共查询到20条相似文献,搜索用时 12 毫秒
1.
C.J. Lu H.M. Shen Y.N. Wang J.H. Gu 《Applied Physics A: Materials Science & Processing》1998,66(4):445-449
0.95 Ti0.05)O3 thin films of an orthorhombic perovskite structure were obtained on SrTiO3(100) substrates by radio frequency sputter deposition. The surface morphology of the films was investigated with atomic force
microscopy, scanning electron microscopy, and reflection electron microscopy. It is shown that the film surfaces are rather
bumpy. There are undulations of about 400 nm in length in an in-plane direction. The mean roughness perpendicular to the surface
is 39.6 nm, for the film thickness of 0.45 μm. The surface roughening was probably caused by island-shaped nucleation and
growth during the film growth. It has also been found that some gorges and a number of small pits remain at the film surfaces.
The surface chemical states of the films were characterized by using X-ray photoelectron spectroscopy. A Pb enrichment layer
and a large amount of adsorbed oxygen have been found at the surfaces of the films. Near the film surface Pb and Zr exist
mainly in the forms of, besides Pb(Zr,Ti)03, metal Pb, metal Zr, oxygen-chemisorbed Pb, and various lead oxides. In addition, a small amount of lead, whose binding energy
of Pb 4f7/2 is much lower than that of metal Pb, was observed at the film surfaces, but its chemical state is unknown up to now.
Received: 2 June 1997/Accepted: 22 September 1997 相似文献
2.
X. Zhu S. Lu H.L.W. Chan C.L. Choy K.H. Wong 《Applied Physics A: Materials Science & Processing》2003,76(2):225-229
Compositionally graded (Ba1-xSrx)TiO3 (BST) (x:0.0∼0.25) thin films were grown on Pt (111)/TiO2/SiO2/Si (100) substrates using layer-by-layer pulsed laser deposition in the temperature range 550–650 °C. Both downgraded (Ba/Sr
ratio varying from 100/0 at the bottom surface to 75/25 at the top surface) and upgraded (Ba/Sr ratio varying from 75/25 at
the bottom surface to 100/0 at the top surface) BST films were prepared. Their microstructures were systematically studied
by X-ray diffractometry and scanning electron microscopy. A grain morphology transition from large ‘rosettes’ (>0.30 μm) to
small compact grains (70–110 nm) was observed in the downgraded BST films as the deposition temperature was increased from
550 to 650 °C. No such grain morphology transition was detected in the upgraded BST films. Dielectric measurements with metal
electrodes revealed an enhanced dielectric behavior in the downgraded films. This enhancement is mainly attributed to the
large compressive stress field built up near the interface between the downgraded film and substrate. Furthermore, the BaTiO3 layer in the downgraded BST films not only serves as a bottom layer but also as an excellent seeding layer for enhancing
the crystallization of the subsequent film layers in the downgraded films.
Received: 10 December 2001 / Accepted: 12 March 2002 / Published online: 19 July 2002
RID="*"
ID="*"Corresponding author. Fax: 86-25/359-5535, E-mail: xhzhu@public1.ptt.js.cn 相似文献
3.
Nucleation and initial growth of diamond by biased hot filament chemical vapour deposition 总被引:1,自引:0,他引:1
W.L. Wang G. Sánchez M.C. Polo R.Q. Zhang J. Esteve 《Applied Physics A: Materials Science & Processing》1997,65(3):241-249
6 cm-2 for non-scratched silicon. The maximum value of the nucleation density was over 1011 cm-2 on mirror-polished Si(100) at -300 V. The transportation process of the ion flux from the filament to the substrate is discussed
in detail for biased substrates. The nucleation enhancement by the positive bias is believed to be a result of the increased
impingement of the electrons emitted from the filament to the substrate surface. The studies have shown that electron emission
from diamond plays a key role in negative-bias-enhanced nucleation by accelerating the dissociation of molecular hydrogen
and hydrocarbon species into various free radicals and
causing a plasma to be ignited near the substrate surface. The negative bias pretreatment is also a critical step in growing
heteroepitaxial diamond films: the enlargement of the area of diamond clusters in contact with the substrate enhances the
orientated growth of the films.
Received: 18 October 1996/Accepted: 4 February 1997 相似文献
4.
