the RPS generator.

Antireflection (AR) coatings allow increased substrate transmission and reduce surface reflection over a specific wavelength range. We proposed a blue-blocking (BB) AR coating that allows maximal visible-light transmittance while minimizing the transmittance of blue light, owing to selective absorption. Admittance diagrams of BB Cr2O3 / SiO2 coatings and traditional AR Ta2O5 / SiO2 coatings were shown to demonstrate that small absorption affects the reflectance much less than it affects the transmittance. Therefore, by controlling the degree of absorption, the lower residual reflection can be obtained by optimizing the thickness of different layers of the overall stacked structure. Coatings were fabricated using remote plasma sputtering to meet the requirements of low residual reflectance (

We present the reduction in number of post process particles by use of YF 3 coatings on an alumina plasma reactor for fluorine chemistry based dry cleaning. With the introduction of highly reactive gases such as fluorine in semiconductor dry cleaning processes, especially within highly energetic plasmas, physical and chemical reactions between equipment parts and process gases continues to become an issue. Unaccounted for compounds and microstructures on tools leads to increasing particle defects on product wafers. The plasma density and ion energy is especially high at the dielectric walls of the remote plasma source (RPS). By utilizing a 150 micron YF 3 layer to coat the plasma dielectric walls of our high selectivity oxide removal tool, we were able to eliminate the formation of AlO x F y microstructures on the ceramic reactor surface, which in turn led to a greater than 85% reduction of “spark”-like particle contaminants near the centers of product wafer surface. Meanwhile electrical properties, etch rates, and selectivity were largely unaffected when compared to uncoated reactors. Surface profiler measurements showed an increase in surface roughness after coating, however a large reduction in reactor surface etch depth was shown after several hundred hours of processing. Furthermore, AlO x F y particles were not detected by Energy Dispersive X-Ray Spectroscopy (EDS) on wafers processed with the YF 3 coated RPS, in contrast to results from uncoated sources.

A remote plasma enhanced chemical vapor deposition (CVD) process using GeH4, SiH4, and SnCl4 precursors has been developed for epitaxial growth of group-IV alloys directly on Si (100) substrates, without the need for buffer layers. X-ray diffraction measurements of a representative Ge1–xSnx sample which is 233 nm thick, with x = 9.6% show it to be highly oriented along the [001] direction and nearly relaxed, with 0.37% compressive strain. Ellipsometry measurements provide a pseudo-dielectric function which is well fitted by a 3-layer (substrate/alloy/surface oxide) model. Cross-sectional transmission-electron-microscope images show a highly defective interface layer, ∼ 60 nm thick, containing edge dislocations and stacking faults; above this layer, the lattice is well-ordered, with a much lower density of defects. Atomic force microscopy measurements show an RMS roughness of 1.2 nm for this film.

The unique growth conditions of BluGlass’ low growth temperature technology Remote Plasma Chemical Vapour Deposition (RPCVD) are capable of producing Activate As-Grown (AAG) buried p-GaN layers. This ability renders RPCVD a highly attractive technique to produce GaN-based Tunnel Junctions (TJ) without the complexities associated with the post-growth lateral activation steps required by MOCVD. In this paper we discuss the use of hybrid RPCVD/MOCVD TJs for MOCVD-grown ridge guide laser diode (LD) applications. The impact of both the structure and placement of the TJ on the total optical loss of the LD are investigated. TJs conforming to the strict compositional requirements in order to yield a net reduction in optical loss are demonstrated, paving the way to improved conversion efficiencies through the replacement of the highly resistive p-AlGaN cladding layers and p-type Ohmic contacts with lower resistance n-AlGaN cladding layers and n-type Ohmic contacts.

