Solution-Derived Yba2Cu,Sub3O7−Δ. Thin Films And Barrier Layers

1990 ◽  
Vol 180 ◽  
Author(s):  
G. E. Whitwell ◽  
J. H. Wandass ◽  
F. M. Cambria ◽  
M. F. Antezzo

ABSTRACTHydrolyzed metal alkoxide solutions were spin-coated on Si substrates with subsequent thermal processing. Barrier layers of alkaline earth oxides, perovskites, Y2O3, ZrO2 and others were produced. Characterization was performed via SEM, XRD, ESCA, Auger depth profiling and resistivity measurements. Barrier layer films were fairly smooth with some cracking and pitting present. Si migration was severe for alkaline earth thin films on Si wafers. Some perovskite films on Si showed formation of Ba-Si-O phases at the Si interface. Thin films of 1–2–3 on barrier layers of SrTiO3 or ZrO2 on Si showed Ba pileup at the Si interface and were not superconducting. 1–2–3 layers deposited on single crystal ZrO2 were superconducting and showed onset temperatures of 90 K with zero resistance reached at about 55 K.

1995 ◽  
Vol 391 ◽  
Author(s):  
E.M. Zielinski ◽  
R.P. Vinci ◽  
J.C. Bravman

abstractPreferred crystallographic orientation and grain size distribution were characterized as a function of processing for sputtered Cu films on Ta underlayers. The Ta barrier layer was deposited at two temperatures, 30 and 100 °C. Cu was deposited at 30, 150 and 250 °C on the 30 °C Ta, and at 100, 150, 200 and 250 °C on the 100 °C Ta. In the first set of samples, with increasing deposition temperature, the Cu (111) fiber texture grew weaker and the volume fraction of randomly oriented grains increased from 0.23 to 0.74. In contrast, for the films deposited on the 100 °C Ta, with increasing deposition temperature, Cu (111) fiber texture strengthened and the fractions of randomly oriented and twinned grains decreased. Grain size was lognormally distributed in all samples and varied approximately parabolically with deposition temperature. At a given deposition temperature, median grain size in the Cu was larger in the films deposited on the 100 °C Ta. These results will be related to the microstructure of the Ta underlayers. Cu microstructure on the 100 °C Ta is shown to be influenced by textural inheritance from the Ta underlayer. Microstructure of the Cu on 30 °C Ta is discussed in terms of trace contaminants.


2003 ◽  
Vol 795 ◽  
Author(s):  
D. E. Nowak ◽  
S. P. Baker

ABSTRACTSynchrotron x-ray diffraction experiments were used to study the thermomechanical behavior of individual texture components in passivated Cu thin films. Films were deposited to a thickness of 500 nm on SiNx barrier layers on Si substrates and then passivated with SiNx. The films were highly textured with grains having (111) or (100) planes parallel to the plane of the film. In-plane film stresses were determined separately in the two texture components as a function of temperature during thermal cycles and also during isothermal holds at 140°C. The results are compared to models of yield behavior and anelastic recovery.


2000 ◽  
Vol 612 ◽  
Author(s):  
Yuxiao Zeng ◽  
Linghui Chen ◽  
T. L. Alford

AbstractHSQ (hydrogen silsesquioxane) is one of the promising low-k materials used in VLSI technology as an intra-metal dielectric to reduce capacitance-related issues. Like any other dielectrics, the integration of HSQ in multilevel interconnect schemes has been of considerable importance. In this study, the compatibility of HSQ with different nitride barrier layers, such as PVD and CVD TiN, PVD TaN, and CVD W2N, has been investigated by using a variety of techniques. The refractory metal barriers, Ti and Ta, are also included for a comparison. The degradation of HSQ films indicates a strong underlying barrier layer dependence. With CVD nitrides or refractory metals as barrier, HSQ exhibits a better structural and property stability than that with PVD nitrides. The possible mechanisms have been discussed to account for these observations.


2014 ◽  
Vol 67 (2) ◽  
pp. 21301 ◽  
Author(s):  
Carlos Macchi ◽  
Juan Bürgi ◽  
Javier García Molleja ◽  
Sebastiano Mariazzi ◽  
Mattia Piccoli ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1605 ◽  
Author(s):  
Marietta Seifert

This paper reports on a significant further improvement of the high temperature stability of RuAl thin films (110 nm) on the piezoelectric Ca 3 TaGa 3 Si 2 O 14 (CTGS) and La 3 Ga 5 SiO 14 (LGS) substrates. RuAl thin films with AlN or SiO 2 cover layers and barriers to the substrate (each 20 nm), as well as a combination of both were prepared on thermally oxidized Si substrates, which serve as a reference for fundamental studies, and the piezoelectric CTGS, as well as LGS substrates. In some films, additional Al layers were added. To study their high temperature stability, the samples were annealed in air and in high vacuum up to 900 °C, and subsequently their cross-sections, phase formation, film chemistry, and electrical resistivity were analyzed. It was shown that on thermally oxidized Si substrates, all films were stable after annealing in air up to 800 °C and in high vacuum up to 900 °C. The high temperature stability of RuAl thin films on CTGS substrates was improved up to 900 °C in high vacuum by the application of a combined AlN/SiO 2 barrier layer and up to 800 °C in air using a SiO 2 barrier. On LGS, the films were only stable up to 600 °C in air; however, a single SiO 2 barrier layer was sufficient to prevent oxidation during annealing at 900 °C in high vacuum.