X.S. Wang Y.J. Zhang L.Y. Zhang X. Yao 《Applied Physics A: Materials Science & Processing》1999,68(5):547-552
Ferroelectric Bi4Ti3O12 thin films with single phase and nanosized microstructure were prepared on Pt/Ti/SiO2/Si(111) substrate by metalorganic solution deposition using titanium butoxide and bismuth nitrate at relatively low annealing
temperatures. The internal strain in Bi4Ti3O12 thin films was calculated from the peak shifts and broadening of XRD patterns. With increase in annealing temperature, the
uniform strain decreased from positive to zero and then to negative, and the non-uniform strain decreased and was negative.
The total strain was negative and in the range of -0.2%–-1.0%, from which the stress of the films was calculated to be about
-1.4×109 N/m2. The mode values of strain decreased with increase in annealing temperature and increased with increase in film thickness.
The dielectric constant increased with increase in annealing temperature and film thickness. The dielectric properties were
interpreted by considering the influence of strain, grain size, and grain boundaries. The strain lowered the polarization
and increased the dielectric constant. The larger the grain size and the thinner the grain boundary, the greater the dielectric
constant. The influence of grain size and grain boundary was stronger than that of the strain.
Received: 23 September 1998 / Accepted: 6 January 1999 / Published online: 24 March 1999 相似文献
5.
The low-temperature fabrication of silicon nitride films by ArF excimer laser irradiation has been studied. Two fabrication methods are presented. One is photoenhanced direct nitridation of a silicon surface with NH3 for very thin gate insulators, and the other is photo-enhanced deposition of silicon nitride films with Si2H6 and NH3 gases for stable passivation films. The ArF excimer laser irradiation dissociates the NH3 gas producing NH and NH2 radicals which proved effective in instigating the nitridation reaction. The quality of both films has been much improved and the growth temperature has been lowered by using laser irradiation. These photo-enhanced processes seem to be promising ULSI techniques because they do not depend on high temperatures and are free from possible reactor contamination. 相似文献
6.
0.95 Ti0.05)O3 (PZT 95/5) thin films of perovskite structure were prepared on various substrates by the radio-frequency magnetron sputtering
with a stoichiometric ceramic target. The crystal structure of the films showed a strong dependency on the crystal structure
of the substrates. After conventional-furnace annealing at 750 °C, crack-free and transparent epitaxial PZT 95/5 films were
successfully obtained on SrTiO3(100) substrates, and highly oriented films on LaAlO3(012). The films on r-sapphire exhibit slightly preferred orientation along both the (040) and (122) axes of the orthorhombic
PZT 95/5 phase. The films on YSZ(100) consist principally of the perovskite PZT 95/5 phase with random orientation with a small
portion of unknown phase. However, the formation of the perovskite PZT 95/5 phase was not observed in the films on Si(110)
or (111)Pt-coated Si substrates. The crystallization of the perovskite PZT 95/5 on these substrates could be improved by rapid
thermal annealing (RTA). Single perovskite phase was obtained in the films on (111)Pt/Si which had RTA at 750 °C for 1 min.
No tangible loss of Pb from the films occurred during either the sputtering or annealing.
Received: 17 April 1997/Accepted: 18 November 1997 相似文献
7.
Structural, optical and electrical properties of ZnO and ZnO-Al2O3 films prepared by dc magnetron sputtering 总被引:1,自引:0,他引:1
X.Q. Meng W. Zhen J.P. Guo X.J. Fan 《Applied Physics A: Materials Science & Processing》2000,70(4):421-424
ZnO and ZnO-Al2O3 thin films were prepared by dc magnetron sputtering and their structural, optical and electrical properties were studied
comparatively. It is discovered that the ZnO-Al2O3 thin films remain transparent in a shorter wavelength range than the ZnO films, resulting from the increase of their band
gap. Their resistivity decreases by seven orders of magnitude, which is caused by doping of Al to ZnO grains in the film.
Preferential orientation of ZnO grains in the ZnO-Al2O3 thin films deteriorates because of the existence of Al2O3 impurity phase in the film.
Received: 5 January 1999 / Accepted: 11 October 1999 / Published online: 8 March 2000 相似文献
8.
