ZnSe多量子阱横向磁阻的无接触测量

用微波无接触法测量了ＺｎＳｅ外延层和两种ＺｎＳｅ多量子阱样品的横向磁阻,在低磁场时,这三种样品都表现为负磁阻,并且也可以用Ｋｈｏｓｌａ和Ｆｉｓｃｈｅｒ的半经验表示式进行拟合,实验还发现了在两层ＺｎＳｅ超晶格之间的Ｚｎ＋Ｇａ单原子层也呈现为较大的负磁阻     

Siδ掺杂GaAs多量子阱的磁量子输运

使用ＭＢＥ技术低温生长了含有３个Ｓｉδ掺杂层的ＧａＡｓ外延片，形成三量子阱结构。在４．２～３００Ｋ温区０．１Ｔ的电磁铁上测量了样品载流子浓度和迁移率随温度的变化。在０．３～４．２Ｋ（＾３Ｈｅ温区）和０～７Ｔ强磁场下测量了样品的横向磁阻、纵向磁阻和霍尔电阻。观察到了横向磁阻的ＳｄＨ振荡和纵向磁阻的抗磁ＳｄＨ振荡。根据实验结果着重讨论了纵向磁阻振荡的起源以及霍尔振荡的含义，简单分析了δ掺杂二维电子气中     

应变Si—xGex／Si异质结材料的GSMBE生长及X射线双晶衍射研究

用ＧＳＭＢＥ技术在国内首次研究了应变Ｓｉ１－ｘ Ｇｅｘ／Ｓｉ异质结材料的生长，并用Ｘ射线双晶线双晶衍射技术对样品进行了测试分析，对于Ｓｉ０．９１Ｇｅ０．０９和Ｓｉ０．８６Ｇｅ０．１４单层，其半宽度ＦＷＨＭ分别为１００〃和２０２〃，对于Ｓｉ０．８９Ｇｅ０．１１／Ｓｉ多量子阱，其卫星峰多达１５个以上，三种样品中的ＧｅＳｉ外延层干涉条纹清晰可见，结果表明，用ＧＳＭＢＥ技术生长的Ｓｉ－ｘＧｅｘ／Ｓｉ异质结     

Si_(1-x)Ge_x材料和双极型器件的进展

Ｓｉ１－ｘＧｅｘ材料具有许多优良的性质,高质量的应变外延层可以把能带工程的概念引入到Ⅳ族器件之中。外延Ｓｉ１－ｘＧｅｘ基区的异质结双极型晶体管（ＨＢＴ）获得了优良的性能,并且,其具有可以同硅工艺兼容的优点,把Ｓｉ１－ｘＧｅｘ同Ｓｉ集成的ＢｉＣＭＯＳ工艺取得了很大的发展,已经达到了工业应用的水平。Ｓｉ１－ｘＧｅｘ工艺的发展,电路速度的提高,也促进了微波集成电路的进步,提高了ＳｉＭＭＩＣ的应用频段。从目前的发展现状来看,已经达到了在射频（ＲＦ）通信中广泛应用的阶段。     

三元硅化物(Co_xNi_(l-x))Si_2薄膜的制备及特性

在Ｓｉ（１００）衬底上用离子束溅射方法淀积Ｎｉ,Ｃｏ,Ｔｉ薄膜,形成Ｃｏ／Ｎｉ／Ｓｉ,Ｎｉ／Ｃｏ／Ｓｉ和Ｃｏ／Ｎｉ／Ｓｉ等结构,通过氮气中快速热退火反应生成三元硅化物（ＣｏｘＮｉｌ－ｘ）Ｓｉ２。用ＡＥＳ,ＸＲＤ,ＲＢＳ沟道谱,ＳＥＭ及四探针等方法对（ＣｏｘＮｉｌ－ｘ）Ｓｉ２薄膜的物理特性和电学特性进行了测试,在Ｓｉ衬底上Ｃｏ,Ｎｉ多层膜经快速热退火可形成高电导的（ＣｏｘＮｉｌ－ｘ）Ｓｉ２薄膜,其电阻率在１５～２０μΩ·ｃｍ之间。Ｃｏ／Ｎｉ／Ｔｉ／Ｓｉ（１００）多层结构固相反应可以得到外延（ＣｏｘＮｉｌ－ｘ）Ｓｉ２薄膜。（ＣｏｘＮｉｌ－ｘ）Ｓｉ２的晶格为ＣａＦ２立方结构,晶格常数介于ＣｏＳｉ２和ＮｉＳｉ２之间。通过热处理和选择腐蚀等工艺,可在有ＣＭＯＳ图形的衬底上形成自对准的三元硅化物源漏接触和栅极互连图形。     

