Depletion Mode HEMT with Refractory Metal Silicide WSi Gate

ＤｅｐｌｅｔｉｏｎＭｏｄｅＨＥＭＴｗｉｔｈＲｅｆｒａｃｔｏｒｙＭｅｔａｌＳｉｌｉｃｉｄｅＷＳｉＧａｔｅ￥ＣＨＥＮＤｉｎｇｑｉｎ；ＺＨＯＵＦａｎ（ＩｎｓｔｉｔｕｔｅｏｆＳｅｍｉｃｏｎｄｕｃｔｏｒｓ，ＡｃａｄｅｍｉａＳｉｎｉｃａ，Ｂｅｉｊｉｎｇ１０００８...     

难熔金属硅化物的喇曼散射

用电子束蒸发方法在10~(-7)托真空中使单晶硅上蒸上一层Ti膜后,于N_2中进行从500-1000℃10秒钟的快速热退火,由激光喇曼光谱结合薄层电阻测量和转靶X射线衍射研究分析了TiSi_2的形成.退火温度高于680℃时,观察到207和244cm~(-1)波数处的两个TiSi_2的特征喇曼峰,当退火温度为580℃时,只有270,297和3ncm~(-1)的三个喇曼峰,这些可能是钛的氧化物和不包括TiSi的钛硅化物.     

Pd/a-Si:H界面的光电子能谱研究

本文利用光电子能谱(XPS、UPS)技术研究了Pd淀积层与离子注入制备的a-Si∶H层组成的系统.本工作分析了Pd/a-Si∶H的界面键合状态及组分分布的变化对价带谱与芯能级谱的影响,并与Pd/C-Si系统的结果进行了比较.结果表明:Pd/a-Si∶H界面具有与Pd/C-Si界面相似的电子结构;但是,Pd原子在a-Si∶H中具有较大的扩散速率,因此,处于更富Si的环境中。     

MoSi_2硅化物的形成及电子结构的研究

利用XPS、UPS、AES、X-光衍射和拉曼散射等技术,研究了在稳态热退火条件下共溅射的Mo-Si合金膜,硅化物的形成及电子结构特性.     

高纯难熔金属及其硅化物在微电子领域的应用

现代微电子装置使用了高纯难熔金属硅化作为接点，栅极，布线，阻挡层和集成电路的喷涂金属粉。这些材料良好的化学稳定性和热稳定性为厚度不到１μｍ的集成电路的设计铺平了道路。这些应用的重要的先决条件是制取碱金属，碱土笔过渡族元素的含量低于０．０５ｍｇ／ｋｇ（ｐｐｍ）的高纯难熔金属及其硅化物。铀和钍的残余浓度甚至降到０．０００５ｍｇ／ｋｇ（ｐｐｂ）以下。     

Implant Compositional Disordering on InGaAs／InP MQW Structures

ＩｍｐｌａｎｔＣｏｍｐｏｓｉｔｉｏｎａｌＤｉｓｏｒｄｅｒｉｎｇｏｎＩｎＧａＡｓ／ＩｎＰＭＱＷＳｔｒｕｃｔｕｒｅｓ￥ＺＨＡＯＪｉｅ；ＬＩＵＢａｏｊｕｎ；ＷＡＮＧＹｕｆａｎｇ；ＷＡＮＧＹｕｏｎｇｃｈｅｎ；ＴｈｏｍｐｓｏｎＤＡ（ＴｉａｎｊｉｎＮｏｒｍａｌＵ...     