Ferroelectricity of lanthanum-modified lead titanate thin films obtained by a diol-based sol-gel method 总被引:1,自引:0,他引:1
M. Algueró M.L. Calzada C. Quintana L. Pardo 《Applied Physics A: Materials Science & Processing》1999,68(5):583-592
Lanthanum-modified lead titanate thin films have been prepared by a diol-based sol-gel method from precursor solutions with
a growing excess of PbO. The films were crystallized with thermal treatments at 650 °C and heating rates of 10 °C min-1 and higher than 500 °C min-1 by direct insertion in a pre-heated furnace. The structure, microstructure, and composition of the films were studied by
grazing-incidence X-ray diffraction, electron microscopies, and energy-dispersive X-ray spectroscopy. A 20 mole % excess of
PbO must be included in the precursor solution in order to compensate PbO volatilization occurring during the thermal treatment
and, thus, obtain single-phase perovskite-type structure films. Non-textured porous films were obtained when a 10 °C min-1 rate is used, whereas [001]/[100] oriented films without porosity were obtained when rapid heating was used. Dielectric permittivity,
ac current density, hysteresis loops, and switching curves were measured in the films. Values of remanent polarization and
coercive field are comparable to those reported for similar films. The effects on the ferroelectric properties of an electrical
and a post-crystallization thermal treatments were characterised.
Received: 5 January 1998 / Accepted: 20 November 1998 / Published online: 17 March 1999 相似文献
9.
Q. Meng R. Moerman A.H. Sonnenberg G.J. Gerritsma 《Applied Physics A: Materials Science & Processing》1999,68(2):239-245
3 films on single-crystal MgO(100) substrates. Meanwhile, surface morphologies of as-polished and post-annealed MgO(100) substrates
are investigated as well. Effects of the miscut (or misorientation) of the substrate surface on morphologies and growth mechanisms
are discussed. For comparison, a typical surface morphology and growth mechanism of the spiral island structure in sputtered
PrBa2Cu3O7-δ films on MgO(100) substrates are presented.
Received: 27 March 1998 相似文献
10.
X.Y. Chen K.H. Wong C.L. Mak J.M. Liu X.B. Yin M. Wang Z.G. Liu 《Applied Physics A: Materials Science & Processing》2002,74(5):703-706
Selective growth of single-oriented (110), (100) and (111) MgO films on Si (100) substrates without buffer layers was obtained
via a two-step method by pulsed laser deposition. It was found that the orientation of the films was determined at the initial
deposition stage by the substrate temperature only. The ambient pressure during deposition, the laser fluence and the etching
of the Si substrates have no apparent effect on the orientation of the films, but affect their crystalline quality. Under
the present deposition conditions, the surfaces of all three different single-oriented films were very smooth and devoid of
any particulates.
Received: 23 January 2001 / Accepted: 6 June 2001 / Published online: 2 October 2001 相似文献
11.
S.U. Adikary A.L. Ding H.L.W. Chan 《Applied Physics A: Materials Science & Processing》2002,75(5):597-600
BaxSr1-xTiO3 thin films with a compositional gradient of x=0.3 to 1 (in 0.1 mole fraction increments) were fabricated on Pt/Ti/SiO2/Si substrates using a modified sol–gel technique. The graded film crystallised in a perovskite structure and consists of
a uniform microstructure with comparatively larger grains. The room-temperature relative dielectric constant (εr) and dielectric loss (cosδ) at 100 kHz were found to be 305 and 0.03 respectively. Dielectric peaks were not observed in
the temperature range from -20 °C to 120 °C. The dielectric constant and dielectric loss were almost independent of temperature.
Polarisation–electric field measurements at room temperature revealed a saturated but slim hysteresis loop with a remanent
polarisation (Pr) of 0.6 μC/cm2 and a coercive field (Ec) of 2.4 kV/mm. The graded film behaves as a stack of BaxSr1-xTiO3 capacitors connected in series and hence the dielectric Curie peaks are removed.
Received: 4 October 2001 / Accepted: 17 October 2001 / Published online: 23 January 2002 相似文献
12.
Growth and characterization of silicon nitride films on various underlying materials 总被引:3,自引:0,他引:3
G.C. Han P. Luo K.B. Li Z.Y. Liu Y.H. Wu 《Applied Physics A: Materials Science & Processing》2002,74(2):243-247
Characteristics of silicon nitride (SiNx:H) films, grown by plasma enhanced chemical vapor deposition (PECVD) on various metals such as Ta, IrMn, NiFe, Cu, and CoFe
at various temperatures down to 100 °C, were studied using measurements of BHF etch rate, surface roughness and Auger electron
spectroscopy (AES). The results were compared with those obtained for SiNx:H films on Si. The deposition rate of SiNx:H films increased slightly as deposition temperature decreased, and showed a weak dependence on the underlying materials.
