Deposition Of Metal Films Research Articles

Metallization of ZnSb and contact resistance

We present results on electrical resistance of metal contacts to ZnSb. We synthesized the thermoelectric semiconductor ZnSb with specific doping concentrations by adding Cu as an acceptor to the melt, followed by solidification, crushing, ball-milling, hot-pressing, sawing, and polishing yielding wafers suitable for substrates for further processing. Many batches were made yielding different doping concentrations. We defined transmission line geometries in deposited metal films for specific contact resistance measurements. We prepared sets of Cu, Ti, and Ni films, respectively. We measured the contact resistance vs annealing temperatures. For Cu/ZnSb samples, we observed a specific contact resistance from 5 × 10−7 to 4 × 10−5 Ω cm2. We also measured the carrier concentration of ZnSb. The measurement data of the specific contact resistance had systematic dependence on doping concentration and annealing temperature and were analyzed by a model incorporating different transport mechanisms across the energy barrier at the metal–semiconductor interface. The data were discussed in terms of systematic variation in barrier height and density of states effective mass. We proposed these arising as a consequence of interactions at the interface and a nonparabolic valence band. We have also monitored the interface of the ZnSb substrate and metal films with transmission electron microscopy.

Deposition of nanoscale metal films with the help of arc discharge

The method of magnetron sputtering using arc discharge is one of the most advanced and high-performance techniques for producing nanoscale films, especially metal films and, in particular, titanium and copper ones. The cathode spots that form during arc discharge are the discharge centers and they provide channels along which current travels from the cathode to the anode in the form of dense plasma jets of the cathode material forming a so-called plasma torch. The ion energy in such plasma torch is higher than in the conventional magnetron sputtering, which ensures a significantly better adhesion of the resulting films. At the same time, nanoscale titanium films are often used to create transition mating sublayers between the substrate and the main working film. Out of non-metallic films, titanium nitride films are of special interest. The main disadvantage of magnetron arc sputtering is the presence of a droplet phase in the plasma torch, which hinders the creation of nanoscale structures by forming condensate on the substrate. The resulting microdroplets are usually electrically neutral, therefore they cannot be removed and neutralized by means of electric or magnetic fields. The arc evaporator needs to be retrofitted so that the droplet phase was eliminated and thin-film coatings (including nanoscale coatings) could be produced. A plasma torch is formed with the help of a focusing coil, in which both ions of the sprayed substance and its droplets are present. A special flap prevents direct-flying droplets from getting in the flow of sprayed substance, and at least one more flap installed in the housing of the focusing coil protects the flow from droplets flying at an angle from the cathode. The flap is designed as a truncated cone made of non-magnetic metal, with the diameter of the larger base of the cone being equal to the inner diameter of the focusing coil, and the smaller diameter of the cone that faces the cooled cathode is equal to twice the diameter of the flap. The flap is coaxial with the cooled cathode of the arc evaporator.

Cobalt Metal ALD: Understanding the Mechanism and Role of Zinc Alkyl Precursors as Reductants for Low-Resistivity Co Thin Films

In this work, we report a new and promising approach toward the atomic layer deposition (ALD) of metallic Co thin films. Utilizing the simple and known CoCl2(TMEDA) (TMEDA = N,N,N′,N′-tetramethylethylenediamine) precursor in combination with the intramolecularly stabilized Zn aminoalkyl compound Zn(DMP)2 (DMP = dimethylaminopropyl) as an auxiliary reducing agent, a thermal ALD process is developed that enables the deposition of Zn-free Co thin films. ALD studies demonstrate the saturation behavior of both precursors and linearity depending on the applied number of cycles as well as temperature dependency of film growth in a regime of 140–215 °C. While the process optimization is carried out on Si with native oxide, additional growth studies are conducted on Au and Pt substrates. This study is complemented by initial reactivity and suitability tests of several potential Zn alkyl-reducing agents. For the CoCl2(TMEDA)–Zn(DMP)2 combination, these findings allow us to propose a series of elemental reaction steps hypothetically leading to pure Co film formation in the ALD process whose feasibility is probed by a set of density functional theory (DFT) calculations. The DFT results show that for reactions of the precursors in the gas phase and on Co(111) substrate surfaces, a pathway involving C–C coupling and diamine formation through reductive elimination of an intermediate Co(II) alkyl species is preferred. Co thin films with an average thickness of 10–25 nm obtained from the process are subjected to thorough analysis comprising atomic force microscopy, scanning electron microscopy, and Rutherford backscattering spectrometry/nuclear reaction analysis as well as depth profiling X-ray photoemission spectroscopy (XPS). From XPS analysis, it was found that graphitic and carbidic carbon coexist in the Co metal film bulk. Despite carbon concentrations of ∼20 at. % in the Co thin film bulk, resistivity measurements for ∼22 nm thick films grown on a defined SiO2 insulator layer yield highly promising values in a range of 15–20 μΩ cm without any postgrowth treatment.

