共查询到20条相似文献,搜索用时 62 毫秒
1.
L. Gao P. Hrter Ch. Linsmeier J. Gstttner R. Emling D. Schmitt-Landsiedel 《Materials Science in Semiconductor Processing》2004,7(4-6):331
Deposition of Ag films by direct liquid injection-metal organic chemical vapor deposition (DLI-MOCVD) was chosen because this preparation method allows precise control of precursor flow and prevents early decomposition of the precursor as compared to the bubbler-delivery. Silver(I)-2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedionato-triethylphosphine [Ag(fod)(PEt3)] as the precursor for Ag CVD was studied, which is liquid at 30 °C. Ag films were grown on different substrates of SiO2/Si and TiN/Si. Argon and nitrogen/hydrogen carrier gas was used in a cold wall reactor at a pressure of 50–500 Pa with deposition temperature ranging between 220 °C and 350 °C. Ag films deposited on a TiN/Si diffusion barrier layer have favorable properties over films deposited on SiO2/Si substrate. At lower temperature (220 °C), film growth is essentially reaction-limited on SiO2 substrate. Significant dependence of the surface morphology on the deposition conditions exists in our experiments. According to XPS analysis pure Ag films are deposited by DLI-MOCVD at 250 °C by using argon as carrier gas. 相似文献
2.
The epitaxial growth of ZnO on sapphire and MgAl spinel using the vapor phase reaction of Zn and H2O
The gas phase reaction of Zn and H2O in a He carrier gas has been used as the basis for the chemical vapor deposition of ZnO on sapphire and MgAl spinel. Deposit
characteristics were studied as a function of reactor linear gas stream velocity, Zn/H2O vapor phase ratio, temperature and substrate preparation. It was round that the substrate support can influence the surface
morphology significantly and that in situ pretreatment can affect epitaxial relationships between deposit and substrate. Transparent,
visually smooth deposits of (11–24) ZnO can be obtained on chemically polished (0001) sapphire at 815°C using average linear
gas stream velocities, ν, of 6-12 cm/sec referenced to room temperature in conjunction with a Zn/H2O reactor input-pressure ratio of 0.02–0.09 (using Zn reactor pressures of 1.2–5.0 × 10−3 atm) . The substrates are given an H2O in situ pretreatment at 900°C prior to deposition at ν = 3 cm/sec with the partial pressure of H2O in He = 5.7 × 10 atm. 相似文献
3.
D. M. Hansen D. Charters Y. L. Au W. K. Mak W. Tejasukmana P. D. Moran T. F. Kuech 《Journal of Electronic Materials》2000,29(11):1312-1318
A reaction mechanism and film morphology as a function of reactor conditions and post growth thermal annealing for borosilicate
glass (BSG), (SiO2)x(B2O3)1−x, films deposited from tetraethylorthosilicate (TEOS), trimethylborate (TMB), and oxygen (O2) precursors by low-pressure chemical vapor deposition (LPCVD) was determined. An empirically derived reaction model for BSG
film growth is proposed that predicts the growth rate and composition of BSG films up to 70 mole% B2O3. The BSG reaction model includes a strongly adsorbed TEOS-derived intermediate that forms SiO2 and a direct surface reaction of TMB, in O2, to form B2O3. This model is supported by growth rate and mass spectroscopic data. The BSG film morphology, investigated using atomic force
microscopy, was found to have a root-mean-square roughness of 0.5 nm, with the precise film morphology being a function of
reactor conditions. The BSG film roughness increases with film thickness, temperature, and boron content. Thermal annealing
of the films in a water-free environment leads to planarization of the BSG governed by the film composition and anneal temperature. 相似文献
4.
Ferroelectric PbTiO3 thin films were deposited on bare silicon and Pt/SiO2/Si substrates by metalorganic chemical vapor deposition in a temperature range from 270 to 550°C. The deposition of a single
phase PbTiO3 thin film did not occur on bare silicon substrates. Instead a double layer of lead-silicate and PbTiO3 was formed owing to a serious diffusion of lead and oxygen ions into silicon substrates. But on Pt/SiO2/Si substrates, a single phase PbTiO3 oriented parallel to a-and c-axis was grown at a substrate temperature as low as 350°C even without a high temperature post-annealing.
To get an optimal film, a precise control of input gas composition and also a deposition in a low temperature range from 350
to 400°C are necessary. 相似文献
5.
