共查询到19条相似文献,搜索用时 140 毫秒
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研究了垂直梯度凝同法(VGF法)生长的掺Si低阻GaAs单品材料的晶格缺陷和性质,并将VGF法和LEC法生长的非掺半绝缘GaAs单晶进行了比较.利用A-B腐蚀显微方法比较了两种材料中的微沉积缺陷,对其形成原因进行了分析.利用荧光光谱研究了掺Si-GaAs单晶中Si原子和B原子的占位情况和复合体缺陷.Hall测量结果表明,掺Si低阻VGF-GaAs单晶中存在很强的Si自补偿效应,造成掺杂效率降低.VGF-GaAs单品生长过程中高的Si掺杂浓度造成晶体中产生大量杂质沉积,而杂质B的存在加重了这种现象.对降低缺陷密度,提高掺杂效率的途径进行了分析. 相似文献
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低阻GaAs单晶的获得,一般是通过掺入掺杂剂Si来实现的。本文分析了VB-GaAs单晶的掺Si机理及作用,并在理论掺杂公式的基础上,通过实验和理论分析,确定了掺杂剂量的经验关系式。按此公式,在VB-GaAs单晶中得到了理想的掺Si浓度。 相似文献
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《固体电子学研究与进展》1991,(1)
<正>LEC法要求有适当的轴向和径向的温度梯度来控制GaAs晶体的直径,但为了降低GaAs单晶的位错密度,又需要降低它们的温度梯度.对大直径GaAs单晶的生长,上述矛盾更为突出.HB法虽然能生长低位错GaAs单晶,但对大直径圆形晶体的生长却无能为力.通常采用VGF(垂直梯度凝固)法来解决大直径和低位错的矛盾.但由于VGF法中要有As源来 相似文献
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小角晶界是Si单晶中的严重缺陷,生产中需要极力避免。对于重掺B直拉<111>Si单晶,当掺杂浓度接近固溶度时就容易产生小角晶界。对直拉Si单晶中小角晶界产生的原因进行梳理及深入分析,在理论上提出减少过冷度来减少小角晶界缺陷的方法。分别采用增加加热器功率减小过冷度及降低埚位减少过冷度的两种工艺方法,成功实现生长无小角晶界重掺B<111>Si单晶。通过生产中实际晶体生长情况对比分析发现,低埚位生长无小角晶界的重掺B直拉<111>Si单晶工艺更具备生产优势。 相似文献
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用水平布里奇曼法(HB法)研制掺Si补偿Cu的n-GaAs高阻单晶.既要提高多晶背景纯度,减少总杂质含量(包括减少掺Cu量和掺Si量,单晶中Cu的质量分数要≤2.00×10-5,Si的质量分数要≤1.00×10-6),又要采用熔体Cu,Si双掺的方法生长单晶,将单晶切片,并划成圆片,然后分组放入炉内在确定温度下和一定时间内进行退火.研制中发现Cu主要集中在晶体表面,导致同一晶片的上部呈p型高阻,而中下部呈n型低阻,退火可使Cu在晶片中均匀分布. 相似文献
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3.GaAs中的杂质和缺陷的行为 3.1 GaAs中的施主、受主、中性、双性和深能级杂质 GaAs中的掺杂技术比Si中复杂,可选择的杂质较多,杂质在GaAs中可替代Ga或As原子,也可处于GaAs晶格的间隙位置上,因而表现出不同的电学性质。 相似文献
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做为衬底材料的各种掺杂和不掺杂的GaAs单晶材料中的微沉淀及微夹杂,都影响GaAs器件及集成电路的性能。我们用JEM-1000超高压电镜,采用选区电子衍射技术,研究了掺Si、掺Cr及纯度水平法生长(HB)低位错GaAs单晶中的As和C微小第二相的形态及结构。采用约化胞法、借助电子计算机计算约化胞数据表,来分析标定电子衍射花样确定结构。经电子衍射分析表明,掺Si、掺Cr及纯度水平法生(?)GaAs单晶中有二种结构类型As沉淀、一种为六方晶系As(a_0=3.76埃,c=10.55埃),另一种为正交晶系As(a_0=3.63埃,b_0=4.45埃,C_0=10.96埃),而且它们往往与α-方石英微沉淀(或微夹杂)或c微夹杂、或Cr_n As微沉淀共存(照片1)。电子衍射分析还表明,GaAs单晶中c的微夹杂是简单立方结构(a_0=5.55埃)。为了进一步验证水平法生长GaAs单晶中有c微夹杂存在,用JXA—50A扫描电子探针分析观察了,刚刚做好的电镜样品。 相似文献
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《半导体学报》2009,30(12)
The stresses, structural and electrical properties of n-type Si-doped GaN films grown by metalorganic chemical vapor deposition (MOCVD) are systemically studied. It is suggested that the main stress relaxation is induced by bending dislocations in low doping samples. But for higher doping samples, as the Si doping concentration increases, the in-plane stresses in the grown films are quickly relaxed due to the rapid increase of the edge dislocation densities. Hall effect measurements reveal that the carrier mobility first increases rapidly and then decreases with increasing Si doping concentration. This phenomenon is attributed to the interaction between various scattering process. It is suggested that the dominant scattering process is defect scattering for low doping samples and ionized impurity scattering for high doping samples. 相似文献
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The stresses, structural and electrical properties of n-type Si-doped GaN films grown by metaiorganic chemical vapor deposition (MOCVD) are systemically studied. It is suggested that the main stress relaxation is induced by bending dislocations in low doping samples. But for higher doping samples, as the Si doping concentration increases, the in-plane stresses in the grown films are quickly relaxed due to the rapid increase of the edge dislocation densities. Hall effect measurements reveal that the carrier mobility first increases rapidly and then decreases with increasing Si doping concentration. This phenomenon is attributed to the interaction between various scattering process. It is suggested that the dominant scattering process is defect scattering for low doping samples and ionized impurity scattering for high doping samples. 相似文献
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Terahertz Emission from GaAs Films on Si(100) and Si(111) Substrates Grown by Molecular Beam Epitaxy
Takashi Yoshioka Satoru Takatori Pham Hong Minh Marilou Cadatal-Raduban Tomoharu Nakazato Toshihiko Shimizu Nobuhiko Sarukura Elmer Estacio John Vincent Misa Rafael Jaculbia Michael Defensor Armando Somintac Arnel Salvador 《Journal of Infrared, Millimeter and Terahertz Waves》2011,32(4):418-425
