High‐resolution x‐ray diffraction to determine the self‐limiting growth in atomic layer epitaxy of InP and InAs/InP heterostructures

1993 ◽  
Vol 62 (19) ◽  
pp. 2375-2377 ◽  
Author(s):  
C. A. Tran ◽  
R. A. Masut ◽  
J. L. Brebner ◽  
R. Leonelli
1999 ◽  
Vol 581 ◽  
Author(s):  
Travis L. Wade ◽  
Billy H. Flowers ◽  
Raman Vaidyanathan ◽  
Kenneth Mathe ◽  
Clinton B. Maddox ◽  
...  

ABSTRACTElectrochemical atomic-layer epitaxy (EC-ALE) is an approach to electrodepositing thin-films of compound semiconductors. It takes advantage of underpotential deposition (UPD), deposition of a surface limited amount (a monolayer or less) of an element at a potential less negative than bulk deposition, to form a thin-film of a compound--one atomic layer at a time. Ideally, the 2-D growth mode should promote epitaxial deposition.Many II-VI and a few III-V compounds have been formed by EC-ALE. TI-VI films such as CdSe, CdS, and CdTe have been successfully formed. In addition, deposition of III-V compounds of InAs and InSb are being explored, along with initial studies of GaAs deposition. Depositions of the I-VI systems are better understood so this report will focus on the III-V's, particularly InAs and InSb.Building compounds an atomic layer at a time lends electrochemical-ALE to nanoscale technology. Deposited thickness ranged from a few nanometers to a few hundred. The films are typically characterized by atomic-force microscopy (AFM), X-ray diffraction (XRD), electron microprobe analysis (EPMA) and ellipsometry. InAs deposits are also characterized by infrared reflection absorption.


1996 ◽  
Vol 74 (S1) ◽  
pp. 85-88 ◽  
Author(s):  
R. Arès ◽  
C. A. Tran ◽  
S. P. Watkins

Reflectance difference spectroscopy (RDS) has been used to monitor the anisotropy of the surface of InAs and GaAs grown by atomic layer epitaxy (ALE). Saturation of the RDS signal is observed when the surface is fully covered with one monolayer of the impinging surface species. This property is used to optimize the growth interruptions for the ALE cycle. Good correlation of the RDS saturation is observed with growth-rate measurements obtained by X-ray diffraction (XRD). When exposure times are sufficiently long for saturation to be observed in the RDS signal, a growth rate of one monolayer per cycle (1 ML/cycle) is achieved. In principle all the different growth parameters such as exposure and purge times as well as gas flows can be determined in a few cycles performed on a single substrate. Without RDS the same results would require several growth runs and time consuming X-ray characterization.


2002 ◽  
Vol 744 ◽  
Author(s):  
Raman Vaidyanathan ◽  
Mkhulu K. Mathe ◽  
Patrick Sprinkle ◽  
Steve M Cox ◽  
Uwe Happek ◽  
...  

ABSTRACTElectrochemical atomic-layer epitaxy (EC-ALE) is an approach to electrodepositing thin-films of compound semiconductors. It takes advantage of underpotential deposition (UPD), deposition of a surface limited amount (a monolayer or less) of an element at a potential less negative than bulk deposition, to form a thin-film of a compound--one atomic layer at a time. Ideally, the 2-D growth mode should promote epitaxial deposition.We report the formation of compound Cu2Se, at room temperature by electrochemical atomic layer epitaxy (EC-ALE). Cyclic voltammograms were used to determine the deposition potentials of each element. An automated deposition program was used to form 750 cycles of Cu2Se thin films. Electron probe microanalysis was done to determine the stoichiometry of the thin films. X-ray diffraction of the 200 cycle deposit indicated the presence of polycrystalline Cu2Se. The atomic ratio of Cu/Se in the thin films was found to be 2. Band gap of the thin films were determined by reflection absorption measurements. The band gap of the 200 cycle Cu2Se films was found to be 1.6 eV. X-ray diffraction of 350 and 750 cycle Cu2Se films, indicated the deposits consisted of Cu3Se2 and Cu2Se.