As feature sizes of devices shrink every year, deposition and etching processes change to be very challenge, especially for sub-7 nm technology node. The acceptable variability of feature size is expected to be several atoms of silicon/germanium in the future. Therefore, Remote Plasma-Enhanced Atomic Layer Deposition (RPE-ALD) and Atomic Layer Etching (ALE) change to be more and more important in the semiconductor fabrication. Due to their self-limiting behavior, the atomic-scale fidelity could be realized for both of them in the processes. Compared with traditional Physical Vapor Deposition (PVD) and Chemical Vapor Deposition (CVD) methods, atomic-scale thickness controllability and good conformality can be achieved by RPE-ALD. Unlike conventional plasma etching, atomicscale precision and excellent depth uniformity can be achieved by ALE. The fundamentals and applications of RPE-ALD and ALE have been discussed in this paper. Using the combination of them, atomic-level deposition/etch-back method is also mentioned for achieving high quality ultra-thin films on three dimensional (3D) features.

The electrical characteristics and XPS analysis for the amorphous tungsten and zinc doped indium oxide thin film transistor, which was performed with single or double different fluorine based remote plasma treatment, were investigated in this study. A high mobility TFT device with the tungsten doped channel was fabricated in the previous study, but there was an inevitable negative shift for the threshold voltage, which will be a limit for the application of systemic circuit design. Therefore, a double fluorine based remote plasma treatment process is proposed for the high electronegativity of fluorine element and its similar radius as oxygen, which can be used to terminate the donor-like oxygen vacancy. It may induce a positive shift of threshold voltage, while carrier concentration and field effect mobility might be maintained. As a result, the sample with CF4/N2 + O2 plasma treatment exhibits a higher on/off current ratio of ~4.73 × 106, a lower sub-threshold swing value of 0.070 V/decade, and a lower interfacial trap density value of 5.21 × 1011 eV−1 cm−2 than other samples, while there is even a desirable positive shift of threshold voltage and acceptable field effect mobility of 31.2 cm2/Vs. This research proposes an effective approach to improve the reliability characteristic and adjust the inevitable negative shift of threshold voltage without sacrificing the carrier mobility of device.

Hafnium oxide (HfO2) thin films have received significant attention due to its excellent properties, such as large band gap, good thermodynamic stability, high density and high dielectric constant. The post-annealing temperature is also essential to their properties and application possibilities. In this work, HfO2 thin films were prepared on p-type silicon (100) substrates by remote plasma atomic layer deposition using tetrakis (ethylmethylamino) hafnium and remote oxygen plasma at 250 °C. The effect of rapid thermal annealing on the properties of the thin films was investigated using grazing incidence X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy and field-emission transmission electron microscope (FE-TEM). FE-TEM and GIXRD results show that the as-deposited films are mostly amorphous and the crystallization initiates at about 500 °C. They also unveil a positive correlation between interface properties of the HfO2 thin films and a dependence of the crystallinity on annealing temperature.

For horizontally stacked nanowires or-sheets to compete with finFET, the development of a robust inner spacer module is essential. These inner spacers are required to reduce the parasitic capacitance due to the overlap between the source/drain and gate regions. Here we propose an inner spacer integration scheme for Si gate-all-around (GAA) taking advantage of the selective oxidation and oxide removal of SiGe versus Si. Compared to thermal oxide, we found a very high SiGe-oxide etch rate in aqueous HF solutions. When using an NH3/NF3remote plasma, a reduction in etch rate was found for SiGe-oxide versus thermal oxide. We show Si0.75Ge0.25-oxide meets inner spacer requirements for leakage current and electrical breakdown field and finally demonstrate the proposed inner spacer integration scheme using a fin-shaped SiGe/Si multilayer topological-test-structure.

In this study, nanoscale-thickness Al2O3 layers for moisture barrier films were developed by a spatially resolved remote plasma atomic layer deposition process. The effect of various process parameters was investigated on the atomic concentration of Al2O3 films including the substrate temperature, plasma power, and scanning speed of the substrates. Carbon components were identified as major impurities in the films and is reduced at high temperature, high plasma power and low speed. Optimum conditions are maximum temperature of 80 °C to prevent plastic substrate deformation, a maximum plasma power of 150 W without surface damage and maximum speed of 125 mm/sec to maintain a low carbon contents. The water vapor transmission rate (WVTR) of 3.2 × 10 −4 g/(m2·day) was achieved with 30 nm-thick film in optimum condition.

