Harry Protzmann

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The quality of heterostructures greatly depends on the accurate placement of dopants. However, doping transients remain as drawback in vapor-phase epitaxy. In this work starting transients of doping profiles of Si and Mg in GaN layers grown by low pressure metal-organic vapor-phase epitaxy (MOVPE) on sapphire have been investigated. Here we restric...

Production scale MOVPE reactors such as the AIXTRON 2000HT Planetary Reactor{reg_sign} offer unique possibilities to fabricate highly efficient GaN based devices at a low cost of ownership. The scope of this investigation is to understand the dependence of wavelength, thickness and doping uniformity on parameters such as total gas flow, temperature...

AlN layers were grown by metalorganic vapor-phase epitaxy at high temperatures up to 1500°C. Nucleation layer growth parameters and flow conditions before nucleation were changed and the effect on the AlN layer grown on top was studied. Structural analysis performed by high-resolution X-ray diffractometry and transmission electron microscopy showed...

We report on the growth of high quality AlN films on sapphire by MOVPE in an AIX2400G3-HT planetary reactor. Specific reactor hardware modifications were conducted to facilitate growth temperatures of up to 1600 °C and to obtain reduced parasitic gas phase reactions. Growth was optimized regarding growth rate and surface morphology as well as optic...

The modelling and subsequent experimental validation of nitride growth processes in commercial, production scale multi-wafer reactors is investigated with focus on group-III nitride compounds GaN and InGaN. The paper also deals with the development of group-III nitride growth processes at elevated process pressures, highlighting the effects of gas-...

The metalorganic vapor-phase epitaxy (MOVPE) growth of GaN from TMGa and NH3 at higher process pressures up to near-atmospheric pressure in commercial production scale multi-wafer reactors is investigated. The Planetary Reactor® and close coupled showerhead reactor are compared and their suitability for near-atmospheric pressure growth is demonstra...

Laser and optical properties of InGaN/GaN multiple quantum well heterostructures were investigated as functions of temperature (T=80-450 K) and excitation intensity (Iexc=10-1100 kW/cm2) of the N2 laser radiation. Laser action was achieved in all types of the MQWs from the violet up to the blue spectral region (λlas=405-470 nm). The laser threshold...

The electroluminescence properties of InGaN/GaN electroluminescence test heterostructures grown on sapphire and silicon substrates in the temperature interval of 300–380 K were investigated as a function of current at DC and pulsed excitation. A competition between the short wavelength shift of the spectral maximum position with current increase du...

ZnSe/ZnMgSSe and InGaN/GaN heterostructure based lasers under optical transverse pumping by pulsed N2-laser radiation were investigated in a wide spectral, temperature and excitation intensity range for various types of heterostructures which differed in the epitaxial layer composition, layer sequence and thickness. The spectral- angular distributi...

In this letter a number of latest results from the process development on AIXTRON production scale MOVPE reactors will be reported. Growth of GaN on alternative substrates has been examined. Up to 900 nm crack free GaN layer were deposited on Si using a double nucleation interfacing technique. Low yellow band vs. band-edge related photoluminescence...

The growth conditions for GaN/GaInN MQW structures have been studied in detail on AIX 2000 HT G3 Planetary Reactors. Major process variables, such as precursor supply, growth time and growth temperature have been varied. To describe the dependencies of MQW growth a second order polynomic model has been developed. The average prediction error within...

The influence of layer thickness, heterostructure design, optical confinement factor and spontaneous emission efficiency on laser parameters of GaN based quantum well optically pumped lasers is studied in wide spectral (373 - 470 nm), temperature (77 - 600 K) and excitation intensity (102 - 3 106 W/cm2) regions. The laser threshold enhancement from...

Lasing under optical pumping by N2-laser radiation in InGaN/GaN multiple quantum well heterostructures grown in AIXTRON MOVPE reactors was achieved and investigated in the wavelength range of 450–470 nm. The laser operation wavelength depends most strongly on V/III ratio during quantum well barrier growth. The total energy and power per pulse of th...

Optically pumped lasing in the wavelength range of 450–470 nm in InGaN/GaN multiple-quantum-well heterostructures grown by metalorganic vapor phase epitaxy was achieved and investigated. The energy and power per pulse of the laser were 80 nJ and 10 W correspondingly for one facet at room temperature. The far-field patterns of the laser emission con...

