Nature of the parasitic chemistry during AlGaInN OMVPE

Creighton, J. R.; Wang, George T.; Breiland, William G.; Coltrin, Michael E.

doi:10.1016/j.jcrysgro.2003.11.074

Cited by 137 publications

(159 citation statements)

References 40 publications

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“…Yet another potential issue with the growth of the ScGaN and YGaN alloys is that gas phase adduct and cluster formation may decrease the amount of Sc and Y that can reach the surface. Recently, Creighton et al studied adduct and cluster formation for GaN and AlN and found that different reaction mechanisms may contribute to Ga and Al cluster formation [29]. One finding from this study is that the cluster formation and precursor depletion reaction rates can be decreased by reducing the metal flow and this has recently been demonstrated by Allerman et al for AlGaN growth [27].…”

Section: Potential Of Scgan and Ygan Alloys For Longer Wavelength Ledssupporting

confidence: 65%

Issues associated with the metalorganic chemical vapor deposition of ScGaN and YGaN alloys.

Koleske¹,

Knapp²,

Lee³

et al. 2009

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We report on issues associated with the metalorganic chemical vapor deposition growth of ScGaN and YGaN. Based on the proposed bandgaps of ScN (2.15 eV), YN (0.8 eV) and the known bandgap of GaN (3.4 eV), we expected that LEDs could be fabricated from the UV (410 nm) to the IR (1600 nm), resulting in LED over all visible wavelengths for solid state lighting However, due to the low volatility of scandium and yttrium metalorganic precursors, we were only able to incorporate doping level concentrations of these atoms into a GaN film. This report highlights the difficulties encountered during the growth of these alloys and how some of these difficulities were overcome. We also investigated the nitridation of thin scandium metal films deposited on GaN using pulsed laser deposition. GaN was also grown on these thin ScN films to as a means to lower the GaN dislocation density. 4This page has been left intentionally blank 5 Extended AbstractThe most energy efficient solid state white light source will likely be a combination of individually efficient red, green, and blue LED. For any multi-color approach to be successful the efficiency of deep green LEDs must be significantly improved. While traditional approaches to improve InGaN materials have yielded incremental success, we proposed a novel approach using group IIIA and IIIB nitride semiconductors to produce efficient green and high wavelength LEDs.To obtain longer wavelength LEDs in the nitrides, we attempted to combine scandium (Sc) and yttrium (Y) with gallium (Ga) to produce ScGaN and YGaN for the quantum well (QW) active regions. Based on linear extrapolation of the proposed bandgaps of ScN (2.15 eV), YN (0.8 eV) and GaN (3.4 eV), we expected that LEDs could be fabricated from the UV (410 nm) to the IR (1600 nm), and therefore cover all visible wavelengths. The growth of these novel alloys potentially provided several advantages over the more traditional InGaN QW regions including: higher growth temperatures more compatible with GaN growth, closer lattice matching to GaN, and reduced phase separation than is commonly observed in InGaN growth. One drawback to using ScGaN and YGaN films as the active regions in LEDs is that little research has been conducted on their growth, specifically, are there metalorganic precursors that are suitable for growth, are the bandgaps direct or indirect, can the materials be grown directly on GaN with a minimal defect formation, as well as other issues related to growth.The major impediment to the growth of ScGaN and YGaN alloys was the low volatility of metalorganic precursors. Despite this impediment some progress was made in incorporation of Sc and Y into GaN which is detailed in this report. Primarily, we were able to incorporate up to 5x10 18 cm -3 Y atoms into a GaN film, which are far below the alloy concentrations needed to evaluate the YGaN optical properties.After a no-cost extension was granted on this program, an additional more "liquid-like" Sc precursor was evaluated and the nitridation of Sc metals on GaN w...

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Section: Potential Of Scgan and Ygan Alloys For Longer Wavelength Ledssupporting

confidence: 65%

Issues associated with the metalorganic chemical vapor deposition of ScGaN and YGaN alloys.

Koleske¹,

Knapp²,

Lee³

et al. 2009

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“…• C. 30 The jump of γ GaN at 50 mbar mentioned above certainly shows the presence of the driving forces advantageous to Ga solid incorporation at T ceil = 950…”

Section: 27mentioning

confidence: 87%

“…• C. 30 The M(CH 3 ) 3 then proceed chains of homogenous homolytic fissions to form radical fragments as temperature is elevated. 31,32 Further increasing the temperature may cause parts of them to recombine together, which act as nucleation, and provoke agglomeration or coalescence processes for particle growth.…”

Section: 27mentioning

confidence: 99%

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Incorporation Behaviors of In and Ga in the Two-Heater MOVPE Growth of InGaN Films

Cheng

Lee

et al. 2016

ECS J. Solid State Sci. Technol.

