简介:摘 要:本文介绍了Ti-6Al-4V基材表面CVD制备钽涂层制备原理及方法,通过采用扫描电镜(SEM)对涂层形貌、厚度进行分析、采用XRD物相分析以及拉开法分析结合强度检测,研究了不同厚度钽涂层的性能,结果表面采用此工艺最终获得结合力>100N,涂层厚度>10μm,结构致密的钽涂层。
简介:ThisworkismainlytostudytheeffectofheavyionirradiationonthedamageofsinglelayerMoS2.ThenumberoflayersofMoS2preparedbyCVD(chemicalvapordeposition)methodwasdeterminedbyopticalmicroscopyandRamanspectroscopy.ThemonolayerMoS2preparedbyCVDunderhighenergy209BiionirradiationwasanalyzedbyRamananalysisandAFMobservation.AndtheresultsarecomparedandanalyzedbeforeandafterthebeamirradiationofsinglelayerMoS2preparedbymechanicalstrippingmethod.
简介:Siliconfilmsweregrownonaluminium-coatedglassbyinductivelycoupledplasmaCVDatroomtemperatureusingamixtureofSiH4andH2asthesourcegas.ThemicrostructureofthefilmswasevaluatedusingRamanspectroscopy,scanningelectronmicroscopyandatomicforcemicroscopy.Itwasfoundthatthefilmsarecomposedofcolumnargrainsandtheirsurfacesshowarandomanduniformdistributionofsiliconnanocones.Suchamicrostructureishighlyadvantageoustotheapplicationofthefilmsinsolarcellsandelectronemissiondevices.Fieldelectronemissionmeasurementofthefilmsdemonstratedthatthethresholdfieldstrengthisaslowas~9.8V/μmandtheelectronemissioncharacteristicisreproducible.Inaddition,amechanismissuggestedforthecolumnargrowthofcrystallinesiliconfilmsonaluminium-coatedglassatroomtemperature.
简介:用C3H6作为碳源气,Ar作为稀释气体和载气,TaCl5为钽源,采用化学气相沉积法(chemicalvapordeposition,CVD)在高纯石墨表面制备TaC涂层。采用X射线衍射(XRD)和扫描电镜(SEM)等对涂层进行表征,研究1000℃下稀释气体(Ar)流量对TaC涂层成分、织构及表面形貌的影响。结果表明:随着稀释气体流量增大,表面均匀性和光滑度提高,晶粒尺寸减小,晶体择优取向降低,沉积速率减小,涂层中C含量增多。当稀释气体流量为100mL/min时,TaC涂层晶粒尺寸与沉积速率分别为32.5nm和0.60μm/h;而当稀释气体流量增大到600mL/min时,涂层晶粒尺寸与沉积速率分别下降到21nm和0.25μm/h。
简介:Anultrahighvacuumchemicalvapordeposition(UHV/CVD)systemisintroduced.SiGealloysandSiGe/Simultiplequantumwells(MQWs)havebeengrownbycold-wallUHV/CVDusingdisilane(Si2H6)andgermane(GeH4)asthereactantgasesonSi(100)substrates.ThegrowthrateandGecontentsinSiGealloysarestudiedatdifferenttemperatureanddifferentgasflow.ThegrowthrateofSiGealloyisdecreasedwiththeincreaseofGeH4flowathightemperature.X-raydiffractionmeasurementshowsthatSiGe/SiMQWshavegoodcrystallinity,sharpinterfaceanduniformity.Nodislocationisfoundintheobservationoftransmissionelectronmicroscopy(TEM)ofSiGe/SiMQWs.TheaveragedeviationofthethicknessandthefractionofGeinsingleSiGealloysampleare3.31%and2.01%,respectively.
