Annealing In O2 Atmosphere Research Articles

The Influence of Annealing on the Compositional and Crystallographic Properties of Sputtered Li–Al–O Thin Films

Li–Al–O materials are interesting for several applications. Herein, a Li–Al–O thin‐film materials library, deposited by inert magnetron sputtering and postdeposition annealing in O2 atmosphere, is used to study the effects of different annealing temperatures (300–850 °C) and durations (1 min to 7 h) on crystallinity and composition of the films. X‐ray photoelectron spectroscopy depth profiling reveals inhomogeneous compositional depth profiles of conventionally annealed films (300–650 °C, 3–7 h) with increased Li contents toward the film surface and increased Al contents toward the film–substrate interface, as confirmed by a combination of Rutherford backscattering spectrometry and deuteron‐induced nuclear reaction analysis. The minimum temperature for the formation of crystalline LiAlO2 in the otherwise amorphous films is 550 °C. The undesired inhomogeneous depth profiles are transformed into homogeneous ones by rapid thermal annealing (750–850 °C, 1–10 min), while simultaneously causing the formation of crystalline LiAlO2. Therefore, rapid thermal annealing is shown to be more suitable than conventional annealing for the thermal processing of Li–Al–O thin films. Moreover, this conclusion is expected to have broader relevance beyond Li–Al–O materials, as it is likely to apply to other Li metal oxides, of which there are many technologically relevant ones.

A study on the Raman response of TiO2 upon ion-implantation and annealing in O2 atmosphere

The doped TiO2 materials exhibit extraordinary opto-electronic properties and in this regard, Ion-Implantation process offers extreme control and flexibility to fabricate such materials. In this work, it is shown that the electronic structure, optical absorption and raman response of TiO2 to be modified by single ion and sequential implantation process with Ag− (65 KeV), Au− (80 KeV) ions and post-implantation annealing at 450 °C for an hour in O2 atmosphere. The raman spectra of implanted and implanted/annealed TiO2 films depict anatase phase characteristics and implantation-induced effects are believed to alter the crystallinity in these materials. The sequentially implanted films Au_Ag_1 × 1016/TiO2, Au_Ag_1.5 × 1016/TiO2 depict an additional band at 65 cm−1 prior to Eg(1) band at 144.35 cm−1 and are further bettered upon annealing. The absorbance of the implanted TiO2 films is increased in the visible spectral region when compared to pristine TiO2 and are further enhanced upon annealing. The film Au_Ag_1 × 1016/TiO2 (A) exhibited optical band gap ∼2.96 eV when compared to 3.13 eV of pristine TiO2 and these materials with modified optical properties have implications for Photocatalysis, Photo-electrochemical water-splitting and Photovoltaic applications.

High-performance tin oxide field-effect transistors deposited by thermal atomic layer deposition

In this study, we investigated the impact of annealing ambient on the performance of SnO2-based field-effect transistors (FETs) while adhering to the thermal budget constraint (process temperature < 450 °C). The SnO2 films were deposited by thermal atomic layer deposition (T-ALD). After annealing the films for 2 h at 400 °C, it was observed that annealing in an O2 ambient resulted in a SnO2 film with an excessive number of background carriers, which made it difficult to fully deplete the channel. Conversely, annealing in an N2 ambient led to an unstable channel that could not be effectively modulated, despite having a carrier concentration about an order of magnitude lower than that of the O2-annealed film. Surprisingly, the devices annealed in an air ambient exhibited the best performance. X-ray photo-emission spectroscopy revealed that annealing in O2 ambient resulted in a higher level of oxygen vacancy, while N2 annealing was more effective in creating stoichiometric SnO. The best device performance achieved in this study was observed in a 6-nm thick channel that was annealed in the air. This device exhibited an on/off ratio of 1.2 × 1011, subthreshold swing of 0.4 V/dec., field-effect mobility of 14.6 cm2/V·s, and threshold voltage of 1.1 V, operating in an enhancement mode. These results emphasize the potential of ALD SnO2 channels for high-performance transistors that are compatible with back-end-of-line processes in Si technology.

