摘要:

The formation of a ternary phase (TiTa)Si2has been observed in a bulk system of Ti‐Ta‐Si which has been prepared by arc melting and annealing at high temperature for extended time. Before annealing, two separate phases were found by x‐ray diffraction to coexist, TaSi2and TiSi2. This alloy served for comparison of the tendency to form the ternary compound in a binary Ti‐Ta layer configuration also. This geometry was achieved by depositing individual Ta and Ti layers consecutively on Si single crystals. A trend to form the ternary silicide was observed at sufficiently high temperatures. This phase is isomorphous with TaSi2. The slow process of its formation, i.e., the high temperature needed for the formation of the ternary phase is explained on the basis of the different diffusion rates of Si through TaSi2and the interdiffusion in the Ta‐Ti system. It seems very probable that the effect of oxygen in slowing down the progress of the ternary formation, at least in our experiments, might be crucial.

ISSN:0021-8979    

DOI:10.1063/1.345427

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Diamondlike carbon films were prepared by electron cyclotron resonance chemical vapor deposition. Structures of the carbon films were characterized by Raman spectroscopy and Fourier‐transform infrared spectroscopy. The relationship between the properties of films and growth conditions has been examined. High‐energy ion species extracted from a discharge of methane in the electron cyclotron resonance cavity, which is positively‐biased electrically against the earthed substrate, have an important role in the growth behavior of hard diamondlike carbon films.

ISSN:0021-8979    

DOI:10.1063/1.345428

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Self‐propagating explosive reactions can occur in multilayer thin films. Explosive silicidation in nickel/amorphous‐silicon multilayer thin films has been investigated using a combination of high‐speed photography, high‐speed temperature measurements, plan‐view transmission electron microscopy, and thin film x‐ray diffraction. The multilayer films had an atomic concentration ratio of 2 Ni atoms to 1 Si atom. The silicide phase formed by explosive silicidation was Ni2Si. This was the same phase formed by conventional thermal annealing of the multilayer thin film. The temperature of the explosive reaction front was measured to be approximately 1565 K. The reaction‐front velocity was found to vary from 22 to 27 m/s and to be at most weakly dependent on the modulation period and the total film thickness. The resulting Ni2Si grain structure formed by explosive silicidation is less defective than Ni2Si formed by conventional thermal annealing. This was attributed to the higher reaction temperatures and the shorter reaction times of explosively formed Ni2Si as compared to Ni2Si formed via conventional annealing.

ISSN:0021-8979    

DOI:10.1063/1.345429

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Solid phase reactions and change in stress of TiN/Ti/Si which is expected to have a low contact resistance to bothn+andp+silicon and good adhesion to the Si substrate has been investigated. The TiN layer is a uniform polycrystal on the Si substrate; however, its texture is caused by the textured Ti layer. By annealing at 600 °C, Si and N atoms diffuse into the Ti layer which causes a distortion of the Ti lattice and an increase in the sheet resistance. By annealing at a higher temperature, as Ti starts to react with Si, the sheet resistance decreases. The silicidation sequences are the same as the previous results and the kinetics slightly differ. The change in film stress is well explained by these solid phase reactions. A TiN layer has excellent thermal stability in an Al/TiN/Ti/Si system, because TiN does not react with Al, Ti, and Si up to 600 °C.

ISSN:0021-8979    

DOI:10.1063/1.345430

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

It is proposed that the structure of a new layerAB, which forms between the componentsAandB, is defined by parameters of two‐stage interfacial reactions. The two stages, namely transition ofAatoms through theAB/Bboundary and rearrangement of atoms inBintoAB, have independent rates. In the initial stage of the interaction between the two components the flow through the thin new layer does not control the reaction rate. The high rate of atomic flow through the interface combined with the relatively low rate of diffusion at the interface will result in the formation of metastable (amorphous, quasicrystalline, or crystalline) phases. The additional growth of the layer results in a decrease in the growth rate down to a critical value. The thickness of the metastable layer is thus limited and a stable crystalline phase starts to form at the interface. The critical thickness of the metastable phase depends on the diffusion parameters of the initial and intermediate phases.

ISSN:0021-8979    

DOI:10.1063/1.345431

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The &bgr;‐SiC (or 3C‐SiC) synthesis through high‐dose carbon implantation into a silicon substrate heated at high temperature is studied by means of cross‐sectional transmission electron microscopy, x‐ray diffraction, infrared absorption spectroscopy, Auger electron spectroscopy, Rutherford backscattering spectrometry, channeling, and nuclear reaction analysis. It is shown that a thick buried layer of &bgr;‐SiC (about 300 nm) is directly formed after multiple implantations at 860 °C without post‐implantation annealing. This layer is not continuous but consists of small monocrystalline grains (average size ∼7 nm) in a near‐perfect epitaxial relationship with the silicon matrix. These grains are only slightly misorientated (∼3.5°) but are severely twinned on {111} planes.

ISSN:0021-8979    

DOI:10.1063/1.346092

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Periodic structures have been obtained during nominally unpolarized excimer laser (ArF)‐assisted organometallic vapor phase epitaxy of GaP on GaAs. Both crystalline properties and chemical composition of these structures have been examined. The chemical analysis showed a variation in composition across a ripple which was attributed to the modulated thermal profile due to interference.

ISSN:0021-8979    

DOI:10.1063/1.345409

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The effect of zinc diffusion on InGaAsP/InP single and multiple quantum well structures was studied by secondary ion mass spectrometry (sims), Auger electron spectroscopy (AES), capacitance‐voltage measurements, photoluminescence, and x‐ray diffraction. Significant interdiffusion of In and Ga is found. The structures are stale against annealing without the presence of zinc. Interdiffusion of As and P is negligible. In a multiple quantum well Zn diffusion at 500 °C causes In and Ga intermixing: The AES profiles have become flat. At higher diffusion temperatures an ordering is found such that now the Ga concentration is at a maximum in the original InP layers. This can be explained by minimization of the free energy, which is balanced by an increasse in mismatch strain energy. Photoluminescence shows the interdiffusion starts at temperatures above 420 °C. By the Zn diffusion the lattice parameter values of the InGaAsP and InP layers are changed and the average value is decreased, as was shown by x‐ray diffraction on a multiple quantum well structure. This is substantiated by results of x‐ray rocking curves.

ISSN:0021-8979    

DOI:10.1063/1.345410

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Direct x‐ray diffraction determination of elastic strain and stress in aluminum and aluminum‐silicon films and patterned lines has been used to investigate the effect of various passivations. Passivation over uniform metal films has very little effect. Passivation over patterned metal results in substantial triaxial tensile stress. Contrary to the conventional wisdom, high compressive stress in the passivation does not result in additional tensile stress in the metal. The deleterious effects of highly compressive silicon nitride on metal is probably due to the effect of excess hydrogen in the silicon nitride.

ISSN:0021-8979    

DOI:10.1063/1.345411

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The reactions between thin refractory metal Ti or Nb films and SiO2substrates in the temperature range 650–1000 °C in a vacuum have been studied by Rutherford backscattering spectrometry and glancing angle x‐ray diffraction. The reactions started with the growth of measureable phases at 700 and 900 °C and completed with the configurations of SiO2/Ti5Si3/ TiO and SiO2/Nb5Si3/NbO. Marker experiments indicated that the Ti atoms were the dominant diffusing species in the formation of Ti5Si3in the SiO2/Ti reaction. The formation rate of the Ti5Si3layer was thickness dependent: The thicker the original thin Ti film, the higher the rate.

ISSN:0021-8979    

DOI:10.1063/1.345412

出版商:AIP    

年代:1990

数据来源: AIP