(Invited) Precursors for the Thermal Atomic Layer Deposition of Cobalt Metal Films and Alloys Thereof

Herein, we will describe recent progress in our laboratory on the development of chemical precursors for the thermal atomic layer deposition (ALD) of cobalt metal, titanium metal, cobalt-titanium alloy, and other metal and metal alloy films. The nanoscale dimensions of current and future microelectronics devices now require alternative, ultrathin barrier materials for copper and other interconnect metals as well as new ultrathin liner materials. Sputtered cobalt-titanium alloys have been demonstrated to function as barrier materials and liners at dimensions as small as 1 nm. Hence, these materials may replace current barrier and liner materials such as TiN, TaN, and W metal. However, the narrow and deep nanoscale features require growth of cobalt-titanium alloy films by ALD to meet the strict conformality and thickness requirements. Moreover, thermal ALD is preferred over plasma-based processes, since recombination of atomic hydrogen on feature walls can afford poor conformal coverage. Thermal ALD processes for Co and Ti metal films are poorly developed, because the negative electrochemical potentials of the ions in precursors (Co2+ ↔ Co, E° = -0.280 V, Ti2+ ↔ Ti, E° = -1.628 V) require strong reducing co-reactants, which are not available. We will report new thermal ALD processes for cobalt metal films that employ various ligands, in combination with hydrazine-based co-reactants. These processes afford high purity cobalt metal films. We will also describe our efforts to develop new precursors for the thermal ALD of titanium metal films. Initial depositions of cobalt-titanium metal films will also be described.

Polymer inhibitors enable >900 cm2 dynamic windows based on reversible metal electrodeposition with high solar modulation

Dynamic windows with adjustable tint give users control over the flow of light and heat to decrease the carbon footprint of buildings and improve the occupants’ comfort. Despite the benefits of dynamic windows, they are rarely deployed in buildings because the existing technology cannot achieve fast and colour-neutral tinting at an agreeable cost. Reversible metal electrodeposition is a promising approach to solve these problems. Here, we demonstrate the use of polymer inhibitors to reversibly deposit metal films with controlled morphology in dynamic windows. The windows that employ the polymer inhibitor can readily tint to below 0.001% visible transmittance in less than 3 min and exhibit high infrared reflectance (>70%), colour-neutral transmittance (C* < 5) and an ultrawide range of optical and solar modulation (ΔTvis = 0.76 and ΔSHGC = 0.56). The polymer inhibitors also increase the efficiency and improve the durability of the windows and enable construction of >900 cm2 dynamic windows with fast response and excellent uniformity.

Area Selective Deposition of Metals from the Electrical Resistivity of the Substrate.

Area selective deposition (ASD) of films only on desired areas of the substrate opens for less complex fabrication of nanoscaled electronics. We show that a newly developed CVD method, where plasma electrons are used as the reducing agent in deposition of metallic thin films, is inherently area selective from the electrical resistivity of the substrate surface. When depositing iron with the new CVD method, no film is deposited on high-resistivity SiO2 surfaces whereas several hundred nanometers thick iron films are deposited on areas with low resistivity, obtained by adding a thin layer of silver on the SiO2 surface. On the basis of such a scheme, we show how to use the electric resistivity of the substrate surface as an extension of the ASD toolbox for metal-on-metal deposition.