Interface and oxide trap states of SiO2/GaN metal–oxide–semiconductor capacitors and their effects on electrical properties evaluated by deep level transient spectroscopy

The relationship between the electrical properties and the carrier trap properties of the SiO2/GaN metal–oxide–semiconductor (MOS) capacitors was investigated using electrical measurements and deep level transient spectroscopy (DLTS). The capacitance–voltage (C–V) measurement showed that the frequency dispersion of the C–V curves became smaller after an 800 °C annealing in O2 ambient. DLTS revealed that before the annealing, the interface trap states, in a broad energy range above the midgap of GaN, were detected with the higher interface state density at around 0.3 and 0.9 eV below the conduction band minimum (EC) of GaN. Moreover, the oxide trap states were formed at around 0.1 eV below the EC of GaN, plausibly indicating a slow electron trap with a tunneling process. Although both trap states affect the electrical reliability and insulating property of the SiO2/GaN MOS capacitors, they were found to drastically decrease after the annealing, leading to the improvement of the electrical properties.

Revival of Smooth MgO(100) Surface: Ar Ion‐Beam Milling and Postvacuum Annealing in Oxygen Atmosphere

A recreation procedure for achieving the smooth and clean surface morphology of the degraded MgO(100) substrates is presented. The surfaces of the degraded MgO(100) substrates are treated with Ar ion‐beam milling (IBM) and annealing in O2 atmosphere. After each treatment, the changes in the MgO(100) substrate surface morphology are characterized using X‐ray diffraction (XRD), a 3D optical profilometer, atomic force microscopy, and Fourier‐transform infrared (FTIR) spectroscopy and compared with a fresh MgO substrate. It is shown that before any treatment, XRD and FTIR spectra show peaks corresponding to hydroxyl and carbonate groups in the degraded samples, whereas after treatment, XRD and FTIR spectra are comparable with the fresh sample. Further, after treatment, the surface roughness Rav value for two used/degraded samples reduces from 129 and 186 nm to 3.96 and 7.91 nm, respectively, after combined Ar IBM and annealing treatment. It is shown that the surface quality of the treated MgO(100) substrate improves in comparison with as it was before any treatment and can be reused for the good quality thin‐film deposition.

Substitution-site and ambient annealing dependences of upconversion emission of SrTiO3

We investigated the upconversion (UC) emissions and their ambient dependences of SrTiO3 polycrystals co-doped in Er3+ and Yb3+ at different substitution sites. i.e., the A-site and B-sites in ABO3-type perovskite, and its response to H2 and O2 ambient annealing. Under near-infrared excitation at 980 nm, the as-synthesized samples exhibited strong UC emission features in the green (525 and 550 nm) and red (660 nm) region from Er3+ ions owing to sensitization by Yb3+; the emission was much stronger for A-site doping than for B-site doping. Interestingly, annealing in the H2 atmosphere to increase the oxygen vacancies suppressed the photoluminescence and UC emission of the A-site doped samples, but enhanced the emission signals of the B-site doped samples. After subsequent annealing in the O2 atmosphere to decrease the oxygen vacancies, the emission intensities showed a tendency to return to those in the as-synthesized A-site doped and B-site doped samples. These intriguing behaviors were explained in terms of the relationship between the substitution site and charge compensation. We performed the temperature dependent UC emissions and found that the intensity ratio between two green emissions changed significantly with temperature. This strong fluorescence intensity ratio could be used for optical thermometry.

