Electrical characterization of isoelectronic In-doping effects in GaN films grown by metalorganic vapor phase epitaxy

Chung, H. M.; Chuang, Wen‐Han; Pan, Yung-Chung; Tsai, Chuen-Tinn; Lee, M. C.; Chen, W. H.; Chen, Wei–Kuo; Chiang, C. I.; Lin, Chia Hui; Chang, Hen‐Hong

doi:10.1063/1.125622

Cited by 83 publications

(22 citation statements)

References 14 publications

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“…Only one of these traps, the T2 trap, has been reported in the literature. This trap, with the activation energy at E C − 0.50 ÷ 0.62 eV and labelled B2, D2, or E2 in the literature, tends to be the most prominent electron trap revealed by DLTS in n-type GaN [10][11][12][13][14][15]. Hacke et al [12] and Haase et al [13] assigned this trap to the nitrogen antisite point defect, N Ga , on the ground of the results of tight-binding calculations determining the deep donor level of N Ga at E C − 0.54 eV [16].…”

Section: Discussionmentioning

confidence: 79%

“…Hacke et al [12] and Haase et al [13] assigned this trap to the nitrogen antisite point defect, N Ga , on the ground of the results of tight-binding calculations determining the deep donor level of N Ga at E C − 0.54 eV [16]. More recent results by Chung et al [14] and Cho et al [10], showing that the concentration of this trap could be effectively suppressed by In doping, support this assignment. Very recently, this trap has been also revealed as the dominant deep-level defect in MOVPE-grown LD heterostructure [11].…”

Section: Discussionmentioning

confidence: 94%

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Deep-Level Defects in MBE-Grown GaN-Based Laser Structure

et al. 2007

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We present results of deep-level transient spectroscopy investigations of defects in a GaN-based heterostructure of a blue-violet laser diode, grown by plasma-assisted molecular beam epitaxy on a bulk GaN substrate. Three majority-carrier traps, T1 at E C − 0.28 eV, T2 at E C − 0.60 eV, and T3 at EV + 0.33 eV, were revealed in deep-level transient spectra measured under reverse-bias conditions. On the other hand, deep-level transient spectroscopy measurements performed under injection conditions, revealed one minority--carrier trap, T4, with the activation energy of 0.20 eV. The three majority--carrier traps were revealed in the spectra measured under different reverse--bias conditions, suggesting that they are present in various parts of the laser--diode heterostructure. In addition, these traps represent different charge--carrier capture behaviours. The T1 trap, which exhibits logarithmic capture kinetics, is tentatively attributed to electron states of dislocations in the n-type wave-guiding layer of the structure. In contrast, the T2, T3, and T4 traps display exponential capture kinetics and are assigned to point defects.

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Section: Discussionmentioning

confidence: 79%

Section: Discussionmentioning

confidence: 94%

Deep-Level Defects in MBE-Grown GaN-Based Laser Structure

et al. 2007

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“…Hacke et al [18] and Haase et al [19] assigned this trap to the nitrogen antisite point defect, N Ga , on the grounds of the results of tight-binding calculations determining the deep donor level of N Ga at E C − 0.54 eV [25]. More recent results by Chung et al [20] and Cho et al [15], showing that the E2 trap concentration could be effectively suppressed by In doping, support this assignment since isoelectronic In atoms, occupying vacant Ga sites in the GaN crystal lattice during the growth, result in a lowering the density of Ga vacancy-related defects. However, several authors revealed that the E2 traps displayed the logarithmic capture kinetics [14,16] and that their concentration increased with the increase of dislocation density [16,22,24], and concluded that the traps were associated with dislocations themselves or were created during the dislocation generation process.…”

Section: Dlts Resultsmentioning

confidence: 95%

Capture kinetics at deep‐level electron traps in GaN‐based laser diode

Yastrubchak

Wosiński

Mąkοsa

et al. 2007

Phys. Status Solidi (c)

