Arturo Escobosa - Academia.edu (original) (raw)
Papers by Arturo Escobosa
IEEE Journal of the Electron Devices Society, 2021
of America. He serves as a member of the Distinguished Lecturer program of the Electron Devices S... more of America. He serves as a member of the Distinguished Lecturer program of the Electron Devices Society. He has been a member of advisory and technical committees in several international and national conferences. Arturo Escobosa received the Ph.D. degree from RWTH, Aachen, Germany. He is a full-time Professor with the Electrical Engineering Department, Cinvestav, Mexico, where he has been a member of the Solid-State Electronics Section. His research activity includes the fields of III-V semiconducting compounds, optoelectronic devices, MOCVD growth, optical characterization of electronic materials, and X-ray diffraction techniques. He has volunteered at the Electron Devices Society, as a member of technical committees. He was an Elected Member of the EDS Board of Governors from 2010 to 2016. Since 2018, he has been the Region Chair of EDS Region and Chapters Committee.
Applied Surface Science, 2019
Controlling the film/substrate crystallographic relationships is of great interest since a good i... more Controlling the film/substrate crystallographic relationships is of great interest since a good interface results in an improved crystal homogeneity and quality. In this work, texture analysis on Bi 2 Te 3 films grown by physical vapor transport was carried out in order to study the influence of growth conditions such as time and substrate orientation. Two types of substrates were used: Si (1 0 0) and Si (1 1 1). It was found that the c-axis of the hexagonal structure of Bi 2 Te 3 is always perpendicular to the substrate surface, while the orientation of the a-axes depends on the growth parameters. The in-plane orientation of the Bi 2 Te 3 crystallites was improved as the growth time increased and textured epitaxial growth was achieved. The epitaxial relationships between the cubic Si and the hexagonal Bi 2 Te 3 lattices were studied through pole diagrams. It was found that the a-axes of the Bi 2 Te 3 lattice are oriented along the 〈1 1 0〉 directions of the Si surface in both types of substrates. In contrast to other reports, the observed growth rate was not constant, but it decreased with time. This effect is discussed in relation with the characteristic spiral growth mechanism.
Inorganic chemistry, Jan 20, 2018
BiTe is a well-studied material because of its thermoelectric properties and, recently, has also ... more BiTe is a well-studied material because of its thermoelectric properties and, recently, has also been studied as a topological insulator. However, it is only one of several compounds in the Bi-Te system. This work presents a study of the physical vapor transport growth of Bi-Te material focused on determining the growth conditions required to selectively obtain a desired phase of the Bi-Te system, i.e., BiTe, BiTe, and BiTe. Epitaxial films of these compounds were prepared on sapphire and silicon substrates. The results were verified by X-ray diffraction, Raman spectroscopy, and Rutherford backscattering spectrometry.
Materials Sciences and Applications, 2015
Crystallinity refers to the degree of structural order in a solid and has a big influence on hard... more Crystallinity refers to the degree of structural order in a solid and has a big influence on hardness, density, transparency and diffusion. Even within materials that are crystalline completely, the degree of structural perfection can vary, reflecting size and elastic strain of many independent crystalline regions (grains or crystallites) of which these materials are composed. In this work it was attempted to reduce the crystallinity of human enamel using a technique of mechanical grinding (MG) with an ultra-compact FRITSCH Mini-Mill PULVERISETTE 23 machine. Variation in the crystallinity through the MG was monitored by X-ray diffraction (XRD) by broadening of the diffraction peak and examined using the Williamson-Hall plot method. Crystallites in human enamel are regularly arranged and oriented (in the [001] direction) perpendicularly to the interface of enameldentin junction. The results showed an anisotropic feature in crystallinity. Reduction of the crystallinity along the a-axis is due to the crystal strain rather than to the refinement of crystal, and vice versa along the c-axis. After 230 h of the MG, the length of crystallites decreased from 100 nm to 30 nm and width from 40 nm to 37 nm approximately.