Reversible conversion of the valence states of Eu ions in ABaPO4 (A = Li, Na, and K) in terms of change in luminescence property

We investigated the emission properties of Eu ion-doped ABaPO4 (ABaPO4:Eu, A = Li, Na, and K) in which the valence state of the Eu ions was controlled by annealing in various ambients, gamma-ray (γ-ray) irradiation, and hydrogen ion (H+) implantation. We synthesized the ABaPO4:Eu samples by solid-state reaction in air. The as-synthesized samples showed sharp red emission near 600 nm, which originated from Eu3+ ions. Interestingly, annealing under H2 ambient changed the valence state of the Eu ions from 3+ to 2+, which was indicated by the disappearance of the red emission and concurrent emergence of strong blue emission. After subsequent annealing in O2 atmosphere, the red emission of Eu3+ was recovered. The reversible switching between the 2+ and 3+ states was found to be repeatable by alternating H2 and O2 annealing. The valence state was also changed from 3+ to 2+ by H+ implantation and γ-ray irradiation of the as-synthesized samples, possibly owing to the formation of oxygen vacancies. Our results suggest that the luminescence color of the ABaPO4:Eu phosphors can be controlled within a range from red to blue by simple annealing in various ambients.

Voids and vacancy-type defects in SiO2/GaN structures probed by monoenergetic positron beams

Voids in SiO2 films deposited on GaN were probed by using monoenergetic positron beams. The films were fabricated on GaN substrates by using plasma-enhanced chemical vapor deposition. The size and density of the voids in the films increased up to an annealing temperature of 800 °C and then decreased at 1000 °C. The observed annealing behaviors of the voids were attributed to the desorption of impurities incorporated during the deposition process and the shrinkage of the Si–O matrix by high-temperature annealing. Vacancy-type defects were introduced into the GaN substrate after 1000 °C annealing in O2 atmosphere due to the diffusion of Ga from the substrate to the SiO2 film. No out-diffusion of Ga into the SiO2 film was observed for the annealing in N2 atmosphere. Thus, the observed out-diffusion of Ga was attributed to the enhanced oxidation of GaN during the annealing in O2 atmosphere. The diffusion of positrons implanted into the GaN substrate toward the SiO2 film was suppressed by annealing, suggesting a decrease in the negative charges in the SiO2 film or near the SiO2/GaN interface.

In-situ XRD studies of arc evaporated Al-Cr-O coatings during oxidation

The structural evolution of cathodic arc evaporated Al-Cr-O coatings with hugely different Al, Cr, and O contents was investigated by in-situ XRD measurements upon annealing in oxygen up to 1200 °C. Different chemical compositions are achieved by arc evaporation of Al0.90Cr0.10, Al0.75Cr0.25, Al0.70Cr0.30, Al0.50Cr0.50, or Al0.25Cr0.75 cathodes and using either 20 standard cubic centimetres per minute (sccm) Ar, 50 sccm O2, or 100 sccm O2 per active source (p.a.s.). Generally, the crystallinity of the as-deposited coatings decreases with increasing O2 flow rate during arc evaporation, while their Al/Cr ratio increases significantly (with respect to the cathode composition). The coatings prepared from Al-rich cathodes show first indications for the formation of corundum structured α-(Al,Cr)2O3 phases at ~900 °C during annealing in O2 atmosphere. Those, prepared from the Cr-rich cathode (Al0.25Cr0.75) with 20 sccm Ar or 50 sccm O2 p.a.s., exhibit the formation of α-(Al,Cr)2O3 phases already at 700–800 °C. Their corresponding coatings prepared with the highest oxygen flow rate of 100 sccm p.a.s., exhibit a considerable phase fraction of α-(Al,Cr)2O3 already in the as-deposited state.Upon oxidation at 1200 °C, most coatings are basically composed of α-oxides, with a wide range of their Al/Cr-ratio. The coatings prepared with 100 sccm O2 p.a.s., however, show the formation of α-(Al,Cr)2O3 with a rather narrow Al/Cr-ratio, which is due to the sufficient mixing of Al, Cr, and O species already in the as-deposited state. Furthermore, selective oxidation (preference for Al2O3) leads in most cases to the formation of Cr, which is detectable up to 1200 °C.Between 950 and 1050 °C, the formation of θ-(Al,Cr)2O3 could be detected for cathodes with Al ≥ 50 at.% prepared with 20 sccm Ar or 50 sccm O2 p.a.s. Coatings prepared with Al0.75Cr0.25, Al0.70Cr0.30, and Al0.50Cr0.50 cathodes and 100 sccm O2 p.a.s. show the formation of θ-(Al,Cr)2O3 already in the as-deposited state. α-(Al,Cr)2O3 could only be detected for as-deposited coatings when preparing them with Al0.25Cr0.75 and 100 sccm O2 p.a.s.