We have developed the AIX 2000 G3 HT MOVPE system for large scale production of nitride semiconductors. Extensive numeric modeling of the reactor chamber has enabled us to establish process windows for the growth of nitride semiconductors. We report excellent wafer to wafer, on-wafer and run to run uniformities across all wavelength regions accessi...

We report results on the transferability of a blue-green electroluminescence test structure (ELT) process across different reactor geometries and substrate materials. The process was transferred from the conditions of our well-known 6 X 2 inch to the 5 X 3 inch AIX 2400 G3 geometry by simple up-scaling of the respective process parameters in accord...

Energy transfer processes in the InGaN/GaN multiple quantum well (MQW) laser heterostructures are studied using photoluminescence (PL), photoluminescence excitation (PLE) and laser spectroscopy in a wide interval of temperatures (4.2-300 K) and excitation intensities (0.01-1 MW/cm(2)). It was shown that there are two efficient channels of the energ...

We present results obtained from a 2400G3HT reactor with a maximum wafer capacity of 8×3 inch. To achieve uniformity of the growth, we increased the temperature uniformity on each satellite to 0.9°C and that from satellite to satellite to 0.8°C. The optimum reactor geometry has been found by extensive modeling of the reactor design. Thus, an optimi...

We have developed the AIX 2000 G3 HT MOVPE machine for large scale production of nitride semiconductors. Extensive numerical modeling of the reactor chamber has enabled us to establish process windows for the growth of nitride quantum wells. We report excellent wafer-to-wafer, on wafer and run to run uniformities across all wavelength regions acces...

We report on recent results obtained using an AIX 2400G3HT production-type Planetary Reactor® in the 5×3inch configuration for growth of typical group-III nitride layer structures consisting of GaN, InGaN and AlGaN. The optimum reactor geometry has been found by extensive modeling of the reactor design. Increased thermal management allows maximum r...

Electroluminescence test and SQW InGaN/GaN heterostructures were characterised with electroluminescence, photoluminescence, photoluminescence excitation and stimulated emission spectroscopy. It was found that the electroluminescence emission from the heterostructure edge reveals leaking modes. Laser action under optical excitation was achieved up t...

Normal incidence reflectivity measurements were carried out in an AIX 2000G3HT Multiwafer Planetary ReactorR MOVPE system, a large scale production tool for GaN-based devices, and in the single wafer AIX 200 RF system. In situ monitoring was used to investigate nucleation behavior, temperature dependence of GaN growth, and the deposition of GaN/InG...

300-nm-thick InGaN layers with In concentrations up to 21% were grown by low-pressure metalorganic chemical-vapor deposition. Besides the InGaN and GaN Bragg peaks, the symmetric (0002) x-ray spectra of strain-relaxed samples show an additional signal which could be identified stemming from metallic tetragonal indium. The indium is incorporated in...

We investigated the influence of doping and InGaN layer thickness on the emission wavelength and full width at half maximum (FWHM) of InGaN/GaN single quantum wells (SQW) of thicknesses between 1 nm and 5 nm by temperature and intensity resolved photoluminescence (PL). The crystalline quality of the GaN claddings was assessed by low temperature PL...

Production scale MOVPE reactors such as the AIXTRON 2000HTG3 Planetary Reactor(R) used for LED production offer unique possibilities to fabricate highly efficient GaN based devices at a low cost of ownership. Scope of this investigation is to understand the dependence of wavelength, thickness and doping uniformity on parameters such as total gas fl...

We report on recent results obtained using an AIX 2400G3HT production type Planetary Reactor® in the 5×3 inch configuration for growth of typical group-III nitride layer structures consisting of GaN, InGaN and AlGaN. The optimum reactor geometry has been found by extensive modeling of the reactor design. Increased thermal management allows maximum...

Lasing, stimulated emission and photoluminescence in InGaN/GaN multiquantum well (MQW) heterostructures were investigated in a wide temperature interval from the liquid nitrogen temperature up to 600 K. Laser action was achieved up to T = 585 K in a heterostructure consisting of ten quantum wells with a width of 10 nm. Laser thresholds at T = 78, 3...

In the present work the structural and optical properties of GaN/InGaN-multi quantum well (MQW) structures as function of growth conditions are investigated. The samples were grown by MOVPE using an AIX2000G3 large scale production system with up to 7 × 2″ wafer capability. The investigation was focused on photoluminescence (PL) emission wavelength...

