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氮化铝陶瓷直接覆铜基板是将铜箔在高温下直接键合到氮化铝陶瓷表面而制成的一种复合陶瓷基板,具有高导热性、高电绝缘性、大电流容量、高机械强度等特点,广泛应用于智能电网、动力机车、汽车电子等电力电子领域.本文从机理上分析了氮化铝覆铜基板界面空洞产生的原因,研究了影响界面空洞的主要技术参数,得出结论:氮化铝和无氧铜表面氧化层均匀性是影响界面空洞的主要因素;采用纯干氧气氛氧化氮化铝陶瓷可以在其表面形成致密氧化膜,有效减少界面空洞的产生;采用低氧含量高温氧化的方法氧化无氧铜后,有助于减少铜与氮化铝界面空洞;当氮化铝直接覆铜工艺的氧含量为5×10-4时,氮化铝覆铜基板界面空洞比例达到2%. 相似文献
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采用溶胶凝胶工艺制备了铝源和碳源的均匀混合物,分析了铝源与碳源的比例对合成氮化铝物相的影响规律,研究表明,在一定的碳铝比范围内生成很纯的氮化铝粉体,比值较小时含有较多的氧化铝相,较大时含有的碳很难排除完全,并且也容易发生氮化铝粉体的氧化,使纯度降低.对铝源与碳源的混合物通过高温氮化还原煅烧处理,分析了煅烧温度与合成物相的关系,随着温度的提高,形成的氮化铝峰明显增强,直至合成纯的氮化铝相.并与氧化铝通过氮化还原法制备氮化铝粉体的煅烧温度进行了比较,明显降低了合成纯氮化铝粉体的煅烧温度. 相似文献
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采用溶胶凝胶工艺制备了铝源和碳源的均匀混合物,分析了铝源与碳源的比例对合成氮化铝物相的影响规律,研究表明,在一定的碳铝比范围内生成很纯的氮化铝粉体,比值较小时含有较多的氧化铝相,较大时含有的碳很难排除完全,并且也容易发生氮化铝粉体的氧化,使纯度降低。对铝源与碳源的混合物通过高温氮化还原煅烧处理,分析了煅烧温度与合成物相的关系,随着温度的提高,形成的氮化铝峰明显增强,直至合成纯的氮化铝相,并与氧化铝通过氮化还原法制备氮化铝粉体的煅烧温度进行了比较,明显降低了合成纯氮化铝粉体的煅烧温度。 相似文献
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本文研究了不同氧化处理下氮化铝陶瓷的氧化情况,并使用Mo-Mn法进行金属化,测试封接强度及气密性,从而探究氮化铝瓷的氧化机制,氮化铝基瓷与氧化层之间的结合。结果表明:经过1100℃/1h高温氧化处理,氮化铝陶瓷表面几乎没有氧化。在1250℃/1h、1250℃/2h,表面生成了氧化铝,氧化层主晶相为AlN与Al2O3;在1350℃/1h下,氧化层主晶相为Al2O3;氧化层表面有明显的裂纹,均漏气。对不同处理后的氧化铝层表面进行Mo-Mn法金属化,当氧化层厚度较薄时,断裂发生在氧化层。氮化铝瓷与氧化铝层之间的结合机理可能是在两者之间产生了AlON等中间物,从而实现了氮化铝瓷与氧化层之间牢固的连接。 相似文献
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氮化铝陶瓷因其热导率高、绝缘性好以及无毒害等特点在许多领域有着广泛的应用。多层共烧氮化铝陶瓷是采用厚膜印厣j的方式将多层的电路金属化做入氮化铝基板并在特定气氛中高温烧结的一种高性能陶瓷。金属化是多层共烧氮化铝陶瓷的一个关键工艺,文章主要介绍了对金属化工艺的研究。重点研究了其中的印刷工艺、叠片层压工艺和烧结工艺。通过对印刷和烧结参数的研究,使得生产陶瓷的热导率大于170W(m·K)^-1,金属化的方阻小于18mΩ/□,金属化的抗拉力大于1.8N(1mm^2焊接面积),能满足大功率LED封装、大功率功率管封装的性能要求,已经在多种陶瓷外壳和基板中应用。 相似文献
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用扫描电镜和X射线能谱分析仪研究高温氧化及薄膜工艺过程中主要溶液对氮化铝陶瓷(AIN)基板的影响。结果表明:高温氧化使表面氧含量增加,在1000℃氧化2h,表面已形成致密的氧化层。碱性溶液清洗和去离子水煮会使表面产生多孔的疏松化合物。采用高温氧化、酸性清洗、溅射前加强离子轰击等措施,磁控溅射TiCu,其薄膜膜层附着力不低于15MPa。 相似文献
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Hee Jin Kim Suk Choi Dongwon Yoo Jae-Hyun Ryou Michael E. Hawkridge Zuzanna Liliental-Weber Russell D. Dupuis 《Journal of Electronic Materials》2010,39(5):466-472
We report the growth of ternary aluminum gallium nitride (AlGaN) layers on AlN/sapphire template/substrates by digitally alloyed
modulated precursor flow epitaxial growth (DA-MPEG), which combined an MPEG AlN sub-layer with a conventional metalorganic
chemical vapor deposition (MOCVD)-grown GaN sub-layer. The overall composition in DA-MPEG Al
x
Ga1−x
N was controlled by adjustment of the growth time (i.e., the thickness) of the GaN sub-layer. As the GaN sub-layer growth
time increased, the Al composition in AlGaN decreased to 50%, but the surface morphology of the AlGaN layer became rough,
and a three-dimensional structure with islands appeared for the DA-MPEG AlGaN with relatively thick GaN sub-layers, possibly
resulting from the Ga adatom surface migration behavior and/or the strain built up from lattice mismatch between AlN and GaN