2012 8th International Caribbean Conference on Devices, Circuits and Systems (ICCDCS), 2012
ABSTRACT An irregular erosion rate in SIMS can lead to erroneous results during depth profiling a... more ABSTRACT An irregular erosion rate in SIMS can lead to erroneous results during depth profiling analysis of semiconductor hetero-structures. In this work the dependence of erosion on the composition of AlxGA1−xAs is determined. High resolution X-ray diffraction is used to measure the alloy composition considering the deformation due to a good coupling between substrate and layer. The result shows that the erosion rate is reduced to 70% when the AlAs fraction (x) increases from 0 to 0.65.
Solar Energy Materials and Solar Cells, 2015
produce an increase of the average concentration of CdTe towards the surface of the films. Due to... more produce an increase of the average concentration of CdTe towards the surface of the films. Due to Zn/Cd inter-diffusion during the growth process the sequence of layers was converted into a relatively smooth graded composition film. According to X-ray diffraction characterization the layers grew coherently with the (100) oriented GaAs substrates although they showed a relatively high mosaicity. 2 plots show very wide diffraction peaks as expected from variable composition samples. The band gap grading effect in light absorption was also verified through transmission measurements, using transparent substrates. Graded composition profiles of the thin films were confirmed by x-ray photoelectron and secondary ion mass spectroscopies. Moreover, quantitative Cd, Zn and Te profiles were obtained by the analysis of Rutherford backscattering spectra of the samples. This analysis showed a CdTe molar fraction profile ranging from approximately x = 0.8 at the surface of the sample and x = 0.35 at the interface with the substrate. The possibility of growing graded composition layers using a simple and cost-effective procedure was demonstrated. This could be interesting in technological applications like CdxZn1-xTe layers of variable composition in CdS/CdTe solar cells.
2010 7th International Conference on Electrical Engineering Computing Science and Automatic Control, 2010
Here, a characterization methodology for integrated silicon-based photo-devices is presented. Dev... more Here, a characterization methodology for integrated silicon-based photo-devices is presented. Devices are phototransistors ("P+/N-Well/P-substrate") and photodiodes ("N-Well/P-substrate") with similar sizes, (9µmx9µm). They were integrated in a 1.5µm CMOS technology through MOSIS. Through these characterizations it is possible also to find out in general, the performance advantages and disadvantages, comparing measurements made on these kinds of structures. It was found that phototransistors have a better performance compared with photodiodes. The contribution from substrate leakage current in N-Well/P-substrate structures is high, as well as from carriers generated in the neighborhood of the pixel circuit. It is shown that crosstalk is the phenomenon that deviates the measured photo-response from the ideal model of photo-devices.
2006 3rd International Conference on Electrical and Electronics Engineering, 2006
ABSTRACT
Materials Letters, 2014
Strong white luminescence, visible to naked eye at room temperature, was observed from as grown S... more Strong white luminescence, visible to naked eye at room temperature, was observed from as grown SiO x C y thin films without the need of annealing. SiO x C y thin films were prepared by using catalytic chemical vapor deposition method (Cat-CVD) employing TEOS solution as the precursor and bubbled with the argon gas to form vapors. TEOS vapors were catalytically decomposed in the deposition chamber with the help of a tungsten filament. Scanning electron microscope (SEM) and transmission electron microscope (TEM) confirmed the formation of nano-crystals in SiO x C y matrix. Inter-atomic spacing shows the transition of Si-SiC nano-crystals in matrix. The intense emission is believed to come up either from the carbon incorporation in the nanocrystalline-structured film and/or quantum confinement effect of the observed nano-crystals in SiO x C y matrix.
2005 2nd International Conference on Electrical and Electronics Engineering
A new substrate for the growth of GaN by MOCVD is presented. Photoluminescence spectra show the b... more A new substrate for the growth of GaN by MOCVD is presented. Photoluminescence spectra show the bandgap emission and yellow luminescence. The latter can be reduced by optimizing the growth parameters. The optical properties of the films are comparable to those of layers obtained epitaxially on sapphire substrates.
(ICEEE). 1st International Conference on Electrical and Electronics Engineering, 2004.