简介:以三氯甲基硅烷(CH3SiCl3)为前驱体,采用化学气相沉积法(Chemicalvapordeposition,CVD),在原位生长有碳纳米管(Carbonnanotubes,CNTs)的C/C复合材料表面制备SiC涂层。用扫描电镜(SEM)和X射线能谱仪(EDS)观察和分析涂层微观形貌及成份。研究沉积温度(1000~1150℃)对SiC涂层的表面、截面以及SiC颗粒的微观形貌的影响。结果表明:在1000℃下反应时,得到晶须状SiC;沉积温度为1050℃时涂层平整、致密;沉积温度提高到1100℃时,涂层粗糙,致密度下降;1150℃下形成类似岛状组织,SiC颗粒团聚长大,涂层粗糙,并有很多裂纹和孔洞,致密度低。对涂层成份和断口形貌研究表明,基体和涂层之间有1个过渡区,SiC涂层和基体之间结合良好。
简介:CVD金刚石可以用各种方法合成,其中晶粒生长速度最快的则为热等离子体CVD工艺。我们试验室过去曾试图用DC等离子体CVD工艺合成金刚石厚膜,并就膜与基底的附着强度和膜的性质作过探讨。但是,热等离子体工艺存在沉积面积和膜质量都不如其它CVD工艺等问题。CVD金刚石薄膜应用中对扩大沉积面积有着强烈的需求。本研究试图通过控制沉积压力、输入功率等沉积参数扩大等离子体直径,以沉积出大面积金刚石薄膜。我们的目的是利用热等离子体CVD工艺沉积出生长速度高、面积大且膜厚均匀的金刚石薄膜。同时探讨了合成条件对金刚石薄膜形状的影响。本研究得出的结果如下:(1)随着沉积压力的降低,金刚石晶粒尺寸减小,成核密度增加。金刚石的结晶性则几乎不受沉积压力的影响。(2)随着等离子体电流的增加,金刚石晶粒尺寸减小,成核密度增加。增加等离子体电流也可改善金刚石的结晶性。(3)降低沉积压力和增加等离子体电流均可扩大等离子体射流,但是金刚石沉积面积的变化并不明显。(4)随着沉积压力的降低和等离子体电流的增加,金刚石的结晶性均会增加。降低沉积压力和增加等离子体电流有利于改善金刚石薄膜的均匀性。
简介:UsingdoublecrystalX-raysdiffraction(DCXRD)andatomicforcemicroscopy(AFM),theresultsofGexSi1-xgrownUHV/CVDfromSi2H6andSiH4areanalyzedandcompared.Adsorbatescanmigratetotheenergy-favoringpositionduetotheslowgrowthratefromSiH4.Inthiscase,aSibufferthatisolatestheeffectofsubstrateonepilayercouldnotbegrown,whichresultsinapitpenetratingintoepilayerandbuffer.TheFWHMis0.055°inDCXRDfromSiH4.Thepresenceofdiffractionfringesisanindicationofanexcellentcrystallinequality,TheroughnessofthesurfaceisimprovedifgrownbySi2H6:however,thecrystalqualityoftheGex2Si1-xmaterialbecameworsethanthatfromSiH4duetomuchlargergrowthratefromSi2H6.ThecontentofGeisobtainedfromDCXRD,whichindicatesthegrowthratefromSi2H6islargest,thenGeH4andthatfromSiH4isleast.
简介:搞社会主义市场经济,企业家们在经营管理中都面临一系列的新情况、新问题。如何提高自身的素质和能力,不断地把经营管理工作提高到一个新水平,这是企业领导人不能不考虑的一个重要问题。哲学是管理行为的一个组成部分,一个核心部分,不少的企业家看到了提高自身哲学素养的重要性。他们自觉地学习、应用唯物辩证法,增强了观察、分析、处理问题的能力,在经营管理中取得了很好的成绩。天津市圣罗衬衫总厂厂长吴树旺就是生动的例证。同时,广大的理论工作者也始终关注着经济建设的这个中心。当前企业的经营管理问题是哲学界非常关心的问题之一,愿企业界朋友和哲学专家们携起手来,让哲学在群众中、在实践中,焕发出更强的生命力。
简介:Wehavesuccessfullydemonstratedthathighqualityandhighdielectricconstantlayerscanbefabricatedbylowtemperaturephoto-inducedor-assistedprocessing.Ta2O5andZrO2havebeendepositedatt<400℃bymeansofaUVphoto-CVDtechniqueandHfO2byphoto-assistedsol-gelprocessingwiththeaidofexcimerlamps.TheUVannealingofas-grownlayerswasfoundtosignificantlyimprovetheirelectricalproperties.Lowleakagecurrentdensitiesontheorderof10-8A/cm2at1MV/cmfordepositedultrathinTa2O5filmsandca.10-6A/cm2forthephoto-CVDZrO2layersandphoto-irradiatedsol-gelHfO2layershavebeenreadilyachieved.TheimprovementintheleakagepropertiesoftheselayersisattributedtotheUV-generatedactiveoxygenspeciesO(1D)whichstronglyoxidizeanysuboxidestoformmorestoichiometricoxidesonremovingcertaindefects,oxygenvacanciesandimpuritiespresentintheas-preparedlayers.Thephoto-CVDTa2O5filmsdepositedacross10.16-cmSiwafersexhibitahighthicknessuniformitywithavariationoflessthan±2.0%beingobtainedforultrathinca.10nmthickfilms.Thelamptechnologycaninprinciplebeextendedtolargerareawafers,providingapromisinglowtemperatureroutetothefabricationofarangeofhighqualitythinfilmsforfutureULSItechnology.