退火温度对磁控溅射制备的β-FeSi2薄膜的影响

采用磁控溅射的方法，在高真空条件下，沉积金属Fe到Si（100）衬底上，然后通过真空退火炉在不同温度条件下对样品进行热处理，直接形成了β-FeSi2薄膜．采用X射线衍射仪（XRD）对样品进行了晶体结构分析，利用卢瑟福背散射（RBS）对Fe-Si化合物的形成过程中的Fe原子和Si原子的互扩散机理进行了研究，利用扫描电镜（SEM）对样品表面的显微结构进行表征，结果表明，在900℃条件下退火能够得到质量很好的β-FeSi2薄膜，超过这一温度β相将开始向α相转化，到1000℃，β-FeSi2全部转化为α-FeSi2。     

铝诱导晶化P型非晶硅薄膜实验研究

利用PECVD设备在普通玻璃基片上沉积硼掺杂P型非晶硅薄膜,采用铝诱导晶化法（AIC）在氮气气氛保护下进行退火处理制备出P型多晶硅薄膜,研究了不同厚度的金属铝膜和热处理温度对非晶硅薄膜的微观结构、表面形貌的影响。实验结果表明：铝膜相对厚度越厚,对a—Si的晶化诱导效果则越好,在一定温度条件下,相对较厚的铝膜可以缩短a—Si晶化为polv-Si的时间,并且能使a—Si的晶化更加完整,产生尺寸较大的硅晶颗粒。在铝膜厚度相同,退火温度相同的条件下,热处理的时间越长,则晶化发生的程度越深,晶化越为彻底。     

Fe／Si薄膜中硅化物的形成和氧化

用磁控溅射方法制备Fe/Si薄膜,采用卢瑟福背散射(RBS)技术研究了退火过程中的相变过程和氧化.结果表明:未退火的Fe/Si薄膜界面清晰,873K退火后,界面附近Fe、si原子开始相互扩散,973K退火后富金属相Fe1 xSi形成,而1073K退火后形成中间相FeSi,当温度增加至1273K后所有硅化物完全转变为富硅相FeSi2,即随退火温度的升高,Fe、Si原子间扩散增强,从而形成不同化学计量比的Fe-Si化合物,且薄膜中易迁移原子种类由Fe变为Si.同时,质子束RBS和XRD测量结果显示,在未退火及低温退火的样品中,薄膜有氧化现象,随退火温度增加,由于高温下金属氧化物被还原并逐渐挥发,样品中氧的含量逐渐减少最后完全消失.     

纳米Ta-Al-N薄膜的制备及其扩散阻挡特性的研究

采用直流反应磁控溅射方法在P型（100）Si衬底上制备了Ta-Al—N纳米薄膜与Cu／Ta-Al—N复合膜，并对薄膜样品进行了卤钨灯快速热退火（RTP）。用四探针电阻测试仪（VPP）、AFM、SEM—EDS、Alpha—stepIQ台阶仪和XPd）等分析测试方法对样品的形貌结构与特性进行了分析表征。实验结果表明，本实验条件下制得的Ta-Al—N纳米薄膜表面光滑；随着Al靶溅射功率的增加，Ta-Al—N薄膜中Al含量和方块电阻相应增大，均方根粗糙度降低，而沉积速率变化不大，且Ta-Al—N膜层对Cu扩散的阻挡能力增强。但在过高的温度下退火，导致Cu通过Ta-Al—N的晶界扩散到Ta-Al—N／Si界面并形成Cu3Si，从而引起阻挡层的失效。     

Mg2Si／Si异质结的制备

采用射频磁控溅射和低真空退火方法制备Mg2Si／Si异质结,首先在n型Si（111）衬底上沉积Mg膜,经低真空退火形成Mg2Si／Si异质结,Mg膜厚度约为484nm,退火后形成的Mg2Si薄膜厚度约400nto,利用xRD和sEM分别研究了Mg2Si薄膜的晶体结构和表面形貌,霍尔效应结果表明,制备的Mg2Si薄膜呈现n型导电特性。     

