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1

The influence of quantum well and barrier thicknesses on photoluminescence spectra of InGaAs/AlInAs superlattices grown by LP-MOVPE

Łozińska Adriana, Badura Mikołaj, Bielak Katarzyna, Ściana Beata, Tłaczała Marek

Optica Applicata

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2020

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Vol. 50, nr 2

251--256

EN

In the presented work, the influence of the quantum well and barrier thicknesses on optical characteristics of InGaAs/AlInAs superlattices was reported. Six different structures of In0.53Ga0.47As/Al0.48In0.52As superlattices lattice-matched to InP were grown by low pressure metal organic vapour phase epitaxy (LP-MOVPE). Optical properties of the obtained structures were examined by means of photoluminescence spectroscopy. This technique allows quick, simple and non-destructive measurements of radiative optical transitions in different semiconductor heterostructures.The analysis of recorded photoluminescence spectra revealed the influence of the quantum well and barrier thicknesses on the emission line energy.

2

Technology and properties of low-pressure metalorganic vapour phase epitaxy grown InGaAs/AlInAs superlattice for quantum cascade laser applications

Badura M., Bielak K., Ściana B., Radziewicz D., Pucicki D., Dawidowski W., Żelazna K., Kudrawiec R., Tłaczała M.

Optica Applicata

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2016

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Vol. 46, nr 2

241--248

EN

Quantum cascade laser is one of the most sophisticated semiconductor devices. The active region of the quantum cascade laser consists of hundreds thin layers, thus the deposition precision is the most crucial. The main technique for the fabrication of quantum cascade laser structure is molecular beam epitaxy, however, the prevalence of metalorganic vapour phase epitaxy techniques in the fabrication of semiconductor structures causes a perpetual work on the improvement production of the entire quantum cascade laser structure by the metalorganic vapour phase epitaxy. The paper presents technological aspects connected with the metalorganic vapour phase epitaxy growth of InGaAs/AlInAs low-dimensional structures for quantum cascade laser active region emitting ~9.6 μm radiation. Epitaxial growth of superlattice made of InGaAs/AlInAs lattice matched to InP was conducted at the AIXTRON 3x2″ FT system. Optical and structural properties of such heterostructures were characterised by means of high resolution X-ray diffraction, photoluminescence, contactless electroreflectance and scanning electron microscope techniques. Epitaxial growth and possible solutions of structure improvements are discussed.

3

Epitaxial regrowth of InP/InGaAs heterostructure on patterned, nonplanar substrates

Kosior Ł., Radziewicz D., Zborowska-Lindert I., Stafiniak A., Badura M., Ściana B.

Materials Science Poland

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2016

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Vol. 34, No. 4

872--880

EN

The main goal of the studies on epitaxial regrowth process of InP on patterned substrates is to gain knowledge about growth rates and interface quality on various areas to improve the fabrication technology for future applications. Prepared samples were measured at every step of the process by scanning electron microscope (SEM), optical microscope with dark field and phase contrast modes, atomic force microscope (AFM) and also using optical profilometer WLI (White Light Interferometer). Fabrication steps were divided into three main groups. First was the epitaxial growth of 5 µm thick InP layer. Next was patterning, which was made by applying a mask film on the epilayer. Shapes of the mesas after wet chemical etching with photoresist as a mask as well as the shapes of mesas slopes were irregular on the whole substrate area. These problems were solved by the use of silicon nitride mask. The mesas shapes and their slopes became then regular, independently of etching depth. Second fabrication step was etching of selected area. Couple of solutions were examined, but in details HCl:H3PO4 mixture in various proportions, which gave the best results in mesas shapes and orientations relative to the substrate. After that, the etching mask material was removed from the epilayer using a buffered hydrofluoric acid (BHF). The last step was epitaxial regrowth. To see how the epitaxial growth process was performed on different areas of patterned substrate it was suggested using a “sandwich”, which consisted of 50 layers of indium phosphide and indium gallium arsenide. This idea helped to understand the phenomena occurring during the epitaxial growth on that kind of substrate. The highest growth rate occurred on the top of the mesas and the lowest on their slopes. Described experiments are introduction to the studies on epitaxial growth of buried heterostructure (BH).

4

Technologia LP-MOVPE heterostruktur InGaAs/InP do konstrukcji kwantowych laserów kaskadowych

Badura M., Bielak K., Ściana B., Radziewicz D., Pucicki D., Dawidowski W., Tłaczała M.