1994 ◽  
Vol 361 ◽  
Author(s):  
Y. Gao ◽  
W. Dong ◽  
B.A. Turtle

ABSTRACTFerroelectric PbTiO3 and Pb(Zr,Ti)O3 thin films with a perovskite structure were grown on MgO and Pt/Ti/SiO2/Si by MOCV.D. The microstructure and composition of the films were characterized by x-ray diffraction, SEM, and AES. Preferred orientation of either (111) or (100)/(001) was obtained on the Pt/Ti/SiO2/Si substrates at temperatures from 600 °C to 650 °C The preferred (111) orientation was attributed to the formation of the Pt3Ti phase in the Pt layer of the substrates, whereas the (100)/(001) orientations were inferred as the growth rate effect. AES depth profiling indicated a uniform composition through the thickness of the PZT films. However, SEM showed different topography and microstructure of the PZT films deposited in different oxygen partial pressure. Electrical properties of the PZT films appear varied as a function of the oxygen partial pressure in the reactor.


1999 ◽  
Vol 14 (2) ◽  
pp. 494-499 ◽  
Author(s):  
S. Arscott ◽  
R. E. Miles ◽  
J. D. Kennedy ◽  
S. J. Milne

0.53Ti0.47)O3 have been prepared on platinized GaAs (Pt–GaAs) substrates using a new 1,1,1-tris(hydroxymethyl)ethane (THOME) based sol-gel technique. Rapid thermal processing (RTP) techniques were used to decompose the sol-gel layer to PZT in an effort to avoid problems of GayAs outdiffusion into the PZT. A crystalline PZT film was produced by firing the sol-gel coatings at 600 or 650 ° for a dwell time of 1 s using RTP. A single deposition of the precursor sol resulted in a 0.4 μm thick PZT film. X-ray diffraction measurements revealed that the films possessed a high degree of (111) preferred orientation. Measured average values of remanent polarization (Pr ) and coercive field (Ec) for the film annealed at 650 ° for 1 s were 24 μC/cm2 and 32 kV/cm, respectively, together with a low frequency dielectric constant and loss tangent at 1 kHz of 950 and 0.02. These values are comparable to those obtainable on platinized silicon (Pt–Si) substrates using conventional sol-gel methods, and are an improvement on PZT thin films prepared on platinized GaAs using an earlier sol-gel route based on 1,3-propanediol.


1985 ◽  
Vol 54 ◽  
Author(s):  
R. E. Thomas ◽  
J. H. Perepezko ◽  
J. D. Wiley

ABSTRACTInteractions between amorphous metal thin films and either a substrate or an overlayer can limit their effectiveness as diffusion barriers. We have found in previous studies that Au and Al polycrystalline thin films in contact with amorphous W-Si lowers the crystallization temperature of the a-(W-Si) by at least 100C. In contrast Cu and Mo have no apparent effect on the stability of the amorphous layer. The mechanisms leading to premature crystallization are not well understood. Amorphous W .72Si.28 was deposited by D.C. sputtering onto single crystal Si substrates. Overlayers of Al were then evaporated onto the W-Si. Using Auger electron spectroscopy depth profiling coupled with cross-section TEM, we have studied interfacial reactions between the amorphous layer and polycrystalline Al. Auger profiling results show that in the case of Al overlayers, W and Si diffuse out of the a-(W-Si) into the Al where WAl12 forms. These results can be explained in the context of three binary diffusion couples, W-Si, W-Al, Al-Si, and the individual interactions associated with these couples.


Author(s):  
R. M. Anderson ◽  
T. M. Reith ◽  
M. J. Sullivan ◽  
E. K. Brandis

Thin films of aluminum or aluminum-silicon can be used in conjunction with thin films of chromium in integrated electronic circuits. For some applications, these films exhibit undesirable reactions; in particular, intermetallic formation below 500 C must be inhibited or prevented. The Al films, being the principal current carriers in interconnective metal applications, are usually much thicker than the Cr; so one might expect Al-rich intermetallics to form when the processing temperature goes out of control. Unfortunately, the JCPDS and the literature do not contain enough data on the Al-rich phases CrAl7 and Cr2Al11, and the determination of these data was a secondary aim of this work.To define a matrix of Cr-Al diffusion couples, Cr-Al films were deposited with two sets of variables: Al or Al-Si, and broken vacuum or single pumpdown. All films were deposited on 2-1/4-inch thermally oxidized Si substrates. A 500-Å layer of Cr was deposited at 120 Å/min on substrates at room temperature, in a vacuum system that had been pumped to 2 x 10-6 Torr. Then, with or without vacuum break, a 1000-Å layer of Al or Al-Si was deposited at 35 Å/s, with the substrates still at room temperature.


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