SiO2 films were deposited in an rf inductive discharge plasma (13.56 MHz) at a substrate temperature of-550 K and an ion energy
of 35 eV. Variable parameters were silane and oxygen flow rates, pressure (0.3–1.2 Pa), and ion current density (1–2.5 mA/cm2). In these ranges of the process parameters, good silicon dioxide films with a composition close to that of thermally oxidized
SiO2 were obtained. The film growth rate was found to be 65 nm/min. The deposition nonuniformity was <4% over 100-mm silicon wafers. 相似文献
6.
Copper MOCVD (metalorganic chemical vapor deposition) using liquid injection for effective delivery of the (hfac)Cu(vtmos)
[1,1,1,5,5,5-hexafluoro-2,4-pentadionato(vinyltrimethoxysilane) copper(I)] precursor has been performed to clarify growth
behavior of copper films onto TiN, <100> Si, and Si3N4 substrates. Especially, we have studied the influences of process conditions and the substrate on growth rates, impurities,
microstructures, and electrical characteristics of copper films. As the reactor pressure was increased, the growth rate was
governed by a pick-up rate of (hfac)Cu(vtmos) in the vaporizer. The apparent activation energy for copper growth over the
surface-reaction controlled regime from 155°C to 225°C was in the range 12.7–32.5 kcal/mol depending upon the substrate type.
It revealed that H2 addition at 225°C substrate temperature brought about a maximum increase of about 25% in the growth rate compared to pure
Ar as the carrier gas. At moderate deposition temperatures, the degree of a <111> preferred orientation for the deposit was
higher on the sequence of <Cu/Si<Cu/TiN<Cu/Si3N4. The relative impurity content within the deposit was in the range 1.1 to 1.8 at.%. The electrical resistivity for the Cu
films on TiN illustrated three regions of the variation according to the substrate temperature, so the deposit at 165°C had
the optimum resistivity value. However, the coarsened microstructures of Cu on TiN prepared above 275°C gave rise to higher
electrical resistivities compared to those on Si and Si3N4 substrates. 相似文献
7.
Sun-Hong Park Chul-Hwan Choi Kyoung-Bo Kim Seon-Hyo Kim 《Journal of Electronic Materials》2003,32(11):1148-1154
High-quality ZnO thin films were prepared by metal-organic chemical vapor deposition (MOCVD) on a sapphire (a-Al2O3) substrate. The synthesis of ZnO films was performed over a substrate temperature of 400–700°C and at chamber pressures of
0.1–10 torr. The structural and optical properties of ZnO films were investigated in terms of deposition conditions, such
as substrate temperature, working pressure, and the ratio of Zn precursor (Diethylzinc (DEZn)) to oxygen. The ZnO films, preferentially
oriented to 34.42° diffraction because of the (002) plane, were obtained under processing conditions of 700°C and 3 torr.
This film shows a full-width at half-maximum (FWHM) of 0.4–0.6°. The results of photoluminescence (PL) spectroscopy also show
a strong near band-edge emission at 3.36 eV at 10 K as well as a very weak emission at deep levels around 2.5 eV at room temperature.
In addition, we are interested in the introduction of ZnO buffer-layer growth by the sputtering process to reduce lattice
mismatch stress. This paper addresses how to advance the crystalline and optical properties of film. The ZnO film grown with
the aid of a buffer layer shows a FWHM of 0.06–0.1° in the x-ray diffraction (XRD) pattern. This result indicates that crystalline
properties were highly improved by the ZnO buffer layers. The PL spectroscopy data of ZnO film also shows a strong near band-edge
emission and very weak deep-level emission similar to films synthesized without a buffer layer. Accordingly, synthesized ZnO
films with buffer layers indicate fairly good optical properties and low defect density as well as excellent crystallinity. 相似文献
8.
P. Tiwari Mary Longo G. Matera S. Sharan P. L. Smith J. Narayan 《Journal of Electronic Materials》1991,20(7):775-778
We have investigated the formation of TiSi2 and CoSi2 thin films on Si(100) substrates using laser (wave length 248 nm, pulse duration 40 ns and repetition rate 5 Hz) physical
vapor deposition (LPVD). The films were deposited from solid targets of TiSi2 and CoSi2 in vacuum with the substrate temperature optimized at 600° C. The films were characterized using x-ray diffraction, scanning
electron microscopy (SEM), transmission electron microscopy (TEM) and four point probe ac resistivity. The films were found
to be polycrystalline with a texture. The room temperature resistivity was found to be 16 μΩ-@#@ cm and 23 μΩ-cm for TiSi2 and CoSi2 films, respectively. We optimized the processing parameters so as to get particulate free surface. TEM results show that
the silicide/silicon interface is quite smooth and there is no perceptible interdiffusion across the interface. 相似文献
9.
