Materials Science in Semiconductor Processing最新文献

{"title":"Investigation of the effect of oxygen partial pressure during reactive sputtering of tantalum oxide resistive random access memory switching layer","authors":"","doi":"10.1016/j.mssp.2024.109060","DOIUrl":"10.1016/j.mssp.2024.109060","url":null,"abstract":"<div><div>Resistive Random Access Memory (ReRAM) is a novel non-volatile memory technology, with potential applications spanning high-density memory and embedded memory in various non-von Neumann computing architectures. This study investigated the dependency of ReRAM switching parameters on the stoichiometry of the tantalum oxide switching layer. Devices were fabricated using reactive sputtering where oxygen partial pressure was varied during deposition of the switching layer. X-ray photoelectron spectroscopy was employed to evaluate the resulting tantalum oxide film composition, showing distinct Ta sub-oxides for each oxygen partial pressure implemented during reactive sputtering. Electrical characterization revealed optimal device performance, with sub-3 V forming voltage and memory window &gt;10 for ReRAM devices deposited with 0.14 mTorr pO₂. Devices fabricated at lower pO₂ and excessively high pO₂ failed to exhibit resistive switching behavior.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation of the crystal structure, bond characteristics, and microwave dielectric properties of (1-x)MgTiO3 – xCa0.5Sr0.5TiO3 ceramic for DRA applications","authors":"","doi":"10.1016/j.mssp.2024.109061","DOIUrl":"10.1016/j.mssp.2024.109061","url":null,"abstract":"<div><div>In this current work, we report the impact of Ca_0.5Sr_0.5TiO₃ in the crystal structures, microstructures, and the dielectric performances in the microwave region on MgTiO₃ perovskite ceramic with standard formula of (1-x)MgTiO₃-xCa_0.5Sr_0.5TiO₃ [x = 0.025–0.1] (referred to as (1-x)MTO-xCSTO). The samples were prepared by employing the well-known solid-state reaction route. The crystal structure analysis was carried out using X-ray diffraction and Rietveld refinement confirms the existence of a dual phase in the composition. Scanning electron microscope techniques have been utilized to examine the crystal structure and microstructural characteristics of materials. The dense and homogeneous microstructures of (1-x)MTO-xCSTO materials have been verified by the SEM images. The various vibrational modes associated with the composition were identified from the Raman spectroscopy and the variation of the width of the spectra is correlated with the dielectric performance. The dielectric parameters were obtained from the vector network analyzer and the temperature coefficient (at the resonating frequency) and quality factor from the TE_01δ mode of (1-x)MTO-xCSTO compound. The bond strength, bond valency, and tolerance factor of the samples were correlated with the quality factor and temperature coefficient. The (1-x)MTO-xCSTO composition exhibits exceptional thermal stability due to a linearly zero temperature coefficient. The variation of quality factor with the variation of Ca_0.5Sr_0.5TiO₃ was correlated with the variation of the width of the Raman spectra. Among all the compositions, x = 0.05 shows a high-quality factor and nearly zero temperature coefficient.</div><div>Further, the infrared reflectance spectra of the optimum composition have been analyzed and the various phonon modes were identified using the standard harmonic oscillator model. Furthermore, the dielectric resonator antenna has been developed with (1-x)MTO-xCSTO ceramics as resonators, and several antenna parameters have been analyzed by HFSS software. The observed microwave dielectric properties and the antenna characteristics indicate that the (1-x)MTO-xCSTO (for x = 0.05) composition can be a prominent dielectric resonator for 5G applications operating at the C frequency band.