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Enhancements of Structural and Optical Properties of MgO: SnO2 Nanostructure Films MgO: SnO2纳米结构薄膜结构和光学性能的增强
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-64
R.H. Ayoub, Muhammad H. AL-Timimi, M.Z. Abdullah
This study investigates the structural and optical properties of MgO:SnO2 nanoparticles using the Chemical precipitation method, The thin films were deposited by the spin coating technique on glass substrates. X-ray diffraction analysis proved the crystalline structure of prepared thin films, with the peaks corresponding to the (110), (101), (200), (211), and (220) planes, with the tetragonal SnO2 crystal structure, Fourier transforms infrared (FTIR), and scanning electron microscope (SEM) used to characterize the functional groups, shape, and dimensions of synthesized metal oxide nanoparticles. The optical properties of the films were studied by UV-Vis spectroscopy, and the bandgap energy was estimated to be in the range of (3.9 - 3.4 eV). The refractive index and extinction coefficient of the films were also determined, and the results indicated that the films had good transparency in the visible region, The study concludes that MgO:SnO2 thin films obtained by spin coating technique have potential applications in optoelectronics and gas sensors.
本研究采用化学沉淀法对MgO:SnO2纳米颗粒的结构和光学性质进行了研究,并采用自旋镀膜技术在玻璃衬底上沉积了薄膜。x射线衍射分析证实了所制备薄膜的晶体结构,其峰对应于(110)、(101)、(200)、(211)和(220)面,并利用SnO2的四方晶体结构,利用傅里叶变换红外(FTIR)和扫描电子显微镜(SEM)表征了所合成的金属氧化物纳米颗粒的官能团、形状和尺寸。利用紫外可见光谱对薄膜的光学性质进行了研究,估计其带隙能量在(3.9 ~ 3.4 eV)之间。测定了薄膜的折射率和消光系数,结果表明薄膜在可见光区具有良好的透明度。研究表明,采用自旋镀膜技术制备的MgO:SnO2薄膜在光电子学和气体传感器方面具有潜在的应用前景。
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引用次数: 0
Effects of Quantum Confinement Energy on the Transmittance of Cadmium Telluride (CdTe) Within the Near Infrared Region (700-2500nm) 量子约束能量对碲化镉(CdTe)近红外(700 ~ 2500nm)透射率的影响
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-33
Ali Hussein Hammad Asal, Saeed Naif Turki Al-Rashid
This study investigates how the energy of quantum confinement affects the transmittance of cadmium telluride, because of the importance of this substance, as it crystallizes in the form of cubes as thin films that are used in solar cells and liquid crystal imaging devices, as well as in infrared optics [1]. The MATLAB computer program version (2012a) was used, which is based on the characteristic matrix theory and Brus model, in addition to the quantum confinement energy equation. We found that the transmittance value of the nano CdTe thin film at normal incidence reaches 96.4% at a quantum confinement energy Eco = 2.7eV and at a particle size PS =2.6nm, while the value reaches 73.6% at a quantum confinement energy Eco = 0.01eV and at a particle size of PS=50nm.
本研究探讨了量子约束的能量如何影响碲化镉的透射率,因为这种物质的重要性,因为它以立方体形式结晶为薄膜,用于太阳能电池和液晶成像设备,以及红外光学[1]。采用MATLAB计算机程序版本(2012a),基于特征矩阵理论和Brus模型,外加量子约束能量方程。我们发现,纳米CdTe薄膜在量子约束能量Eco = 2.7eV、粒径PS= 2.6nm时,正入射透射率达到96.4%,而在量子约束能量Eco = 0.01eV、粒径PS=50nm时,透射率达到73.6%。
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引用次数: 0
Generation of O-Mode in the Presence of Ion-Cyclotron Drift Wave Turbulence in a Nonuniform Plasma 非均匀等离子体中离子回旋漂移波湍流存在下o模式的产生
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-09
Banashree Saikia, P.N. Deka
This study aims to investigate the effect of ion-cyclotron drift wave turbulence on the generation of ordinary mode (O-mode) in the presence of density and temperature gradients. For this, a Vlasov plasma is considered where a resonant, and non-resonant modes are considered to be present in the system. Here, the non-resonant mode is a perturbation caused by O-mode in a quasi-steady state of plasma, which is characterised by the presence of low frequency ion-cyclotron resonant mode waves. The interaction between these waves is studied by the Vlasov-Maxwell set of equations and a modified Maxwellian-type distribution function for particles that includes the external force field and associated density and temperature gradient parameters . The study analyses the growth rate of electromagnetic O-mode at the expense of ion-cyclotron drift wave energy and the associated impact of the density and temperature gradient. This model uses the linear response theory on weakly turbulent plasma, evaluates the responses due to turbulent and perturbed fields, and obtains the nonlinear dispersion relation for O-mode.