GaN layers were grown at low pressure by nitridation of GaAs substrates. The films showed photolu... more GaN layers were grown at low pressure by nitridation of GaAs substrates. The films showed photoluminescence when excited with ultraviolet light. The luminescence color could be tuned by adjusting the growth parameters.
Surface and Interface Analysis, 2010
Reconstruction of original element distribution at semiconductor interfaces using experimental SI... more Reconstruction of original element distribution at semiconductor interfaces using experimental SIMS profiles encounters considerable difficulties because of the matrix effect, sputtering rate change at the interface, and also a sputtering-induced broadening of original distributions. We performed a detailed depth profiling analysis of the Al step-function distribution in GaAs/Al x Ga 1−x As heterostructures by using Cs + primary ion beam sputtering and CsM + cluster ion monitoring (where M is the element of interest) to suppress the matrix effect. The experimental Depth Resolution Function (DRF) was obtained by differentiation of the Al step-function profile and compared with the 'reference' DRF found from depth profiling of an Al delta layer. The difference between two experimental DRFs was explained by the sputtering rate change during the interface profiling. We experimentally studied the sputtering rate dependence on the Al x Ga 1−x As layer composition and applied it for a reconstruction of the DRF found by differentiating the Al step-function distribution: the 'reconstructed' and 'reference' DRFs were found to be in good agreement. This confirmed the correctness of the treatment elaborated.
2012 8th International Caribbean Conference on Devices, Circuits and Systems (ICCDCS), 2012
ABSTRACT
2008 7th International Caribbean Conference on Devices, Circuits and Systems, 2008
ABSTRACT
28th Symposium on Microelectronics Technology and Devices (SBMicro 2013), 2013
ABSTRACT Titanium Oxide (TiOx) is a material that can be used as optical spacer and injection/tra... more ABSTRACT Titanium Oxide (TiOx) is a material that can be used as optical spacer and injection/transport layer in organic devices as OLEDs and OPDs, as well as a high relative dielectric constant, (high-k), dielectric for organic thin film transistors, (OTFTs). For this last application, a low temperature and low cost deposition method of these layers using a sol-gel technique can be more adequate. Therefore, in this paper we present the physical characterization of TiOx layers deposited from a sol-gel technique, which includes the refraction index and layer thickness determination by ellipsometry, as well as XRD and FTIR spectroscopy to determine the structure and composition of the deposited layer, respectively. In addition, we compare differences in the characteristics observed in TiOx prepared by the sol-gel technique with those fabricated by reactive sputtering.
2008 5th International Conference on Electrical Engineering, Computing Science and Automatic Control, 2008
In this paper we report the conclusions about the analysis between the characteristics of nitride... more In this paper we report the conclusions about the analysis between the characteristics of nitrided thin gallium nitride (GaN) films on GaAs and epitaxial GaN films on buffer nitrided films. We use the metal-organic chemical vapour deposition technique for synthesize these films. Also ones films were characterized using X-ray diffraction (XRD), photoluminescence (PL) and atomic force microscopy (AFM).
ECS Transactions, 2006
The decomposition of ammonia in the MOCVD growth of GaN has been assisted by the use of strong il... more The decomposition of ammonia in the MOCVD growth of GaN has been assisted by the use of strong illumination. Epitaxial growth was successful at 700ºC and ammonia flow rates as low as 50 sccm.