应变Si_（1－x）Ge_x层本征载流子浓度和有效态密度的解析计算

计算了应变Ｓｉ１－ｘＧｅｘ层的本征载流子浓度及导带和价带有效态密度。用解析方法研究了它们与Ｇｅ组分ｘ和温度Ｔ的依赖关系。发现随Ｇｅ组分ｘ的增加，导带和价带有效态密度随之快速减小，而本征载流于浓度却随之而近乎指数式地增加。而且，温度Ｔ越低，导带和价带有效态密度随Ｇｅ组分ｘ的增加而减小得越快，而本征载流于浓度上升得越快。同时还发现，具有大Ｇｅ组分ｘ的应变Ｓｉ１－ｘＧｅｘ层，其用Ｓｉ相应参数归一化的导带和价带有效态密度及它们的积对温度Ｔ的依赖关系弱，而具有小Ｇｅ组分ｘ的应变Ｓｉ１－ｘＧｅｘ层，上述归一化参数对温度Ｔ的依赖关系强，这和目前仅有的文献［８］中，它们与温度依赖关系的定性研究结果相一致。     

可调节势垒高度的Al／Si_（1—x）Gex肖特基接触

本文首次报道了Ａｌ／ｐ－Ｓｉ１－ｘＧｅｘ肖特基（Ｓｃｈｏｔｔｋｙ）接触的制备与电学性质．Ｓｉ１－ｘＧｅｘ／Ｓｉ应变外延层采用快速加热、超低压化学气相淀积方法生长．实验表明，改变Ｇｅ组分ｘ的大小可以调节肖特基势垒高度．随着Ｇｅ组分的增大，肖特基势垒高度降低，其降低值与Ｓｉ１－ｘＧｅｘ应变层带隙的降低值相一致，界面上费米能级钉扎于导带下约０．４３ｅＶ处．文中还研究了ＳｉＧｅ合金层的应变弛豫以及Ｓｉ顶层对肖特基接触特性的影响．     

GaAs,AlxGa1—xAs外延层少子扩散长度及霍耳迁移率的无接触测试

用微波介质波导法无接触测试了生长在半绝缘衬底上的ＧａＡｓ、ＡｌｘＧａ１－ｘＡｓ外延层的微波光是导谱和横向磁阻，给出了从微波光电导谱计算了少子扩散长度和从横向磁阻计算霍耳迁移率的方法，并且由此算得外延层的少子扩散长度和霍耳迁移度，本方法对波测样品的几何形状和尺寸无特殊要求，测试区域小于５×５ｍｍ＾２，具有无损伤，不污染的优点，并配有微机控制，测试迅速方便。     

GaAs、Al_xGa_（1－x）As外延层少子扩散长度及霍耳迁移率的无接触测

用微波介质波导法无接触测试了生长在半绝缘衬底上的ＧａＡｓ、ＡｌｘＧａ１－ｘＡｓ外延层的微波光电导谱和横向磁阻，给出了从微波光电导谱计算少子扩散长度和从横向磁阻计算霍耳迁移率的方法，并且由此算得外延层的少于扩散长度和霍耳迁移率．本方法对被测样品的几何形状和尺寸无特殊要求，测试区域小于５×５ｍｍ２，具有无损伤、不污染的优点，并配有微机控制，测试迅速方便．     

应变Si1—xGex层本征载流子浓度和有效态密度的解析计算

计算了应变Ｓｉ１－ｘＧｅ层的本征载流子浓度及导带和价带有效态密度。用解析方法研究了它们与Ｇｅ组分ｘ和温度Ｔ的依赖关系。发现随Ｇｅ组分ｘ的增加，导带和价带有效态密度随之快速减小，而本征载流子浓度却随之而近乎指数式地增加。而且，温度Ｔ越低，导带和价带有效态密度随Ｇｅ组分ｘ的增加而减小得越快，而本征载流子浓度上升得越快。同时还发现，具有大Ｇｅ组分ｘ的应变Ｓｉ－ｘＧｅｘ层，其用Ｓｉ相应参数归一化的导带和价     

GexSi1－x／Si超晶格PIN波导探测器结构及性能参数

从ＰＩＮ波导探测器性能参数的定义出发，阐述了各参数之间的内在联系，说明量子效率与带宽、灵敏度等物理量之间的矛盾现象。通过对具体结构及参数的分析比较，说明结构与参数之间的影响方式以及ＧｅｘＳｉ１－ｘ／Ｓｉ超晶格波导探测器的特有性质，进一步论证了波导探测器的优点     

Annealing Behavior of Si1-xGex/Si Heterostructures

There are two reasonsfor people studying on the materialsannealing.Firstly,deviceswith semiconductor heterostructure may unavoidably experience some high-temperatureprocesses during both fabrication and operation.The thermal stability...     