MBE生长的GaAs1—xSbx／GaAs系中缺陷的研究

GaAs_(1-x)Sb_x作为有前途的长波长光电材料已受到了广泛的重视。但是由于GaAs_(1-x)Sb_x在GaAs衬底上进行外延生长时存在过大的晶格失配度(约7.5％)而遇到了较大的困难。为了提高材料的质量,对于GaAs_(1-x)Sb_x/GaAs体系异质结界面失配位错的分析已成为了有兴趣的研究课题。本文对用分子束外延(MBE)生长的GaAs_(1-x)Sb_x/GaAs系材料的界面缺陷进行了横断面透射电子显微镜和高分辩电子显微镜的研究,目的在于了解界面的缺陷行为并探讨改进材料质量的途径。     

Self-aligned Ti germanosilicide formation on a polycrystalline Si/SiGe/Si extrinsic base for SiGe heterojunction bipolar transistors

This work reports our investigation of a microstructure of self-aligned Ti germanosilicide made on polycrystalline Si/SiGe/Si multilayers. The existence of the SiGe layer restricted the growth of the Ti germanosilicide layer and produced protrusions penetrating the underlying polycrystalline layer. Each protrusion corresponded to a stacking-faulted single grain of the C49 phase. The microstructure of the thin Ti germanosilicide layer and the deep protrusions caused an increase of the sheet resistance and the contact resistivity of the extrinsic base region. The raised contact resistivity led to a degradation of radio frequency (RF) and noise characteristics of the SiGe heterojunction bipolar transistor (HBT).     

InP基MOCVD及MBE外延生长HBT的制备与分析

设计并研制了用于光电集成(OEIC)的InP基异质结双极晶体管(HBT),介绍了工艺流程及器件结构。分别采用金属有机化学气相沉积(MOCVD)及分子束外延(MBE)生长的外延片,并在外延结构、工艺流程相同的条件下,对两种生长机制的HBT直流及高频参数进行和分析。结果表明,采用MOCVD生长的InP基HBT,直流增益为30倍,截止频率约为38GHz;MBE生长的HBT,直流增益达到100倍,截止频率约为40GHz。这表明,MBE生长的HBT外延层质量更高,在相同光刻条件下,所对应的HBT器件的性能更好。     

GaAs基InAs/AlSb二维电子气结构的生长优化

采用分子束外延设备 (MBE) , 外延生长了InAs/AlSb二维电子气结构样品.样品制备过程中, 通过优化AlGaSb缓冲层厚度和InAs/AlSb界面厚度、改变AlSb隔离层厚度, 分别对比了材料二维电子气特性的变化, 并在隔离层厚度为5nm时, 获得了室温电子迁移率为20500cm2/V·s, 面电荷密度为2.0×1012/cm2的InAs/AlSb二维电子气结构样品, 为InAs/AlSb高电子迁移率晶体管的研究和制备提供了参考依据.     

A comparative study of metamorphic InP/InGaAs double heterojunction bipolar transistors with InP and InAIP buffer layers grown by molecular beam epitaxy

We present a comparison of material quality and device performance of metamorphic InGaAs/InP heterojunction bipolar transistors (HBTs) grown by molecular beam epitaxy (MBE) on GaAs substrates with two different types of buffer layers (direct InP and graded InAlP buffers). The results show that the active layer of InP-MHBT has more than one order of magnitude more defects than that of the InAlP-MHBT. The InAlP-MHBTs show excellent direct current (DC) performance. Low DC current gain and a high base junction ideality factor from the InP-MHBT are possibly due to a large number of electrically active dislocations in the HBT active layers, which is consistent with a large number of defects observed by cross-sectional transmission electron microscopy (TEM) and rough surface morphology observed by atomic force microscopy (AFM).     

以金属为缓冲层在Si(111)上分子束外延GaN及其表征

用电子束蒸发方法在Si(111)衬底上蒸发了Au/Cr和Au/Ti/Al/Ti 两种金属缓冲层,然后在金属缓冲层上用气源分子束外延(GSMBE)生长GaN. 两种缓冲层的表面都比较平整和均匀,都是具有Au(111)面择优取向的立方相Au层. 在Au/Cr/Si(111)上MBE生长的GaN,生长结束后出现剥离. 在Au/Ti/Al/Ti/Si(111)上无AlN缓冲层直接生长GaN,得到的是多晶GaN;先在800℃生长一层AlN缓冲层,然后在710℃生长GaN,得到的是沿GaN(0001)面择优取向的六方相GaN. 将Au/Ti/Al/Ti/Si(111)在800℃下退火20min,金属层收缩为网状结构,并且成为多晶,不再具有Au(111)方向择优取向.     