本研究旨在探讨在存在密度和温度梯度的情况下,离子回旋漂移波湍流对普通模式(o模式)产生的影响。为此,在考虑系统中存在共振模式和非共振模式的情况下,考虑弗拉索夫等离子体。这里,非共振模式是等离子体准稳态下由o模式引起的扰动,其特征是存在低频离子回旋共振模式波。利用Vlasov-Maxwell方程组和修正的麦克斯韦分布函数研究了这些波之间的相互作用,其中包括外力场和相关的密度和温度梯度参数。研究分析了离子回旋加速器漂移波能量损失下电磁o模的增长速度以及密度梯度和温度梯度的影响。该模型利用弱湍流等离子体的线性响应理论,计算了湍流场和扰动场对等离子体的响应,得到了o型的非线性色散关系。
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引用次数: 0
Permittivity Model Selection Based on Size and Quantum-Size Effects in Gold Films 基于金薄膜尺寸和量子尺寸效应的介电常数模型选择
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-44
Beloshenko, Konstantin, Riabenko, Iuliia, Shulga, Sergey, Makarovskii, Nikolai
The article is focused on optical properties of nanostructures containing spherical gold nanoparticles of various radii. We explore correlation between the particle radius and the choice of permittivity model applied to describe optical absorption spectra of gold granules. The experiments show splitting of the absorption band of granular gold films to form a second absorption peak. The first peak is associated with the phenomenon of plasmon resonance, while the second one reflects quantum hybridization of energy levels in gold. Quantum effects are shown to prevail over size effects at a granule diameter of about 5-6 nm. The Mie theory gives a rigorous solution for the scattered electromagnetic field on a sphere taking into account optical properties of the latter, however, it does not specify the criteria for selecting a model to calculate dielectric permittivity. Both calculations and experiments confirm the limiting diameter of gold nanoparticles where the Hampe-Shklyarevsky model is applied. Meanwhile, this model is still unable to predict the splitting of the plasma absorption band. The data presented in the article can be used for a predetermined local field enhancement in composite media consisting of a biolayer and metal nanoparticles. The conducted research provides a deeper understanding of the influence of a terahertz high-intensity electromagnetic field localized in the space on quantum dots.
本文主要研究了含不同半径球形金纳米粒子的纳米结构的光学性质。探讨了金颗粒的光吸收光谱中介电常数模型的选择与粒子半径的关系。实验表明,颗粒金薄膜的吸收带发生分裂,形成第二吸收峰。第一个峰与等离子体共振现象有关,而第二个峰反映了金中能级的量子杂化。在直径约5-6纳米的颗粒中,量子效应优于尺寸效应。Mie理论给出了考虑球的光学特性的球上散射电磁场的严格解,但没有规定选择介质介电常数计算模型的标准。计算和实验均证实了采用Hampe-Shklyarevsky模型的金纳米颗粒的极限直径。同时,该模型仍不能预测等离子体吸收带的分裂。本文中提供的数据可用于在由生物层和金属纳米颗粒组成的复合介质中预先确定的局部场增强。所进行的研究提供了对空间定位的太赫兹高强度电磁场对量子点的影响的更深层次的理解。
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引用次数: 0
Investigating the Effect of Gravity Modulation on Weakly Nonlinear Magnetoconvection in a Nonuniformly Rotating Nanofluid Layer 研究重力调制对非均匀旋转纳米流体层中弱非线性磁对流的影响
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-18
Michael I. Kopp, Volodymyr V. Yanovsky
This paper investigates the impact of gravity modulation on weakly nonlinear magnetoconvection in a nanofluid layer that is nonuniformly rotating. The fundamental equations are obtained for the Cartesian approximation of the Couette flow using the Boussinesq approximation and gravitational modulation. The weakly nonlinear regime is analyzed using the method of perturbations with respect to the small supercritical parameter of the Rayleigh number, considering the effects of Brownian motion and thermophoresis in the nanofluid layer. Heat and mass transfer are evaluated in terms of finite amplitudes and calculated from the Nusselt numbers for the fluid and the volume concentration of nanoparticles. The findings demonstrate that gravitational modulation, nonuniform rotation, and differences in the volume concentration of nanoparticles at the layer boundaries can effectively control heat and mass transfer. Additionally, the negative rotation profile has a destabilizing effect. The study shows that the modulated system conveys more heat and mass than the unmodulated system.