Thin Solid Films, 2005
Microcrystalline phase-involved oxygen-rich a-Si:H (hydrogenated amorphous silicon) films have be... more Microcrystalline phase-involved oxygen-rich a-Si:H (hydrogenated amorphous silicon) films have been obtained using catalytic chemical vapor deposition (Cat-CVD) process. Pure SiH4 (silane), H2 (hydrogen), and O2 (oxygen) gases were introduced in the chamber by maintaining a pressure of 0.1 Torr. A tungsten catalyzer was fixed at temperatures of 1750 and 1950 °C for film deposition on glass and crystalline silicon substrates
Surface Review and Letters, 2002
We report the results of a study of Al 0.065 Ga 0.935 Sb avalanche photodetectors grown on n-GaSb... more We report the results of a study of Al 0.065 Ga 0.935 Sb avalanche photodetectors grown on n-GaSb substrates. The devices have been fabricated from layers with the structure p-Al 0.13 Ga 0.87 Sb/n-Al 0.065 Ga 0.935 Sb:Te/n-GaSb (substrate) grown by liquid phase epitaxy (LPE) with a composition matched to detect light of 1.55 μm. The heterostructures were grown from Ga-rich solutions at 400°C. Just after their growth, the structures were subjected to baking processes inside the growth chamber. The baking time was varied and its influence on the breakdown voltages of the junctions was observed. Breakdown voltages up to 12 V, very low net donor concentration in the active layer (1E15 cm -3), and avalanche multiplication factors of around 50 have been obtained. The carrier concentration was determined by the C–V method. Photoluminescence and X-ray diffraction measurements were carried out to investigate the properties of the LPE-grown ternary layers, to determine the band gap and to est...
Semiconductors, 2011
Nanotechnology of obtainment of diluted magnetic semiconductors based on the GaInAsSb compounds i... more Nanotechnology of obtainment of diluted magnetic semiconductors based on the GaInAsSb compounds is developed using the laser deposition of Mn atoms on the surface of the epitaxial layer of a qua ternary alloy obtained by liquid phase epitaxy. Fabricated heterostructures were studied using high resolution X ray diffraction for the Bragg and grazing diffraction geometries, and the layer by layer analysis is per formed by secondary ion mass spectrometry. It is established that the near boundary region of the Ga 0.96 In 0.04 As 0.11 Sb 0.89 layer near the deposition surface of atomic Mn exhibits the presence of a quinary compound with Mn atoms in the lattice and Mn 3 As 2 type binary inclusions. Saturation of the GaIn(Mn)AsSb multicomponent diluted semiconductor with the Mn compounds makes it possible to spec ify the concentration of the magnetic impurity in the crystal and control the magnetic properties of the het erostructure.
IEEE Journal of the Electron Devices Society, 2021
of America. He serves as a member of the Distinguished Lecturer program of the Electron Devices S... more of America. He serves as a member of the Distinguished Lecturer program of the Electron Devices Society. He has been a member of advisory and technical committees in several international and national conferences. Arturo Escobosa received the Ph.D. degree from RWTH, Aachen, Germany. He is a full-time Professor with the Electrical Engineering Department, Cinvestav, Mexico, where he has been a member of the Solid-State Electronics Section. His research activity includes the fields of III-V semiconducting compounds, optoelectronic devices, MOCVD growth, optical characterization of electronic materials, and X-ray diffraction techniques. He has volunteered at the Electron Devices Society, as a member of technical committees. He was an Elected Member of the EDS Board of Governors from 2010 to 2016. Since 2018, he has been the Region Chair of EDS Region and Chapters Committee.
Applied Surface Science, 2019
Controlling the film/substrate crystallographic relationships is of great interest since a good i... more Controlling the film/substrate crystallographic relationships is of great interest since a good interface results in an improved crystal homogeneity and quality. In this work, texture analysis on Bi 2 Te 3 films grown by physical vapor transport was carried out in order to study the influence of growth conditions such as time and substrate orientation. Two types of substrates were used: Si (1 0 0) and Si (1 1 1). It was found that the c-axis of the hexagonal structure of Bi 2 Te 3 is always perpendicular to the substrate surface, while the orientation of the a-axes depends on the growth parameters. The in-plane orientation of the Bi 2 Te 3 crystallites was improved as the growth time increased and textured epitaxial growth was achieved. The epitaxial relationships between the cubic Si and the hexagonal Bi 2 Te 3 lattices were studied through pole diagrams. It was found that the a-axes of the Bi 2 Te 3 lattice are oriented along the 〈1 1 0〉 directions of the Si surface in both types of substrates. In contrast to other reports, the observed growth rate was not constant, but it decreased with time. This effect is discussed in relation with the characteristic spiral growth mechanism.