Elektronika : konstrukcje, technologie, zastosowania

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2014

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Vol. 55, nr 11

34-36

PL

Kwantowe lasery kaskadowe (QCLs), tzw. lasery unipolarne, które emitują fale o długości z zakresu okna atmosferycznego 3…5 μm, wymagają zastosowania układu materiałowego o dużej nieciągłości pasma przewodnictwa i bardzo dobrej przewodności cieplnej. Wymagania te spełnia układ materiałowy InGaAs/AlInAs/InP. W pracy przedstawiono wyniki badań związanych z epitaksją związków potrójnych InGaAs, dopasowanych sieciowo do InP, przy zastosowaniu niskociśnieniowej metody MOVPE. Pierwszym etapem badań było opracowanie kinetyki wzrostu niedomieszkowanych warstw In- GaAs, dopasowanych sieciowo do InP. Otrzymane warstwy wykazały bardzo dobre właściwości optyczne, co zostało potwierdzone wynikami pomiarów fotoluminescencji. Morfologia tych warstw, badana przy użyciu mikroskopu AFM, wykazała tarasowy wzrost typu „step-flow” i atomową gładkość powierzchni. Kolejnym etapem prowadzonych badań są prace technologiczne związane z domieszkowaniem heterostruktury InGaAs/InP krzemem.

EN

Quantum cascade lasers (QCL) so-called unipolar lasers, which emit light with wavelength at range of atmospheric window 3÷5 μm, require construction from the material system with sufficient conduction band discontinuity and high thermal conductivity. Such requirements are fulfilled by InGaAs/AlInAs/InP. In these paper are shown results of investigation of metalorganic vapor phase epitaxy of ternary alloy InGaAs lattice matched to InP. Grown layers have good optical properties, what is confirmed by photoluminescence measurements. Surface morphology of described samples tested by AFM exhibits step-flow growth and atomic scale surface smoothness. The next stage of ours research will be focused on n-type doping of InGaAs/InP heterostructure with SiH4 as a dopant source.

5

Influence of AlN spacer on the properties of AlGaN/AlN/GaN heterostructures

Wosko M, Paszkiewicz B, Paszkiewicz R, Tlaczala M

Optica Applicata

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2013

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Vol. 43, nr 1

61--66

EN

AlGaN/GaN heterostructures attract attention of many research groups over the last decade because of their superior properties (high mobility and saturation velocity of 2DEG) and strong capability in high frequency/power electronics and sensors applications. One of the factors which reduces the mobility of two-dimensional electron gas (2DEG) is the alloy and interface roughness scattering mechanism occurring at the heterointerface. Mathematical calculations of a wave-function of 2DEG in the channel show that theses two phenomena play an important role, due to the fact that some electrons in 2DEG can migrate into AlGaN barrier and be strongly dissipated. One of the proposed solutions against alloy scattering in the buffer layer is the use of thin AlN spacer at the heterointerface between AlGaN and GaN layers. AlN layer enhances the conduction band offset due to a polarization-induced dipole in the AlN layer, and therefore increases carrier confinement. Several Al0.18GaN0.82/AlN/GaN heterostructures with different AlN spacer layer thickness were grown by MOVPE method for studies of the Hall mobility and sheet carrier concentration of 2DEG. Hall measurements performed using Van der Pauw shown mobility maximum at nominally 1.3 nm AlN spacer thickness and almost linear dependence of sheet carrier concentration with AlN spacer thickness in the range from 0.7 to 2 nm.

6

Heterostruktury AlGaN/AlN/GaN na podłożach 4H-SIC uzyskane metodą LP MOVPE do zastosowań w technologii tranzystorów HEMT

Caban P., Strupiński W., Szmidt J.

Elektronika : konstrukcje, technologie, zastosowania

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2010

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Vol. 51, nr 3

145-149

PL

W pracy przedstawiono podstawowe problemy technologiczne związane z otrzymywaniem metodą LP MOVPE warstw heteroepitaksjalnych azotku galu na podłożach z węglika krzemu. Przedstawiono wyniki charakteryzacji buforowych warstw epitaksjalnych GaN na SiC otrzymywanych przy różnych ciśnieniach. Przydatność opracowanej technologii krystalizacji bufora GaN zweryfikowano poprzez wykonanie pełnej heterostruktury AlGaN/AlN/GaN/SiC wykorzystanej do wytwarzania tranzystorów HEMT. Przedstawiono rezultaty pomiarów parametrów pracy przyrządów.