The surface of the nitride films deposited on all underlying materials at lower temperatures (below 150 °C) became rougher.
In particular, a bubble-like surface was observed on the nitride film deposited on NiFe at 100 °C. At higher deposition temperatures
(above 200 °C), SiNx:H films on all the above metals had small RMS values, except for films on Cu which cracked at 250 °C. BHF (10:1) etch rate
increased dramatically for nitride films deposited below 150 °C. For different underlying films, the BHF etch rate was quite
different, but exhibited the same trend with decrease in deposition temperature. AES measurements showed that Si and N concentrations
in the SiNx:H films were only slightly different for the various deposition temperatures and underlying materials. AES depth profile
of nitride films indicated that both surface O content and the depth of oxygen penetrating into SiNx:H increased for low temperature-deposited films. However, there was no observed oxygen signal from within the films, even
for films deposited at 100 °C, and both Si and N concentrations were uniform throughout the film.
Received: 26 October 2001 / Accepted: 2 March 2001 / Published online: 20 June 2001 相似文献
13.
A.K. Viswanath J.I. Lee C.R. Lee J.Y. Leem D. Kim 《Applied Physics A: Materials Science & Processing》1998,67(5):551-556
Received: 1 May 1998/Accepted: 23 June 1998 相似文献
14.
S. Deki Hnin Yu Yu Ko T. Fujita K. Akamatsu M. Mizuhata A. Kajinami 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,16(1):325-328
Au nanoparticles dispersed SiO2-TiO2 composite films have been prepared by a novel wet process, Liquid Phase Deposition (LPD) method. The composite films were
characterized by XRD, XPS, TEM, ICP, SEM and UV-VIS absorption spectroscopy. The results showed that the SiO2-TiO2 composite films containing AuIII and AuI ionic species were co-deposited from a mixed solution of ammonium silicofluoride, ammonium hexafluorotitanate, boric acid
and tetrachloroauric acid. The heat treatment induced the reduction of Au ions and formation of Au nanoparticles in the film.
TEM observation revealed that the Au nanoparticles with 5-10 nm in diameter were found to be dispersed uniformly in the SiO2-TiO2 matrix. The optical absorption band due to the surface plasmon resonance of dispersed Au particles were observed at the wavelength
of 550 nm and shifted toward longer wavelength with increasing heat treatment temperature.
Received 28 November 2000 相似文献
15.
The orientation-selective growth of LaNiO3 films on Si(100) by pulsed laser deposition using a MgO buffer 总被引:4,自引:0,他引:4
X.Y. Chen K.H. Wong C.L. Mak J.M. Liu X.B. Yin M. Wang Z.G. Liu 《Applied Physics A: Materials Science & Processing》2002,75(4):545-549
Highly (100)-oriented, (110)-oriented and polycrystalline LaNiO3 (LNO) films were successfully prepared on Si(100) using an oriented MgO film as a buffer. It was somewhat surprising to find
that that the orientation relation between the LNO film and the corresponding MgO buffer was: LNO(100)\MgO(110), LNO(110)\MgO(111)
and LNO(polycrystalline)\MgO(100). The crystalline quality of the LNO films was shown to be sensitive to the preparation conditions
of the MgO buffer. The film surface was very smooth, without micrometer-sized droplets being observed. All LNO films were
of metallic conductivity, with a room-temperature resistivities of approximately 250, 280 and 420 μΩ cm for the (110)-oriented,
(100)-oriented and polycrystalline LNO, respectively.
Received: 2 April 2001 / Accepted: 23 October 2001 / Published online: 3 June 2002 相似文献
16.
C.J. Lu H.M. Shen S.B. Ren Y.N. Wang 《Applied Physics A: Materials Science & Processing》1997,65(4-5):395-401
3 thin films is systematically studied by using X-ray diffraction (XRD). The PbTiO3 thin films with different average grain sizes were prepared on various substrates by a sol-gel process. The films on NaCl
and fused glass are randomly grain-oriented, while those on (111)Pt/Ti/SiO2/Si are highly {100} cubic index grain-oriented . It is found from the XRD patterns of the films on NaCl that with decreasing
average grain size from 230 to 80 nm, the intensities of high h index (h>l) peaks (hkl), such as (100), (110), (200), (201),
(210), (211), etc., decrease rapidly and ultimately disappear, whereas another set of peaks (lkh), including (001), (002),
(102), (112), etc., are still intense. This interesting result suggests that at grain size below a certain critical size an
increasing number of grains no longer show 90°-domains, which is confirmed by TEM observations. Meanwhile, X-ray evidence
of such a grain-size-related absence of 90°-domains is also found for PbTiO3 films on Pt(111) and fused-glass substrates. The volume fractions of single-domain grains (without 90°-domains) in the films
are estimated from their XRD patterns. By combining SEM and TEM investigations, the critical grain size for the formation
of 90°-domains is further determined to be near 200 nm.
