The Mechanisms and Kinetics of Surface Reactions of Trimethylgallium on GaAs (001) Surfaces and Its Relevance to Atomic Layer Epitaxy

1991 ◽  
Vol 222 ◽  
Author(s):  
B. Y. Maa ◽  
P. D. Dapkus
Keyword(s):  
Photoelectron Spectroscopy ◽  
Selective Adsorption ◽  
Surface Reactions ◽  
Optimal Strategies ◽  
Atomic Layer ◽  
High Energy ◽  
Reflectance Difference Spectroscopy ◽  
Reconstructed Surfaces ◽  
Surface Reaction Kinetics ◽  
Kinetics Of

ABSTRACTX-ray photoelectron spectroscopy (XPS) and reflection high energy electron diffraction (RHEED) have been applied to study the stable adsorbed Ga species and surface structures after GaAs (001) 2 × 4 As-rich surfaces are exposed to TMGa. These studies show that Ga atoms are the final adsorbed species, that Ga deposition is saturated at one atomic layer at temperatures between 360 and 530 °C and that the surface converts from a 2 × 4 to a 4 × 6 reconstruction after TMGa adsorption. To understand the surface reaction kinetics involved, reflectance-difference spectroscopy (RDS), an in situ rea-ltime optical technique developed by Aspnes et al., is applied to investigate TMGa adsorption on (001) GaAs surfaces. The kinetics of the surface reactions and reconstructions have been characterized over the temperature range from 400 to 500 °C using RDS. The transient RDS behaviors are interpreted by the application of a model that involves selective adsorption and reaction of TMGa at surface As sites and at Ga vacancies on Ga-rich reconstructed surfaces. Based upon these interpretations, rates of reaction and by product desorption are determined that suggest optimal strategies for ALE growth of GaAs.

Kinetics of the WF6 and Si2H6 surface reactions during tungsten atomic layer deposition

2001 ◽  
Vol 479 (1-3) ◽  
pp. 121-135 ◽  
Author(s):  
J.W Elam ◽  
C.E Nelson ◽  
R.K Grubbs ◽  
S.M George
Keyword(s):  
Atomic Layer Deposition ◽  
Surface Reactions ◽  
Atomic Layer ◽  
Layer Deposition ◽  
Kinetics Of

Low Temperature Cleaning of Ge and GaAs Surfaces Using Hydrogen Dissociated with a Remote Noble-Gas Discharge

1989 ◽  
Vol 165 ◽  
Author(s):  
S. V Hatitangady ◽  
R. A. Rudder ◽  
M. J. Mantini ◽  
G. G. Fountain ◽  
J. B. Posthill ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Noble Gas ◽  
High Energy ◽  
Plasma Cvd ◽  
X Ray ◽  
Native Oxides ◽  
Novel Structure ◽  
Reconstructed Surfaces ◽  
Mis Structures

AbstractThe native oxides of Ge and GaAs have long been known to preclude the formation of suitable MIS structures. In situ cleaning of Ge and GaAs surfaces has been achieved at 300–375 °C using a novel technique employing hydrogen that is dissociated using a remote Ar discharge. Such a technique circumvents the problems of cross contamination introduced from a directly excited hydrogen discharge due to erosion of the quartz tube walls by the active hydrogen. Reconstructed surfaces characteristic of clean Ge and GaAs surfaces have been observed with Reflection High Energy Electron Diffraction (RHEED) following such a treatment. Auger and X-ray Photoelectron Spectroscopy (XPS) analyses show that such a treatment removes both oxygen and carbon contamination from the surface. XPS window scans on the Ga-3d and the As-3d peaks show that the treatment is successful in removing oxygen bonded to both Ga and As on the GaAs surface.Following the in situ cleaning, excellent MIS structures on Ge and GaAs have been realized with a novel structure that utilizes an ultra-thin Si interlayer (1.5 nm) between the insulator-oxide and the clean semicondutor surface. The Si interlayer prevents any sub-cutaneous oxidation of the underlying semiconductor while exploiting the advantages of the excellent Si-SiO2 interface. The entire structure is fabricated in a single-chamber remote plasma CVD unit.