Inorganic chemistry, Jan 20, 2018
BiTe is a well-studied material because of its thermoelectric properties and, recently, has also ... more BiTe is a well-studied material because of its thermoelectric properties and, recently, has also been studied as a topological insulator. However, it is only one of several compounds in the Bi-Te system. This work presents a study of the physical vapor transport growth of Bi-Te material focused on determining the growth conditions required to selectively obtain a desired phase of the Bi-Te system, i.e., BiTe, BiTe, and BiTe. Epitaxial films of these compounds were prepared on sapphire and silicon substrates. The results were verified by X-ray diffraction, Raman spectroscopy, and Rutherford backscattering spectrometry.
Materials Sciences and Applications, 2015
Crystallinity refers to the degree of structural order in a solid and has a big influence on hard... more Crystallinity refers to the degree of structural order in a solid and has a big influence on hardness, density, transparency and diffusion. Even within materials that are crystalline completely, the degree of structural perfection can vary, reflecting size and elastic strain of many independent crystalline regions (grains or crystallites) of which these materials are composed. In this work it was attempted to reduce the crystallinity of human enamel using a technique of mechanical grinding (MG) with an ultra-compact FRITSCH Mini-Mill PULVERISETTE 23 machine. Variation in the crystallinity through the MG was monitored by X-ray diffraction (XRD) by broadening of the diffraction peak and examined using the Williamson-Hall plot method. Crystallites in human enamel are regularly arranged and oriented (in the [001] direction) perpendicularly to the interface of enameldentin junction. The results showed an anisotropic feature in crystallinity. Reduction of the crystallinity along the a-axis is due to the crystal strain rather than to the refinement of crystal, and vice versa along the c-axis. After 230 h of the MG, the length of crystallites decreased from 100 nm to 30 nm and width from 40 nm to 37 nm approximately.
2012 8th International Caribbean Conference on Devices, Circuits and Systems (ICCDCS), 2012
ABSTRACT An irregular erosion rate in SIMS can lead to erroneous results during depth profiling a... more ABSTRACT An irregular erosion rate in SIMS can lead to erroneous results during depth profiling analysis of semiconductor hetero-structures. In this work the dependence of erosion on the composition of AlxGA1−xAs is determined. High resolution X-ray diffraction is used to measure the alloy composition considering the deformation due to a good coupling between substrate and layer. The result shows that the erosion rate is reduced to 70% when the AlAs fraction (x) increases from 0 to 0.65.
Solar Energy Materials and Solar Cells, 2015
produce an increase of the average concentration of CdTe towards the surface of the films. Due to... more produce an increase of the average concentration of CdTe towards the surface of the films. Due to Zn/Cd inter-diffusion during the growth process the sequence of layers was converted into a relatively smooth graded composition film. According to X-ray diffraction characterization the layers grew coherently with the (100) oriented GaAs substrates although they showed a relatively high mosaicity. 2 plots show very wide diffraction peaks as expected from variable composition samples. The band gap grading effect in light absorption was also verified through transmission measurements, using transparent substrates. Graded composition profiles of the thin films were confirmed by x-ray photoelectron and secondary ion mass spectroscopies. Moreover, quantitative Cd, Zn and Te profiles were obtained by the analysis of Rutherford backscattering spectra of the samples. This analysis showed a CdTe molar fraction profile ranging from approximately x = 0.8 at the surface of the sample and x = 0.35 at the interface with the substrate. The possibility of growing graded composition layers using a simple and cost-effective procedure was demonstrated. This could be interesting in technological applications like CdxZn1-xTe layers of variable composition in CdS/CdTe solar cells.