Fe3O4缓冲层对CoFe2O4薄膜磁性能的影响

采用射频磁控溅射在基片Si（100）和Fe3O4（20nm）/Si（100）上制备了钴铁氧体（CoFe2O4）薄膜，制备的薄膜在空气气氛中进行300～1000℃的退火处理，采用XRD、VSM分析了薄膜的微结构以及磁性能。结果表明，制备的钴铁氧体薄膜均具有尖晶石结构，Fe3O4缓冲层薄膜促进了钴铁氧体薄膜的结晶，但降低了钴铁氧体薄膜的垂直各向异性和垂直于膜面方向的矫顽力，而钴铁氧体薄膜的磁化强度和矩形度得到了一定的提高。     

β-FeSi2/Si异质结的制备及性质研究

采用直流磁控溅射和真空退火方法制备β-FeSi2/Si异质结,首先在n型Si(100)衬底上沉积Fe膜,经真空退火形成β-FeSi2/Si异质结,Fe膜厚度约238nm,退火后形成的β-FeSi2薄膜厚度约为720nm。利用XRD、SEM和红外光谱仪分别研究了β-FeSi2薄膜的晶体结构、表面形貌和光学性质。霍尔效应结果表明,制备的β-FeSi2薄膜为n型导电,载流子浓度为9.51×1015cm-3,电子迁移率为380cm2/(V.s)。     

真空热处理制备β-FeSi2光电薄膜的研究

磁控溅射法沉积的Fe／Si多层膜和Fe单层膜经真空热处理后制备了β-FeSi2薄膜。[Fe1nm／Si3.2nm]60多层膜在〈880℃温度下真空热处理2h后，样品均呈现β（220）／（202）择优取向，而Fe单层膜制备的样品则易形成β-FeSi2与ε-FeSi相的混合物，且取向杂乱。在920℃真空热处理后，两种样品都形成了α-FeSi2薄膜。原子力显微镜分析表明，样品表面粗糙度随热处理温度升高而变大，最大表面均方根粗糙度约为16nm。卢瑟福背散射分析发现，Fe／Si多层膜样品热处理过程中元素再分布很小。根据光吸收谱测量，Fe／Si多层膜制备的β-Fesi2薄膜的禁带宽度为0．88eV。     

磁控溅射技术制备硅纳米晶多层膜及微观结构表征

在室温下,分别利用常规磁控溅射和反应磁控溅射技术交替沉积Si薄膜和Si1-xNx薄膜在单晶硅基体上制备了Si/Si1-xNx纳米多层膜。接下来,在高温下对Si/Si1-xNx多层膜进行退火诱发各层中形成硅纳米晶。研究了Si1-xNx层厚度和N2流量沉积对Si/Si1-xNx多层膜中Si量子点形成的影响。TEM检测结果表明,N2流量为2.5mL/min时沉积的多层膜退火后形成了尺寸为20～30nm的等轴Si3N4纳米晶;N2流量为5.0mL/min时沉积的多层膜退火后在Si层和Si1-xNx多层中均形成了硅纳米晶,而在7.5mL/min N2流量下沉积的Si/Si1-xNx多层膜退火后仅在Si层中形成了硅纳米晶。     

真空退火引起的VOx薄膜生长过程的变价问题研究

本文以Ｖ２Ｏ５粉末为原料，采用真空蒸发镀膜与真空退火相结合的方法，在载玻片和单晶Ｓｉ（１００）衬底上得到了ＶＯ２为主的薄膜。利用Ｘ射线光电子能谱（ＸＰＳ）对不同退火条件下所得膜的价态组份进行了分析，得到了膜中Ｖ的价态与退火温度、退火时间以及膜厚的关系。     

Formation of iron silicide on Si(001) studied by high resolution Rutherford backscattering spectroscopy

The initial stage of the formation of iron silicides has been investigated by high resolution Rutherford backscattering spectroscopy (HRBS). Just after Fe is deposited on Si(001) at room temperature, the deposited Fe atoms dig themselves into subsurface ejecting Si atoms into outer surface. Upon annealing at 300-400 °C, significant number of Si atoms are displaced from their lattice position near the interface between the crystalline Si and the Fe-Si mixing layer. Such displaced Si diffuses into the Fe-Si mixing layer and forms the layer with the composition of Fe:Si≈1:2. This layer is considered to be a precursive state of FeSi₂.     