By using a remote plasma enhanced chemical vapor deposition system, we grow a silicon rich silicon nitride thin film on the surface of five different substrates: silicon wafer, fused silica, highly oriented pyrolytic graphite, muscovite mica and potassium chloride. By means of high-resolution transmission electron microscopy we studied the influence that each substrate has on the auto-formation of silicon quantum dots (≤4.2 nm) embedded in the grown film. We conjecture that the growth of the film is carried out by the formation of highly reactive intermediates that are chemisorbed on the substrate surface. We conclude proposing the hypothesis that the substrate surface profile has minimal influence on the growth of a silicon nitride thin film that can embed silicon quantum dots.

This letter presents a remote NH3/N2 plasma treatment after gate oxide deposition for improving the electrical characteristics and the reliability of In0.53Ga0.47As FinFET. The plasma treatment enhanced drive current ( ${I}_{\textsf {DS}}$ ), transconductance ( ${G}_{m}$ ), subthreshold swing (SS), flicker noise, and positive bias temperature lifetime, suggesting that this plasma treatment significantly improves the quality of the etched In0.53Ga0.47As channel interface. In0.53Ga0.47As FinFETs and gate-all-around FETs were fabricated with the proposed in situ remote-plasma treatment and characterized.

Direct growth of carbon nanotubes (CNTs) on 316 stainless-steel (SS) substrates could facilitate versatile commercial applications. For the successful synthesis of CNTs on SS substrate, hydrofluoric acid (HF) etching renders suitable surface roughness to promote CNT growth. For catalyst preparation and also subsequent CNT growth, H2-plasma treatment plays essential roles. Reversing the aging effect of Fe/Ni from its unwanted oxides of reduced catalytic activity and formation of Fe nanoparticles from the sheet are accomplished using H2-plasma. High-density plasma, along with specific gas precursors with its energetic ions, required for uniform CNT growth is attained by microwave plasma-enhanced chemical vapor deposition. By using CO2, providing suitable oxidizer precursors, in (CH4 + H2) diffuse plasma, necessary ambience for low-temperature nucleation (300 °C) and high-yield CNT growth is obtained. Reduction in the deposition rate by highly-energetic ion collisions in high-power plasma is resolved by introducing remote plasma configuration using a specially designed mask assembly. Considering the optimum magnitudes of the intensity ratios of D- and 2D-peaks to the G-peak in the Raman spectra of CNTs, a time span of 2 h of HF-etching appears optimum for proper functioning of the Fe/Ni nanoparticle catalyst. Furthermore, H2-plasma polishing is effectively utilized as the last step of pretreatment, leading to the growth of lower-diameter CNTs. Finally, using a shadow mask assembly and weak oxidizing gas, low-temperature growth of CNTs is successfully accomplished on SS substrates, pretreated by optimum HF-etching and H2-plasma polishing on the Fe-nanoparticle catalyst layer, avoiding the conventional steps of high-temperature annealing for catalyst nanoparticle formation as well as high-temperature nucleation for CNT growth. Even without the use of a separate Fe-catalyst layer, CNT growth is accomplished directly on HF-etched and H2-plasma polished SS substrates, utilizing mostly Fe/Ni nano-grains that originate from the intrinsic composition of SS as the nucleation sites. Use of limited action-steps and of a low-temperature (~300 °C) distinguish this as a realistic avenue for commercial production of CNTs.

Traditional annealing has limitations of long-treatment time, excessive grain size and energy-intensive, inhibiting the quality and applications of the semiconductor thin films. Herein, an effect of rapid post-annealing (RPA) on the properties of cupric oxide (CuO) thin films deposited by a remote plasma sputtering technique was studied systemically. The chemical composition, microstructure, and the optoelectronic properties, including transmission, absorption, band gap, Urbach energy, carrier concentrations, and hall mobility, etc., were characterized by XRD, Raman, XPS, AFM, SEM TEM, optical transmission/absorption spectra and Hall measurements, correspondingly. The results reveal that the as-deposited and annealed (250, 350 and 450oC for 5 min) films all possess a single monoclinic CuO phase. All films possess compact nanostructures and the surface root-mean-square (RMS) roughness is around 1.5 nm because tiny and plain grains distribute uniformly within the films. The thermal annealing under higher temperature partially removes (or suppresses) the defects and this yields a broader bandgap for the CuO thin film, while the Urbach energy monotonous decreases with the increasing annealing temperature, signifying the minimizing disorder of the thin films. Meanwhile, the annealed CuO thin films possess decreased carrier concentration and enhanced hall mobility with increasing annealing temperature. For the 450oC-annealed CuO thin film, the carrier concentration is of 5.3 × 1015 cm−3 and the Hall mobility is of 2.3 cm2 V−1 s−1. This offers an essential material basis for photonic devices.