Novel fully self-aligned MESFET using source and drain regrown nonalloyed contacts by ALE

A new low temperature, nonalloyed, self-aligned FET process using regrowth technology on a patterned substrate has been demonstrated. A double 8-doped MESFET with regrown n⁺⁺ source and drain contact regions using atomic layer epitaxy (ALE) were fabricated and characterized. In this novel regrowth technique, a silicide gate was embedded by molybdenum and a side wall oxide to prevent any contamination or unwanted reaction during the ALE growth. Two main features associated with our process that makes it an attractive technology for more uniform device performance across a large area wafer are: a) the refractory gate/GaAs interface is not subjected to any high temperature process, and b) nonalloyed ohmic contacts are achieved without undesirable lateral diffusion of n⁺ regions caused by annealing of implanted source and drain. The preliminary unoptimized device results show a transconductance of 40 mS/mm for gate length of 0.65 μn.     

Effect of parasitics on electrochemical capacitance-voltage profiling of pseudomorphic high electron mobility transistor structures

The effect of parasitic series resistances on electrochemical capacitance-voltage (EC-V) profiling is simulated numerically for Al_xGaj_1-xAs/InyGa_1-yAs pseudomorphic high electron mobility transistor (p-HEMT) structures. The actual EC-V measurement is simulated numerically by reconstructing the charge distribution from an intrinsic distribution calculated from a self-consistent k p model. The calculated charge distribution then forms the basis for examining the possible profiles an EC-V measurement would produce when parasitics are taken into account. From a simple lumped-circuit model, it is shown that parasitic resistances distort the shape of the charge distribution by changing the relative heights of the 5-layer and channel charges. Hysteresis effects may also occur and may be accompanied by a change in material type from n to p even though the material is known to be n-type over the entire range of measurement. Additionally, an undesirable dependence of the charge profile on the probe signal frequency is found.     

基于TMD材料的CMOS反相器电路研究现状

对目前基于过渡金属硫族化合物(TMD)材料(MoS2、WSe2等)的互补金属氧化物半导体(CMOS)反相器电路相关研究进行了综述.总结了TMD材料的物理性质、制备方法和基于TMD的场效应晶体管器件的研究进展.对基于TMD的集成电路技术研究进行了介绍与分析.分别在结构设计、集成工艺、性能优化及电路集成等方面对基于TMD材...     

Metallo‐Hydrogel‐Assisted Synthesis and Direct Writing of Transition Metal Dichalcogenides

Two dimensional (2D) transition metal dichalcogenides (TMDCs) have attracted interest for their compelling nanoscale new properties and numerous potential applications including fast optoelectronic devices, ultrathin photovoltaics, and high‐performance catalysts. Large‐scale growth of uniform TMDC materials is essential for investigating their physics and for their integration into devices. However, the wafer scale deposition of TMDCs on arbitrary nonselective substrates is still beyond the current state‐of‐the‐art. In this article, a method to synthesize layered TMDCs (MoS₂ and WS₂) at the wafer‐scale by sulfurization of transition metal ions (Mo⁵⁺ and W⁶⁺) in a gelatin template (metallo‐hydrogel) is reported. This process is adaptable to versatile substrates, including amorphous silicon oxide, high‐temperature quartz, and silicon. Although the products are nominally few layer materials, direct band photoluminescent (≈1.8 eV), similar to single‐ or decoupled multilayer MoS₂ is observed. Finally, the solution‐based deposition enables contact printing of TMDC channels to be useable for device applications including thin film transistors with printed silver contacts using the same process.     

基于AlN和GaN形核层的AlGaN/GaN HEMT外延材料和器件对比

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.