INTERACTION BETWEEN Zn AND Cd ATOMS DURING THE ATOMIC LAYER EPITAXY GROWTH OF CdZnTe/ZnTe QUANTUM WELLS

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1725-1728 ◽  
Author(s):  
ERICK M. LARRAMENDI ◽  
EDGAR LÓPEZ-LUNA ◽  
OSVALDO DE MELO ◽  
ISAAC HERNÁNDEZ-CALDERÓN
Keyword(s):  
Quantum Wells ◽  
Atomic Layer ◽  
High Energy ◽  
Atomic Layer Epitaxy ◽  
Temporal Behavior ◽  
High Energy Electron ◽  
Substrate Temperatures ◽  
Kinetics Of ◽  
Znte Film ◽  
Cdte Surface

Layers of 6 and 16 Cd–Te–Zn–Te periods were grown by atomic layer epitaxy (ALE) within ZnTe thin films. Different samples were grown at substrate temperatures of 260 and 290°C. Information about the kinetics of growth and surface reconstruction during the ALE growth of CdTe and ZnTe films, and Cd–Te–Zn–Te periods was obtained by means of reflection high-energy electron diffraction (RHEED) experiments and through the analysis of the temporal behavior of the intensities of several features of the RHEED patterns. The photoluminescence of the sample grown at 260°C presents two narrow and intense peaks corresponding to emission from quantum wells (QWs). However, the spectrum of the samples grown at 290°C does not show any feature associated with QWs, the spectrum resembling that of a ZnTe film. Cd replacement by Zn atoms explains the absence of the CdZnTe QWs at 290°C and a lower Cd content than expected at 260°C. The replacement of Cd atoms by Zn atoms in the CdTe surface was clearly demonstrated by Auger experiments.

Rheed Measurement and Chemical Kinetics of Chemical Beam Epitaxial growth of GaAs

1989 ◽  
Vol 145 ◽  
Author(s):  
T.H. Chiu
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Atomic Layer ◽  
High Energy ◽  
Reaction Model ◽  
Atomic Layer Epitaxy ◽  
Dynamic Evolution ◽  
High Energy Electron ◽  
Incident Flux ◽  
Kinetics Of

AbstractRecent efforts employing reflection high energy electron diffiaction measurements to study the chemical beam epitaxial growth of GaAs is reviewed. A reaction model which assumes the dominance of Ga alkyls and their derivatives adsorbed on the growing surface can explain most of the growth results in a consistent way. Dynamic evolution of the reconstruction pattern of the adsorbed triethylgallium or trimethylgallium overlayer illustrates how the alkyl-Ga bonds are cleaved sequentially. The growth rate dependence on temperature and incident flux can be fitted quite well in this reaction model. In the absence of As flux, the existence of a metastable Ga alkyl overlayer makes possible the atomic layer epitaxy of GaAs.

Oxygen Vacancies at the γ-Al2O3/STO Heterointerface Grown by Atomic Layer Deposition

2015 ◽  
Vol 1730 ◽  
Author(s):  
Thong Q. Ngo ◽  
Martin D. McDaniel ◽  
Agham Posadas ◽  
Alexander A. Demkov ◽  
John G. Ekerdt
Keyword(s):  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Atomic Layer ◽  
High Energy ◽  
Ex Situ ◽  
X Ray ◽  
Layer Deposition ◽  
Dimensional Electron Gas

ABSTRACTWe report the epitaxial growth of γ-Al2O3 on SrTiO3 (STO) substrates by atomic layer deposition (ALD). The ALD growth of γ-Al2O3 on STO(001) single crystal substrates was performed at a temperature of 345 °C. Trimethylaluminum and water were used as co-reactants. In-situ reflection high-energy electron diffraction and ex-situ x-ray diffraction were used to determine the crystallinity of the Al2O3 films. In-situ x-ray photoelectron spectroscopy was used to characterize the Al2O3/STO heterointerface. The formation of a Ti3+ feature is observed in the Ti 2p spectrum of STO after the first few ALD cycles of Al2O3 and even after exposure of the STO substrate to trimethylaluminum alone at 345 °C. The presence of a Ti3+ feature is a direct indication of oxygen vacancies at the Al2O3/STO heterointerface, which provide the carriers for the quasi-two dimensional electron gas at the interface.

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