研究了重力调制对非均匀旋转纳米流体层中弱非线性磁对流的影响。利用Boussinesq近似和重力调制,得到了Couette流的笛卡尔近似的基本方程。考虑到纳米流体层中布朗运动和热泳现象的影响,采用微扰法对瑞利数这一小超临界参数进行了弱非线性分析。传热和传质用有限振幅进行评估,并根据流体的努塞尔数和纳米颗粒的体积浓度计算。研究结果表明,重力调制、非均匀旋转和纳米颗粒在层边界处的体积浓度差异可以有效地控制传热传质。此外,负旋转剖面具有不稳定效应。研究表明,调制系统比未调制系统传递更多的热量和质量。
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引用次数: 0
Investigation the Structural Influences of Silver Oxide Addition in the Bioactive Phosphate Glasses 氧化银对生物活性磷酸盐玻璃结构影响的研究
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-32
Ruqaya H. Hussian, Dunia K. Mahdi
This research investigates the impact of varying concentrations of silver oxide on the structure and morphology of phosphate bioactive glass (PBG). PBGs are gaining popularity as a potential replacement for traditional silicate glasses in biomedical applications due to their adjustable chemical resistance and exceptional bioactivity. Upon examination of the scanning electron microscope of the composites without Ag2O, it was observed that the grains tended to merge together, and the surface particles appeared to be larger than those in composites with Ag2O at concentrations of 0.25, 0.5, and 0.75 wt%. The study found that the diffraction pattern of phosphate bioactive glass composites sintered without Ag2O showed the presence of Strontium di-phosphate and Calcium di-phosphate. The XRD pattern of these composites without Ag2O revealed specific planes that corresponded to both types of di-phosphate. However, when Ag2O was added, a new cubic phase was detected, and the intensity of the calcium and strontium diphosphate increased with higher Ag2O content. The XRD pattern of the composites with Ag2O displayed specific planes that corresponded to Ag2O. In other words, the absence of Ag2O in the composite material led to larger particle sizes and less distinct boundaries between grains. In addition, it has been found that, as the concentration of Ag2O increased from 0 to 0.25, 0.5, and 0.75 wt%, the average crystallite size decreased from 36.2 to 31.7, 31.0, and 32.8 nm, respectively. These results suggest that the addition of Ag2O can effectively reduce the average crystallite size of the composite materials. Also, as the concentration of Ag2O increased from 0 g to 0.5 wt% within the composite material, the average lattice strain increased from 3.41·10-3 to 4.40·10-3. In simpler terms, adding Ag2O to the composite material resulted in a slight increase in the average lattice strain.
