Microstructural Evolution of Cu/Ta/GaAs Multilayers with Thermal Annealing

2003 ◽  
Vol 783 ◽  
Author(s):  
Wei-Cheng Wu ◽  
Chang-You Chen ◽  
Chen-Shih Lee ◽  
Edward Yi Chang ◽  
Li Chang

ABSTRACTCopper metallization for GaAs was evaluated by using Cu/Ta/GaAs multilayers for its thermal stability. A thin Ta layer of 30 nm thickness was sputtered on the GaAs substrate as the diffusion barrier before copper film metallization. As judged from the results of sheet resistance, X-ray diffraction, Auger electron spectroscopy and transmission electron microscopy, the Cu/Ta films on GaAs were very stable up to 500 °C without Cu migration into GaAs. After 550 °C annealing, the interfacial mixing of Ta with GaAs substrate occurred, resulting in the formation of TaGa2 and TaAs2, and the diffusion of Ga and As through the Ta layer formed the Cu3Ga and Cu3As phases at the Cu/Ta interface. After 600 °C annealing, the reaction of GaAs with Ta and Cu formed TaAs and Cu3Ga, as a result of Cu migration and interfacial instability.

1987 ◽  
Vol 102 ◽  
Author(s):  
M. Genut ◽  
M. Eizenberg

ABSTRACTModifications in the course of reaction between Co thin films and single crystal GaAs substrate due to the addition of a Ge film either on top or below the metal layer have been studied. The microstructure and phase formation for the systems: Co/GaAs, Co/Ge/GaAs, and Ge/Co/GaAs have been studied by Auger electron spectroscopy, transmission electron microscopy and X-ray diffraction.


1994 ◽  
Vol 363 ◽  
Author(s):  
Y. W. Bae ◽  
W. Y. Lee ◽  
T. M. Besmann ◽  
P. J. Blau ◽  
K. L. More ◽  
...  

AbstractComposite coatings consisting of discrete phases of TiN and MoS2 were codeposited on graphite substrates from Ti((CH3)2N)4/NH3/MoF6/H2S gas mixtures in a cold-wall reactor at 1073 K and 1.3 kPa. Chemical composition and microstructure of the coatings were characterized by Auger electron spectroscopy, X-ray diffraction, and transmission electron microscopy. Kinetic friction coefficients of the coatings were determined by a computer-controlled friction microprobe and values less than 0.2 were obtained with a type-440C stainless-steel counterface under ambient condition.


1989 ◽  
Vol 146 ◽  
Author(s):  
E.J. Yun ◽  
H.G. Chun ◽  
K. Jung ◽  
D.L. Kwong ◽  
S. Lee

ABSTRACTIn this paper, the interactions of sputter-deposited Ti on SiO2 substrates during rapid thermal annealing in nitrogen at 550°C - 900°C for 10 - 60 s have been systematically studied using X-ray diffraction, Auger electron spectroscopy, transmission electron diffraction, TEM & cross-sectional TEM, and sheet resistance measurements.


1995 ◽  
Vol 10 (7) ◽  
pp. 1790-1794 ◽  
Author(s):  
Kyu Ho Park ◽  
Cha Yeon Kim ◽  
Young Woo Jeong ◽  
Hyun Ja Kwon ◽  
Kwang Young Kim ◽  
...  

The microstructural variation and the interdiffusion of Pt (80 nm)/Ti (70 nm)/SiO2/Si during annealing in O2 were investigated using Auger electron spectroscopy, x-ray diffraction, transmission electron microscopy, and scanning electron microscopy. While the as-deposited and 400 °C annealed samples showed well-defined layer structures without any significant interfacial reaction, the degree of oxidation remarkably increased with increasing temperature above 500 °C. The PtTi alloy phase with Pmma structure (AuCd type) was observed from the 500 °C annealed sample. Drastic interdiffusion occurring above 600 °C changed the Pt/Ti bilayer into a very entangled structure. Some TiO2 phases were exposed to the ambient between Pt hillocks. In addition, a small amount of Pt-silicide was found near the TiOx/SiO2 interface.


2010 ◽  
Vol 638-642 ◽  
pp. 3597-3602 ◽  
Author(s):  
Ludovica Rovatti ◽  
Roberto Montanari ◽  
Nadia Ucciardello ◽  
Alessio Mezzi ◽  
Saulius Kaciulis ◽  
...  

The discontinuous precipitation of a high-nitrogen (0.8 wt%) austenitic steel has been investigated after successive steps of heat treatment at two different temperatures (800 and 850 °C). After each step of heating the material has been examined by X-ray diffraction (XRD), optical microscopy (OM), transmission electron microscopy (TEM), Auger electron spectroscopy (AES) and microhardness tests. The precipitation of Cr2N induces the formation of a secondary austenitic phase, leads to the redistribution of N between transformed and untransformed zones and to local variations of mechanical properties.