We report on the terahertz emission from femtosecond-laser-irradiated GaAs layers grown on Si(100) and Si(111) substrates. The results show that the terahertz emission from GaAs on Si is stronger than that of a semi-insulating bulk GaAs crystal. This increase is attributed to the strain field at the GaAs/Si interface. In the GaAs of the Si(100) sample, the stronger terahertz emission is observed compared with GaAs on Si(111). Moreover, the effect of changing the doping type of the Si substrate from n-type to semi-insulating was also studied and it was found that the terahertz emission intensity of GaAs on semi-insulating Si(100) is stronger than that of GaAs on n-type Si(100). Finally, strong terahertz emission from GaAs on semi-insulating Si(100) was observed not only in the reflection geometry but also in the transmission geometry. These results hold promise for new applications of terahertz optoelectronics. 相似文献
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Effect of As overpressure on Si-doped (111)A, (211)A and (311)A GaAs grown by molecular beam epitaxy
Si-doped (111)A, (211)A and (311)A GaAs samples grown by molecular beam epitaxy (MBE) at different As over-pressures have been studied. Hall effect measurements have revealed that the doping changes from p- to n-type when the As pressure is increased. The transition As pressure is lower for the (211)A than for the (311)A surfaces. Photo-luminescence measurements have shown that, when the As pressure is increased, arsenic vacancy defects are changed into pairs of Ga vacancy and Ga antisite defects. These results are explained by considering the orientation dependence of the surface bonding and the kinetics of the MBE growth process. 相似文献
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N. G. Yaremenko M. V. Karachevtseva V. A. Strakhov G. B. Galiev V. G. Mokerov 《Semiconductors》2008,42(13):1480-1486
The effect of arsenic pressure on the amphoteric behavior of Si during the growth of the Si-doped (100)-, (111)Ga-, and (111)As-oriented GaAs layers is studied by photoluminescence spectroscopy. The edge luminescence band is examined, and the concentration and the degree of compensation as functions of the arsenic pressure are determined. Nonstoichiometry defects in GaAs layers grown with a deficit and an excess of arsenic are studied. It is shown that the defects formed in the (111)Ga- and (111)As-oriented layers are different in nature. 相似文献
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Influence of arsenic incorporation on surface morphology and Si doping in GaAs(110) homoepitaxy 总被引:3,自引:0,他引:3
E. S. Tok J. H. Neave M. R. Fahy F. E. Allegretti J. Zhang T. S. Jones B. A. Joyce 《Microelectronics Journal》1997,28(8-10):833-839
We have studied the relationship between the arsenic incorporation kinetics and the surface morphology and Si doping behaviour in GaAs(110) films grown by molecular beam epitaxy (MBE). The homoepitaxial growth of GaAs(110) requires low substrate temperatures and high As/Ga flux ratios to obtain films with good surface morphology, and under these conditions Si doped layers exhibit n-type behaviour. At higher growth temperatures and lower As/Ga flux ratios, the epitaxial films are highly faceted and the Si doped layers are p-type. We show that this growth related site switching behaviour and variation in surface morphology is due to a decrease in the As coverage arising from a small and temperature dependent incorporation coefficient of arsenic on this surface. 相似文献
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采用低温光荧光谱测试方法,研究了MBE生长的轻掺硅GaAs材料的杂质特性,并结合Hall测量结果,讨论了MBE关键生长条件Ⅴ/Ⅲ束流比等对Si在GaAs中掺杂特性的影响,研究表明掺杂元素Si在GaAs中起两性(施主或受主)杂质作用,适当提高Ⅴ/Ⅲ束流比可以抑制Si的自补偿效应,从而减小载流子的补偿度,进一步提高迁移率。通过优化生长条件,本实验已获得了杂质浓度小于1012cm-3,77K下迁移率大于1.6×105cm2/V·s的高纯、高迁移率GaAs材料。 相似文献
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《Electron Device Letters, IEEE》1984,5(8):329-332
A thin, highly Si-doped (n-type) interfacial layer is used for controlled barrier lowering in n-type GaAs. The thickness and the doping density of the interfacial n+ layer in the range of 50-100 Å, are extracted from the measured electrical characteristics of Schottky contacts. A model for field-enhanced tunneling current in metal--nGaAs Schottky structures is presented and the experimental results for Al-n+ GaAs devices fabricated using molecular beam epitaxy (MBE) show good agreement. 相似文献