本研究探讨了不同浓度的氧化银对磷酸生物活性玻璃(PBG)结构和形态的影响。由于其可调节的耐化学性和卓越的生物活性,pbg作为传统硅酸盐玻璃的潜在替代品在生物医学应用中越来越受欢迎。对未添加Ag2O的复合材料的扫描电镜观察发现,在Ag2O浓度为0.25、0.5和0.75 wt%时,复合材料的晶粒趋于合并,表面颗粒比添加Ag2O的复合材料的表面颗粒大。研究发现,不含Ag2O烧结的磷酸盐生物活性玻璃复合材料的衍射图显示了二磷酸锶和二磷酸钙的存在。不含Ag2O的复合材料的XRD谱图显示出两种类型的二磷酸对应的特定平面。然而,当Ag2O加入时,检测到新的立方相,并且随着Ag2O含量的增加,钙和二磷酸锶的强度增加。Ag2O复合材料的XRD谱图显示出与Ag2O对应的特定平面。换句话说,复合材料中Ag2O的缺失导致了更大的颗粒尺寸和更不明显的晶粒边界。此外,我们还发现,当Ag2O的浓度从0 wt%增加到0.25、0.5和0.75 wt%时,平均晶粒尺寸分别从36.2 nm减小到31.7 nm、31.0 nm和32.8 nm。结果表明,Ag2O的加入可以有效降低复合材料的平均晶粒尺寸。同时,随着Ag2O在复合材料中的浓度从0 g增加到0.5 wt%,平均晶格应变从3.41·10-3增加到4.40·10-3。简而言之,在复合材料中加入Ag2O导致平均晶格应变略有增加。
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引用次数: 0
Unsteady Flow Past an Accelerated Vertical Plate with Variable Temperature in Presence of Thermal Stratification and Chemical Reaction 热分层和化学反应作用下加速变温垂直板的非定常流场
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-49
Nitul Kalita, Rudra Kanta Deka, Rupam Shankar Nath
This work aims to investigate the effect of thermal stratification on fluid flow past an accelerated vertical plate in the presence of first order chemical reaction. The dimensionless unsteady coupled linear governing equations are solved by Laplace transform technique for the case when the Prandtl number is unity. The important conclusions made in this study the effect of thermal stratification is compared with the scenario in which there was no stratification. The results of numerical computations for different sets of physical parameters, such as velocity, temperature, concentration, skinfriction, Nusselt number and Sherwood number are displayed graphically. It is shown that the steady state is attained more quickly when the flow is stratified.
本工作旨在研究在一级化学反应存在的情况下,热分层对流体流过加速垂直板的影响。在普朗特数为单位的情况下,用拉普拉斯变换技术求解了无量纲非定常耦合线性控制方程。本研究得出的重要结论是热分层的影响与没有分层的情况进行了比较。对不同物理参数,如速度、温度、浓度、摩擦、努塞尔数和舍伍德数的数值计算结果以图形形式显示。结果表明,分层流动能更快地达到稳态。
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引用次数: 0
Effect of Calcination Temperature on Structural and Optical Properties of Nickel Aluminate Nanoparticles 煅烧温度对铝酸镍纳米颗粒结构和光学性能的影响
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-37
Katrapally Vijaya Kumar, Sara Durga Bhavani
Nickel aluminate (NiAl2O4) nanoparticles were synthesized using sol-gel method with auto-combustion. The prepared nanoparticles were made into four parts and calcinated at 700, 900, 1100 and 13000C and taken up for the present study. The taken-up nanoparticles were characterized using powder X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersion X-Ray Spectroscopy (EDS), Fourier Transform and Infrared (FT-IR) spectroscopy and UV-Vis spectroscopy techniques. The X-ray diffraction patterns confirmed the spinel structure and Fd3m space group. Scherrer formula was used to calculate the crystallite size and found in the range 5.78 to 20.55 nm whereas the lattice parameter was found in the range of 8.039 to 8.342 Å. The average grain size was found in the range 142.80 to 187.37 nm whereas interplanar spacing was found in the range of 2.100 to 2.479 Å. The FTIR spectroscopy showed six absorption bands in the range 400 to 3450 cm-1 and confirmed the spinel structure. The optical band gap (Eg) was decreased with calcination temperature and found in the range 4.2129-4.3115eV.