Ambient annealing influence on surface passivation and stoichiometric analysis of molybdenum oxide layer for carrier selective contact solar cells

Effective carrier contact with excellent surface passivation is essential for archiving high efficiency silicon solar cells. In this study, optical, passivation and stoichiometric characteristics of MoOx thin films were analyzed by varying thickness, temperature and ambient annealing. The 10 nm thick MoOx films showed high optical transmittance (89.81%) in the visible near infra-red (NIR) wavelength (380–1100) nm region and wide optical bandgap of 3.25 eV. An improved minority carrier lifetime of 2.24 ms was recorded for O2 ambient at 130 °C due to less additional defects in the MoOx films. X-rays photoelectron spectroscopic analysis confirmed that O2 ambient annealing greatly influenced the MoOx stoichiometric and reduce the formation defective state densities at the Fermi energy initiating from the tail of an oxygen vacancy and inducted the defect band within the energy bandgap. Carrier selective contact (CSC) solar cells were fabricated by using 10 nm thick MoOx film as hole extraction layer exhibited the high performance as; open circuit voltage (Voc) = 708 mV, current density (Jsc) = 37.80 mA/cm2, fill factor (FF) = 74.95% and efficiency (η) = 20.06%. These results implies that the MoOx is an important material to use in future CSC solar cell applications with the concept of new advantages such as dopant free, non-toxic and low temperature fabrication process.

Enhancement of superconducting properties of MgB2 thin films by using oxygen annealing atmosphere

In this work, we show that significant enhancement of superconducting properties of MgB2 thin films prepared by vacuum evaporation and ex-situ annealing can be obtained when the annealing is performed in O2 atmosphere instead of the usually employed inert atmosphere (Ar in the current study). Rapid annealing in O2 significantly improves the critical transition temperature (Tc), critical current density (jc), and upper critical magnetic field (Hc2) compared to the control sample prepared in the same way, but annealed in Ar. Structural and composition analyses of the films demonstrate that the annealing in O2 atmosphere produces a sufficiently thick MgO layer on the surface of MgB2 thin films, which acts as a protective barrier preventing out-diffusion of Mg from the films during the high-temperature annealing. This consequently leads to better stoichiometry (B/Mg ratio), increased MgB2 grain size and enhanced intergrain connectivity. The higher residual resistivity of the films annealed in O2 atmosphere also indicates higher concentration of intragrain impurities, which causes a further increase of the jc and Hc.

Magnesium incorporation efficiencies in MgxZn1−xO films on ZnO substrates grown by metalorganic chemical vapor deposition**Project supported by the National Natural Science Foundation of China (Grant No. 61474121) and the Major Scientific Project of Fujian Province, China (Grant No. 2014NZ0002-2).

We investigate the magnesium (Mg) incorporation efficiencies in MgxZn1−xO films on c-plane Zn-face ZnO substrates by using metalorganic chemical vapor deposition (MOCVD) technique. In order to deposit high quality MgxZn1−xO films, atomically smooth epi-ready surfaces of the hydrothermal grown ZnO substrates are achieved by thermal annealing in O2 atmosphere and characterized by atomic force microscope (AFM). The AFM, scanning electron microscope (SEM), and x-ray diffraction (XRD) studies demonstrate that the MgxZn1−xO films each have flat surface and hexagonal wurtzite structure without phase segregation at up to Mg content of 34.4%. The effects of the growth parameters including substrate temperature, reactor pressure and VI/II ratio on Mg content in the films are investigated by XRD analysis based on Vegard’s law, and confirmed by photo-luminescence spectra and x-ray photoelectron spectroscopy as well. It is indicated that high substrate temperature, low reactor pressure, and high VI/II ratio are good for obtaining high Mg content.