B. Anthony T. Hsu L. Breaux R. Qian S. Banerjee A. Tasch 《Journal of Electronic Materials》1990,19(10):1089-1094
The reaction kinetics in Remote Plasma-enhanced Chemical Vapor Deposition (RPCVD) have been studied for a chamber pressure
of 200 mTorr, rf powers between 4 and 8 W, diluted silane flow rates between 5 and 40 sccm, and temperatures between 190 and
480° C. The observed temperature dependence of growth rate reveals a change in activation energy at 300–325° C, suggesting
that hydrogen desorption is the rate limiting step in the deposition reaction. A strong dependence of growth rate on rf power
has been attributed in part to the extension of the glow discharge region closer to the substrate at higher rf powers. Growth
rate has been shown to increase when the sample is positioned closer to the glow, indicating that the reaction precursor is
a short-lived species, probably SiH2 or SiH3. Growth rate has been shown to exhibit a sublinear dependence on silane partial pressure. Oxygen incorporation in the deposited
films has been studied using Secondary Ion Mass Spectroscopy (SIMS), and it has been found that the main source of oxygen
contamination is the process gases. However, it has also been found that “point of use” purification of the process gases
reduces water and oxygen contamination significantly, reducing the oxygen incorporation in the films by an order of magnitude. 相似文献
10.
In this work, we report the preparation of phospho-silicate-glass (PSG) films using RF magnetron sputtering process and its application as a sacrificial layer in surface micromachining technology. For this purpose, a 76 mm diameter target of phosphorus-doped silicon dioxide was prepared by conventional solid-state reaction route using P2O5 and SiO2 powders. The PSG films were deposited in a RF (13.56 MHz) magnetron sputtering system at 200-300 W RF power, 10-20 mTorr pressure and 45 mm target-to-substrate spacing without external substrate heating. To confirm the presence of phosphorus in the deposited films, hot-probe test and sheet resistance measurements were performed on silicon wafers following deposition of PSG film and a drive-in step. As a final confirmatory test, a p-n diode was fabricated in a p-type Si wafer using the deposited film as a source of phosphorus diffusion. The phosphorus concentration in the target and the deposited film were analyzed using energy dispersive X-rays (EDAX) tool. The etch rate of the PSG film in buffered HF was measured to be about 30 times higher as compared to that of thermally grown SiO2 films. The application of RF sputtered PSG film as sacrificial layer in surface micromachining technology has been explored. To demonstrate the compatibility with MEMS process, micro-cantilevers and micro-bridges of silicon nitride were fabricated using RF sputtered PSG as a sacrificial layer in surface micromachining. It is envisaged that the lower deposition temperature in RF sputtering (<150 °C) compared to CVD process for PSG film preparation is advantageous, particularly for making MEMS on temperature sensitive substrates. 相似文献
11.
M. S. Haque U. V. Patel H. A. Naseem W. D. Brown 《Journal of Electronic Materials》1995,24(6):761-766
Atmospheric pressure chemical vapor deposition (APCVD) of tungsten films using WF6/H2 chemistry has been studied. A statistical design of experiments approach and a surface response methodology were used to
determine the most important process parameters and to obtain the best quality film possible in the parameter range studied.
It was found that the deposition rate depends strongly on WF6 flow rate, temperature, and the interaction between hydrogen flow rate and temperature. The resistivity was found to have
a strong dependence on WF6 and H2 flow rates and temperature. An activation energy of 0.4 eV was calculated for the reaction rate limited growth regime. Empirical
equations for predicting the deposition rate and resistivity were obtained. The resistivity decreases with both increasing
film thickness and grain size. The films grown in the studied process parameter range indicate that (110) is the preferred
orientation for films deposited with low WF6/H2 flow rate ratios at all deposition temperatures (350–450°C), whereas, the (222) orientation dominates at high WF6/H2 flow ratios and high deposition temperatures. Also, the grain size is larger for (222) oriented films than for (110) oriented
films. The results of this study suggest that high-quality, thin film tungsten can be deposited using APCVD. 相似文献
12.