Graphene growth on Cu foil was demonstrated by plasma enhanced chemical vapor deposition (PECVD) with a microwave-excited non-equilibrium atmospheric pressure remote plasma (MNAPP) using CH4 and H2 gases diluted by He gas. The density of graphene grain decreased and their average sizes increased with decreasing the CH4 flow rate. Moreover, the sizes were almost constant at each condition. In the MNAPP, emission intensities of CH and C2 radicals normalized by that of He atom decreased with decreasing the CH4 flow rate. From the results, nucleation of graphene on Cu surface caused by the precursors such as CH x and C2 radicals occur only at the early period of PECVD, and after the initial nucleation, these precursors are mainly consumed for the planar growth of graphene without inducing subsequent nucleation. Therefore, flux control of precursors at the early period is important for synthesizing graphene with more large size in PECVD using MNAPP.

Recently, Plasma Assisted Atomic Layer Deposition Technique will easily control the thickness and the composition of semiconductor films. The radical generated by using the plasma techniques, gave the decrease of the defect into the semiconductor films. In this investigation, the relationship between microwave plasma power, nitrogen gas flow rate and concentration of generated nitrogen radical, was evaluated. At the first, Plasma emission spectrum at microwave plasma power (0 to 400W) was measured using a mixed 200sccm argon gas and 10sccm nitrogen gas. Next, the plasma emission spectrum was measured in the mixing of nitrogen gas flow rate (0 to 40sccm) with 200sccm argon gas flow rate. At that time, the microwave plasma power was set to 200W. Nitrogen radical spectrum were identified from all the emission spectrum, and the nitrogen radical intensity was calculated. As a result, the nitrogen radical intensity became the largest at 200sccm argon gas flow rate and 10sccm nitrogen gas flow rate. In addition, the nitrogen radical intensity increased in proportion to the microwave plasma power. The concentration of generated nitrogen radical could be controlled by changing the microwave plasma power and the nitrogen gas flow rate. Mentioned above, nitride thin films will be obtained on Si Substrates by microwave generated remote plasma assisted atomic layer deposition technique.

Improving the energy conversion efficiency of light-emitting diodes (LEDs) for blue light emission has been a continuing pursuit for the past several decades. Here, we report InGaN/GaN LEDs with improved energy efficiency through the simple deposition of multifunctional ultrathin AlN/Al2O3 layers on top of p-type GaN (i.e., GaN:Mg) using remote plasma pretreatment and plasma-enhanced atomic-layer deposition (PEALD). The AlN/Al2O3 stacked layers played principal roles in improving the LED energy efficiency: 1) The surface defect states of p-type GaN were reduced to minimize leakage current and oxidation was prevented by passivating the GaN surface; 2) the net positive charges formed at the AlN/GaN interface enhanced the hole injection rate into the multi-quantum well (MQW) by formation of downward band bending with the increased surface potential; and 3) the increased hole injection rate induced the band-filling effect and screening of internal polarization fields in the MQW. The AlN/Al2O3 stacked layers deposited on the GaN:Mg have overall improved the radiative recombination rate of the InGaN/GaN LEDs and thus light-emission efficiency. X-ray photoelectron spectroscopy was used to characterize the surface potential change of GaN. The peak efficiency values of wall-plug efficiency, the external-quantum efficiency, and the efficacy of the AlN/Al2O3 coated InGaN/GaN LEDs were improved by 29%, 29%, and 30%, respectively. The corresponding efficiency droop rates were decreased by 13%, 6% and 3%, respectively, as compared to those of reference LEDs.

