Growth of SrS Thin Films by Atomic Layer Epitaxy

1991 ◽  
Vol 222 ◽  
Author(s):  
M. Leskela ◽  
L. Niinistö ◽  
E. Nykänen ◽  
P. Soininen ◽  
M. Tiitta
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Substrate Temperature ◽  
Flow Rate ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Source Temperature ◽  
Large Size ◽  
Monolayer Growth ◽  
Purge Gas

ABSTRACTThe growth of strontium sulfide thin films in a flow-type Atomic Layer Epitaxy reactor from Sr(thd)2 (thd = 2,2,6,6-tetramethyl-3,5-heptanedione) and H2S has been studied. The growth is independent on flow rate and duration of the purge gas (N2) pulse and it does not depend on the Sr(thd)2 and H2S pulses either provided their amounts are sufficient to saturate the surface. The variables significantly affecting the growth rate are the substrate temperature and source temperature for Sr(thd)2. The observed lower than one monolayer growth rate is mainly due to the large size of the Sr(thd)2 molecule.

Plasma-Enhanced Atomic Layer Deposition of GaN Thin Film at Low Temperature

2017 ◽  
Vol 727 ◽  
pp. 907-914
Author(s):  
Wen Hui Tang ◽  
Yi Jia ◽  
Bo Cheng Zhang ◽  
Chang Wei Yang ◽  
You Zhi Qu ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Low Temperature ◽  
Atomic Layer Deposition ◽  
Flow Rate ◽  
Nitrogen Sources ◽  
Atomic Layer ◽  
Gas Mixture ◽  
X Ray ◽  
Layer Deposition

Polycrystalline GaN thin films were successfully grown at low temperature (250 °C) by plasma-enhanced atomic layer deposition with NH3, N2, N2/H2 gas mixture and trimethylgallium (TMG) as precusor. The growth rate, crystal structure, surface composition and the valence state of the corresponding element of the GaN thin films using different nitrogen sources were characterized and examined systematically via the spectroscopic ellipsometry, the x-ray diffractometer, the x-ray photoel-ectron spectrometer. It is showed that all the GaN thin films using different nitrogen sources were polycrystalline structure and the preffered orientation were mainly (100). The films using N2 and N2/H2 gas mixture had a higher crystal quality than films using NH3. The GPC (growth rate per cycle) would increase with the increase of the N2 flow rate. The films using a suitable ratio of N2/H2 flow rate had not only a high GPC but a good crystal quality. The ratios of Ga/N element of the films using N2/H2 gas mixture were approximated to 1:1, it would increase with the ratio of the N2/H2 flow rate in the gas mixture, which is showing much effect of the ratios of N2/H2 flow rate on the nitrogen content of the thin films.

Structural Properties of CdTe Thin Films for Solar Cell Applications Deposited on Flexible Foil Substrates

2009 ◽  
Vol 1165 ◽  
Author(s):  
Vasilios Palekis ◽  
Deidra Ranel Hodges ◽  
Don L Morel ◽  
Lee Stefanakos ◽  
Chris S Ferekides
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Growth Rate ◽  
Grain Size ◽  
Solar Cells ◽  
Solar Cell ◽  
Substrate Temperature ◽  
Source Temperature ◽  
Cdte Solar Cells ◽  
Cdte Thin Films

AbstractCadmium telluride (CdTe) is a leading thin film photovoltaic (PV) material due to its near ideal band gap of 1.45 eV and its high optical absorption coefficient. The typical CdTe thin film solar cell is of the superstrate configuration where a window layer (CdS), the absorber (CdTe), and a back contact are deposited onto a glass slide coated with a transparent electrode. Substrate CdTe solar cells where the above listed films are deposited in reverse order are not common. In this study, the growth of CdTe thin films deposited on foil substrates by the close-spaced sublimation (CSS) has been investigated for the purpose of fabricating substrate based CdTe solar cells. The CdTe films were deposited at substrate temperatures (TSUB) in the range of 300 to 600°C, and source temperatures (TSRC) in the 600 to 650°C range. The effect of the substrate-source temperature variations on the growth rate, film structure and morphology were studied using XRD and SEM. It was found that for low substrate temperature and as the growth rate increases, grain size was the same but the films appeared to be more uniform and more densely packed with less or no pinholes. The growth rate increased as the source temperature increased. The substrate temperature clearly influences the grain growth and the preferred orientation. As the substrate temperature increased the growth rate decreased and the grain size varied from 2 to 6 μm. XRD analysis showed that with the increase in substrate temperature film orientation changes from preferential along the (111) direction to a mix of (111) (220) and (311).

Low Temperature Deposition of Polycrystalline Silicon thin Films by Hot-Wire CVD

1995 ◽  
Vol 377 ◽  
Author(s):  
Shuangying Yu ◽  
Sadanand Deshpande ◽  
Erdogan Gulari ◽  
Jerzy Kanicki
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Growth Rate ◽  
Substrate Temperature ◽  
Flow Rate ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Hot Wire ◽  
Hydrogen Flow ◽  
Si Films

ABSTRACTIn this study, we have deposited polycrystalline silicon (poly-Si) thin films by hot-wire Chemical Vapor Deposition (CVD) using hydrogen and disilane as the reactive gases. We selectively activate hydrogen and let disilane bypass the hot tungsten filament assembly and enter the reactor downstream from hydrogen. This may provide a better process chemistry, and by this approach, we have deposited poly-Si films at a substrate temperature as low as 310°C and at a growth rate as high as 100 Å/min. The substrate temperature is more than 2000C lower and the growth rate is more than twice higher compared to those of LPCVD poly-Si films. The effect of hydrogen flow rate, disilane flow rate and substrate temperature on the deposition rate and structural properties of the polysilicon films are investigated. The deposited films are characterized by transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and X-ray diffraction.

