钒离子注入硅合成硅化钒薄层

用大束流密度的钒金属离子注入硅，能够直接合成性能良好的薄层硅化物，随束流密度的增加，硅化钒相生长，薄层硅化物的方块电阻Ｒｓ明显下降吵流密度为２５μＡ／ｃｍ＾２时，Ｒｓ达到最小值２２Ω／□，说明连续的硅化物已经形成。Ｘ衍射分析表明，注入层中形成了Ｖ３Ｓｉ、Ｖ５Ｓｉ３、Ｖ３Ｓｉ５和ＶＳｉ２四种硅化钒。经过退炎后，Ｒｓ明显地下降，Ｒｓ最大可降到９Ω／□，电阻主可小到７２μΩｍ，说明硅化钒薄层质量得到了进     

用强流金属离子源研究Ti－Si化合物的形成

利用金属蒸汽真空弧（ＭＥＶＶＡ）离子源引出强流Ｔｉ离子注入单晶硅，当ＭＥＶＶＡ源引出电压为４０ｋＶ，束流密度达到１００μＡ／ｃｍ２，Ｔｉ离子剂量为５×１０１７／ｃｍ２，Ｔｉ离子注入单晶硅可得到Ｃ５４－ＴｉＳｉ２的注入层，且薄层电阻低于３．０Ω／□．本文用束流热效应讨论了形成硅化物的机理．     

自对准Ti－SALICIDE LDD MOS工艺研究

本文着重研究了０．６μｍ自对准Ｔｉ－ＳＡＬＩＣＩＤＥＬＤＤＭＯＳ工艺技术．ＴｉＳｉ２的形成采用两步快速热退火及选择腐蚀完成，Ｔｉ膜厚度的最佳选择使ＳＡＬＩＣＩＤＥ工艺与０．２μｍ浅结相容，源／漏薄层电阻为４Ω／□．上述技术已成功地应用于０．６μｍ自对准Ｔｉ－ＳＡＬＩＣＩＤＥＬＤＤＮＭＯＳ器件及其Ｅ／ＤＭＯＳ３１级环形振荡器的研制，特性良好．     

SiGe外延层中硼注入和退火

对采用快速加热、超低压－化学汽相沉积（ＲＴＰ／ＶＬＰ－ＶＣＤ）技术生长的Ｓｉ０．８Ｇｅ０．２／Ｓｉ应变外延层进行硼注入，注入能量为４０ｋｅＶ，注入剂量为２．５×１０＾１４ｃｍ＾－２。然后，进行不同时间、不同温度的快热退为（ＲＴＡ）稳态炉退火。结果表明，ＲＴＡ优于稳态炉退火，其最佳条件下：退火时间为１０ｓ，退火温度范围为７５０℃－８５０℃，或者退火温度为７００℃，时间为４０ｓ，基本可消除由注入引起的     

离子注入硅快速退火合成Y硅化物的特性

用金属蒸发真空弧离子源注入机将 Y离子注入硅 ,制备出特性良好的硅化物。用掠角沟道技术和透射电子显微镜分析了这种硅化物的结构。用束流密度为 2 5μA/ cm2的 Y注入硅可形成三层结构的硅化钇。硅化钇层的厚度大约为 60— 80 nm.其缺陷密度 Nd 和薄层电阻 Rs随束流密度的增加而下降。快速退火后 ,Nd和 Rs都明显下降。Rs从 54Ω/□下降到 1 4Ω/□。最小电阻率为 84μΩ·cm.这说明快速退火可以改善硅化钇的电特性。X射线衍射分析表明 YSi和 YSi2 硅化物已经形成。掠角沟道技术有益于研究薄层硅化物的原子深度分布和晶格缺陷密度分布     

离子注入硅快速退火合成Y硅化物的特性

用金属蒸发真空弧离子源注入机将Y离子注入硅,制备出特性良好的硅化物.用掠角沟道技术和透射电子显微镜分析了这种硅化物的结构.用束流密度为25μA/cm2的Y注入硅可形成三层结构的硅化钇.硅化钇层的厚度大约为60-80nm.其缺陷密度Nd和薄层电阻Rs随束流密度的增加而下降.快速退火后,Nd和Rs都明显下降.Rs从54Ω/□下降到14Ω/□.最小电阻率为84μΩ·cm.这说明快速退火可以改善硅化钇的电特性.X射线衍射分析表明YSi和YSi2硅化物已经形成.掠角沟道技术有益于研究薄层硅化物的原子深度分布和品格缺陷密度分布.     