Available from http://www3.interscience.wiley.com/cgi- bin/abstract/67500630/START

The influence of ultraviolet light-assisted annealing on the optical properties of InGaN/GaN single quantum wells (SQW), and thick single and double heterostructures (SH, DH) was investigated. It was shown that annealing promotes an increase of the photoluminescence (PL) intensity from the active layers of the SQW and double heterostructures by as...

An InGaN/GaN multiple quantum well structure grown by low pressure MOCVD on c-Al2O3 substrate is investigated using spectral-time-resolved cathodoluminescence microscopy (CL). At 6 K the laterally integrated CL spectrum shows a very efficient blue emission from the InGaN multiple quantum well centered at 2.841 eV with an FWHM of 50 meV (σ = 21 meV)...

An X-ray and cathodoluminescence analysis of thick InGaN/GaN single layers and 10 × (InGaN/GaN) multiple quantum wells (MQWs) is presented. The layers were grown by low-pressure metal organic chemical vapor deposition (LP-MOCVD). The strain state and the In concentration in (InGaN/GaN) MQW systems are evaluated with the help of reciprocal space map...

We investigated the optical and structural properties of InGaN single layers, double heterostructures (DH) and single quantum wells (SQW) grown by MOVPE using low-temperature photoluminescence (PL) and five crystal X-ray diffraction spectrometry (XRD). The In content was found to increase with decreasing growth temperature and increasing reactor to...

Using production scale AIXTRON MOVPE reactors various heterostructures and quantum wells in the GaInN/GaN system have been studied. In an optimization from single quantum well structures to 10 period multi quantum well structures the photoluminescence emission intensity was increased by a factor of 18. MQW structures emitting at 490 nm were achieve...

A comprehensive x-ray analysis including Θ–2Θ scans, reciprocal space mapping, and x-ray reflectivity of 10×(InGaN/GaN) multiple quantum wells (MQWs) is presented. The layers were grown by low-pressure metal–organic chemical-vapor deposition. The strain state and the In concentration in (InGaN/GaN) MQW systems are evaluated with the help of recipro...

Reactive ion etching of GaN metallorganic vapor-phase epitaxy grown on a (0001) sapphire substrate has been investigated using various chemistries based on SiCl4. The influence of gas combinations, gas flow, pressure, and radio-frequency (rf) power on etch rate and morphology was studied. Very high etch rates (160 nm/min) were obtained by adding SF...

Since the invention of the Planetary Reactors® a reliable tool for mass production of various III–V compounds has existed. These reactors have proven to grow extremely uniform films together with a highly efficient utilization of the precursors. Now a new generation of Planetary Reactors® is introduced: the so-called G3 systems. Their main features...

Reactive Ion Etching (RIE) of GaN epitaxially grown on (0001) sapphire substrate has been investigated using various chemistries based on SiCl₄, Ar and SF₆. Plasma deposited SiN_x is used for masking. We studied the influence of gas flow, pressure and RF-power on etch rate and morphology. High etch rates up to 150 n...

Due to an increased interest in the large scale production of GaN-based devices we have used our AIXTRON single wafer horizontal tube and Multiwafer Planetary(R) MOVPE systems for the fabrication of GaN/InGaN/GaN heterostructures, multiquantum well structures and LEDs. The AM 2000HT was set up in a configuration of 7×2 inch which provides unique un...

In this work a series of InGaN samples 0.1 mum thick grown by metalorganic vapour phase epitaxy are analysed by SEM, micro-Raman and photoluminescence. The mole fraction of indium is determined by microanalysis. Sample morphology varies widely in different samples, ranging from good uniformity to cellular structure, where hexagonal pits are observe...

The liquid Si-compound ditertiarybutyl silane (DTBSi) has been investigated as a doping source for the metal organic vapour-phase epitaxy (MOVPE) of InP and GaAs using TBP or DTBP and TBAs as less hazardous group-V-sources. For both material systems the measured carrier concentration is directly proportional to the DTBSi/group-III-partial pressure...

Since the invention of the Planetary Reactors(R) a reliable tool for mass production of various III-V compounds is existing. These reactors haven proven to grow extremely uniform films together with a highly efficient utilization of the precursors. Now a new generation of Planetary Reactors(R) is introduced: the so-called G3 systems. Their main fea...

Since the invention of the Planetary Reactors a reliable tool for mass production of various III-V compounds is existing. These reactors have proven to grow extremely uniform films together with a highly efficient utilization of the precursors. Now a new generation of Planetary Reactors is introduced: the so-called G3 systems. Their main features a...

