The 'in-situ' preparation and properties of Y-Ba-Cu-O thin films on the SrTiO/sub 3/, Al/sub 2/O/sub 3/ and Si substrates

1991 ◽  
Vol 27 (2) ◽  
pp. 1475-1478 ◽  
Author(s):  
M.I. Faley ◽  
M.E. Gershenson ◽  
N.P. Kuchta ◽  
V.S. Salun
Keyword(s):  
Thin Films ◽  
Si Substrates ◽  
In Situ Preparation

Interfacial adhesion of nanoporous zeolite thin films

2006 ◽  
Vol 21 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Lili Hu ◽  
Junlan Wang ◽  
Zijian Li ◽  
Shuang Li ◽  
Yushan Yan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Interfacial Adhesion ◽  
Interfacial Strength ◽  
Future Generation ◽  
In Situ Growth ◽  
Seeded Growth ◽  
Si Substrates ◽  
Film Substrate

Nanoporous silica zeolite thin films are promising candidates for future generation low-dielectric constant (low-k) materials. During the integration with metal interconnects, residual stresses resulting from the packaging processes may cause the low-k thin films to fracture or delaminate from the substrates. To achieve high-quality low-k zeolite thin films, it is important to carefully evaluate their adhesion performance. In this paper, a previously reported laser spallation technique is modified to investigate the interfacial adhesion of zeolite thin film-Si substrate interfaces fabricated using three different methods: spin-on, seeded growth, and in situ growth. The experimental results reported here show that seeded growth generates films with the highest measured adhesion strength (801 ± 68 MPa), followed by the in situ growth (324 ± 17 MPa), then by the spin-on (111 ± 29 MPa). The influence of the deposition method on film–substrate adhesion is discussed. This is the first time that the interfacial strength of zeolite thin films-Si substrates has been quantitatively evaluated. This paper is of great significance for the future applications of low-k zeolite thin film materials.

IN-SITU PREPARATION OF YBa2Cu3O7 SUPERCONDUCTING THIN FILMS BY PULSED Nd:YAG LASER DEPOSITION

1992 ◽  
Vol 06 (08) ◽  
pp. 477-483 ◽  
Author(s):  
QINGXIN SU ◽  
SHIFA XU ◽  
DAFU CUI ◽  
HUIBIN LU ◽  
YONGJUN TIAN ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Nd:Yag Laser ◽  
Ac Susceptibility ◽  
Substrate Surface ◽  
Zero Magnetic Field ◽  
Superconducting Thin Films ◽  
In Situ Preparation ◽  
Zero Resistance

High-T c superconducting thin films of YBa 2 Cu 3 O 7 were grown in-situ on (100) SrTiO 3 substrates by Nedymium:yttrium aluminum garnet [Nd:YAG] laser ablation. The effects of the substrate temperature on the transition temperature, microcrystalline structure and surface morphology of the films were discussed. Best results were obtained in the 730°–770°C range. X-ray diffraction analysis showed that these films were highly c-oriented with the c-axis perpendicular to the substrate surface. At the optimum substrate temperature, a very smooth morphology with only a few small particles were observed by scanning electron microscopy. The zero resistance temperature of these films were ≥ 90 K with a narrow transition width and the ac susceptibility measurement also gave the same result. The highest critical current density obtained at 77 K and zero magnetic field was 3.8 × 106 A/cm 2.