Investigation of structural and electrical properties on substrate material for high frequency metal–oxide–semiconductor (MOS) devices

Hafnium oxide (HfO2) thin films were grown on cleaned P-type 〈1 0 0〉 Ge and Si substrates by using atomic layer deposition technique (ALD) with thickness of 8 nm. The composition analysis of as-deposited and annealed HfO2 films was characterized by XPS, further electrical measurements; we fabricated the metal–oxide–semiconductor (MOS) devices with Pt electrode. Post deposition annealing in O2 ambient at 500 °C for 30 min was carried out on both Ge and Si devices. Capacitance–voltage (C–V) and conductance–voltage (G–V) curves measured at 1 MHz. The Ge MOS devices showed improved interfacial and electrical properties, high dielectric constant (~19), smaller EOT value (0.7 nm), and smaller Dit value as Si MOS devices. The C–V curves shown significantly high accumulation capacitance values from Ge devices, relatively when compare with the Si MOS devices before and after annealing. It could be due to the presence of very thin interfacial layer at HfO2/Ge stacks than HfO2/Si stacks conformed by the HRTEM images. Besides, from current–voltage (I–V) curves of the Ge devices exhibited similar leakage current as Si devices. Therefore, Ge might be a reliable substrate material for structural, electrical and high frequency applications.

Structural and Optical Properties of HfO2 Films on Sapphire Annealed in O2 Ambient

The structural properties of HfO₂ films could be improved by thermal treatment owing to their crystallization. We deposited HfO₂ films on sapphire by radio frequency (RF) magnetron sputtering, whose base vacuum pressure was lower than 4.5 × 10 −6 ㎩, RF power was 100 W, working temperature was 200°C, working pressure was 3 mTorr, and the density of the active gas (Argon) was 20 sccm. After depositing the HfO₂ films, the samples were thermally treated by rapid thermal annealing (RTA) in O₂ ambient at different temperatures. Subsequently, the measured physical properties (structural, morphological, and optical) indicated that the crystallite size, refractive index at a wavelength of 632 ㎚, and packing density increased with rising temperatures. In particular, an HfO₂ film thermally treated at 800℃ in O₂ ambient had the highest refractive index of 2.0237 and packing density of 0.9638. The relation between optical and structural properties was also analyzed.

Influences of high-temperature annealing on atomic layer deposited Al2O3/4H-SiC

High-temperature annealing of the atomic layer deposition (ALD) of Al2O3 films on 4H-SiC in O2 atmosphere is studied with temperature ranging from 800 °C to 1000 °C. It is observed that the surface morphology of Al2O3 films annealed at 800 °C and 900 °C is pretty good, while the surface of the sample annealed at 1000 °C becomes bumpy. Grazing incidence X-ray diffraction (GIXRD) measurements demonstrate that the as-grown films are amorphous and begin to crystallize at 900 °C. Furthermore, C—V measurements exhibit improved interface characterization after annealing, especially for samples annealed at 900 °C and 1000 °C. It is indicated that high-temperature annealing in O2 atmosphere can improve the interface of Al2O3/SiC and annealing at 900 °C would be an optimum condition for surface morphology, dielectric quality, and interface states.

Fabrication of P-Type ZnO:N Film by Radio-Frequency Magnetron Sputtering for Extremely Thin Absorber Solar Cell Applications

We successfully fabricate p-type ZnO:N films by using rf magnetron sputtering and in situ annealing in O2 atmosphere. These p-type ZnO:N films can be used as p-type window materials for extremely thin absorber (ETA) solar cells composed of quartz glass/p-ZnO:N/i-ZnO/CdSe/i-ZnO/n-ZnO:Al. The short-circuit photocurrent density, open circuit voltage, fill factor and conversion efficiency of the ETA solar cells can be determined to be 8.549 mA/cm2, 0.702V, 0.437 and 2.623%, respectively, through measurements of photovoltaic properties under illumination with a 100mW/cm2 at air-mass (AM) 1.5.