Sol-Gel工艺Si基Bi4 Ti3 O12铁电薄膜制备与晶相结构研究

采用Sol-Gel工艺制备了Si基Bi4TiO12铁电薄膜.研究了退火温度、退火时间、薄膜厚度等对薄膜晶相结构的影响.研究表明,退火温度对Si基Bi4Ti3O12铁电薄膜晶相结构的影响最为显著,而且随退火温度升高,Bi4Ti3O12薄膜更趋向于沿c-轴取向的生长;退火时间在30分钟内对薄膜晶相结构的影响比较明显;薄膜厚度及30分钟以上的退火处理对薄膜晶相结构的影响不大.     

Synthesis, characterization and thermal history dependence of the polymorphic structure of nylon6/montmorillonite nanocomposites

Nylon6/clay nanocomposites with 5-wt% montmorillonite (NCN5) were prepared by a twin-screw extruder. The effects of thermal histories including annealing temperature (195 °C, solid-state annealing; 245 °C, melt-state annealing), annealing time and cooling rate on the polymorphic behavior and thermal property of NCN5 have been studied using Modulated Differential Scanning Calorimetry (MDSC) and wide angle X-ray diffraction. It was found that longer annealing time and faster cooling rate favored the formation of the γ crystal when NCN5 samples were annealed at 195 °C. As the annealing temperature was elevated to 245 °C, the α crystal became the absolutely dominating crystalline phase independent on the annealing durations and cooling rate. Moreover, a small endothermic peak was observed around 195 °C in NCN5 samples and this new transition peak was also found to be dependent on the thermal history.     

The effect of underlayer-modified atomic monolayer on the mechanism of subsequent film growth

We have studied the influence of the upper Si monolayer (ML) in Fe-Si interlayers on the mechanism of subsequent growth of 7-ML-thick Cu films during molecular beam deposition. The Fe-Si interlayers and Cu films were studied in ultrahigh vacuum by the methods of electron energy loss spectroscopy (EELS) and Auger electron spectroscopy (AES). The final morphology of samples was examined in air by the atomic force microscopy. It is established that the growth of a Cu film on a Si(1 ML)/Fe₂Si₃(5 ML)/Si(001) structure has a pseudolayer character (with dissolution of the uppermost Si monolayer), while the growth of Cu on a Si(1 ML)/Fe(1 ML)/Si (1 ML)/Fe(1 ML)/Si(001) structure proceeds in the form of islands. This behavior is explained by different chemical states of the uppermost Si monolayer, which is modified by Fe-Si underlayers with different structures.     

The structural and magnetic properties of Fe-Si and Fe-C solid solutions as a function of milling times

We have studied the formation of metal-metalloid alloys for Fe-Si and Fe-C as a function of milling times. These alloys were produced using mechanical alloying. The effect of milling time on local structural changes of Fe-Si and Fe-C has been investigated by means of Mössbauer spectrometry, EXAFS study and XRD. Saturation magnetization was also measured by VSM. XRD pattern from mechanically alloyed Fe-Si and Fe-C powders indicates the formation of solid solution. The different variation of lattice parameters could be analysed from the different substitution of Si and C atoms into the Fe structure. The Mössbauer spectrum showed typical sextets in the 1 h milled sample corresponding to alpha-Fe spectrum. Increasing the milling time, the sextets became broader due to appearance of disordered Fe atoms in both solid solutions. The hyperfine field distributions were decreased as increasing milling time, which is similar trend with magnetization distribution.     

Al2O3对氩弧熔覆Fe-Si金属间化合物涂层组织及性能的影响

目前Fe-Si涂层的相关研究较少。为制备Fe-Si金属间化合物复合涂层并改善其力学性能,采用氮弧.熔覆原位合成的方法在Q235钢表面制备Fe-Si涂层和Fe-Si/Al2O3金属间化合物复合涂层,利用金相电子显微镜、X射线衍射仪(XRD)、冲蚀磨损试验机、高温氧化炉等设备对涂层的显微组织、耐冲蚀磨损性能和抗高温氧化性能进行测试与分析。结果表明:Fe-Si熔覆层由Fe3Si和FeSi相构成,添加A12O3后熔覆层除存在Fe3Si,FeSi外还有AI2O3相产生;Fe-Si/Al2O3熔覆层耐冲蚀磨损性优于Fe-Si熔覆层,最高为基体的4.65倍;熔覆层的耐高温氧化性能相对基体明显提高,在800℃下Fe-Si熔覆层和Fe-Si/Al2O3熔覆层相比于基体分别提高了5.50和5.83倍。     