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Incorporation behaviors of In and Ga of InGaN films grown by the two-heater metal-organic vapor-phase epitaxial horizontal reactor is investigated by varying growth parameters, such as the substrate temperature, ceiling temperature and reactor pressure. Two In loss mechanisms are observed by the analysis of the concentration and temperature profiles in the deposition zone. The gas-phase parasitic-loss mechanism (activation energy ∼ 34.2 ± 0.1 kcal/mol) is significant in the ceiling temperature T ceil ≥ 800 • C and at substrate temperature (T sub ) of 600 • C. The decomposition-loss mechanism, which arises from In desorption on the growing surface, is significant in T sub > 625 • C region. The desorption activation energy obtained is 28.0 ± 0.1 kcal/mol, which is close to that of . This suggests the In decomposition-loss mechanism in InGaN growth does not differ substantially from that in binary InN growth. On the other hand, the gas-phase parasitic-loss mechanism of Ga is negligible in the growth condition that we have explored. Exception is found for reactor pressure at T ceil = 950 • C, where both factors advantageous and disadvantageous to Ga incorporation are unambiguously observed. We have proposed explanation for the above observation. The promising electronic and optical properties of InGaN alloy, such as high two-dimensional electron gas (2DEG) electron mobility, wide tunability of photon emission energy from 0.7 to 3.4 eV, have given rise to numbers of applications in the past decade. These include high power and high electron mobility transistor (HEMT), visible light emitting devices, tandem solar cell, and solid state lighting.1-7 To realize, a method that capable of growing device-quality III-V nitrides is essential. Among all growth methods, metal-organic vapor-phase epitaxy (MOVPE) has proved itself to be the most reliable and major tool to produce these devices with mass-production feasibility. However, difficulties arise for this method in preparing high In content In x Ga 1−x N film (x > 30%) with acceptable optical and electrical properties. This stems mainly from the intrinsic properties of material itself, such as thermal instability of InN, wide miscibility gap, and large thermal-and lattice-mismatch between InGaN layer and underlying GaN base layer, and poor cracking efficiency of NH 3 . These lead to generations of considerable amounts of nitrogen vacancies, pits, In-rich clusters and/or structure defects in the film to deteriorate its material properties. [8][9][10][11][12][13][14][15][16][17] In our previous work, we have employed a so-called the two-heater MOVPE horizontal reactor, consisting of a pair of paralleled ceiling and substrate heaters, 18 to grow InGaN films. We demonstrated its ability in preparing high In-content thick InGaN films with emission wavelength extended into infrared color region, and more importantly exhibiting good optical-quality and high spectral uniformity. For instance, a sample with x = 0.40 In x Ga 1−x N film has a mean emission wavelength of 808 ± 6 nm a...

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“…[20][21][22] 39 However, a model that can describe the growth behavior consistently in all reactor configurations and for all process conditions remains elusive. This is our concern, and necessitates comprehensive investigation on the behavior of GaN growth under a wide variety of conditions, from both experimental and theoretical standpoints.…”

Section: -10mentioning

confidence: 99%

Kinetic Analysis of GaN-MOVPE via Thickness Profiles in the Gas Flow Direction with Systematically Varied Growth Conditions

Momose

Kamiya

Suzuki

et al. 2016

ECS J. Solid State Sci. Technol.

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We carried out a kinetic analysis of metallorganic vapor phase epitaxy (MOVPE) of GaN to investigate the dependence of the growth rate on the process conditions as a function of residence time of the precursors in the reactor. The wafer was not rotated during growth, allowing us to analyze the thickness profile of the film in the direction of gas flow, and hence the dependence of the growth rate on the residence time. The growth rate is determined mainly by the concentration of the growth species and mass transfer of the growth species to the wafer surface. The growth rate peaked in the flow direction, and the position of this peak could, in most cases, be explained by considering a combination of the linear gas velocity and the time constant for vertical diffusion of trimethylgallium (TMGa) and/or growth species across the NH 3 feed stream to the wafer surface. In some cases this was not possible, indicating that more complex effects were significant. This work is expected to contribute to understanding of the reaction pathways for GaN-MOVPE, and the growth rate data reported here are expected to provide useful benchmarks for growth simulations that combine computational fluid dynamics and reaction models. Gallium nitride (GaN) is a III/V compound semiconductor material with considerable potential for optoelectronic and high-power electronic devices due to its wide bandgap and high breakdown voltage.1-5 For these reasons, GaN is currently used for mass-produced light-emitting diodes (LEDs), lasers, and high-frequency devices. 6-10Metalorganic vapor phase epitaxy (MOVPE) is commonly employed to manufacture GaN films using trimethylgallium (TMGa) and NH 3 as group-III and group-V precursors, respectively. Research into the growth mechanisms involved in GaN-MOVPE in both academic and industrial institutions has found that the reaction chemistry is relatively complicated, consisting of gas-phase reactions followed by surface reactions. [11][12][13][14][15][16][17] This intrinsic complexity of the reactions suggests that it is not straightforward to design optimal reactors for mass production as well as settling the optimal growth conditions via conventional empirical approaches. Therefore, a variety of studies have been carried out with the aim of understanding GaN-MOVPE. Initially, attention mainly focused on identification of intermediate species that are generated from the gas-phase precursors, which contribute to the layer growth. It then became apparent that parasitic reactions in the gas phase resulted in the formation of adducts, even in the non-heated area of the reactor, in addition to those formed in the hot zone in the vicinity of the heated substrate.18,19 Some of these reaction products led to particle formation without contributing to layer growth. [20][21][22] 39 However, a model that can describe the growth behavior consistently in all reactor configurations and for all process conditions remains elusive. This is our concern, and necessitates comprehensive investigation on the behavior of GaN growt...

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Nature of the parasitic chemistry during AlGaInN OMVPE

Cited by 137 publications

References 40 publications

Issues associated with the metalorganic chemical vapor deposition of ScGaN and YGaN alloys.

Issues associated with the metalorganic chemical vapor deposition of ScGaN and YGaN alloys.

Incorporation Behaviors of In and Ga in the Two-Heater MOVPE Growth of InGaN Films

Kinetic Analysis of GaN-MOVPE via Thickness Profiles in the Gas Flow Direction with Systematically Varied Growth Conditions

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