sub-layers with increasing GaN sub-layer growth time. Through strain analysis by high-resolution x-ray diffraction, reciprocal
space mapping, and scanning transmission electron microscopy, it was found that there was compositional inhomogeneity in the
DA-MPEG AlGaN with AlN and GaN binary sub-layers for the case of the layer with relatively thick GaN sub-layers. 相似文献
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I. A. Supryadkina K. K. Abgaryan D. I. Bazhanov I. V. Mutigullin 《Semiconductors》2013,47(12):1621-1625
The results of a theoretical study based on ab initio calculations of the polarization properties of AlN, GaN, and AlGaN semiconductors with the wurtzite structure are presented. The values of the spontaneous and piezoelectric polarizations, as well as the piezoelectric constants, are calculated for these nitride compounds. With the aim of further considering prospective heterostructures based on (Al,Ga,AlGa)N compounds, the charge densities at the AlN/GaN, AlGaN/AlN, and AlGaN/GaN interfaces and carrier concentration at the AlGaN/GaN heterointerface is estimated and compared with the experimental data. 相似文献
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A new surface-potential-based model for AlGaN/AlN/GaN high electron mobility transistor(HEMT) is proposed in this paper. Since the high polarization effects caused by AlN interlayer favorably influence the two dimensional electron gas(2DEG) and scattering mechanisms, we first add spontaneous and piezoelectric charge terms to the source equation of surface-potential, and a mobility model for AlGaN/AlN/GaN HEMT is rewritten. Compared with TCAD simulations, the DC characteristics of AlGaN/AlN/GaN HEMT are faithfully reproduced by the new model. 相似文献
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A. N. Alekseev A. É. Byrnaz D. M. Krasovitsky M. V. Pavlenko S. I. Petrov Yu. V. Pogorel’sky I. A. Sokolov M. A. Sokolov M. V. Stepanov A. P. Shkurko V. P. Chalyi 《Semiconductors》2007,41(9):1005-1010
The effect of growth conditions (V/III ratio, substrate temperature) on the properties of materials in AlN-GaN systems is discussed. A concept of the growth of the AlN/AlGaN/GaN multilayer heterostructure, which provides the improvement of crystal quality and surface morphology of the layers, is suggested and realized. The improvement of the properties of GaN in the AlN/AlGaN/GaN/AlGaN multilayer heterostructure is confirmed by a considerable increase in electron mobility in the two-dimensional electron gas formed at the upper heterointerface GaN/Al0.3Ga0.7N. 相似文献