For the fabrication of epitaxial films of silicon carbide or the Group III nitrides, high growth temperatures (up to 1700°C) and fast heating and cooling of the growth environment have been found to be necessary. A range of production systems meeting these requirements has been designed with different loading capacities. In this paper, we present r...

Using production scale AIXTRON MOCVD systems various heterointerfaces in the GaInN/GaN system have been studied in depth. GaInN single hetero layers were investigated to optimise photoluminescence properties. Several approaches of capping GaInN/GaN with another GaN layer to develop high quality double-hetero (DH) structures were presented. Using an...

We present an investigation of the growth of InP based materials in a Multiwafer Planetary Reactor (R). A reactor suited for the simultaneous growth of 15×2", 8×3" or 5×4" wafers was used to grow InP, GaInAs and various GaInAsP compositions. As predicted by the theory of the Planetary Reactor (R) principle, excellent uniformities of all layer prope...

In this study, the use of novel, liquid, organic arsenic precursors as substitutes for the highly toxic hydride gas arsine (AsH3) in low pressure metalorganic vapor phase epitaxy (LP-MOVPE) of (GaIn)As lattice matched on InP has been investigated. The model precursors out of the classes of (alkyl)3-nAsHn (n = 0,1,2) are tertiarybutyl arsine (TBAs),...

In this work the use of the novel ditertiarybutyl-phosphorous and arsenic precursors for low pressure metalorganic vapor phase epitaxy (LP-MOVPE) application with respect to InP/(GaIn)As-heterostructures and pin-detector device structures has been studied. Layer quality has been investigated by means of optical and scanning electron microscopy, tem...

In this study, the use of a novel phosphorous precursor for low pressure metalorganic vapor phase epitaxy (LP-MOVPE) application has been investigated. Ditertiarybutyl phosphine ((C4H9)2-P-H, DitBuPH) as substitute for the standardly used hydrid gas phosphine (PH3) promises apart from strongly reduced toxicity due to the reduction of P-H bonds, an...

A variety of monoalkyl, dialkyl as well as trialkyl P-compounds, containing ethyl, isopropyl, and tertiarybutyl rest groups have been synthesized and used for the growth of InP bulk epitaxial layers by low pressure metalorganic vapour phase epitaxy. Almost uncompensated, n-type InP-layers (1.0·10¹⁵ cm^-3 59600 cm^-2...

The alternative group V sources trisdimethylamino-arsine (TDMAAs) and trisdimethylamino-phosphine (TDMAP) have been used as substitutes for the highly toxic group V hydrides AsH3 and PH3 for the growth of GaAs, (AlGa)As and InP epitaxial layers by low-pressure metalorganic vapour phase epitaxy (MOVPE). The properties of the layers have been investi...

New group III hydride precursors have been synthesized in high yield and their purities have been measured by atomic absorption spectroscopy analysis, ion chromatography and metal-organic vapour-phase epitaxy. With these compounds, which have no metal-to-carbon bond, a decrease in carbon incorporation into (Al, Ga)As/GaAs heterostructures is achiev...

In this study we report on the chemical synthesis, thermal decomposition and first metal-organic vapour-phase epitaxy (MOVPE) growth studies for a new class of metal-organic As compounds, designed as substitutes for the highly toxic AsH3. The key feature of these molecules is the in-situ formation of AsH functions only in the hot temperature zone...

Novel gallane-amine adducts have been synthesized and tested as alternative sources for the epitaxial growth of GaAs and (AlGa)As thin layers by metal organic vapor phase epitaxy. These precursors solve the problem of unwanted incorporation of carbon that arises with standard metalorganic sources. A single-crystal X-ray diffraction study provides m...

We report on the chemical synthesis, thermal decomposition studies and the first low pressure MOVPE growth experiments for a new class of metalorganic As compounds, designed as substitutes for the highly toxic AsH3. The key feature of these molecules is the in-situ formation of As-H-functions, formed by thermal decomposition under beta-elimination...

The Group III hydride compounds trimethylamine alane (AlH3·N(CH3)3 (TMAAl)) and dimethylamine gallane (GaH3· N(CH3)2H (DMAGa)) have been synthesized and used successfully for the growth of GaAs and (AlGa)As bulk epitaxial layers and (AlGa)As/GaAs heterostructures by low-pressure metalorganic vapour phase epitaxy (LP-MOVPE) in combination with both...