Application of Glow Discharge Plasma for Cleaning (Activation) and Modification of Metal Surfaces while Welding, Brazing, and Coating Deposition

As known, the surface phenomena play a crucial role in the formation of strong interatomic bonds while joining dissimilar materials and the deposition of metal films. Thus, the presence of various contaminants, including oxides, on the metal surface reduces drastically the metal surface energy, thereby, preventing the diffusion processes in the contact zone and wetting them with liquid solder and adhesion of condensed films on the substrate surface. As a result, the processes of cleaning (activating) of metal surfaces before welding or coatings’ deposition begin to play a significant role. In some cases, metal surfaces have to be modified in order to give them the desired properties. Recently, for activation and modification of surfaces before welding and coatings’ deposition, gas-discharge plasma of abnormal glow discharge is widely used. The latter allows treating the surfaces of different configurations, including internal cavities, and various areas from units to tens of thousands of square centimetres. This review contains the results of research on the activation and modification of metal surfaces with low-energy ions (&lt; 10 keV) initiated in the plasma of an abnormal glow discharge for welding, brazing, and coatings’ deposition. Particularly, we present results of studies of ion treatment with the glow discharge surface of samples, which are made of steels С45 and DC04, a number of active metals and alloys as well as chromium-containing steels 41Cr4, X20Cr13, and X6CrNiTi18-10, which possess the chemically and thermally stable Cr2O3 oxides on their surfaces. The decisive influence on the efficiency of purification and modification of metal surfaces with glow discharge by means of such regime parameters as electrode voltage, discharge current density, working chamber pressure, and ion exposure time is indicated. The optimal values of these parameters, in most cases, are determined by the technological conditions of the process and vary in the following ranges: U = 1500–3500 V, J = 0.4–1 mA/cm2, P = 3.99–7.98 Pa, t = 120–300 s, respectively.

Glucose biosensor electrode fabrication based on CuO /ZnO nanostructures

Zinc oxide nanowires (ZnO NWs) were successfully synthesized by Zn-metal evaporation and deposition of a thin metal film about 20 µm on quartz substrates. Followed by the subsequent oxidation process in the air at 550 oC for 4h. Copper oxide nanoparticles (CuO NPs) were then deposited on ZnO NWs, using the drop-casting technique. The crystal structure and morphology of ZnO nanowires were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results of XRD confirmed that the ZnO has the Wurtizite polycrystalline structure along [101] direction. The SEM images revealed that the highest density of ZnO nanowires was distributed over a large area of the substrate with many wrinkles. The current response to glucose of the CuO/ZnO/Qz electrode gives a linear dependence range from 50 µM to 500 µM of glucose. The typical sample of CuO/ZnO NWs was used for a glucose biosensor electrode. It was found that CuO NPs layer on ZnO NWs has well improved the performance of the electrode and increased the electrocatalytic ability towards glucose oxidation.

An upgraded ultra-high vacuum magnetron-sputtering system for high-versatility and software-controlled deposition

Magnetron sputtering is a widely used physical vapor deposition technique. Reactive sputtering is used for the deposition of, e.g, oxides, nitrides and carbides. In fundamental research, versatility is essential when designing or upgrading a deposition chamber. Furthermore, automated deposition systems are the norm in industrial production, but relatively uncommon in laboratory-scale systems used primarily for fundamental research. Combining automatization and computerized control with the required versatility for fundamental research constitutes a challenge in designing, developing, and upgrading laboratory deposition systems. The present article provides a detailed description of the design of a lab-scale deposition chamber for magnetron sputtering used for the deposition of metallic, oxide, nitride and oxynitride films with automated controls, dc or pulsed bias, and combined with a coil to enhance the plasma density near the substrate. LabVIEW software (provided as Supplementary Information) has been developed for a high degree of computerized or automated control of hardware and processes control and logging of process details.

Nano-optoelectrodes Integrated with Flexible Multifunctional Fiber Probes by High-Throughput Scalable Fabrication.

Metallic nano-optoelectrode arrays can simultaneously serve as nanoelectrodes to increase the electrochemical surface-to-volume ratio for high-performance electrical recording and optical nanoantennas to achieve nanoscale light concentrations for ultrasensitive optical sensing. However, it remains a challenge to integrate nano-optoelectrodes with a miniaturized multifunctional probing system for combined electrical recording and optical biosensing in vivo. Here, we report that flexible nano-optoelectrode-integrated multifunctional fiber probes can have hybrid optical-electrical sensing multimodalities, including optical refractive index sensing, surface-enhanced Raman spectroscopy, and electrophysiological recording. By physical vapor deposition of thin metal films through free-standing masks of nanohole arrays, we exploit a scalable nanofabrication process to create nano-optoelectrode arrays on the tips of flexible multifunctional fiber probes. We envision that the development of flexible nano-optoelectrode-integrated multifunctional fiber probes can open significant opportunities by allowing for multimodal monitoring of brain activities with combined capabilities for simultaneous electrical neural recording and optical biochemical sensing at the single-cell level.