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Using the measured capacitance–voltage and current–voltage characteristics of the rectangular Al N/Ga N heterostructure field-effect transistors(HFETs) with the side-Ohmic contacts, it was found that the polarization Coulomb field scattering in the Al N/Ga N HFETs was greatly weakened after the side-Ohmic contact processing, however, it still could not be ignored. It was also found that, with side-Ohmic contacts, the polarization Coulomb field scattering was much stronger in Al N/Ga N HFETs than in Al Ga N/Al N/Ga N and In0:17Al0:83N/Al N/Ga N HFETs, which was attributed to the extremely thinner barrier layer and the stronger polarization of the Al N/Ga N heterostructure. 相似文献
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R. Venugopal J. Wan M. Melloch G. Kim G. Zank S. Tsoi A. Ramdas 《Journal of Electronic Materials》2003,32(5):371-374
A comparison of gallium-nitride (GaN) films grown on large-area Si(111) using a single aluminum-nitride (AlN) buffer, an AlN/graded-AlxGa1−xN buffer, and the introduction of additional low-temperature (LT)-grown AlN interlayers is reported. A graded-AlGaN buffer
followed by additional LT-AlN interlayers is shown to completely eliminate cracking in nitride films of thickness >2 μm and
also reduce the threading-dislocation density significantly. A partial compensation of GaN-tensile strain by the compressive-lattice
strain induced by the AlGaN and AlN layers is responsible for this effect. The surface roughness is increased by the introduction
of the LT-AlN buffers. 相似文献
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采用一个AlN缓冲层和两个Al组分阶变的AlGaN过渡层作为中间层,在76.2mm Si衬底上外延生长出1.7μm厚无裂纹AlGaN/GaN异质结材料,利用原子力显微镜、X射线衍射、Hall效应测量和CV测量等手段对材料的结构特性和电学性能进行了表征。材料表面平整光滑,晶体质量和电学性能良好,2DEG面密度为1.12×1013cm-2,迁移率为1 208cm2/(V.s)。由该材料研制的栅长为1μm的AlGaN/GaN HEMT器件,电流增益截止频率fT达到10.4GHz,这些结果表明组分阶变AlGaN过渡层技术可用于实现高性能Si基GaN HEMT。 相似文献
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A. F. Tsatsulnikov V. W. Lundin E. E. Zavarin M. A. Yagovkina A. V. Sakharov S. O. Usov V. E. Zemlyakov V. I. Egorkin K. A. Bulashevich S. Yu. Karpov V. M. Ustinov 《Semiconductors》2016,50(10):1383-1389
The effect of the layer thickness and composition in AlGaN/AlN/GaN and InAlN/AlN/GaN transistor heterostructures with a two-dimensional electron gas on their electrical and the static parameters of test transistors fabricated from such heterostructures are experimentally and theoretically studied. It is shown that the use of an InAlN barrier layer instead of AlGaN results in a more than twofold increase in the carrier concentration in the channel, which leads to a corresponding increase in the saturation current. In situ dielectric-coating deposition on the InAlN/AlN/GaN heterostructure surface during growth process allows an increase in the maximum saturation current and breakdown voltages while retaining high transconductance. 相似文献
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使用金属有机物化学气相淀积(MOCVD)方法在蓝宝石衬底上分别采用AlN和GaN作为形核层生长了AlGaN/GaN高电子迁移率晶体管(HEMT)外延材料,并进行了器件制备和性能分析.通过原子力显微镜(AFM)、高分辨率X射线双晶衍射仪(HR-XRD)和二次离子质谱仪(SIMS)等仪器对两种样品进行了对比分析,结果表明采用AlN形核层的GaN外延材料具有更低的位错密度,且缓冲层中氧元素的拖尾现象得到有效地抑制.器件直流特性显示,与基于GaN形核层的器件相比,基于AlN形核层的器件泄漏电流低3个数量级.脉冲Ⅰ-Ⅴ测试发现基于GaN形核层的HEMT器件受缓冲层陷阱影响较大,而基于AlN形核层的HEMT器件缓冲层陷阱作用不明显. 相似文献