Thermal conductivity due to magnons in high-quality single crystals of the two-leg spin-ladder system (Ca,Sr,La)14Cu24O41

In order to enhance the thermal conductivity due to magnons, κmagnon, in the two-leg spin-ladder system (Ca,Sr,La)14Cu24O41, we have grown the single crystals using raw materials with high purity and tried to improve the quality of the single crystals through the annealing in O2 atmosphere. A large enhancement of κmagnon has been observed through the O2-annealing in Sr14Cu24O41, while there has been little change in κmagnon of Ca9La5Cu24O41 nor Sr9La5Cu24O41 in spite of the increase of the purity of the raw materials and the O2-annealing. It has been concluded that the extension of the mean free path of magnons is limited by the disorder of the atomic arrangement due to the mismatch between the (Ca,Sr,La) plane and the Cu2O3 spin-ladder plane in both Ca9La5Cu24O41 and Sr9La5Cu24O41 and that the removal of the disorder of the atomic arrangement in the spin-ladder plane is necessary for the enhancement of κmagnon in (Ca,Sr,La)14Cu24O41.

Growth of stoichiometric TiO2 thin films on Au(100) substrates by molecular beam epitaxy

The present study reports on the growth of thin TiO2 films onto Au(100) single crystals by Ti evaporation in a reactive O2 atmosphere at two different substrate temperatures: room temperature (RT) and 300°C. The growth of the oxide films was monitored by means of X-ray photoemission spectroscopy, while the valence and conduction band electronic structure was investigated by UV and inverse photoemission spectroscopy, respectively.The TiO2 film grows epitaxially on the Au(100) substrate at 300°C exhibiting the rutile (100) surface. The evolution of the Ti 2p lineshape with the oxide coverage shows the presence of reduced oxide species (characterized by Ti3+ ions) at the Au(100) interface. A crystalline and stoichiometric TiO2 oxide is produced at high substrate temperature, while growth at RT gives a measurable concentration of defects. Post growth annealing in ultra-high vacuum of the RT grown film increases this concentration, while subsequent annealing in O2 atmosphere restores the sample to the as-grown conditions.

A Novel Gate Dielectric with ZrxLa1−xOy Material for the Future of Nano Transistor Devices

In the present work, ZrxLa1-xOy nanocrystallites was synthesized by Sol-Gel technique and used to deposit ZrxLa1-xOy thin film on Si(100) substrate by spin-coating at room temperature in air, followed by post annealing in O2 ambient at different temperatures from 300 to 900°C. The molecular structure of the ZrxLa1-xOy nanocrystallites determined with using X-Ray Diffraction (XRD) analysis. The nanocrystallites size, morphology, surface structure and composition of deposited films were investigated by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) techniques and elemental qualitative analysis was performed with Energy Dispersive X-ray (EDX) spectra confirmed above claims. Using these techniques, the different reactions in various processing steps have been clarified. The dielectric constant of crystalline Zr0.5La0.5Oy thin film is about 34 determined from the Capacitance-Voltage (C-V) measurement.

High-Performance Ge MOS Capacitors by $\hbox{O}_{2}$ Plasma Passivation and $\hbox{O}_{2}$ Ambient Annealing

Very promising capacitance-voltage (C-V) characteristics of capacitors on both p- and n-type Ge substrates are demonstrated by using an in situ O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> plasma passivation and an O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ambient annealing. The capacitors exhibited a small equivalent oxide thickness of ~1.5 nm and a low D <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">it</sub> (<; 6 * 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> eV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ) energy distribution covering the major part of the Ge bandgap (>; 0.51 eV). The surface potential modulation efficiency was estimated to be ~80% from Hatband to strong inversion on both types of Ge. C-V hysteresis was less than 10 mV with positive bias up to 1.5 V. A low gate leakage current density of <; 9 * 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-8</sup> A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FB</sub> ± 1 V indicates high quality of the HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /GeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gate stacks. Excellent comprehensive properties suggest that a combination of O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> plasma passivation and O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ambient annealing provides a promising technology for GeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based CMOS devices.