In‐Situ Fabrication of YBa2Cu3O7‐x Superconducting Thin Films Directly on Silicon Substrates with Tc0 > 77K

1989 ◽  
Vol 169 ◽  
Author(s):  
C. B. Lee ◽  
R. K. Singh ◽  
S. Sharan ◽  
A. K. Singh ◽  
P. Tiwari ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Pulses ◽  
Superconducting Film ◽  
Laser Evaporation ◽  
Silicon Substrates ◽  
Superconducting Thin Films ◽  
Si Substrates ◽  
In Situ Fabrication ◽  
Substrate Temperatures

AbstractWe report in‐situ fabrication of c‐axis textured YBa2Cu3O7‐x superconducting thin films with Tco > 77K on unbuffered silicon substrates by the biased pulsed laser evaporation (PLE) technique in the temperature range of 550‐650°C. At substrate temperatures below 550°C, no c‐axis texturing of the superconducting film was observed. The YBa2Cu3O7‐x superconducting films were fabricated by ablating a bulk YBa2Cu3O7 target by a XeCl excimer laser (λ = 308 nm, τ = 45 × 10‐9 sec) in a chamber maintained at an oxygen pressure of 0.2 torr . The thickness of the films was varied from 0.3 to 0.5 nm depending on the number of laser pulses. Extensive diffusion was observed in thin films deposited at substrate temperatures above 550°C. However, microstructurally, with increase in the substrate temperature the films exhibited larger grain size and greater degree of c‐axis texturing (measured by the ratio of the (005) and (110) X‐ray diffraction peaks). This was found to give rise to better superconducting properties with Tco exceeding 77 K for YBa2Cu3O7‐x films deposited on Si substrates at 650°C.

RF Microwave Switches Based on Reversible Metal-Semiconductor Transition Properties of VO2 Thin Films: An Attractive Way To Realise Simple RF Microelectronic Devices

2008 ◽  
Vol 1129 ◽  
Author(s):  
Frédéric Dumas-Bouchiat ◽  
Corinne Champeaux ◽  
Alain Catherinot ◽  
Julien Givernaud ◽  
Aurelian Crunteanu ◽  
...  
Keyword(s):  
Thin Films ◽  
Geometrical Parameters ◽  
Si Substrates ◽  
Thermally Activated ◽  
Microelectronic Devices ◽  
Microwave Switches ◽  
Vo2 Thin Films ◽  
Insertion Losses ◽  
Rf Signal

AbstractMicrowave switches in both shunt and series configurations are developped using semiconductor to metal (SC-M) transition of vanadium dioxide (VO2) thin films deposited by in situ pulsed laser deposition on C-plane sapphire and SiO2/Si substrates. The influence of geometrical parameters such as the length of the switch is shown. The VO2-based switches exhibit up to 30-40 dB average isolation of the radio-frequency (RF) signal on a very wide frequency band (500 MHz-35 GHz) with weak insertion losses, when thermally activated. Furthermore, they can be electrically activated. Finally these VO2-based switches are integrated in the fabrication of innovative tunable band-stop filters which consist in a transmission line coupled with four U-shaped resonators and operate in 9-11 GHz frequency range. Its tunability is demonstrated using electrical activation of each VO2-based switch.

In-Situ Preparation of Y-Ba-Cu-O Thin Films Using Mass-Spectrometer Rate Control and Atomic Oxygen

1992 ◽  
Vol 275 ◽  
Author(s):  
H. Ohlsén ◽  
M. Ottosson ◽  
J. Hudner ◽  
M. ÖStling ◽  
L. Stolt ◽  
...  
Keyword(s):  
Thin Films ◽  
Mass Spectrometer ◽  
Rate Control ◽  
Atomic Oxygen ◽  
Film Structure ◽  
Rocking Curve ◽  
In Situ Preparation ◽  
Layer Structures

ABSTRACTThin films of YBCO were prepared using a mass-spectrometer controlled coevapora-tion/MBE process with atomic oxygen. Under the conditions of low pressure, necessary for mass-spectrometer rate control, it is shown that an atomic oxygen beam source can be utilized in order to grow high quality thin films of YBCO as well as multi-layer structures involving YBCO and Y2O3. Values of Tc = 88.5 K and Jc = 6–106 A/cm2 at 77 K were determined for a strip with a width of 10 μm of YBCO deposited on a LaAlO3 substrate. Film structure is analyzed by XRD and rocking curve measurements. Magnetic characterization of films and multi-layer structures are reported.

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