Transmission and Conversion of Electromagnetic Radiation by Photonic Crystal Metal–Dielectric Systems Based on Opals

An experimental study of the optical properties of two types of metal–dielectric composites based on opal matrices has been carried out: (1) layered structures, obtained by successive deposition of metal and dielectric films on a monolayer of opal globules, where anomalous transmission and absorption of light was found due to the excitation of surface plasmon polaritons of various types; (2) “massive” opal samples, into which the metal was introduced by the method of electrothermal diffusion, where an asymmetric shape of Bragg resonance curves was observed, due to the Fano resonance.

Modification of glass durability in reactive ion etching with thermal poling and ion exchange

The influence of thermal poling and ion exchange on the rate of reactive ion etching of a soda-lime silicate glass in CF4-Ar plasma was studied. It is shown that the replacement of Na+ by Ag+ ions increases the durability of the glass etching while thermal poling of the glass increases the etching rate. The fastest etching was registered for the glasses poled using deposited metal film anodic electrode and using corona discharge in nitrogen atmosphere. Corona poling of the glass in atmospheric air instead of nitrogen essentially decreased the rate.

Hydrogen in Electrolessly Deposited Ni/Au and Ni/Pd/Au Films

For the surface finishing of copper layer on printed circuit boards, autocatalytic electroless deposition of nickel-phosphorus alloy and immersion deposition of gold (ENIG, Ni-P/Au) or autocatalytic electroless deposition of Ni-P, palladium and immersion deposition of Au (ENEPIG, Ni-P/Pd/Au) are widely used. The Ni-P/Pd/Au surface finish is suitable not only for lead-free soldering but also for wire bonding [1]. For soldering, it was reported that hydrogen plasma improved bonding behavior and realized a flux-free process [2]. Electrochemically deposited metal films include hydrogen atoms. The hydrogen adsorbed in metal films causes various phenomena such as atomic diffusion, alloying, crystal growth, void formation. We have been investigating the atomistic state and behavior of hydrogen in electrodeposited metals by thermal desorption spectroscopy [3, 4]. In this study we measured changes in hydrogen amounts in the Ni-P/Au and Ni-P/Pd/Au surface finishes [5]. We used two different electroless Pd baths using formic acid (Ni-P/Pd/Au) and sodium phosphinate (Ni-P/Pd-P/Au) as reducing agents. The Ni-P films contained large amounts of diffusible hydrogen that desorbs at room temperature. During autocatalytic electroless deposition of Pd and Pd-P on Ni-P films, the greater part of the hydrogen in the Ni-P films desorbed. Although no hydrogen evolution accompanied immersion Au deposition, the hydrogen amounts in Ni-P/Au, Ni-P/Pd/Au, and Ni-P/Pd-P/Au films were much greater than in films without a Au layer. Moreover, at room temperature, they remained almost unchanged for one month after deposition, indicating that the thin Au layer (< 0.1 μm) prevents hydrogen desorption from the metal films. The high hydrogen concentration in Ni-P/Au films improved solder wettability.[1] Y. Oda, M. Kiso, S. Kurosaka, A. Okada, K. Kitajima, and S. Hashimoto, Proc. Internal. Microelectronic and Packaging Soc., IMAPS (2008).[2] T. Hagihara, T. Takeuchi, and Y. Ohno, Proc. 10th Electronics Packaging Technology Conf. (IEEE), 595 (2008).[3] N. Fukumuro, S. Kojima, M. Fujino, Y. Mizuta, T. Maruo, S. Yae, and Y. Fukai, J. Alloy. Comp., 645, S404 (2015).[4] N. Fukumuro, K. Tohda, and S. Yae, this symposium.[5] Y. Oda, Y. Sagara, N. Fukumuro, and S. Yae, J. Surf. Finish. Soc. Jpn., 70, 163 (2019).

Atomic-Scale Imprinting by Sputter Deposition of Amorphous Metallic Films.