2018 ◽  
Vol 64 (3) ◽  
pp. 206
Author(s):  
R. S. Castillo Ojeda ◽  
Joel Díaz-Reyes ◽  
M. Galván-Arellano ◽  
K. N. Rivera-Hernández ◽  
M. S. Villa-Ramírez ◽  
...  

In this work are presented the results obtained from the deposition ofCd1-xZnxTe nanolayers using as precursor the vapours of the elementsZn, Te, and a mixture of Cd and Zn on GaAs and GaSb (001) substrates by Atomic Layer Deposition technique (ALD), which allows the deposition of layers of nanometric dimensions. At each exposure of the growth surface to the of cation or anion precursors vapours, this surface is saturated. Therefore, it is considered that the process is self-regulated. The ZnTe layers were grown in a wide range of temperatures; however, ZnTe nanolayers with a shiny mirror-like surface could be grown at temperatures between 370 and 410oC. Temperatures higher than 400oC were necessary for the CdTe growth. The layers of the Cd1-xZnxTe ternary alloy were deposited at temperature range of 400 and 425oC. The grown nanofilms were characterized by Raman spectroscopy and high-resolution X-ray diffraction. The Raman spectrumshows the peak corresponding to LO-ZnTe at 208 cm-1, which is weak and is slightly redshifted in comparison with the reported for the bulk ZnTe. For the case of the CdTe nanolayers, Raman spectrum presents the LO-CdTe peak, which is indicative of the successfully growth of the nanolayers, its weakness and its slight redshifted in comparison with the reported for the bulk CdTe can be related with the nanometric characteristic of this layer. The performed high resolution X-ray diffraction measurements allowed to study some importantcharacteristics, as the crystallinity of the grown layers. Additionally, the performed HR-XRD measurements suggest that the crystalline quality have dependence with the growth temperature.


1989 ◽  
Vol 160 ◽  
Author(s):  
H. Shimawaki ◽  
Y. Kato ◽  
A. Usui

AbstractInAs chloride ALE has been carried out in detail, resulting in successful InGaAs ALE on (111)B InP substrates. InAs growth of 0.9 ML/cycle is obtained for (111)B InAs substrates at temperatures below 375 °C, while growth rates for (100) and (111)A substrates steadily decrease with increases in growth temperature. The growth rates are independent of InCI pressure at 375 °C, suggesting a self-limiting growth factor in InAs chloride ALE. (GaAs)1(InAs)1 and (GaAs)2(InAs)2 superalloys can be prepared on (111)B InP substrates at 375 °C. Growth rates and crystal compositions for both layers agree well with the values expected for ideal superalloys. The presence of superlattice structures is indicated by X-ray diffraction measurement,


1981 ◽  
Vol 67 (2) ◽  
pp. 573-583 ◽  
Author(s):  
V.-P. Tanninen ◽  
M. Oikkonen ◽  
T. O. Tuomi

1985 ◽  
Vol 124 (3-4) ◽  
pp. 317-321 ◽  
Author(s):  
M. Oikkonen ◽  
M. Blomberg ◽  
T. Tuomi ◽  
M. Tammenmaa

1989 ◽  
Vol 160 ◽  
Author(s):  
B.T. Mcdermott ◽  
K.G. Reid ◽  
A. Dip ◽  
N.A. El-Masry ◽  
S.M. Bed Air ◽  
...  

AbstractWe report on the successful growth of GalnP on GaAs substrate by Atomic Layer Epitaxy using organometallic and hydride sources. Growth was achieved by sequential exposure of the substrate to TMGa, PH3, TEIn and PH3. X-ray diffraction showed compositional lattice-matching optimally at 550°C with arbitrary choices of the mole fractions of the precursors in the gas phase. TEM also confirmed the highest ordering at this growth temperature on (100) substrates. Uniformity was excellent using Atomic Layer Epitaxy. Growth on (111)A GaAs substrates produced no evidence of the ordered CuPt phase present on (100) substrates.


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