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"N- and P-type doping of diamonds: A review","authors":"","doi":"10.1016/j.mssp.2024.109024","DOIUrl":"10.1016/j.mssp.2024.109024","url":null,"abstract":"<div><div>Diamond has been one of the most investigated ultrawide bandgap (UWBG) semiconductors for optoelectronics, superconductors, energy, and quantum applications for almost half of a century owing to its unique properties. Diamonds' intrinsic features-a large bandgap (5.47 eV), an extremely high breakdown voltage (10 MV/cm), the highest thermal conductivity (2200 W/m-K), and very high radiation-tolerance, make them promising for high-power, high-frequency devices suitable for high-temperature and extreme radiation environments. Since the demand for high-speed consumer electronics with large power and faster data handling capacity is rising at an unprecedented rate in the post-COVID era, diamonds' excellent mobility of electrons and holes (4500 and 3800 cm²/V-s) make them ideal for servers and systems. To materialize these multipurpose devices with higher efficiency and endurance than Si and SiC-based technologies, diamonds with good p- and n-type conductivity are needed. Therefore, nearly several decades-long efforts have been devoted to understanding and controlling the carrier conductivities in diamonds. Furthermore, diamonds' color centers' remarkable application as the qubit for next-generation quantum computers has also sparked interest in investigating diamond point defects at the quantum level. Hence, it is necessary to comprehensively study the fabrication, doping, and applications in semiconducting and quantum devices to stay relevant to the diamond revolution and thus advance this flourishing field. Therefore, this review article summarizes the current status and breakthroughs in diamond doping and devices fabricated using doped diamonds to provide an overview of the challenges and successes in using this highly promising UWBG material in electronic, superconducting, and quantum applications.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study of chemical mechanical polishing of polycrystalline diamond based on photo-Fenton reaction","authors":"","doi":"10.1016/j.mssp.2024.109072","DOIUrl":"10.1016/j.mssp.2024.109072","url":null,"abstract":"<div><div>Polycrystalline diamond (PCD) is widely used in cutting tools, optical devices, and heat dissipation tools due to its exceptional hardness, wear resistance, and thermal conductivity. However, these excellent properties also make polishing the PCD surface a challenge. Traditional polishing methods struggle to achieve both high material removal efficiency and high-quality surface finishes simultaneously. This paper proposes a chemical mechanical polishing (CMP) method for PCD based on the photo-Fenton reaction. The method utilizes the reaction between H₂O₂ and Fe₃O₄ under ultraviolet (UV) light to generate highly oxidative hydroxyl radicals (·OH), effectively oxidizing the PCD surface to reduce the difficulty of processing. The concentration of ·OH and Fe²⁺/Fe³⁺ in different reaction solutions was measured using spectrophotometry. Results indicate that the concentration of ·OH is highest in the photo-Fenton solution, and UV light promotes the conversion of Fe³⁺ to Fe²⁺, sustaining the ongoing photo-Fenton reaction. Through single-factor polishing experiments, the effects of various processing parameters on the CMP performance of PCD were investigated. The results show that the material removal rate of PCD increases with increasing concentrations of H₂O₂, abrasive particle size, polishing pressure, and polishing disc speed. In contrast, the removal rate first increases and then decreases with increasing UV light intensity and Fe₃O₄ concentration. Additionally, the surface roughness (Ra) of PCD decreases initially and then increases with increasing UV light intensity, abrasive particle size, polishing pressure, and polishing disc speed, while it decreases with increasing Fe₃O₄ and H₂O₂ concentrations. Under the conditions of 100 mW/cm² UV light intensity, 2 wt% Fe₃O₄, 10 wt% H₂O₂, 5 wt% abrasive concentration, 0.5 μm abrasive particle size, 0.89 MPa polishing pressure, and a polishing disc speed of 60 r/min, the material removal rate of PCD reaches 698.7 nm/h, and the surface roughness Ra is 3.78 nm. The photo-Fenton reaction-based CMP method proposed in this paper provides a new approach to polishing hard-to-process materials.