With its ease of implementation, low cost, high throughput, and excellent feature replication accuracy, nanoimprinting is used to fabricate structures for electrical, optical, and biological applications or to modify surface properties. If ultraprecise and/or subnanometer-sized patterns are desired, nanoimprinting has shown only limited success with polymers, silica glasses, or crystalline materials. In contrast, the absence of an intrinsic length scale that would interfere with imprinting resolution enables bulk metallic glasses (BMGs) to replicate structures down to the atomic scale through thermoplastic forming (TPF). However, only a small number of BMG-forming alloys can be used for TPF-based atomic-scale imprinting. Here, we demonstrate an alternative sputter deposition-based approach for the replication of atomic-scale features that is suited for a very broad range of amorphous alloys, thereby dramatically extending the available chemistries. Additional advantages are the method's scalability, its ability to replicate a wide range of molds, its low material consumption, and the fact that the films can readily be applied onto almost any workpiece, which together open up new avenues to atomically defined surface structuring and functionalization. Our method constitutes the advancement from proof of concept to a practical and highly versatile toolbox of atomic-scale imprinting to be explored for the science and technology of atomic-scale imprinting.

Nanostructural evolution in vapor deposited phase-separating binary alloy films of non-equimolar compositions: Insights from a 3D phase-field approach

A rich variety of self-organized nanoscale patterns evolve during physical vapor deposition of phase-separating alloy films. However, our limited understanding of the fundamental mechanisms of morphological evolution during the vapor deposition of multi-component metallic films is a major hurdle in optimizing their mechanical and functional properties. Diffuse interface approaches, such as the phase-field method, can enable the prediction of nanostructured morphologies in a broad class of immiscible binary alloys by achieving a fundamental understanding of self-assembly mechanisms down to the nanometer scale. Here, we adopt a three-dimensional phase-field approach to numerically investigate the role of alloy compositions, deposition rates, and temperature on the morphological self-assembly of nanostructures in vapor deposited alloy films. We explain the influence of alloy composition and deposition parameters on the evolution of novel film morphologies such as perforated layered and aligned rods. Following an extensive parametric study, we construct morphology maps that help expand our knowledge of the different combinations of processing conditions that generate distinct nanoscaled morphologies. Finally, we expand and elucidate a theory based on the minimization of interfacial energy that underpins the mechanisms of morphological transitions in vapor deposition of immiscible alloy films for an entire composition range.

Direct ion-beam deposition of Ag nanoparticles using a solid-state silver ion source

Ion beam technology has shown itself worth to be an efficient method to produce nanoparticles embedded in dielectrics for photoelectronic devices. However, direct ion-beam deposition of nanoparticles (NPs) on the surface of dielectrics is rarely reported because the conventional metal ion source runs into difficulties to generate low energy (<10 keV) ion-beams. Herein, Ag NPs are directly deposited on the surface of Si substrates using the recently developed solid electrolyte ion source (SEIS), which possesses advantages of compactness, simple working conditions, and ability of emitting ion-beam at an energy of few keV. The composition, morphology and size of the synthesized Ag NPs are studied. Precise control of the NPs size including in-plane diameter and height is achieved by a modulation of the ion implantation dose. Localized maskless deposition of metal films on semiconductor surface is also expected using the SEIS device.

Selection of technologies for metal film application using physical deposition techniques

