In situ growth of superconducting YBaCuO thin films by ion-beam sputtering method

We investigated the in situ growth of YBa2Cu3O7−δ superconducting thin films by a sequential ion beam sputtering technique, studying the relations among deposition parameters, structural and superconducting properties. The films were deposited following the stacking sequence of YBa2Cu3O7−δ, with individual layer thicknesses nominally equal to one monolayer. O2 was supplied during deposition. Predominantly c-axis oriented films were grown on (100) SrTiO3, (100) MgO, and oxidized Si (SiO2/Si) substrates. The microstructure and film-substrate orientation relations were studied by transmission electron microscopy. X-ray studies showed the presence of homogeneous and inhomogeneous strains along the c-direction that persisted after low temperature oxygen anneals. Resistivity measurements showed correlations between the superconducting transition characteristics and the lattice distortions along the c-direction. The effect of deposition parameters on the lattice distortions was investigated, finding that the c-axis lattice parameter was larger in films grown at lower temperatures. This was interpreted in terms of the thermally activated dissociation of O2 at the film surface during growth. We assumed that the c-axis lattice expansion was due to kinetic limitations to the incorporation of oxygen into the film during growth. This led to a consistent description of the results obtained in this work and the O2 pressure dependence of the c-axis lattice expansion reported for other in situ techniques. Studies were performed on films grown by this technique as well as on films grown in situ by magnetron sputtering in an attempt to elucidate the nature of the defect structure causing the c-axis lattice distortions.

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In-Situ Real-Time Ellipsometry Study of Dynamic Processes of YBa2Cu3O7−x Thin Films

MRS Proceedings ◽

10.1557/proc-569-77 ◽

1999 ◽

Vol 569 ◽

Cited By ~ 1

Author(s):

Y. Gao ◽

A.H. Mueller ◽

E.A. Irene ◽

O. Auciello ◽

A.R. Krauss ◽

...

Keyword(s):

Thin Films ◽

Real Time ◽

Ion Beam ◽

Oxygen Deficiency ◽

Ion Beam Sputtering ◽

Optical Absorption Peak ◽

Beam Sputtering ◽

Effect Of Oxygen ◽

Deposited Films

ABSTRACTThe optical absorption peak at 4. leV associated with oxygen deficiency in YBa2Cu3O7−x thin films was monitored by spectroscopic ellipsometry (SE) in real time during the growth process. Two regimes dominated by oxygen out- and in-diffusion have been observed during deposition by ion beam sputtering at 700°C.The effect of oxygen partial pressure during the post-deposition cooling process on the oxidation of deposited films has also been investigated. The thermodynamic stability of the grown films was examined by real time SE during post annealing process. In-situ SE measurements have been performed to obtain the dielectric function of oxygen deficient YBa2Cu3O6 films in the temperature range from 27°C to 700°C. It has been demonstrated that real time SE is a sensitive and useful technique for in-situ diagnostics of the dynamics of YBa2Cu3O7−x thin film processes.

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In situ growth of YBaCuO films by ion beam sputtering

Materials Science and Engineering B ◽

10.1016/0921-5107(94)90239-9 ◽

1994 ◽

Vol 22 (2-3) ◽

pp. 165-167

Author(s):

Jianhua Hao ◽

Xingrong Zhao ◽

Fangqiao Zhou ◽

Xinjian Yi ◽

Zaiguang Li

Keyword(s):

Ion Beam ◽

In Situ Growth ◽

Ion Beam Sputtering ◽

Beam Sputtering

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In situ grown YBa2Cu3O7−δ thin films by sequential ion beam sputtering

Materials Letters ◽

10.1016/0167-577x(90)90174-k ◽

1990 ◽

Vol 9 (9) ◽

pp. 336-338 ◽

Cited By ~ 4

Author(s):

J.A. Kittl ◽

C.W. Nieh ◽

D.S. Lee ◽

W.L. Johnson

Keyword(s):

Thin Films ◽

Ion Beam ◽

Ion Beam Sputtering ◽

Beam Sputtering

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Ion beam sputter deposition of YBa2Cu3O7−δ thin films

Journal of Materials Research ◽

10.1557/jmr.1993.3032 ◽

1993 ◽

Vol 8 (12) ◽

pp. 3032-3042 ◽

Cited By ~ 1

Author(s):

B.J. Kellett ◽

J.H. James

Keyword(s):

Thin Films ◽

Oxygen Partial Pressure ◽

Partial Pressure ◽

Ion Beam ◽

High Oxygen ◽

Ion Beam Sputtering ◽

Film Properties ◽

High Oxygen Partial Pressure ◽

Beam Sputtering

This article addresses issues associated with in situ growth of superconducting YBa2Cu3O7−δ thin films by ion beam sputtering. High oxygen partial pressure during ion beam deposition can cause significant beam broadening and oxidation of filaments and grids. Also, many of the targets used for processing YBCO are unstable when sputtered in a high oxygen partial pressure. It is shown that ion beam sputtering can produce YBCO films of comparable quality to those produced by laser ablation or dc magnetron sputtering. Typical film properties are Tco = 91 K and Jc (77 K) = 106 A cm−2. It appears that the oxygen gas pressure during the postdeposition cooldown has a more important influence on film properties than the oxygen partial pressure during deposition.

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Superconducting Yba2Cu3O7-δ Thin Films on Srtio3 and Si Grown In-Situ by Ion Beam Sputtering

MRS Proceedings ◽

10.1557/proc-169-639 ◽

1989 ◽

Vol 169 ◽

Cited By ~ 3

Author(s):

B.J. Kellett ◽

J.H. James ◽

A. Gauzzi ◽

M. Affronte ◽

D. Pavuna

Keyword(s):

Thin Films ◽

Film Thickness ◽

Ion Beam ◽

Buffer Layers ◽

Ion Beam Sputtering ◽

Ybco Films ◽

Beam Sputtering ◽

Uniform Composition

AbstractSuperconducting YBa2Cu3O7‐δ (YBCO) films 100‐300nm thick have been grown in‐situ on (100) SrTiO3 at 650°C by ion beam sputtering. Targets of Cu, CuO, Y, Y2O3, BaF2, BaCO3 and YBa2Cu3O7‐δ have been studied. Uniform composition throughout the film thickness has been achieved by co‐sputtering. Films are metallic (p300=300μΩcm) and textured, with Tc onsets at 92K and Tco=82K. Jc(77K) exceeds 105 Acm‐2. Films grown in‐situ on Si with ZrOx/Y2O3 and In2O3(10 at.%SnO2) buffer layers show Tc onsets at about 90K and Tco at about 50K, annealing improves Tco to 60K with resistivities p30o=2000μΩcm and 4000μΩcm respectively.

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Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071053 ◽

1973 ◽

Vol 31 ◽

pp. 122-123

Author(s):

J. S. Maa ◽

Thos. E. Hutchinson

Keyword(s):

Epitaxial Growth ◽

Film Growth ◽

Ion Beam ◽

Ion Beam Sputtering ◽

Microscopy Technique ◽

Direct Observations ◽

In Situ Electron Microscopy ◽

Beam Sputtering ◽

The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

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