Study of nickel silicide contact on Si/Si/sub 1-x/Ge/sub x/

The properties of nickel silicide formed by depositing nickel on Si/p/sup +/-Si/sub 1-x/Ge/sub x/ layer are compared with that of nickel germanosilicide on p/sup +/-Si/sub 1-x/Ge/sub x/ layer formed by depositing Ni directly on p/sup +/-Si/sub 1-x/Ge/sub x/ layer without silicon consuming layer. After thermal annealing, nickel silicide on Si/p/sup +/-Si/sub 1-x/Ge/sub x/ layer shows lower sheet resistance and specific contact resistivity than that of nickel germanosilicide on p/sup +/-Si/sub 1-x/Ge/sub x/ layer. In addition, small junction leakage current is also observed for nickel silicide on a Si/p/sup +/-Si/sub 1-x/Ge/sub x//n-Si diode. In summary, with a Si consuming layer on top of the Si/sub 1-x/Ge/sub x/, the nickel silicide contact formed demonstrated improved electrical and materials characteristics as compared with the nickel germanosilicide contact which was formed directly on the Si/sub 1-x/Ge/sub x/ layer.     

Damage and strain in pseudomorphic vs relaxed GexSi1−x layers on Si(100) generated by Si ion irradiation

We compare both the strain and damage that 100 keV Si irradiation at room temperature introduces in pseudomorphic and relaxed Ge_xSi_1−x films grown on Si(100) substrates. The ion range is such that the Si/Ge_xSi_1−x interface is not significantly damaged. The amount of damage produced in pseudomorphic and relaxed Ge_xSi_1−x layers of similar x for irradiation doses up to 2.5 × 10¹⁴ Si/cm² is the same, which proves that a pre-existing uniform strain does not noticeably affect the irradiation-induced damage. However, the irradiation-induced strain does depend on the pre-existing strain of the samples. Possible interpretations are discussed. On leave from Inst. voor Kern en Stralingsfysika, Catholic University of Leuven, Belgium.     

The properties of Si/Si1-xGex films grown on Si substrates by chemical vapor deposition

A growth parameter study was made to determine the proper of a SiGe superlattice-type configuration grown on Si substrates by chemical vapor deposition (CVD). The study included such variables as growth temperature, layer composition, layer thickness, total film thickness, doping concentrations, and film orientation. Si and SiGe layers were grown using SiH₄ as the Si source and GeH₄ as the Ge source. When intentional doping was desired, diluted diborane for p-type films and phosphine for n-type films were used. The study led to films grown at ∼1000°C with mobilities from ∼20 to 40 percent higher than that of epitaxial Si layers and ∼100 percent higher than that of epitaxial SiGe layers grown on (100) Si in the same deposition system for net carrier concentrations of ∼8x10¹⁵ cm^-3 to ∼2x10¹⁷ cm^-3. Enhanced mobilities were found in multilayer (100)-oriented Si/Si_1-xGe_x films for layer thicknesses ≥400A, for film thicknesses >2μm, and for layers with x = 0.15. No enhanced mobility was found for (111)-oriented films and for B-doped multilayered (100)-orlented films. Supported in part by NASA-Langley Research Center, Hampton, VA, Contract NAS1-16102 (R. Stermer & A. Fripp, Contr. Mon.)     

应变p型Si1—xGex层中补偿浅能级杂质的低温陷阱效应

研究了ｐ型Ｓｉ１－ｘＧｅｘ应变层中补偿浅能级杂质（Ｐ、Ａｓ、Ｓｂ）的低温陷阱效应。研究发现，１）三种补偿浅能杂质Ｐ、Ａｓ、Ｓｂ相比较，Ｓｂ的陷阱效应最小，Ａｓ的最大；２）Ｇｅ组份ｘ越大，低温陷阱效应越小；３）补偿浅能级杂质浓度ＮＤ越大，低温陷阱效应越显著，温度越低，陷阱作用越明显。     

