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以硅作为砷化镓分子束外延(MBE)生长中的n型掺杂剂,为了确定硅的掺杂浓度,在一片GaAs半绝缘衬底上生长多个GaAs处延层,每一层中进行不同浓度的Si掺杂,然后用电化学C2V的方法确定各层中的载流子浓度,一次性得到了不同Si掺杂浓度与Si炉的温度之
间的关系曲线。本文还介绍了如何采用控制生长的条件得到陡峭的界面,使不同掺杂浓度的层与层之间的界面变化非常明显。 相似文献
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硅分子束外延中硼δ掺杂生长研究 总被引:3,自引:0,他引:3
利用硅分子束外延技术和B2O3掺杂源,成功地实现了硅中的硼δ掺杂,硼δ掺杂面密度NB可达3.4e14cm-2(1/2单层)以上,透射电镜所示宽度为1.5nm.我们首次用原位俄歇电子能谱(AES)对硼在Si(100)表面上的δ掺杂行为进行了初步的研究,发现在NB<3.4e14cm-2时,硼δ掺杂面密度与时间成正比,衬底温度650℃,掺杂源温度9000℃时,粘附速率为4.4e13cm-2/min;在NB>3.4e14cm-2时,粘附有饱和趋势,测量表明在硼δ掺杂面密度NB高达4.4e14c 相似文献
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<正>在低的衬底温度(约300℃)下生长的GaAs层具有较高的电阻率,较小的光敏特性。低温生长的GaAs层用于MESFET作缓冲层,能够消除背栅效应,改善光敏特性等。国外研究结果表明,低温GaAs缓冲层为富砷结。 用国产MBE—Ⅲ型分子束外延设备进行低温生长GaAs层的研究。半绝缘GaAs衬底温度约580℃,生长约50nm GaAs层。反射高能电子衍射(RHEED)的衍射图样为(2×4)结构。然 相似文献
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报道了用 MBE方法生长掺 In N型 Hg Cd Te材料的研究结果。发现 In作为 N型施主在 Hg Cd Te中的电学激活率接近 1 0 0 % ,其施主电离激活能至少小于 0 .6me V。确认了在制备红外焦平面探测器时有必要将掺杂浓度控制在约 3× 1 0 1 5cm- 3水平。比较了高温退火前后 In在 Hg Cd Te中的扩散行为 ,得出在 40 0°C温度下 In的扩散系数约为 1 0 - 1 4cm2 / sec,确认了 In原子作为 Hg Cd Te材料的 N型掺杂剂的可用性和有效性 相似文献
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碲镉汞As掺杂技术研究 总被引:2,自引:0,他引:2
对于MBE原位掺杂,HgCdTe的N型掺杂比较容易,而P型掺杂相对来说难度比较大。作为掺杂杂质的As表现出两性掺杂行为,在富Te的条件下生长,As有很大的几率进入到阳离子位置处。而As必须进入Te位才能参与导电,表现为P型。因此,采取了多种方法,现已获得10^16-10^18坤cm^-3掺杂水平的P型材料。在成功实现As的掺杂后,研究人员对激活退火做了一些研究。研究发现,需要在汞压下经过高温退火,As原子才能占据Te位成为受主杂质。对As在碲镉汞中的扩散系数也进行了研究。 相似文献
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M. Weyers N. Pütz H. Heinecke M. Heyen H. LÜth P. Balk 《Journal of Electronic Materials》1986,15(2):57-59
We report on the intentional ρ-type doping of GaAs layers grown in an UHV system from molecular beams of arsine (AsH3) and mixtures of frimethyl gallium (TMG) and friethyl gallium (TEG). The entire doping range between 1014 cm-3 (growth from pure TEG) and 1020 cm-3 (growth from pure TMG) can be covered by using mixtures of TMG and TEG. As revealed by SIMS and photoluminescence (PL) carbon
is the dominant acceptor in the layers. Comparison of the Hall mobility and of the PL spectra shows that the quality of our
films equals that of the best LPE and MBE grown ρ-type GaAs layers. 相似文献
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L. A. Almeida S. Hirsch M. Martinka P. R. Boyd J. H. Dinan 《Journal of Electronic Materials》2001,30(6):608-610
We report on continuing efforts to develop a reproducible process for molecular beam epitaxy of CdZnTe on three-inch, (211)
Si wafers. Through a systematic study of growth parameters, we have significantly improved the crystalline quality and have
reduced the density of typical surface defects. Lower substrate growth temperatures (∼250–280°C) and higher CdZnTe growth
rates improved the surface morphology of the epilayers by reducing the density of triangular surface defects. Cyclic thermal
annealing was found to reduce the dislocation density. Epilayers were characterized using Nomarski microscopy, scanning electron