Atomic Layer Deposition of Undoped and Al-Doped ZnO Thin Films Usingthe Zn Alkoxide Precursor Methylzinc Isopropoxide

2008 ◽  
Vol 8 (9) ◽  
pp. 4856-4859 ◽  
Author(s):  
Ki-Seok An ◽  
Wontae Cho ◽  
Byung Kook Lee ◽  
Sun Sook Lee ◽  
Chang Gyoun Kim
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Atomic Layer Deposition ◽  
Substrate Temperature ◽  
Deep Level ◽  
Atomic Layer ◽  
Zno Thin Films ◽  
Zno Films ◽  
Layer Deposition ◽  
Doped Zno

Undoped and Al-doped ZnO thin films have been prepared by atomic layer deposition (ALD) using the Zn precursor methylzinc isopropoxide [MZI, (CH3)Zn(OCH(CH3)2)] with water (H2O). Dimethylaluminum isopropoxide (DMAI) was used as an Al precursor. The self-limiting ALD process via alternate surface reactions of MZI and H2O was confirmed by thickness measurements of the ZnO films with varying MZI supply time and numbers of MZI-H2O ALD cycles. Under optimal reaction conditions, the growth rate of the ZnO films was 1.9∼2.0 Å/cycle in the substrate temperature range of 160∼200 °C and the maximum growth rate reached about 2.58 Å/cycle at 240 °C. Room temperature photoluminescence (PL) measurements revealed a strong free excitonic peak at 3.27 eV with almost negligible deep level emission. Resistivities of ZnO films were measured to be 5 × 10−3 ∼3.2 × 10−3 Ωcm depending on the substrate temperature. By Al-doping, the resistivity was minimized to ∼1 35 × 10−4 Ωcm.

Metalorganic Chemical Vapor Deposition of InP by Pulsing Precursors

1989 ◽  
Vol 160 ◽  
Author(s):  
W. K. Chen ◽  
J. C. Chen ◽  
L. Anthony ◽  
P. L. Liu
Keyword(s):  
Chemical Vapor Deposition ◽  
Substrate Temperature ◽  
Vapor Deposition ◽  
Growth Process ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Monolayer Growth ◽  
Metalorganic Chemical

AbstractWe have grown InP by supplying precursors alternately into the reactor of a metalorganic chemical vapor deposition system. Epitaxial growth has been obtained with a substrate temperature as low as 330 °C. The growth process is mass-transport-limited in the temperature range of 420 to 580 °C. It is kinetic-controlled below 400 °C. At 340 °C, we have achieved monolayer growth in each cycle, i.e., atomic layer epitaxy.

Enhanced growth rate in atomic layer epitaxy deposition of magnesium oxide thin films

2000 ◽  
Vol 10 (8) ◽  
pp. 1857-1861 ◽  
Author(s):  
Matti Putkonen ◽  
Timo Sajavaara ◽  
Lauri Niinistö
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Magnesium Oxide ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Oxide Thin Films

Deposition of Cerium Dioxide Thin Films on Silicon Substrates by Atomic Layer Epitaxy

1993 ◽  
Vol 335 ◽  
Author(s):  
Heini Mölsä ◽  
Lauri Niinistö
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Steric Hindrance ◽  
Cerium Dioxide ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Silicon Substrates ◽  
Reactor Pressure

AbstractCeO2 overlayers up to 360 nm thick were deposited on Si(100) substrates in a flowtype ALE reactor from Ce(thd)4 (thd = 2,2,6,6-tetramethyl-3,5-heptanedione) precursor and ozone. The growth rate was studied as a function of deposition and source temperatures, reactor pressure and pulse durations. The films were characterized for crystallinity, thickness and composition by using XRD, profilometry, XRF, RBS, XPS and SIMS techniques. Films deposited at 375 °C showed a preferential (110) orientation while at 425 °C they were (111) preferentially oriented. Due to the steric hindrance caused by the bulky precursor the growth rate was only 0.4 Å/cycle.

scholarly journals Properties and Mechanism of PEALD-In2O3 Thin Films Prepared by Different Precursor Reaction Energy

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 978
Author(s):  
Ming-Jie Zhao ◽  
Zhi-Xuan Zhang ◽  
Chia-Hsun Hsu ◽  
Xiao-Ying Zhang ◽  
Wan-Yu Wu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Substrate Temperature ◽  
Film Growth ◽  
Atomic Layer ◽  
Amorphous Structure ◽  
Reaction Energy ◽  
Film Growth Rate ◽  
In2o3 Film ◽  
Intermediate Temperature Range ◽  
Layer Deposition

Indium oxide (In2O3) film has excellent optical and electrical properties, which makes it useful for a multitude of applications. The preparation of In2O3 film via atomic layer deposition (ALD) method remains an issue as most of the available In-precursors are inactive and thermally unstable. In this work, In2O3 film was prepared by ALD using a remote O2 plasma as oxidant, which provides highly reactive oxygen radicals, and hence significantly enhancing the film growth. The substrate temperature that determines the adsorption state on the substrate and reaction energy of the precursor was investigated. At low substrate temperature (100–150 °C), the ratio of chemically adsorbed precursors is low, leading to a low growth rate and amorphous structure of the films. An amorphous-to-crystalline transition was observed at 150–200 °C. An ALD window with self-limiting reaction and a reasonable film growth rate was observed in the intermediate temperature range of 225–275 °C. At high substrate temperature (300–350 °C), the film growth rate further increases due to the decomposition of the precursors. The resulting film exhibits a rough surface which consists of coarse grains and obvious grain boundaries. The growth mode and properties of the In2O3 films prepared by plasma-enhanced ALD can be efficiently tuned by varying the substrate temperature.

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