采用溶胶-凝胶自燃烧法制备了铝酸镍纳米颗粒。将制备的纳米颗粒分成四部分,分别在700、900、1100和13000C下煅烧,用于本研究。采用粉末x射线衍射(XRD)、扫描电子显微镜(SEM)、能量色散x射线能谱(EDS)、傅里叶变换和红外光谱(FT-IR)以及紫外可见光谱技术对纳米颗粒进行了表征。x射线衍射图证实了尖晶石结构和Fd3m空间群。采用Scherrer公式计算晶体尺寸为5.78 ~ 20.55 nm,晶格参数为8.039 ~ 8.342 Å。平均晶粒尺寸为142.80 ~ 187.37 nm,面间距为2.100 ~ 2.479 Å。FTIR光谱在400 ~ 3450 cm-1范围内显示6个吸收带,证实了尖晶石结构。光学带隙(Eg)随煅烧温度的升高而减小,在4.2129 ~ 4.3115 ev范围内。
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引用次数: 0
Properties of “Higher Manganese Silicide-Silicon” Heterostructure “高硅化锰-硅”异质结构的性质
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-27
Kobiljon K. ugli Kurbonaliev, Nurulla F. Zikrillaev, Akhmadjon Z. Khusanov
Based on the diffusion technology, many scientists and specialists have conducted research on obtaining materials that are fundamentally different in electrical and photo-thermal parameters from the original material by introducing various input atoms into semiconductor materials and creating deep energy levels in their band gap. The electrical, photoelectric, optical, and magnetic properties of these semiconductor materials have been extensively studied with metal group elements, isovalent elements, and rare earth elements added to silicon through the process of growth, ion implantation, or diffusion from the gaseous state. The technology of introducing impurity atoms into silicon by the diffusion method is distinguished from other methods in its simplicity, energy efficiency, and low cost. Up-to-date, the technology of changing the resistivity and conductivity of the initial sample by diffusion of manganese atoms into single-crystal silicon is studied insufficiently. In the article, it was determined that when manganese atoms diffuse into silicon, a high-manganese silicide is formed on its surface and in the near-surface layer. Based on the analysis of the experimental results, the thermal EMF (electromotive force) in Mn4Si7-Si --Mn4Si7 structures in a certain temperature range and under illumination (with monochromatic or integrated light) is explained by the fact that it based on the Pelte effect, observed in semiconductors.The volt-ampere characteristics (VAC) of the obtained structures were measured at various temperatures, in the dark and in the light. Formation of a boundary layer with high resistivity at the boundary of the higher manganese-silicon transition, the transition from higher manganese silicide to the base of the structure due to the effect of ionization of pores during illumination of structures and external influence. The applied field was clarified based on VAC results. The manganese high silicide layer formed on the silicon surface has the properties of a semiconductor, and the formation of a heterojunction upon transition to silicon is shown on the basis of the sphere diagram.
基于扩散技术,许多科学家和专家通过在半导体材料中引入各种输入原子,并在其带隙中产生深能级,来获得与原始材料在电学和光热参数上有根本不同的材料。通过生长、离子注入或从气态扩散的过程,将金属族元素、同价元素和稀土元素添加到硅中,对这些半导体材料的电学、光电、光学和磁性进行了广泛的研究。用扩散法将杂质原子引入硅中的技术具有简单、节能、成本低等特点。目前,通过向单晶硅中扩散锰原子来改变初始样品的电阻率和电导率的技术研究还不够充分。本文确定锰原子扩散到硅中,在其表面和近表面层形成高锰硅化物。根据实验结果分析,Mn4Si7-Si -<Mn>-Mn4Si7结构在一定温度范围和光照(单色光或集成光)下的热电势(电动势)是基于半导体中观察到的Pelte效应来解释的。在不同的温度下,在黑暗和光照下,测量了所得结构的伏安特性(VAC)。在高锰硅过渡的边界处形成具有高电阻率的附面层,由于结构照射过程中孔隙的电离作用和外部影响,从高锰硅化物向结构基底的过渡。根据VAC结果,明确了其应用领域。在硅表面形成的锰高硅化物层具有半导体的性质,并且在球图的基础上显示了向硅过渡时异质结的形成。
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引用次数: 0
Isolation of Responsive Elements of Planar Multi-Element Photodiodes 平面多元光电二极管响应元件的隔离
Q4 Physics and Astronomy Pub Date : 2023-09-04 DOI: 10.26565/2312-4334-2023-3-48