As＋注入Si1—xGex的快速退火行为

用二次离子质谱对Ａｓ＋注入Ｓｉ１－ｘＧｅｘ的快速退火行为进行了研究，Ｓｉ１－ｘＧｅｘ样品中Ｇｅ组分分别为ｘ＝０．０９，０．２７和０．４３，Ａｓ注入剂量为２×１０＾１６ｃｍ＾－２，注放能量为１００ｋｅＶ，快速退火温度分别为９５０℃和１０５０℃，时间均为１８秒，实验结果表明，Ｓｉ２－ｘＧｅｘ样品，Ａｓ浓度分布呈组分密切相关，Ｇｅ组分越大，Ａｓ扩散越快，对于Ｇｅ组分较大的Ｓｉ１－ｘＧｅｘ样吕，Ａｓdispla     

固相外延CoSi_2薄膜作为扩散源形成n~＋p浅结技术研究

通过Ａｓ＋离子注入到由ＴｉＮ／Ｃｏ／Ｔｉ／Ｓｉ多层结构因相反应得到的外延ＣｏＳｉ２层中，利用外延硅化物作为扩散源（ＥＳＡＤＳ），形成了０．１μｍ的浅ｎ＋ｐ结．研究了Ｃｏｓｉ２外延薄膜离子注入非晶化后的再结晶特性、注入杂质退火时的再分布特性和形成的ｎ＋ｐ浅结特性．实验结果表明：外延ＣｏＳｉ２层在非晶化后能有效地再结晶；Ａｓ原子在多晶ＣｏＳｉ２／Ｓｉ结构和单晶ＣｏＳｉ２／Ｓｉ结构中有着不同的再分布特性；同相应的以多晶ＣｏＳｉ２作为扩散源形成的结相比，以外延ＣｏＳｉ２作为扩散源形成的结反向漏电小１～２个数量级，     

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。     

P埋层技术研究

介绍了在Ｓｉ￣＋注入的ｎ－ＧａＡｓ沟道层下面用Ｂｅ￣＋或Ｍｇ￣＋注入以形成ｐ埋层。采用此方法做出了阈值电压０～０．２Ｖ，跨导大于１００ｍＳ／ｍｍ的Ｅ型ＧａＡｓＭＥＳＦＥＴ，也做出了夹断电压－０．４～－０．６Ｖ、跨导大于１００ｍＳ／ｍｍ的低阈值Ｄ型ＧａＡｓＭＥＳＦＥＴ。     

Properties of MoSi2 and WSi2, magnetron cosputtered from elemental targets

A rotating table sputter system was used to coat substrates with refractory metal-silicon mixtures as the substrates alternately passed under refractory metal and silicon elemental targets. By varying target power, silicon rich, silicon defficient, or stoichiometric films of the disilicides could be deposited. Film resistivity was investigated as a function of anneal time and temperature, film thickness and grain size. Sheet resistance of of less than 1 ohm per square was found for WSi₂ films of 300nm thickness and for MoSi₂ films of 500nm thickness when annealed at 1000 °C for 30 min, This corresponds to 30 and 50 micro-ohm cm resistivity respectively. Film thickness was determined from surface profilometry of etched steps for films deposited over silicon nitride and by Rutherford Backscattering Spectrometry for films deposited over single-crystal or polysilicon films.     

微波肖特基势垒二极管硅化物工艺技术研究

对微波肖特基中、低势垒二极管硅化物的工艺技术进行了研究。用Ｎｉ－Ｓｉ硅化物作中势垒硅化物,用Ｔｉ－Ｓｉ硅化物作低势垒硅化物。通过设计和工艺实验,得到温度、时间、真空度等取佳工艺技术条件。在保持微波肖特基二极管势垒特征的同时,提高了反向电压,增强了它的稳定性和可靠性。     

Temperature dependent of the current–voltage (I–V) characteristics of TaSi2/n-Si structure

Tantalum silicide (TaSi₂) thin films were deposited on n-type silicon single crystal substrates using a dual electron-gun system and with Ta and Si targets. The electrical transport properties of the TaSi₂/n-Si structures were investigated by temperature-dependent current–voltage (I–V) measurements. The temperature-dependent I–V characteristics revealed that the forward conduction was determined by thermionic-emission and space-charge-limited current mechanisms at low and high voltage respectively. On the other hand, the reverse current is limited by the carrier generation process.     