The deposition of SiOC thin films via remote plasma atomic layer deposition was investigated. Octamethylcyclotetrasiloxane (OMCTS) and O2, Ar, H2 plasmas were respectively used as a precursor and reactants during the deposition process at 400 °C. Plasma and deposition temperatures had a significant effect on the physical and electrical characteristics of the films. When Ar and H2 plasma was respectively used during the deposition process, films exhibited low dielectric constants while incorporating carbon; however, O2 plasma yielded carbon free SiO2 films. Low dielectric constants resulted in low film densities and the presence of carbon within the films. When Ar and H2 plasma was used as the reactant gas, pores within the films with loose structures and Si C bonds served to lower the dielectric constant. As a result, Ar and H2 plasma conditions exhibited low dielectric constants of 2.7 and 3.1 at 100 °C, respectively. Meanwhile, the presence of carbon and low film densities caused leakage paths within the films. X-ray photoelectron spectroscopy supported analyses demonstrating the bonding characteristics of Si, C, O components.

Here, we report comprehensive investigations of aluminum oxide (Al2O3) high-κ gate oxides deposited via remote plasma enhanced atomic layer deposition (Re-PEALD) with mesh configuration in a commercial 100 mm ALD reactor. Trimethylaluminum (Al(CH3)3), dioxygen (O2) plasma, and Argon (Ar) are used as the metal precursor, oxidant, and carrier/purge, respectively. The growth rate per cycle and non-uniformity of Al2O3 thin films is analyzed with the variation in duration of (Al(CH3)3) pulse, O2 plasma, post-precursor purge, post-oxidant purge, RF power, and substrate temperature. High-quality monolayer type Al2O3 thin films with a growth rate of ~ 1.1 A/cycle are achieved for a wide temperature range from ~ 100 °C to ~ 300 °C suitable for various nanoelectronics applications ranging from flexible substrates to low thermal budget and high mobility alternate semiconductor substrates. Further, the Al/Re-PEALD-Al2O3/p-Si, metal-oxide-semiconductor (MOS) structures are investigated for capacitance-voltage, capacitance-frequency, and leakage current-voltage characteristics to demonstrate the quality of Re-PEALD-Al2O3 thin films. The Al/Re-PEALD-Al2O3/p-Si, MOS structures revealed excellent electrical characteristics with ultralow minimum interface trap density (Dit) ~ 9.9 × 109 eV−1cm−2, negative effective oxide charges (Neff) ~ 5.52 × 1012 cm−2, low leakage current density of ~ 4.1 nA/cm2 at −1 V, hysteresis-free, insignificant Vth shift, and trivial frequency dispersion. Moreover, the chemical analysis using XPS depth profiling disclosed that Re-PEALD deposited Al2O3 thin films results in a high-quality gradient Al2O3/SiOx/Si interface rather than an abrupt Al2O3/Si interface, and the oxygen rich thin films due to the oxygen (O2−) interstitials close to the interface are the sources of negative fixed oxide charges in Re-PEALD-Al2O3/Si, system. These results intend to boost the investigations of Re-PEALD Al2O3 ultrathin films for low thermal budget high mobility alternate semiconductor substrates for nanoelectronics applications.

Molybdenum carbonitride films prepared by plasma enhanced atomic layer deposition were studied for use as Schottky contacts to n-type gallium nitride. Deposited using bis(tertbutylimino)bis(dimethylamino)molybdenum and a remote plasma N2/H2 plasma, the diodes capped with Ti/Au displayed excellent rectifying behavior with a barrier height of 0.87 ± 0.01 eV and an ideality factor of 1.02 ± 0.01 after annealing at 600 °C in N2. These characteristics surpass those of pure metal nitride Schottky diodes, possibly due to work function engineering due to the incorporation of C and use of a remote plasma to avoid process-induced defects. According to x-ray photoelectron spectroscopy and energy-dispersive x-ray spectroscopy, the film composition is approximately MoC0.3N0.7. Grazing incidence x-ray diffraction and plan-view transmission electron microscopy selected area electron diffraction are consistent with a rock salt structure with a lattice parameter of 0.42 nm.

