Atomic Layer Controlled Deposition of Al2O3 Films Employing Trimethylaluminum (TMA) and H2O Vapor

1993 ◽  
Vol 335 ◽  
Author(s):  
A. C. Dillon ◽  
A. W. Ott ◽  
S. M. George ◽  
J. D. Way
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Atomic Layer ◽  
Silicon Surfaces ◽  
Controlled Growth ◽  
Alumina Membranes ◽  
Passivation Layers ◽  
Controlled Deposition ◽  
High Dielectric

AbstractSequential surface chemical reactions for the controlled deposition of Al2O3 films were studied using transmission Fourier transform infrared spectroscopy (FTIR). Experiments were performed in situ in an ultrahigh vacuum UHV chamber using high surface area alumina membranes. Trimethylaluminum [Al(CH3)3] (TMA) and H2O vapor were employed sequentially in an ABAB... binary fashion to achieve atomic layer controlled growth. An optimal Al2O3 growth procedure was established that employed TMA/H2O exposures at .3 Torr and 500 K. The experiments revealed that each reaction was self-terminating and atomic layer controlled growth was dictated by the surface chemistry. The controlled deposition of Al2O3 may be employed on silicon surfaces for the formation of high dielectric gate and passivation layers.

Decomposition of Alkylsilanes on Silicon Surfaces Using Transmission Ftir Spectroscopy

1991 ◽  
Vol 222 ◽  
Author(s):  
A. C. Dillon ◽  
M. B. Robinson ◽  
M. Y. Han ◽  
S. M. George
Keyword(s):  
Porous Silicon ◽  
Silicon Surface ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Layer ◽  
Silicon Surfaces ◽  
Surface Species ◽  
Reaction Products ◽  
Molecular Precursors ◽  
Hydride Elimination

ABSTRACTFourier transform infrared (FTIR) transmission spectroscopy was used to monitor the decomposition of alkylsilanes such as diethylsilane (DES) [(CH3 CH2)2SiH2], di-t-butylsilane (DTBS) [((CH3)3C)2SiH2] and ethylsilane (ES) [CH3CH2SiH3 on high-surface-area porous silicon samples. The FTIR spectra revealed that tKe akylsilanes dissociatively adsorb on porous silicon at 300 K to form SiH and Si-alkyl species. As the silicon surface was progressively annealed, the Si-alkyl species decomposed and produced gas phase ethylene (DES,ES) or isobutylene (DTBS). The decomposition of the alkyl group was accompanied by the growth of additional SiH surface species. These reaction products were consistent with a [β-hydride elimination reaction. Above 700 K, the SiH surface species decreased concurrently with the desorption of H2 from the porous silicon surface. The uptake of surface species was also monitored at various adsorption temperatures to determine the optimal exposure temperatures for carbon-free silicon deposition. Carbon contamination was not detected at adsorption temperatures below 640 K prior to H2 desorption. Because the alkylsilane adsorption process is self-limiting at temperatures below 640 K, alkylsilanes may be useful molecular precursors for the atomic layer epitaxy (ALE) of silicon.

scholarly journals Atomic Layer Deposition of ZnO on Mesoporous Silica: Insights into Growth Behavior of ZnO via In-Situ Thermogravimetric Analysis

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 981 ◽  
Author(s):  
Piyush Ingale ◽  
Kristian Knemeyer ◽  
Mar Piernavieja Hermida ◽  
Raoul Naumann d’Alnoncourt ◽  
Arne Thomas ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Atomic Layer Deposition ◽  
Reaction Mechanisms ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Layer ◽  
Ex Situ ◽  
Direct Access ◽  
Layer Deposition

ZnO is a remarkable material with many applications in electronics and catalysis. Atomic layer deposition (ALD) of ZnO on flat substrates is an industrially applied and well-known process. Various studies describe the growth of ZnO layers on flat substrates. However, the growth characteristics and reaction mechanisms of atomic layer deposition of ZnO on mesoporous powders have not been well studied. This study investigates the ZnO ALD process based on diethylzinc (DEZn) and water with silica powder as substrate. In-situ thermogravimetric analysis gives direct access to the growth rates and reaction mechanisms of this process. Ex-situ analytics, e.g., N2 sorption analysis, XRD, XRF, HRTEM, and STEM-EDX mapping, confirm deposition of homogenous and thin films of ZnO on SiO2. In summary, this study offers new insights into the fundamentals of an ALD process on high surface area powders.

In-situ Mössbauer effect spectroscopy of adsorbed species on high surface area electrodes

1982 ◽  
Vol 10 (3) ◽  
pp. 325-332 ◽  
Author(s):  
D. Scherson ◽  
S.B. Yao ◽  
E.B. Yeager ◽  
J. Eldridge ◽  
M.E. Kordesch ◽  
...  
Keyword(s):  
Surface Area ◽  
Mössbauer Effect ◽  
High Surface ◽  
High Surface Area ◽  
Mossbauer Effect ◽  
Adsorbed Species ◽  
Mössbauer Effect Spectroscopy

In-Situ Transmission Electron Microscopy of the Formation of Metal-Semiconductor Contacts

1990 ◽  
Vol 181 ◽  
Author(s):  
J. M. Gibson ◽  
D. Loretto ◽  
D. Cherns
Keyword(s):  
High Surface ◽  
High Vacuum ◽  
Volume Ratio ◽  
Ultra High Vacuum ◽  
Silicon Surfaces ◽  
Transmission Electron ◽  
Metal Silicides ◽  
Phase Sequence ◽  
Semiconductor Contacts

ABSTRACTWe have studied the formation of metal silicides in-situ in an ultra-high vacuum transmission electron microscope. Metals were deposited on in-situ cleaned, reconstructed silicon surfaces and annealed. For the metals Ni and Co, we find that the phase sequence in ultra-thin films is different from that seen in ≈1000 Å thick films, and attribute this to the high surface-to-volume ratio. In general reactions occur at room temperature, to form an epitaxial phase if possible. We report preliminary new results on the formation of Pd2Si.

scholarly journals The synthesis of a BiOClxBr1−x nanostructure photocatalyst with high surface area for the enhanced visible-light photocatalytic reduction of Cr(vi)

RSC Advances ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 4763-4771 ◽  
Author(s):  
Muhammad Bilal Hussain ◽  
Malik Saddam Khan ◽  
Herman Maloko Loussala ◽  
Muhammad Sohail Bashir
Keyword(s):  
Visible Light ◽  
Surface Area ◽  
Room Temperature ◽  
High Surface ◽  
High Surface Area ◽  
Photocatalytic Reduction ◽  
Synthetic Process ◽  
Visible Light Photocatalytic

Cr(vi) reduction is performed by BiOCl0.8Br0.2 composite produced via a facile in situ synthetic process at room temperature while making use of PVP (Mw = 10 000).

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