钛溅射和硅化钛形成在硅中引进深能级的研究

利用DLTS技术详细研究经钛溅射和RTA950℃处理在n型和p型硅里引进的深能级.结果表明在n型硅里有二个,在p型硅里有三个深能级生成.这些能级的浓度在10~(13)—10~(14)cm~(-3)之间.它们的产生可归因于替位钛原子,钛与RTA相互作用的络合物.     

用于亚微米CMOS的自对准硅化钛工艺

本文研究了用溅射钛和快速退火法与硅反应形成硅化钛的工艺,二氧化硅侧墙轻掺杂漏结构的CMOS工艺加上该工艺后,器件的阈值电压、源漏击穿电压没有明显变化,但使CMOS的栅电阻降低一个数量级,源漏串联电阻为原来的1/4。肌此工艺已研制成功3μm NMOS 12位乘法器,比没有硅化物的器件速度提高一倍。     

Time resolved study on Co/Ni/a-Si phase transition during isothermal annealing at 400 °C

An approach based on in situ sheet resistance analyses during isothermal annealing processes is proposed to find out the critical stages of Co/Ni phase transition on amorphous silicon. Unlike the case of conventional Co/Si systems, it was found that Co/Ni/Si reaction produces a double-peak in the resistance versus time curve. This behaviour was studied by energy filtered transmission electron microscopy (EFTEM), energy dispersive X-ray spectroscopy (EDS) and selected area electron diffraction (SAED) analyses. It was found that cobalt atoms prefer to diffuse through the grain boundaries of the underlying Ni₂Si layer that forms at very low temperature in contact with silicon. The diffusion process stops when cobalt atoms reach the deeper NiSi layer which is located at the interface with the substrate. Finally, CoSi and NiSi phases form separately, and Co(Ni)Si₂ grains nucleate in contact with silicon differently from what is known for thick layer systems.     

Gate shadowing effect on Ni(Pt)Si abnormal diffusion for sub-45 nm technologies

In the frame of the 40 nm technology node development, Ni(Pt)Si abnormal diffusion, usually called NiSi encroachment is studied through voltage contrast electron beam inspection. A typical mapping is found for 300 mm-Si(1 0 0) wafers which is related to NiPt deposition asymmetry, in active zones, between two transistor gates. This observation is related to “gate shadowing effect”, which induces thinner NiPt thickness and then lower Pt amount at the edge of active zones. TEM analyses of the local NiPt thickness and electrical characterizations as junction leakage permit to determine the minimum of NiPt thickness and/or Pt amount needed to guaranty an adequate NiSi stability.     

Plasma etching of ternary silicide top layers

Plasma etching of epitaxial CoSi₂ films with a ternary Co–Ti–Si top layer formed during solid phase reaction of Co/Ti bilayers on Si(100) was investigated. By using a pure argon-RF-plasma the ternary top layer was sputtered without formation of a disturbing overlayer. The main disadvantage of this process is the formation of a crater-like surface morphology connected with a strong increase of the surface roughness. Etching the ternary top layer by a reactive process (CF₄/Ar) leads to a smoother surface, but a Co–fluoride film was grown on top of the silicide surface. In a following argon etch process this disturbing overlayer can be removed completely, simultaneously the roughness of the etched silicide surface is reduced considerably.     

难熔金属及硅化物薄膜特性研究

对难熔金属及其硅化物的形成、特性进行了研究。采用溅射难熔金属、热硅化反应的方法，解决了ＶＬＳＩ工艺中由于ＭＯＳ电路图形尺寸缩小带来的栅电阻增大的问题；采用硅化物阻挡层和Ａ１多层金属布线方法，解决了欧姆接触和铝的电迁移问题。     

Narrow-gap semiconducting silicides: the band structure

Electronic property simulation of the narrow-gap semiconducting rhenium and ruthenium silicides has been performed by the linear muffin-tin orbital method (LMTO) within the local density approximation. ReSi_1.75 was found to have an indirect gap value of 0.16 eV. The first direct transition with appreciable oscillator strength at 0.30 eV is predicted. Ru₂Si₃ is revealed to be a direct gap semiconductor with an energy gap of 0.41 eV, while the isostructural Ru₂Ge₃ has a competitive indirect–direct character of the band gap of about 0.31 eV.