Self-limiting surface reactions are promising for atomic layer etching of materials. Classical treatments with plasmas do not allow for self-limiting functionalization but cause the formation of several functional groups and degradation. To avoid this, the polystyrene was oxidized in the plasma afterglow with the O-atom density 7 × 1017 m−3 and dissociation fraction 7%. X-ray Photoelectron Spectroscopy was used to study the formation of various oxygen groups versus the O-atom dose. The surface was saturated with the OH groups already after the dose of 1 × 1019 m−2, indicating a large initial sticking. The functionalization remained almost intact over an order of magnitude larger doses. Measurable quantities of the C O groups appeared simultaneously with the benzene ring's degradation at a dose of 1 × 1020 m−2. The ring degradation was accomplished with a significant increase in the OH concentration what was explained by the formation of a thicker oxygen-rich film. O C O and O (C O) O groups appeared after the dose of 1 × 1021 m−2, i.e., a 100-times larger dose than required for the initial saturation with the OH. The observations are sound with the predictions from the literature obtained through the density functional theory of oxygen adsorption on polystyrene.

© 2016 Elsevier Ltd ZnO nanowires with various concentrations of nitrogen molecules have been fabricated by remote plasma annealing. X-ray absorption near-edge spectroscopy (XANES) reveals that nitrogen exists mainly in two chemical states: atomic nitrogen substituting oxygen (NO) and molecular nitrogen (N2) weakly bound to the ZnO lattice; the latter state increases substantially with prolonged plasma time. Cathodoluminescence microanalysis of individual nanowires reveals a broad emission band at 3.24 eV at 10 K, attributable to the recombination of a shallow donor and a N2 acceptor state. The Raman modes at 547 and 580 cm−1 from the N-doped nanowires are found to rise in proportion to the N2 concentration, indicating they are related to N2 molecules or defects caused by the incorporation of N2 in the nanowires.

The most important parameter responsible for the quality of high-aspect structures produced by plasmachemical etching is the angular distribution of ions near the processed surface. In this work, the effect of collisions and gas pressure on the angular distributions of ions and chemically active radicals in the chamber of a high-pressure plasmachemical reactor with a remote plasma source is analyzed theoretically.

Hafnium oxide (HfO2) thin films have attracted much attention owing to their usefulness in equivalent oxide thickness scaling in microelectronics, which arises from their high dielectric constant and thermodynamic stability with silicon. However, the surface passivation properties of such films, particularly on crystalline silicon (c-Si), have rarely been reported upon. In this study, the HfO2 thin films were deposited on c-Si substrates with and without oxygen plasma pretreatments, using a remote plasma atomic layer deposition system. Post-annealing was performed using a rapid thermal processing system at different temperatures in N2 ambient for 10 min. The effects of oxygen plasma pretreatment and post-annealing on the properties of the HfO2 thin films were investigated. They indicate that the in situ remote plasma pretreatment of Si substrate can result in the formation of better SiO2, resulting in a better chemical passivation. The deposited HfO2 thin films with oxygen plasma pretreatment and post-annealing at 500 °C for 10 min were effective in improving the lifetime of c-Si (original lifetime of 1 μs) to up to 67 μs.

Large stable ferroelectricity in nanoscale undoped zirconia (ZrO 2 ) thin films prepared without post-annealing has been demonstrated for the first time. Remanent polarizations up to 12 μC cm −2 were obtained in the as-deposited ZrO 2 thin films prepared by remote plasma atomic layer deposition at 300 °C substrate temperature on the Pt electrode. Ferroelectric crystallization of the films was achieved without post-annealing, which is highly beneficial to the application of the films in non-volatile memories and ultralow-power nanoelectronics. The existence of the ferroelectric orthorhombic phase with noncentrosymmetric space group Pbc 2 1 in the as-deposited ZrO 2 thin films was confirmed by high-resolution transmission electron microscopy.