2010 7th International Conference on Electrical Engineering Computing Science and Automatic Control, 2010
Here, a characterization methodology for integrated silicon-based photo-devices is presented. Dev... more Here, a characterization methodology for integrated silicon-based photo-devices is presented. Devices are phototransistors ("P+/N-Well/P-substrate") and photodiodes ("N-Well/P-substrate") with similar sizes, (9µmx9µm). They were integrated in a 1.5µm CMOS technology through MOSIS. Through these characterizations it is possible also to find out in general, the performance advantages and disadvantages, comparing measurements made on these kinds of structures. It was found that phototransistors have a better performance compared with photodiodes. The contribution from substrate leakage current in N-Well/P-substrate structures is high, as well as from carriers generated in the neighborhood of the pixel circuit. It is shown that crosstalk is the phenomenon that deviates the measured photo-response from the ideal model of photo-devices.
2006 3rd International Conference on Electrical and Electronics Engineering, 2006
ABSTRACT
Materials Letters, 2014
Strong white luminescence, visible to naked eye at room temperature, was observed from as grown S... more Strong white luminescence, visible to naked eye at room temperature, was observed from as grown SiO x C y thin films without the need of annealing. SiO x C y thin films were prepared by using catalytic chemical vapor deposition method (Cat-CVD) employing TEOS solution as the precursor and bubbled with the argon gas to form vapors. TEOS vapors were catalytically decomposed in the deposition chamber with the help of a tungsten filament. Scanning electron microscope (SEM) and transmission electron microscope (TEM) confirmed the formation of nano-crystals in SiO x C y matrix. Inter-atomic spacing shows the transition of Si-SiC nano-crystals in matrix. The intense emission is believed to come up either from the carbon incorporation in the nanocrystalline-structured film and/or quantum confinement effect of the observed nano-crystals in SiO x C y matrix.
2005 2nd International Conference on Electrical and Electronics Engineering
A new substrate for the growth of GaN by MOCVD is presented. Photoluminescence spectra show the b... more A new substrate for the growth of GaN by MOCVD is presented. Photoluminescence spectra show the bandgap emission and yellow luminescence. The latter can be reduced by optimizing the growth parameters. The optical properties of the films are comparable to those of layers obtained epitaxially on sapphire substrates.
(ICEEE). 1st International Conference on Electrical and Electronics Engineering, 2004.
GaN layers were grown at low pressure by nitridation of GaAs substrates. The films showed photolu... more GaN layers were grown at low pressure by nitridation of GaAs substrates. The films showed photoluminescence when excited with ultraviolet light. The luminescence color could be tuned by adjusting the growth parameters.
Surface and Interface Analysis, 2010
Reconstruction of original element distribution at semiconductor interfaces using experimental SI... more Reconstruction of original element distribution at semiconductor interfaces using experimental SIMS profiles encounters considerable difficulties because of the matrix effect, sputtering rate change at the interface, and also a sputtering-induced broadening of original distributions. We performed a detailed depth profiling analysis of the Al step-function distribution in GaAs/Al x Ga 1−x As heterostructures by using Cs + primary ion beam sputtering and CsM + cluster ion monitoring (where M is the element of interest) to suppress the matrix effect. The experimental Depth Resolution Function (DRF) was obtained by differentiation of the Al step-function profile and compared with the 'reference' DRF found from depth profiling of an Al delta layer. The difference between two experimental DRFs was explained by the sputtering rate change during the interface profiling. We experimentally studied the sputtering rate dependence on the Al x Ga 1−x As layer composition and applied it for a reconstruction of the DRF found by differentiating the Al step-function distribution: the 'reconstructed' and 'reference' DRFs were found to be in good agreement. This confirmed the correctness of the treatment elaborated.
2012 8th International Caribbean Conference on Devices, Circuits and Systems (ICCDCS), 2012
ABSTRACT
2008 7th International Caribbean Conference on Devices, Circuits and Systems, 2008
ABSTRACT
28th Symposium on Microelectronics Technology and Devices (SBMicro 2013), 2013
ABSTRACT Titanium Oxide (TiOx) is a material that can be used as optical spacer and injection/tra... more ABSTRACT Titanium Oxide (TiOx) is a material that can be used as optical spacer and injection/transport layer in organic devices as OLEDs and OPDs, as well as a high relative dielectric constant, (high-k), dielectric for organic thin film transistors, (OTFTs). For this last application, a low temperature and low cost deposition method of these layers using a sol-gel technique can be more adequate. Therefore, in this paper we present the physical characterization of TiOx layers deposited from a sol-gel technique, which includes the refraction index and layer thickness determination by ellipsometry, as well as XRD and FTIR spectroscopy to determine the structure and composition of the deposited layer, respectively. In addition, we compare differences in the characteristics observed in TiOx prepared by the sol-gel technique with those fabricated by reactive sputtering.