microscopy, x-ray diffraction, defect-decoration etching, and by their use as substrates for HgCdTe epitaxy. 相似文献
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对 Ga As基调制掺杂异质结材料中作为沟道层的 In Ga As的生长条件进行优化 ,并在缓冲层中嵌入LT-Ga As。功率 PHEMT器件结果为在栅长 Lg=1 .7μm时 ,跨导 gm≥ 40 0 m S/mm,BVDS>1 5 V,BVGS>1 2 V,表明该材料有较好的性能 相似文献
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文章报道了Si基碲镉汞分子束外延(MBE)的最新研究进展。尝试用晶向偏角降低高界面应变能的方法,摸索大失配体系中位错的抑制途径,寻找位错密度与双晶半峰宽的对应关系,基本建立了外延材料晶体质量无损检测评价标准,并对外延工艺进行指导。通过上述研究,15~20μm Si基CdTe复合材料双晶半峰宽最好结果为54arcsec,对应位错密度(EPD)小于2×106/cm2,与相同厚度的GaAs/CdTe(211)双晶水平相当,达到或优于国际最好结果。获得的3 in 10μm Si基HgCdTe材料双晶半峰宽最好结果为51arcsec,目前Si基HgCdTe材料已经初步应用于焦平面中波320×240器件制备。 相似文献
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High-quality large-area MBE HgCdTe/Si 总被引:2,自引:0,他引:2
J. M. Peterson J. A. Franklin M. Reddy S. M. Johnson E. Smith W. A. Radford I. Kasai 《Journal of Electronic Materials》2006,35(6):1283-1286
HgCdTe offers significant advantages over other similar semiconductors, which has made it the most widely utilized variable-gap
material in infrared (IR) focal plane array (FPA) technology. HgCdTe hybrid FPAs consisting of two-dimensional detector arrays
that are hybridized to Si readout circuits (ROIC) are the dominant technology for second-generation infrared systems. However,
one of the main limitations of the HgCdTe materials system has been the size of lattice-matched bulk CdZnTe substrates, used
for epitaxially grown HgCdTe, which have been limited to 30 cm2 in production. This size limitation does not adequately support the increasing demand for larger FPA formats which now require
sizes up to 2048×2048, and only a single die can be printed per wafer. Heteroepitaxial Si-based substrates offer a cost-effective
technology that can be scaled to large wafer sizes and further offer a thermal-expansion-matched hybrid structure that is
suitable for large format FPAs. This paper presents data on molecular-beam epitaxy (MBE)-grown HgCdTe/Si wafers with much
improved materials characteristics than previously reported. We will present data on 4- and 6-in diameter HgCdTe both with
extremely uniform composition and extremely low defects. Large-diameter HgCdTe/Si with nearly perfect compositional uniformity
and ultra low defect density is essential for meeting the demanding specifications of large format FPAs. 相似文献
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MOCVD与MBE生长GaAs/AlGaAs量子阱材料的红外探测器特性比较 总被引:2,自引:0,他引:2
用金属有机物化学气相沉积法(MOCVD)生长GaAs/AlGaAs量子阱材料,并制成红外探测器.测量了材料的光致发光光谱和探测器的光电流响应光谱及其它光电特性,峰值波长7.9μm,响应率达到6×103V/W,与分子束外延法(MBE)生长的材料和相关器件进行了比较,MOCVD法可满足量子阱材料和器件的要求. 相似文献
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报道了在Si衬底上微米尺寸的介质膜窗口中,采用分子束外延技术共度生长的Si0.8Ge0.2薄膜的应变及其退火特性. 实验表明,微区生长材料的这些特性,与同一衬底上无边界约束条件下生长的材料相比,有明显的不同.微米尺寸窗口中生长的SiGe/Si材料的应变与窗口尺寸有关,也和窗口的掩膜中的内应力有关.实验还表明,边缘效应对于微区中共度生长的SiGe/Si材料的热稳定性也有显著的影响.在3μm×3μm窗口中共度生长的Si0.8Ge0.2/Si异质结构材料,在950℃高温退火30min后,它的应变弛豫不大于4%.远小于同一衬底上非微区生长材料的应变弛豫.文章还对微区生长材料的这些特性成因进行了探讨. 相似文献