Mykola S. Kukurudziak
In the mass production of multi-element silicon p-i-n photodiodes, the problem of systematic rejection of products due to a decrease in the insulation resistance between the active elements of photodetectors has been revealed. The purpose of this work is to study the causes of insulation resistance degradation and to establish optimal methods for avoiding this phenomenon. A comparative analysis of three insulation methods was carried out: classical insulation by the surface of a non-conductive substrate and a dielectric layer; insulation by means of mesaprofile grooves with a dielectric film; insulation by means of areas of limitation of surface leakage channels isotypic with the substrate material (in this case, p+-type) formed in the gaps between active elements. The study found that the reason for the deterioration of the insulation resistance between the active elements of photodiodes is the presence of conductive inversion channels at the Si-SiO2 interface due to the use of silicon with high resistivity. One mechanism for the formation of inversion channels is the redistribution of impurities in the masking oxide (in particular, phosphorus) and their diffusion to the interface during thermal operations. Another mechanism for the formation of inversion layers is the diffusion of boron from silicon into SiO2 during heat treatment due to the fact that the boron segregation coefficient is less than one. In the manufacture of samples with insulation using non-conductive areas of the substrate, a decrease in insulation resistance was observed as the technological route was performed (after each subsequent operation, the resistance degraded). The degree of degradation can be reduced by reducing the duration of thermal operations. It has been shown that reducing the thickness of the masking oxide causes a decrease in insulation resistance. When using mesa-technology, it is possible to increase the insulation resistance by eliminating the high-temperature oxidation operation and, in fact, due to the absence of a masking coating during phosphorus deposition. Insulation by means of p+-type areas in the gaps between the active elements allows to obtain the highest insulation resistance values. The formation of these regions with a width of 100 μm in the gaps with a width of 200 μm allowed us to obtain an insulation resistance of 25-30 MΩ. To ensure the insulation of the active elements of photodiodes by this method, two thermal operations are added to the technological route. The number of thermal operations can be reduced by doping the entire silicon surface with a low boron concentration before forming a masking coating.
在多元素硅p-i-n光电二极管的批量生产中,由于光电探测器有源元件之间的绝缘电阻降低而导致产品系统性报废的问题已经暴露出来。本工作的目的是研究绝缘电阻退化的原因,并建立避免这种现象的最佳方法。对三种绝缘方法进行了对比分析:经典的非导电衬底表面和介电层表面的绝缘;通过带有介电膜的介面凹槽进行绝缘;通过与衬底材料(在这种情况下,p+型)在有源元件之间的间隙中形成的表面泄漏通道等型的限制区域进行绝缘。研究发现,光电二极管有源元件间绝缘电阻恶化的原因是由于使用了高电阻率的硅,在Si-SiO2界面处存在导电反转通道。形成反转通道的一种机制是在热操作期间掩盖氧化物中的杂质(特别是磷)的重新分配及其向界面的扩散。由于硼偏析系数小于1,热处理过程中硼从硅向SiO2扩散是反转层形成的另一机制。在使用衬底非导电区域制造具有绝缘的样品时,观察到绝缘电阻随着技术路线的执行而减少(在每次后续操作之后,电阻降低)。可以通过减少热操作的持续时间来降低降解的程度。研究表明,减小掩蔽氧化物的厚度会导致绝缘电阻的降低。当使用台面技术时,可以通过消除高温氧化操作来增加绝缘电阻,事实上,由于在磷沉积过程中没有遮蔽涂层。通过在有源元件之间的间隙中采用p+型区域进行绝缘,可以获得最高的绝缘电阻值。在宽度为200 μm的间隙中形成这些宽度为100 μm的区域,使我们获得了25-30 MΩ的绝缘电阻。为了保证光电二极管有源元件的绝缘,该方法在工艺路线上增加了两个热操作。在形成掩蔽涂层之前,通过在整个硅表面掺杂低硼浓度,可以减少热操作的次数。
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引用次数: 0
期刊
East European Journal of Physics
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