This investigation prepares a low-resistivity and self-passivated Cu(In) thin film. The dissociation behaviors of dilute Cu-alloy
thin films, containing 1.5–5at.%In, were prepared on glass substrates by a cosputter deposition, and were subsequently annealed
in the temperature range of 200–600 °C for 10–30 min. Thus, self-passivated Cu thin films in the form In2O3/Cu/SiO2 were obtained by annealing Cu(In) alloy films at an elevated temperature. Structural analysis indicated that only strong
copper diffraction peaks were detected from the as-deposited film, and an In2O3 phase was formed on the surface of the film by annealing the film at an elevated temperature under oxygen ambient. The formation
of In2O3/Cu/SiO2 improved the resistivity, adhesion to SiO2, and passivative capability of the studied film. A dramatic reduction in the resistivity of the film occurred at 500 °C,
and was considered to be associated with preferential indium segregation during annealing, yielding a low resistivity below
2.92 μΩcm. The results of this study can be potentially exploited in the application of thin-film transistor–liquid crystal display
gate electrodes and copper metallization in integrated circuits. 相似文献
13.
Jonathan E. Greenspan 《Microelectronics Journal》2006,37(10):1056-1063
Selective Area Epitaxy (SAE) is the process of locally depositing a semiconductor film on a substrate which has been patterned with an inert masking material such as SiO2. During deposition by metalorganic chemical vapor deposition (MOCVD), the build up of precursors over the SiO2 mask causes material to diffuse into the open areas leading to a growth rate increase. SAE is an important technique for electronic and photonic device fabrication, and for the monolithic integration of these devices. The present work is a single comprehensive study, which reports on the impact of all major MOCVD parameters to SAE indium phosphide films. The parameters include pressure, V/III pressure ratio, growth rate, temperature and mask geometry. 相似文献
14.
We report large-area synthesis of few-layer graphene films by chemical vapor deposition (CVD) in a cold-wall reactor. The
key feature of this method is that the catalytic metal layers on the SiO2/Si substrates are self-heated to high growth temperature (900°C to 1000°C) by high-current Joule heating. Synthesis of high-quality
graphene films, whose structural and electrical characteristics are comparable to those grown by hot-wall CVD systems, was
confirmed by transmission electron microscopy images, Raman spectra, and current–voltage analysis. Optical transmittance spectra
of the graphene films allowed us to estimate the number of graphene layers, which revealed that high-temperature exposure
of Ni thin layers to a carbon precursor (CH4) was critical in determining the number of graphene layers. In particular, exposure to CH4 for 20 s produces very thin graphene films with an optical transmittance of 93%, corresponding to an average layer number
of three and a sheet resistance of ~600 Ω/square. 相似文献
15.
R. Niebuhr K. Bachem K. Dombrowski M. Maier W. Pletschen U. Kaufmann 《Journal of Electronic Materials》1995,24(11):1531-1534
We have studied the growth of gallium nitride on c-plane sapphire substrates. The layers were grown in a horizontal metalorganic
chemical vapor deposition reactor at atmospheric pressure using trimethylgallium (TMG) and ammonia (NH3). Variation of the V/III ratio (150–2500) shows a distinct effect on the growth rate. With decreasing V/III ratio, we find
an increasing growth rate. Variation of the growth temperature (700–1000°C) shows a weak increase in growth rate with temperature.
Furthermore, we performed secondary ion mass spectroscopy measurements and find an increasing carbon incorporation in the
GaN films with decreasing ammonia partial pressure and a growing accumulation of carbon at the substrate interface. Photoluminescence
measurements show that samples with high carbon content show a strong yellow luminescence peaking at 2.2 eV and a near band
gap emission at 3.31 eV. With increasing carbon content, the intensity of the 3.31 eV line increases suggesting that a carbon
related center is involved. 相似文献
16.
Silicon oxide films have been deposited between room temperature and 300°C using disilane and nitrous oxide by plasma enhanced
chemical vapor deposition. Film deposition was investigated as a function of the gas flow ratio of nitrous oxide to disilane,
the substrate temperature, the total gas flow rate, the radio frequency discharge power, and the process pressure. The stoichiometric
SiO2 films were obtained when the gas ratio of nitrous oxide to disilane was in the range of 50-150. The deposition was found
to be nearly temperature independent indicating the mass transport limited regime. 相似文献
17.