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Two deep-level electron traps, E1 at E C − 0.23 eV and E2 at E C − 0.55 eV, have been revealed by means of deep-level transient spectroscopy (DLTS) in a GaN-based laser-diode heterostructure grown by metalorganic vapour-phase epitaxy on a bulk GaN substrate. The two traps represent different electron capture behaviours. The E1 trap, which exhibits the logarithmic capture kinetics and the DLTS-line shape characteristic of band-like electron states, is attributed to the core states of threading dislocations in a p-type layer of the structure. In contrast, the E2 trap, being the most prominent deep-level electron trap in GaN layers, displays the exponential capture kinetics and is assigned to isolated point defects, likely the nitrogen antisite defect.1 Introduction GaN-based III-V nitrides (GaN, InGaN and AlGaN) are wide direct band-gap semiconductors, which have already been applied successfully to optoelectronic devices, such as highbrightness blue light emitting diodes and lasers and solar-blind ultraviolet detectors [1]. Because of low thermal generation of charge carriers and large dielectric breakdown fields of these materials they have also found applications in high-temperature and high-power electronics [2]. However, owing to the large dislocation densities in the GaN epitaxial layers, commonly grown on highly-mismatched sapphire substrates, and self-compensation tendencies of wide band-gap semiconductors, a number of deep-level defects, affecting the performance and reliability of GaN-based devices, are usually present in the layers. Identification and understanding of these defects, especially dislocations, is of particular importance for improving the device technology.Deep-level transient spectroscopy (DLTS) is commonly used from already three decades as a powerful experimental technique for investigations of deep-level defects in semiconductor materials and structures. It allows characterizing and cataloguing deep levels by means of their capture cross-section and activation energy of thermal emission of charge carriers form the levels [3]. Additional information on the structure of deep-level defects can be gained while measuring the kinetics for capture of charge carriers into the defect states by means of recording the dependence of the DLTS-signal amplitude on the filling-pulse duration. In this respect, deep levels associated with extended defects, such as dislocations, distinctly differ from deep levels associated with isolated point defects or impurities, which exhibit exponential capture kinetics. On the contrary, deep levels related to dislocations are distinguished by logarithmic capture kinetics [4,5]. Such a kinetics results from the formation of a Coulombic barrier around the charged dislocations whose height increases with the filling-pulse duration [6].

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“…This level has been reported by several authors, and in many reports it has been associated with the nitrogen antisite (N Ga ). 5,6,9,27 More recently, Look et al 10 performed measurements before and after 1 MeV electron irradiation of HVPE grown GaN sample, and they did not observe any changes in concentration for this trap. Considering this and that it is an electron trap relatively close to the conduction band, they suggested that this level is associated with some more complex defect involving a common impurity such as Si, O, or C or possibly C Ga .…”

mentioning

confidence: 99%

Investigation of deep levels in bulk GaN material grown by halide vapor phase epitaxy

Duc

Pozina

Janzén

et al. 2013

Journal of Applied Physics

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Electron traps in thick free standing GaN grown by halide vapor phase epitaxy were characterized by deep level transient spectroscopy. The measurements revealed six electron traps with activation energy of 0.252 (E1), 0.53 (E2), 0.65 (E4), 0.69 (E3), 1.40 (E5), and 1.55 eV (E6), respectively. Among the observed levels, trap E6 has not been previously reported. The filling pulse method was employed to determine the temperature dependence of the capture cross section and to distinguish between point defects and extended defects. From these measurements, we have determined the capture cross section for level E1, E2, and E4 to 3.2 Â 10 À16 cm 2 , 2.2 Â 10 À17 cm 2 , and 1.9 Â 10 À17 cm 2 , respectively. All of the measured capture cross sections were temperature independent in the measured temperature range. From the electron capturing kinetic, we conclude that trap E1, E2, and E3 are associated with point defects. From the defect concentration profile obtained by double correlated deep level transient spectroscopy, we suggest that trap E4 and E6 are introduced by the polishing process. V C 2013 AIP Publishing LLC. [http://dx

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Electrical characterization of isoelectronic In-doping effects in GaN films grown by metalorganic vapor phase epitaxy

Cited by 83 publications

References 14 publications

Deep-Level Defects in MBE-Grown GaN-Based Laser Structure

Deep-Level Defects in MBE-Grown GaN-Based Laser Structure

Capture kinetics at deep‐level electron traps in GaN‐based laser diode

Investigation of deep levels in bulk GaN material grown by halide vapor phase epitaxy

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