UHV/CVD生长SiGe/Si异质结构材料

以 Si2 H6 和 Ge H4 作为源气体 ,用 UHV/CVD方法在 Si( 1 0 0 )衬底上生长了 Si1- x Gex 合金材料和 Si1- x Gex/Si多量子阱结构 .用原子力显微镜、X光双晶衍射和透射电子显微镜对样品的表面形貌、均匀性、晶格质量、界面质量等进行了研究 .结果表明样品的表面平整光滑 ,平均粗糙度为 1 .2 nm;整个外延片各处的晶体质量都比较好 ,各处生长速率平均偏差为 3.31 % ,合金组分 x值的平均偏差为 2 .0 1 % ;Si1- x Gex/Si多量子阱材料的 X光双晶衍射曲线中不仅存在多级卫星峰 ,而且在卫星峰之间观察到了 Pendellosung条纹 ,表明晶格质量和界面质量都很好 ;Si     

1.55μmSi_(1-x)Ge_x/Si光开关与光探测器集成的分析及设计

对１．５５μｍ波长的Ｓｉ１－ｘＧｅｘ光波导开关和Ｓｉ１－ｘＧｅｘ／Ｓｉ红外探测器的集成结构进行了系统的理论分析和优化设计。设计结果为：（１）对Ｓｉ１－ｘＧｅｘ光开关，Ｇｅ含量ｘ＝０．０５，波导的内脊高、脊宽和腐蚀深度分别为３，８．５和２．６μｍ，分支角为５～６°。要实现对１．５５μｍ波长光的开关作用，ｐｎ＋结上所需加的正向偏压值应为０．９７Ｖ；（２）对Ｓｉ１－ｘＧｅｘ／Ｓｉ探测器，Ｇｅ含量ｘ＝０．５，探测器由２３个周期的６ｎｍＳｉ０．５Ｇｅ０．５和１７ｎｍＳｉ交替组成厚度为５５０ｎｍ，长度约为１．５～２ｍｍ的超晶格，内量子效率达８０％以上。     

气态源分子束外延AlxGa1-xAs(x=0～1)材料中Si的掺杂行为研究

研究了Si在AlxGa1-xAs(0≤x≤1)中的掺杂行为.为比较Al組份对Si掺杂浓度的影响,在用气态源分子束外延生长(GSMBE)掺Si n型AlxGa1-xAs(0≤x≤1)的所有样品时,n型掺杂剂Si炉的温度恒定不变.用Hall效应测量外延层的自由载流子浓度和迁移率,用X射线双晶衍射迴摆曲线测量外延层的组份.测试结果表明,当AlxGa1-xAs中Al组份从0增至0.38时,Si的掺杂浓度从4×1018cm-3降至7.8×1016cm-3,电子迁移率从1900 cm2/Vs降至100 cm2/Vs.这与AlxGa1-xAs材料的Γ-X直接—间接带隙的转换点十分吻合.在AlxGa1-xAs全组份范囲内,自由载流子浓度隨Al组份从0至1呈“V”形变化,在X=0.38处呈最低点.在x>0.4之后,AlxGa1-xAs的电子迁移随Al组分的增加,一直维持较低值且波动幅度很小.     

Structural analysis of Ge x Si1−x /Si layers by remote plasma-enhanced chemical vapor deposition on Si (100)

In this work, remote plasma-enhanced chemical vapor deposition (RPCVD) has been used to grow Ge _x Si_1−x /Si layers on Si(100) substrates at 450° C. The RPCVD technique, unlike conventional plasma CVD, uses an Ar (or He) plasma remote from the substrate to indirectly excite the reactant gases (SiH₄ and GeH₄) and drive the chemical deposition reactions. In situ reflection high energy electron diffraction, selected area diffraction, and plan-view and cross-sectional transmission electron microscopy (XTEM) were used to confirm the single crystallinity of these heterostructures, and secondary ion mass spectroscopy was used to verify abrupt transitions in the Ge profile. XTEM shows very uniform layer thicknesses in the quantum well structures, suggesting a Frank/ van der Merwe 2-D growth mechanism. The layers were found to be devoid of extended crystal defects such as misfit dislocations, dislocation loops, and stacking faults, within the TEM detection limits (∼10⁵ dislocations/cm²). Ge _x Si_1−x /Si epitaxial films with various Ge mole fractions were grown, where the Ge contentx is linearly dependent on the GeH₄ partial pressure in the gas phase for at leastx = 0 − 0.3. The incorporation rate of Ge from the gas phase was observed to be slightly higher than that of Si (1.3:1).