EN

The main aspects of LP MOVPE GaN on SiC substrates were discussed. The influence of GaN growth pressure on crystal quality and surface morphology of GaN layers was investigated by atomic force microscopy (AFM) and high resolution x-ray diffraction (HRXRD). The HEMT structures based on AlGaN/AlN/GaN heterostructure were deposited. The device was fabricated and characterized.

7

Badania wzrostu HgCdTe metodą MOCVD w laboratorium VIGO/WAT

Gawron W., Grudzień M., Kłos K., Piotrowski J.

Elektronika : konstrukcje, technologie, zastosowania

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2006

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Vol. 47, nr 3

14-19

PL

Od 2003 r. w laboratorium VIGO/WAT prowadzono badania nad wzrostem heterostruktur Hg1-xCdxTe o niemal dowolnych profilach składu i poziomie domieszkowania, niezbędnych dla zaawansowanych przyrządów fotoelektrycznych. MOCVD w zastosowaniu do Hg1-xCdxTe jest jedną znajtrudniejszych technologii epitaksjalnych. Omówiono zagadnienia związane ze wzrostem i charakteryzacją warstw Hg1-xCdxTe w technologii MOCVD. Dokonano pomiarów insitu względnego stężenia związków metaloorganicznych analizatorem gazu własnej konstrukcji. Podsumowano stan domieszkowania warstw Hg1-xCdxTe z uwzględnieniem ostatnich badań. Opracowana technologia MOCVD została zastosowana do otrzymywania wszystkich typów produkowanych w VIGO System detektorów podczerwieni pracujących w temperaturach pokojowych.

EN

Since 2003 VIGO System S.A. together with MUT (Military University of Technology) are doing joint efforts to improve MOCVD growth of Hg1-xCdxTe. Photodetectors optimized for any wavelength within 1-15 um spectral range requires complex heterostructures with multiple layers with homogeneous composition and doping, characterized by steep interfaces. Hg1-xCdxTe growth with interdiffused multilayer process (IMP) technique has been improved using self-made in-situ monitoring of gas delivery to the growth zone. The other issues addressed in this work were growth of heavy As-doped low-x and heavy l-doped high-x materials. Special modification to IMP process has been applied for in-situ control of stoichiometry. To maintain low vacancy concentration, special growth finish procedure has been developed. No post-growth thermal anneal was necessary for device-quality material. The MOCVD grown heterostructures have been successfully used for advanced uncooled infrared photodetectors such as multiple heterojunction photodiodes, multicolor and multiabsorber devices with specially shaped spectral response.

8

Advanced technology of AIII-BV and AIII-N structures for microelectronics application

Boratyński B., Korbutowicz B., Paszkiewicz B., Paszkiewicz R., Pucicki D., Radziewicz D., Ściana B., Tłaczała M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2004

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Vol. 52, nr 4

291-299

EN

In this work studies of MOVPE growth of InAlGaAs/ AlGaAs/GaAs heterostructures are presented. The HRXRD and SIMS measurements indicate the high structural and optical properties as well as high uniformity of thickness and composition of InAlGaAs quantum wells. This work is the first step towards elaboration of the technology of the strained InAlGaAs/GaAs heterostructures for advanced optoelectronic devices working in the visible part of the spectrum. The investigations of Si (n-type), Zn (p-type) b-doped GaAs epilayers and centre Si-b-doped InxGa1-xAs single quantum well (SQW) are presented. The b-doping layer was formed by SiH4 or DEZn introduction during the growth interruption. The electrical and optical properties of the obtained structures were examined using C-V measurement, EC-V electrochemical profiler, Raman spectroscopy (RS), photoreflectance (PR) and photocurrent (PC) spectroscopies. Technology of thick GaN layers grown on sapphire by HVPE is very promising as a part of freestanding GaN substrates manufacturing. Further works will be focused on the optimisation of growth, separating layers from substrates and surface polishing. The influence of the growth parameters on the properties of (Ga, Al)N/ Al2O3 and Mg dopant incorporation was studied.

9

Heteroepitaxial technology for high-efficiency UV light-emitting diode

Kamiyama S., Iwaya M., Amano H., Akasaki I.