2008 5th International Conference on Electrical Engineering, Computing Science and Automatic Control, 2008
In this paper we report the conclusions about the analysis between the characteristics of nitride... more In this paper we report the conclusions about the analysis between the characteristics of nitrided thin gallium nitride (GaN) films on GaAs and epitaxial GaN films on buffer nitrided films. We use the metal-organic chemical vapour deposition technique for synthesize these films. Also ones films were characterized using X-ray diffraction (XRD), photoluminescence (PL) and atomic force microscopy (AFM).
ECS Transactions, 2006
The decomposition of ammonia in the MOCVD growth of GaN has been assisted by the use of strong il... more The decomposition of ammonia in the MOCVD growth of GaN has been assisted by the use of strong illumination. Epitaxial growth was successful at 700ºC and ammonia flow rates as low as 50 sccm.
Thin Solid Films, 2005
Microcrystalline phase-involved oxygen-rich a-Si:H (hydrogenated amorphous silicon) films have be... more Microcrystalline phase-involved oxygen-rich a-Si:H (hydrogenated amorphous silicon) films have been obtained using catalytic chemical vapor deposition (Cat-CVD) process. Pure SiH4 (silane), H2 (hydrogen), and O2 (oxygen) gases were introduced in the chamber by maintaining a pressure of 0.1 Torr. A tungsten catalyzer was fixed at temperatures of 1750 and 1950 °C for film deposition on glass and crystalline silicon substrates
Surface Review and Letters, 2002
We report the results of a study of Al 0.065 Ga 0.935 Sb avalanche photodetectors grown on n-GaSb... more We report the results of a study of Al 0.065 Ga 0.935 Sb avalanche photodetectors grown on n-GaSb substrates. The devices have been fabricated from layers with the structure p-Al 0.13 Ga 0.87 Sb/n-Al 0.065 Ga 0.935 Sb:Te/n-GaSb (substrate) grown by liquid phase epitaxy (LPE) with a composition matched to detect light of 1.55 μm. The heterostructures were grown from Ga-rich solutions at 400°C. Just after their growth, the structures were subjected to baking processes inside the growth chamber. The baking time was varied and its influence on the breakdown voltages of the junctions was observed. Breakdown voltages up to 12 V, very low net donor concentration in the active layer (1E15 cm -3), and avalanche multiplication factors of around 50 have been obtained. The carrier concentration was determined by the C–V method. Photoluminescence and X-ray diffraction measurements were carried out to investigate the properties of the LPE-grown ternary layers, to determine the band gap and to est...
Semiconductors, 2011
Nanotechnology of obtainment of diluted magnetic semiconductors based on the GaInAsSb compounds i... more Nanotechnology of obtainment of diluted magnetic semiconductors based on the GaInAsSb compounds is developed using the laser deposition of Mn atoms on the surface of the epitaxial layer of a qua ternary alloy obtained by liquid phase epitaxy. Fabricated heterostructures were studied using high resolution X ray diffraction for the Bragg and grazing diffraction geometries, and the layer by layer analysis is per formed by secondary ion mass spectrometry. It is established that the near boundary region of the Ga 0.96 In 0.04 As 0.11 Sb 0.89 layer near the deposition surface of atomic Mn exhibits the presence of a quinary compound with Mn atoms in the lattice and Mn 3 As 2 type binary inclusions. Saturation of the GaIn(Mn)AsSb multicomponent diluted semiconductor with the Mn compounds makes it possible to spec ify the concentration of the magnetic impurity in the crystal and control the magnetic properties of the het erostructure.