1997 ◽  
Vol 482 ◽  
Author(s):  
Yu. V. Melnik ◽  
A. E. Nikolaev ◽  
S. I. Stepanov ◽  
A. S. Zubrilov ◽  
I. P. Nikitina ◽  
...  

AbstractGaN, AIN and AIGaN layers were grown by hydride vapor phase epitaxy. 6H-SiC wafers were used as substrates. Properties of AIN/GaN and AIGaN/GaN structures were investigated. AIGaN growth rate was about 1 μm/min. The thickness of the AIGaN layers ranged from 0.5 to 5 μm. The AIN concentration in AIGaN layers was varied from 9 to 67 mol. %. Samples were characterised by electron beam micro analysis, Auger electron spectroscopy, X-ray diffraction and cathodoluminescence.Electrical measurements performed on AIGaN/GaN/SiC samples indicated that undoped AIGaN layers are conducting at least up to 50 mol. % of AIN.


1990 ◽  
Vol 5 (6) ◽  
pp. 1169-1175 ◽  
Author(s):  
A. D. Berry ◽  
R. T. Holm ◽  
M. Fatemi ◽  
D. K. Gaskill

Films containing the metals copper, yttrium, calcium, strontium, barium, and bismuth were grown by organometallic chemical vapor deposition (OMCVD). Depositions were carried out at atmospheric pressure in an oxygen-rich environment using metal beta-diketonates and triphenylbismuth. The films were characterized by Auger electron spectroscopy, Nomarski and scanning electron microscopy, and x-ray diffraction. The results show that films containing yttrium consisted of Y2O3 with a small amount of carbidic carbon, those with copper and bismuth were mixtures of oxides with no detectable carbon, and those with calcium, strontium, and barium contained carbonates. Use of a partially fluorinated barium beta-diketonate gave films of BaF2 with small amounts of BaCO3.


1989 ◽  
Vol 4 (6) ◽  
pp. 1320-1325 ◽  
Author(s):  
Q. X. Jia ◽  
W. A. Anderson

Effects of hydrofluoric acid (HF) treatment on the properties of Y–Ba–Cu–O oxides were investigated. No obvious etching of bulk Y–Ba–Cu–O and no degradation of zero resistance temperature were observed even though the oxides were placed into 49% HF solution for up to 20 h. Surface passivation of Y–Ba–Cu–O due to HF immersion was verified by subsequent immersion of Y–Ba–Cu–O in water. A thin layer of amorphous fluoride formed on the surface of the Y–Ba–Cu–O during HF treatment, which limited further reaction between Y–Ba–Cu–O and HF, and later reaction with water. Thin film Y–Ba–Cu–O was passivated by HF vapors and showed no degradation in Tc-zero after 30 min immersion in water. The properties of the surface layer of Y–Ba–Cu–O oxide after HF treatment are reported from Auger electron spectroscopy, x-ray diffraction, and scanning electron microscopy studies.


1990 ◽  
Vol 185 ◽  
Author(s):  
Alain E. Kaloyeros ◽  
Robert M. Ehrenreich

AbstractPhosphorus is found to be a common impurity in many of the iron tools and weapons produced during the pre-Roman and Roman Iron Ages of Britain (600 BC - 300 AD). The effects of this impurity on the properties and performance of antiquarian materials is not well understood, however. This paper presents the initial findings of an in-depth study of the distribution, chemistry, and effects of phosphorus in Romano-British ironwork. For this purpose, two Romano-British iron artifacts from the site of Ircheoter, Northamptonshire, were examined using powerful techniques for archeological materials analysis that include electron microprobe, secondary ion mass spectroscopy (SIMS), transmission electron microscopy (TEM) with energydispersive x-ray spectroscopy capabilities (EDXS), and Auger electron spectroscopy (AES). It was found that phosphorous was indeed present in the artifacts. The phosphorus atoms were predominantly segregated at grain boundaries and thus should have led to a lowering of grain boundary cohesion and a degradation in the performance of the tools.


1997 ◽  
Vol 3 (4) ◽  
pp. 381-396
Author(s):  
S. Chandra ◽  
D. Van Gemert

Abstract Interior plaster from the Abbot's Palace of the Abbey of Villers-la-Ville, Brabant Wallon province, Belgium has been investigated. It is done by using chemical analysis, x-ray diffraction analysis, scanning electron microscopy, energy dispersive electron spectroscopy, and transmission electron microscopy. It is found that the rendering was made with lime rich mortar and animal hairs. The sand used was very fine and the hairs were very short. The solid constituents and the hairs were uniformly dispersed, which could have been obtained by the addition of some other natural polymer, containing protein.


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