Opto-Electronics Review

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2002

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Vol. 10, No. 4

225-230

EN

A high-quality AlGaN layer with a low density of threading dislocations is realised for the use of ultraviolet (UV) light-emitting diodes (LEDs). The new crystal growth method of using a GaN seed crystal with (1122) facets and lateral growth of Al₀.₂₂Ga₀.₇₈N through the low -temperature-deposited AlN interlayer enalbles the overgrown Al₀.₂₂Ga₀.₇₈N to have a low dislocation density of 2 x 10⁷ cm⁻² and be crack-free over the whole wafer. Applying the AlGaN as a base layer in UV-LEDs, high - performance devices with high output powers of more than 0.1 mW under 50 mA drive are demonstrated in a wide range of emission wavelengths from 323 to 363 nm. The highest output power of 1.2 mW at 50 mA driving current is obtained with 363 - nm emission wavelength.

10

MOVPE InP based material for millimeter and submillimeter wave generation and amplification

Strupiński W., Kosiel K., Jasik A., Jakieła R., Jeleński A., Kollberg E., Dillner L., Nawaz M.

Journal of Telecommunications and Information Technology

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2002

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nr 1

8-10

EN

The potential of the MOVPE growth process for millimeter and submillimeter wave generation and amplification is presented. The increase in layer quality, the improved homogeneity and purity, the precision of mono-layers growth and wide spectrum III-V compounds makes MOVPE techniques very attractive for modern device applications. The characterisation results of the heterostructures dedicated for HBV varactors and 2-DEG transistors (HEMT) are described.

11

Optical characterisation of strained-layer In/sub x/Ga/sub 1-x/As/GaAs MQW LED grown by MOVPE.

Sęk G., Ciorga M., Bryja L., Misiewicz J., Radziewicz D., Ściana B., Tłaczała M.

Optica Applicata

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2000

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Vol. 30, nr 1

183-188

EN

We present the use of photoreflectance (PR) spectroscopy combined with the standard photoluminescence (PL) and electroluminescence (EL) for the room temperature optical investigation of strained-layer multiple quantum well (MQW) In/sub x/Ga/sub 1-x/As/GaAs light emitting diode (LED) for 1040 nm. In the PR spectra, except the fundamental transition observed also in the emission spectra, two extra features related to the active region of the device have been seen. The presence of these two excited state transitions allowed the band structure to be analysed and the correctness of the device performance to be checked. We repeated the measurements after the top p-doped GaAs cladding layer had been etched off and discussed the changes of the built-in electric field.

12

Optical studies of MOVPE grown GaN layers

Ciorga M., Jezierski K., Bryja L., Misiewicz J., Paszkiewicz R., Korbutowicz R., Panek M., Paszkiewicz B., Tłaczała M., Trabjerg I.

Opto-Electronics Review

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1999

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Vol. 7, No. 2

93-95

EN

Photoluminescence and reflectance studies of MOVPE grown GaN samples were performed. From reflectance measurements optical constants were calculated by means of Kramers-Kronig analysis in the energy region 0-6 eV.

13

Metalorganic vapour phase epitaxy of GaN and lateral overgrowth

Beaumont B., Gibart P.

Opto-Electronics Review

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1999

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Vol. 7, No. 2

63-74

EN

Nitride semiconductor alloys have merged as the most promising materials for short wavelengths light emiting diodes (LEDs) and laser diodes (LDs). The GaInN multiquantum wells (MQW) structure was used as the active part of LDs and has presently proven to work at room temperature in cw mode for 10,000 h. These achievements would not have been possible without the emergence of new approaches in heteroepitaxy of GaN leading to layers exhibiting lower dislocation densities than those grown using conventional heteroepitaxy. Metalorganic vapour phase epitaxy (MOVPE) has demonstrated its ability to fabricate structures for optoelectronics GaN based devices. Several nitrogen sources have been testede, but so far NH3 remains the best nitrogen precursor despite the stringen requirement of high V/III ratio in the vapour phase. With the epitaxial lateral overgrowth (ELOG), high quality GaN layers have been obtained. HVPE or MOVPE can apply either ELOG technology, on sapphire or 6H-SiC substrates. The dislocation densities in the overgrowth region are orders of magnitude lower than in the standard heteroepitaxial GaN layers.