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and theoretical study of 90Sr/90Y-n-Si/ZnO betavoltaic battery and theoretical prediction of homojunction betavoltaic cells performance","authors":"","doi":"10.1016/j.mssp.2024.109059","DOIUrl":"10.1016/j.mssp.2024.109059","url":null,"abstract":"<div><div>Today, betavoltaic batteries has been considered due to their high energy density and long life for operating electrical systems in inaccessible and hostile environments. Conventional electrochemical batteries, despite their widespread use in electronic devices, have a limited lifetime and tend to degrade in extreme environmental conditions. The current paper pursues three goals. The first goal is to the experimental and theoretical investigation of a n-Si/ZnO heterojunction betavoltaic battery based on ⁹⁰Sr/⁹⁰Y source. The second goal is to optimize ZnO, SnO₂, BN, and diamond homojunction betavoltaic cells in two planar and cubical models by Monte Carlo simulation (MCNP code). The third goal is to present a new approach for estimating the standard error in calculating the parameters of betavoltaic batteries. In order to fabrication of a n-Si/ZnO heterojunction, the ZnO nanospheres were placed on the n-Si (100) substrate using chemical bath deposition (CBD) technology. The Al and Au electrodes were deposited on the formed sample. Then this sample was exposed to the radiation of an external ⁹⁰Sr/⁹⁰Y source with an activity of 12.8 mCi. The experimental values obtained for the short circuit current (I_sc), open circuit voltage (V_oc), efficiency (η), and maximum output power (P_max) were 0.047 μA, 0.015 V, 3.4 × 10⁻⁴ percent, and 0.141 nW, respectively. To compare with the experiment, we investigated the n-Si/ZnO betavoltaic cell by MCNP code. In the simulation, the beta spectrum of the ⁹⁰Sr/⁹⁰Y source was considered. The calculated theoretical values for I_sc, V_oc, η, and P_max were 0.063 μA, 0.020 V, 6.4 × 10⁻⁴ percent, and 0.265 nW, respectively. The experimental results show that the simulation results can be valid. In the optimization of ZnO, SnO₂, BN, and diamond homojunction betavoltaic cells in two planar and cubical models by MCNP code, it was found that the I_sc, V_oc, η, and P_max of the cubical model are better compared to the planar model. In the cubical model, P_max of ZnO, SnO₂, BN, and diamond betavoltaic batteries is 2633.34 nW ± 0.16 %, 1670.49 nW ± 0.15 %, 198.20 nW ± 0.17 %, and 1315.24 nW ± 0.15 %, respectively. In other words, P_max of the ZnO betavoltaic battery is about 58 %, 1229 %, and 100 % more than P_max of SnO₂, BN, and diamond betavoltaic batteries, respectively. P_max of the SnO₂ betavoltaic battery is about 743 % and 27 % more than P_max of BN and diamond betavoltaic batteries, respectively. The results show that ZnO and SnO₂ betavoltaic batteries can perform better compared to BN and diamond betavoltaic batteries. Also, their growth process is less expensive compared to BN and diamond.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semiconductor WO3 thin films deposited by pulsed reactive magnetron sputtering","authors":"","doi":"10.1016/j.mssp.2024.109034","DOIUrl":"10.1016/j.mssp.2024.109034","url":null,"abstract":"<div><div>A pulsed reactive magnetron sputtering system with a tungsten target and a gas mixture of argon and oxygen was investigated as a source for the deposition of semiconductor WO₃ thin films on soda lime glass substrates and on the glass with transparent conductive SnO₂:F (FTO) electrode. The reactive sputtering process was performed in HiPIMS mode with low pulse repetition frequency f_p ≈ 50–100 Hz and short pulse duration in HiPIMS discharge T_on = 100 μs. The second mode investigated was the mid-frequency (MF) magnetron discharge with pulse frequency f_p = 40 kHz and pulse length T_on = 15 μs. The plasma parameters were investigated for both HiPIMS and MF modes using the planar RF probe operating at the frequency f_probe = 350 kHz and the grid QCM with biased collector electrode. Ion density n_i and tail electron temperature (T_e) were determined in both pulsed reactive magnetron sputtering discharge modes with time resolution. The maximum value n_i ≈ 5 · 10¹⁷ m⁻³ was found in the reactive HiPIMS mode, and the maximum value n_i ≈ 7 · 10¹⁶ m⁻³ was found in the reactive MF (40 kHz) mode. The degree of ionization of sputtered particles in reactive HiPIMS was determined for different values of (Q_O2) and was found to be in the range of r_i ≈ 0.1–0.3. The deposition rate determined by QCM in reactive HiPIMS was practically independent on (Q_O2), but in the case of reactive MF, the measured deposition rate decreased significantly with increasing (Q_O2). The WO₃ films deposited in both modes have a predominantly monoclinic crystal structure. The light and dark conductivity and the light/dark conductivity ratio (L_d) were measured under dark conditions and UV light illumination. At higher (Q_O2), the maximum value of L_d ≈ 300 was found for MF deposited WO₃ and the maximum value of L_d ≈ 30 was found for HiPIMS deposited WO₃. The photoelectrochemical measurement of WO₃ deposited on FTO electrodes confirmed the n-type conductivity, and these films functioned as photoanodes in photoelectrochemical cells. MF deposited WO₃ films systematically exhibited slightly higher photocurrents than HiPIMS deposited WO₃. It was shown that these optimum photocurrents for HiPIMS and MF were found at Q_O2 ≈ 80 sccm and could not be improved by further increasing of (Q_O2).