Sung-Do Kwon Byeong-kwon Ju Seok-Jin Yoon Jin-Sang Kim 《Journal of Electronic Materials》2009,38(7):920-924
Bismuth–antimony–telluride based thin film materials were grown by metal organic vapor phase deposition (MOCVD). A planar-type
thermoelectric device was fabricated with p-type Bi0.4Sb1.6Te3 and n-type Bi2Te3 thin films. The generator consisted of 20 pairs of p-type and n-type legs. We demonstrated complex structures of different conduction types of thermoelectric elements on the same substrate
using two separate deposition runs of p-type and n-type thermoelectric materials. To demonstrate power generation, we heated one side of the sample with a heating block and
measured the voltage output. An estimated power of 1.3 μW was obtained for the temperature difference of 45 K. We provide a promising procedure for fabricating thin film thermoelectric
generators by using MOCVD grown thermoelectric materials that may have a nanostructure with high thermoelectric properties. 相似文献
18.
Copper chemical vapor deposition from Cu(hexafluoroacetylacetonate)trimethylvinylsilane (Cu(hfac)TMVS) was studied using a
low pressure chemical vapor deposition system of a cold wall vertical reactor. The Cu films deposited using H2 as a carrier gas revealed no impurities in the films within the detection limits of Auger electron spectroscopy and x-ray
photoelectron spectroscopy. Using hydrogen as a carrier gas, the hydrogen not only acts as a reducing agent, but also reacts
with the residual fragment of precursor. As a result, using H2 as a carrier gas for Cu(hfac)TMVS resulted in Cu films of lower resistivity, denser microstructure and faster deposition
rate than using Ar or N2 as the carrier gas. Moreover, we found that N2 plasma treatment on the substrate surface prior to Cu deposition increased the deposition rate of Cu films. 相似文献
19.
H. Chen J. Zhong G. Saraf Y. Lu D. H. Hill S. T. Hsu Y. Ono 《Journal of Electronic Materials》2006,35(6):1241-1245
ZnO nanotips have been grown on Si (100) using metalorganic chemical vapor deposition (MOCVD). The growth temperature is optimized
for good crystallinity, morphology, and optical properties. ZnO nanotips exhibit a strong near band edge emission of ∼376
nm at room temperature with negligible green band emission. Pregrowth substrate treatment using diluted hydrofluoric acid
(HF) and minimized oxygen exposure before the initial growth significantly reduces the interfacial SiO2 thickness, while maintaining good morphology. An n-ZnO nanotips/p-Si diode is fabricated and its I–V characteristic is measured.
The threshold voltage of the diode is found to be below 2.0 V with small reverse leakage current. The ZnO/p-Si diodes provide
the possibility of integrating the ZnO nanotips with Si-based electronic devices. 相似文献
20.
A study of the thermally activated decomposition of Al(hfa)3 (aluminum hexafluoroacetylacetonate) from the gas phase to form Al2O3 on silicon substrates is reported. The decomposition process was carried out in an open tube atmospheric pressure reactor
in either argon or oxygen/argon mixtures in the temperature range, 350–450° C. The chemical vapor deposition process resulted
in the formation of aluminum oxide films in all instances. The dielectric strength of Al/Al2O3/Si capacitors which received a post-metal anneal, but did not receive a high temperature annealing treatment, with aluminum
oxide films prepared from Al(hfa)3 in argon, was found to be in the range 2–6 MV/cm. The difference between the flatband voltage of the MOS structures and the
metal-silicon work function difference was positive, indicative of a net negative oxide charge with a density of approximately
3 × 1011 – 3 × 1012 cm-2, assuming the charge is located at the oxide-silicon interface. Decomposition of Al(hfa)3 was also carried out in oxygen/argon mixtures with the oxygen concentration in the range 10–60 vol %. This process led to
the deposition of aluminum oxide films with breakdown fields in the range 8–9 MV/cm. However, the flatband voltages of the
Al/Al2O3/Si capacitors were even more positive than those obtained with Al2O3 formed in pure argon. High temperature (800–1000° C) oxygen or nitrogen annealing treatments of alumina films deposited in
either argon or oxygen/argon mixtures were evaluated from the point of view of their influence on the oxide film properties.
In particular, an annealing process in oxygen at 1000° C for 15 min was found to result in a reduction of the net negative
oxide charge, and an improvement of the dielectric strength of films deposited in argon. Films formed in oxygen/argon mixtures
did not change appreciably following oxygen annealing, as far as breakdown fields are concerned, but the oxide net negative
charge was reduced. As in an earlier study by the authors, of copper film deposition from Cu(hfa)2, it was found that essentially carbon free films could be obtained under appropriate conditions. 相似文献