Introduction. Obtaining high-quality thin metal films is important for advances in the technologies of applying antifriction and wear-resistant coatings on cutting tools or parts of friction couples. Various techniques of physical film deposition are applied using technologies of cathode (ion), magnetron and ion beam assisted sputtering. The work objective is to analyze, compare and determine the feasibility of techniques for the physical deposition of thin metal films when applying antifriction and wear-resistant coatings on cutting tools or parts of friction couples. Materials and Methods. Technologies of cathode (ionic), magnetron and ion-beam sputtering are considered. Schematic diagrams, conditions and parameters of the considered processes are presented. Results. An advanced technology for the deposition of thin films, alloying and hardening of the surfaces of metal parts is magnetron sputtering. Continuous wave (cw) magnetrons are used to apply coatings of complex composition or multilayer coatings on flat substrates. Ion beam sputtering is considered a slow sputtering of the target surface by bombardment with a high-energy ion beam and deposition on the substrate surface. Under the ion implantation, the surface of metals is doped with recoil atoms, which receive high energy from accelerated ions and move a few nanometers deeper. This enables to obtain ultra-thin doped layers. Low temperature of ion implantation, the possibility of sufficiently accurate control of the depth and the impurity distribution profile, create the prerequisites for the process automation. Wear tracks are more acidified under the same wear conditions on implanted steel compared to non-implanted steel. The nonequilibrium process under ion implantation causes the formation of such alloys in the surface layers that cannot be obtained under normal conditions due to diffusion of components or limited solubility. Ion implantation makes it possible to obtain alloys of a certain composition in the surface layer. Surface properties can be optimized without reference to the bulk properties of the material. Implantation is possible at low temperatures without a noticeable change in the size of the product. Discussion and Conclusion. Cathode (ion), magnetron and ion-beam sputtering have common advantages: due to the relatively low temperature, the substrate does not overheat; it is possible to obtain uniform coatings; the chemical composition of the deposited coatings is accurately reproduced. The rest of the advantages and disadvantages of the considered methods are individual. The results can be used to create thin films through alternating magnetron and then ionbeam deposition processes, which enables to obtain films uniformly modified in depth. This is important in the production of parts of friction couples and cutting tools to improve their quality.

Making Large‐Area Titanium Disulfide Films at Reduced Temperature by Balancing the Kinetics of Sulfurization and Roughening

AbstractThe synthesis of large‐area TiS2 thin films is reported at temperatures as low as 500 °C using a scalable two‐step method of metal film deposition followed by sulfurization in an H2S gas furnace. It is demonstrated that the lowest‐achievable sulfurization temperature depends strongly on the oxygen background during sulfurization. This dependence arises because TiO bonds present a substantial kinetic and thermodynamic barrier to TiS2 formation. Lowering the sulfurization temperature is important to make smooth films, and to enable integration of TiS2 and related transition metal dichalcogenides—including metastable phases and alloys—into device technology.

Optical diagnostics of the magnetron sputtering process of copper in an argon\u2013oxygen atmosphere

In this paper, a diagnostic tool for magnetron sputtering deposition of copper oxides is presented. The copper oxide thin films were deposited in DC-MF mode for various argon/oxygen mixtures, including deposition in a pure oxygen atmosphere (fully reactive mode). The copper oxides were deposited on quartz glass substrates and carbon foils. The deposition process was monitored using optical emission spectroscopy. The films were further analysed by X-ray diffraction (XRD), optical measurements, and Rutherford backscattering spectroscopy (RBS). The obtained results confirmed that optical emission spectroscopy (OES) can be used as a diagnostic tool for magnetron sputtering technology that enables control of the sputtering mode, and therefore, the deposition of pure metallic (Cu) and various oxide (Cu2O, CuO) films can be performed. The results show that by increasing oxygen content in the argon/oxygen mixture, the sputtering rate is reduced; however, in the oxygen, at 40–100% range, it is stabilised at 12 nm/min.

Oxygen-assisted Cathodic Deposition of Copper-Carboxylate Metal–Organic Framework Films

Reductive deposition is an attractive strategy to prepare films of metal–organic frameworks (MOFs), but to cathodically deposit the intergrown dense films of MOFs containing readily reduced metal ions (e.g., Cu2+) without the plating of the corresponding metals still remains a significant challenge. Here, we report the cathodic deposition of metallic copper-free films of two copper-carboxylate MOFs (HKUST-1 and MOF-14). Our strategy relies on the utilization of O2 as probase to electrochemically trigger the crystallization of MOFs. Systematical cyclic voltammetry studies indicate that the favorable synergistic catalytic effects of the acidic copper ions and benzene-1,3,5-tricarboxylic acid ligands on the O2 reduction can positively shift the deposition potential of HKUST-1 significantly to +0.05 V (vs Ag/AgCl), avoiding effectively the plating of metallic copper and facilitating greatly the control over the crystallization kinetics of MOFs. By the further optimization of experimental conditions relevant to reaction temperature, supporting electrolyte, O2 concentration, and working potential, the intergrown dense MOF films with tunable thicknesses were deposited successfully on several commonly used electrodes including the highly oriented pyrolytic graphite, carbon fiber, carbon cloth, and fluorine-doped tin oxide.