Received: 19 December 1996/Accepted: 24 March 1997 相似文献
17.
Structure and spectroscopic characterization of polycrystalline vanadyl phthalocyanine (VOPc) films fabricated by vacuum deposition 总被引:1,自引:0,他引:1
Y.L. Pan Y.J. Wu L.B. Chen Y.Y. Zhao Y.H. Shen F.M. Li S.Y. Shen D.H. Huang 《Applied Physics A: Materials Science & Processing》1998,66(5):569-573
Received: 24 March 1997/Accepted: 8 September 1997 相似文献
18.
Structure, refractive-index dispersion and the optical absorption edge of chemically deposited ZnxCd(1-x)S thin films 总被引:2,自引:0,他引:2
A.M. Salem 《Applied Physics A: Materials Science & Processing》2002,74(2):205-211
Zinc cadmium sulfide, ZnxCd(1-x)S, thin films have been deposited by a simple and inexpensive chemical bath deposition method from an aqueous medium using
thiourea as a sulfide-ion source. The structure of the deposited films has been characterized by X-ray diffraction and transmission
electron microscopy. It was observed from X-ray diffraction that the as-deposited films were amorphous in nature. However
ZnxCd(1-x)S films annealed at 423 K for 1.5 h show a crystalline structure with a small scattering volume. The obtained results were
confirmed throughout the transmission electron microscopy and the corresponding electron-diffraction patterns. The optical
constants of ZnxCd(1-x)S films annealed at 423 K for 1.5 h in the compositional range 0≤x≤1 were estimated using transmission and reflection spectra
in the wavelength range 300–2500 nm. The band gap varies non-linearly with the value of x. The dependence of the refractive
index on the wavelength obeys the single-oscillation model, from which the dispersion parameters and the high-frequency dielectric
constant were determined. A graphical representation of the surface and volume energy-loss functions was also given.
Received: 23 February 2001 / Accepted: 26 February 2001 / Published online: 27 June 2001 相似文献
19.
M. Ivill M. Patel K. Kim H. Bae S.J. Pearton D.P. Norton J.D. Budai 《Applied Physics A: Materials Science & Processing》2002,75(6):699-702
The epitaxial growth of CeO2 thin films has been realized on (100) InP substrates using reactive r.f. magnetron sputtering. Oxide films were nucleated
in the presence of molecular hydrogen (4% H2/Ar sputtering gas) in order to reduce the native oxide formation on the InP surface, which interferes with CeO2 epitaxy. A metal cerium target was used as the cation source, with water vapor serving as the oxidizing species. Epitaxial
films were sputter-deposited at a substrate temperature of 550 °C in a H2O vapor pressure of approximately 10-3 Torr. Crystallinity of the oxide films was examined using θ–2θ X-ray diffraction, ω-rocking curves, and in-plane φ-scans. The best results were obtained when the initial nucleation layer was deposited with P(H2O)<10-5 Torr, followed by deposition at P(H2O)=10-3 Torr. The epitaxial growth of CeO2 on InP could prove enabling in efforts to integrate functional oxides with InP-based optoelectronic and microwave technologies.
Received: 20 February 20002 / Accepted: 21 February 2002 / Published online: 19 July 2002 相似文献
20.
2 O3 thin films by plasma-enhanced chemical vapour deposition (PECVD) using trimethyl-amine alane (TMAA) as the Al precursor.
The thin films were deposited on both Si and quartz silica (SiO2) substrates. Deposition rates were typically 60 Å min-1 keeping the TMAA temperature constant at 45 °C. The deposited Al2O3 thin films were stoichiometric alumina with low carbon contamination (0.7–1.3 At%). The refractive index ranged from 1.54
to 1.62 depending on the deposition conditions. The deposition rate was studied as a function of both the RF power and the
substrate temperature. The structure and the surface of the deposited Al2O3 thin films were studied using X-ray diffraction, atomic force microscopy (AFM) and scanning electron microscopy (SEM).
Received: 20 May 1997/Accepted: 12 June 1997 相似文献