</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tuning of electrical properties and persistent photoconductivity of SnO2 thin films via La doping for optical memory applications","authors":"","doi":"10.1016/j.mssp.2024.109073","DOIUrl":"10.1016/j.mssp.2024.109073","url":null,"abstract":"<div><div>This work explored the potential of utilizing Lanthanum doped tin oxide Sn_1−xLa_xO₂ (x = 0.01 to 0.1) based Metal-Semiconductor-Metal Ohmic photoconductors for optical memory applications making use of the persistent photoconductivity (PPC) property. The structural, optical, and electrical properties of Sn_1−xLa_xO₂ thin films deposited on glass substrates using the spray pyrolysis method, with a focus on the impact of lanthanum concentration on the photoresponse characteristics was investigated. Raman spectroscopy confirmed the presence of oxygen vacancies and nanometric grain size in the films along with the typical Raman active modes of tin oxide. The Sn⁴⁺ and La³⁺ oxidation states in Sn_1−xLa_xO₂ as well as the contributions from lattice oxygen and oxygen vacancies were identified using XPS. Photoluminescence studies revealed emissions in the UV, violet, blue, and yellow regions, corresponding to tin interstitials, oxygen vacancies, and other defects, with intensity variations based on La concentration. All films exhibited n-type conductivity, with La content influencing both resistivity and carrier concentration. Photoconductivity measurements demonstrated enhanced photocurrent under UV illumination, with La doping affecting energy levels and defect states. The Sn_0.90La_0.10O₂ film possessed a photocurrent retention of nearly 64 % within a span of 10⁴ s, showing that higher concentration of La favoured the enhancement of retention of photocurrent for a comparatively longer duration. The significant persistent photoconductivity requires the conditions like optically active materials, a built-in electric field to separate electron-hole pairs, and defect states to trap carriers, which are all met by the prepared Sn_1-xLa_xO₂ photoconductor with higher La doping levels, confirming the suitability of these films for practical use as optical non-volatile memory elements.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Homoepitaxial growth of device-grade GaAs using low-pressure remote plasma CVD","authors":"","doi":"10.1016/j.mssp.2024.109069","DOIUrl":"10.1016/j.mssp.2024.109069","url":null,"abstract":"<div><div>We have achieved the growth of high-quality, homoepitaxial 100 GaAs thin films at 0.5 mbar and 500 °C using a Remote Plasma Chemical Vapor Deposition (RP-CVD) reactor. With this process, we demonstrate a film growth rate up to 3 μm/h, comparable to the conventional MOCVD technique. The resulting films exhibit structural characteristics close to those of commercial GaAs wafers, with excellent crystalline quality as confirmed by SAED patterns and XRD rocking-curve measurements for the 004 peak with a FWHM of 0.004°. AFM measurements reveal a surface roughness of 0.2 nm, similar to that of a polished wafer. Analysis of the chemical composition – as determined through XPS surface and depth-profiled measurements – indicates that the film is homogeneous, with a constant III/V ratio of 1 throughout the whole layer, and has no detectable carbon or oxygen contamination. Additionally, the films demonstrate a sharp photoluminescence peak (FWHM of 55 meV), a p-type doping concentration of 1.10¹⁸ cm⁻³, and a hole mobility of 172 cm² V⁻¹.s⁻¹. This work thus demonstrates a cost-effective growth method for III-V devices, enabled by the reduced gas consumption (only a few sccm, compared to tens of L/min in MOCVD) in RP-CVD operation at low pressure.