Real-time investigations on the formation reactions during annealing of sulfurized Cu-Sn precursors

The quaternary compound kesterite Cu₂ZnSnS₄ (CZTS) is a promising candidate for the production of low-cost thin film solar cells.Depending on the precursor composition and deposition technique several intermetallic precursor phases may appear, affecting the formation reactions during the crystallization process of the thin film absorber. A better understanding of these formation reactions in the system Cu-Zn-Sn-S is required for the optimization of CZTS absorbers and future development of solar modules.The crystallization of CZTS is completed by the reaction of Cu₂SnS₃ and ZnS. The formation of Cu₂SnS₃ itself depends on the different available precursor compounds after sulfur evaporation. Incomplete conversion of binary sulfides during annealing may lead to the formation of undesirable compounds, i.e. the transformation of Cu₂SnS₃ into Cu₄SnS₄ via reaction with Cu_2-xS, which affect or even inhibit the crystallization of CZTS.Therefore a precise knowledge about formation reactions of binary and ternary Cu-Sn sulfides during annealing at low temperatures is important to crystallize a monophase CZTS absorber. Real-time investigations on the formation reactions in the quaternary and also the ternary subsystems of Cu-Zn-Sn-S while annealing stacked elemental layers elucidate the reaction paths of binary and ternary sulfides.We report on results of time-resolved and angle-dispersive XRD experiments during annealing comparing the formation reactions in sulfurized Cu-Sn precursors prepared by different deposition techniques.     

Effects of annealing on the damage morphologies in BF 2 + ion implanted (1 0 0) silicon

The effects of annealing on the damage morphologies and impurity redistributions in BF ₂ ⁺ ion implanted (1 0 0) silicon were studied using secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM) and Rutherford backscattering (RBS) ion beam channelling technique. An amorphized silicon layer and a heavily-damaged crystal layer containing a high density of point-defect clusters, are formed on the silicon wafer by the ion implantation. SIMS depth profiles of both boron and fluorine are almost Gaussian distribution. Both furnace annealing and rapid thermal annealing cause recrystallization of the amorphized layer and formation of dislocation loop bands out of the point defects. SIMS depth profiles for both impurities show anomalous double peaks at the same depths. These facts suggest that the primary peak is due to the peak of the Gaussian distribution and the secondary peak due to the gettering effects of residual dislocation loop band.     

STO铁电薄膜晶化动力学研究

从经典的成核长大理论出发,建立了STO铁电薄膜的晶化动力学模型,根据模型模拟了热处理温度以及升温速率对STO铁电薄膜微结构的影响.模拟计算结果表明,在热处理温度较低的情况下,薄膜的晶粒较大,晶粒尺寸分布也较宽.随着晶化温度的升高,晶粒生长受到抑制,晶粒较小.当升温速率较小时,晶粒生长充分、晶粒较大,但晶粒大小分布不均匀.当升温速率较大时,薄膜晶粒大小分布均匀,晶粒较小.模拟计算结果与实际情况一致.     

Effect of rapid thermal annealing on the crystal quality and the piezoelectric response of polycrystalline AlN films

This work analyzes the effect of post-deposition rapid thermal annealing (RTA) on the crystal quality and the piezoelectric response of sputtered polycrystalline aluminium nitride (AlN) thin films. AlN films with mixed crystal texture were not significantly affected by RTA processing. However, in films exhibiting clear c-axis preferred orientation, the annealing produced a crystallization process, characterized by an increase in the grain size of the original crystallites, the growth of new small grains, and the reduction of defects. The improvement in the crystal quality was more evident in highly textured c-axis oriented films. However, the enhanced crystal quality of the films due to RTA was not accompanied by a significant improvement in the piezoelectric response. This is attributed to the presence of grains with opposite polarities that could not be rearranged through the RTA treatment.