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Janus α-Au4XY (X/Y = S, Se, Te) monolayers with ultra-high carrier mobility: A first-principles study","authors":"","doi":"10.1016/j.mssp.2024.109045","DOIUrl":"10.1016/j.mssp.2024.109045","url":null,"abstract":"<div><div>In this paper, we theoretically propose a series of Janus <span><math><mi>α</mi></math></span>-Au<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>XY (X/Y = S, Se, Te; X <span><math><mo>≠</mo></math></span> Y) monolayers and investigate their structural stability, electronic features, and transport properties based on first-principle calculations. It is indicated that Janus <span><math><mi>α</mi></math></span>-Au<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>XY monolayers have a structurally stable and can be synthesized experimentally. Janus <span><math><mi>α</mi></math></span>-Au<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>XY monolayers exhibit a low Young’s modulus and their mechanical features are slightly anisotropic. At the ground state, Janus <span><math><mi>α</mi></math></span>-Au<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>XY monolayers possess semiconducting characteristics with very steep band dispersions near the conduction band minimum, which is expected to ultra-high electron mobility. The electronic features of Janus <span><math><mi>α</mi></math></span>-Au<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>XY are highly sensitive to the biaxial strains <span><math><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msub></math></span>, particularly the applied compressive biaxial strains. Interestingly, the transitions from the semiconductor to the metal phases are observed in all three configurations of <span><math><mi>α</mi></math></span>-Au<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>XY at <span><math><mrow><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msub><mo>=</mo><mo>−</mo><mn>6</mn><mtext>%</mtext></mrow></math></span>. Janus <span><math><mi>α</mi></math></span>-Au<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>XY monolayers exhibit superior transport characteristics with the electron mobility reaching up to <span><math><mrow><mn>3</mn><mo>.</mo><mn>20</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup></mrow></math></span> cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>V⁻¹s⁻¹ (<span><math><mi>α</mi></math></span>-Au<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>SSe monolayer). Our findings not only explore the outstanding electronic and transport features of Janus <span><math><mi>α</mi></math></span>-Au<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>XY nanostructures but also indicate their potential applications in nanoelectronics and nanoelectromechanical devices.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges and solutions in Mist-CVD of Ga2O3 heteroepitaxial films","authors":"","doi":"10.1016/j.mssp.2024.109063","DOIUrl":"10.1016/j.mssp.2024.109063","url":null,"abstract":"<div><div>Mist chemical vapor deposition (mist-CVD) has recently attracted interest as a facile, cost-effective, environmentally friendly method for the deposition of Ga₂O₃ films. This paper addresses selected challenges and issues that hinder the fabrication of high-quality Ga₂O₃ epitaxial films. Based on numerical simulations of the gas flow we show that the use of a fan, introducing atmospheric air into the horizontal growth reactor, avoids the formation of vortices and mist velocity fluctuations, which develop when a conventional carrier gas delivery system is employed. We also demonstrate that the presence of organic ligands in Ga acetylacetonate results in undesirable contamination of Ga₂O₃ films by pyrolytic carbon, which strongly affects the optical and morphological properties and can lead to incorrect estimation of the optical band gap. Carbon contamination is shown to be reduced by increasing the growth temperature, by growing under oxygen-rich conditions, or by using carbon-free precursors such as GaCl₃. We further experimentally prove that when the thickness of Ga₂O₃ increases, a multiphase epitaxial film forms, presumably due to enhanced thermal stress. Finally, we experimentally show that nonstoichiometric GaO_xCl_yH_z microparticles form on top of a Ga₂O₃ film in the reactor zone, where the aerosol is completely evaporated and a vapor ambient is formed.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}