Capture Kinetics of Electron Traps in MBE-Grown n-GaN

Hierro, A.; Arehart, Aaron R.; Heying, B.; Hansen, M.; Speck, James S.; Mishra, Umesh K.; DenBaars, Steven P.; Ringel, S. A.

doi:10.1002/1521-3951(200111)228:1<309::aid-pssb309>3.0.co;2-n

Cited by 57 publications

(29 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The DLTS-detected traps at E c Ϫ0.59 and 0.91 eV have capture cross sections of n ϳ2ϫ10 Ϫ15 and ϳ3 ϫ10 Ϫ14 cm 2 , respectively, and correspond to previously reported traps in n-GaN. 10 While the concentration of the 0.59 eV level did not follow a clear trend with Ga/N flux ratio, the 0.91 eV level concentration displays a small decrease towards Ga-lean conditions. This dependence taken together with its position in the band gap suggests a possible correlation between this level and Ga I -complexes that are related to a 0.88 eV photoluminescence band in n-GaN.…”

supporting

confidence: 85%

“…11 Note that for Ga-lean conditions both the activation energy and capture cross section for this level shift to E c Ϫ1.0 eV and ϳ7 ϫ10 Ϫ14 cm 2 , respectively, suggesting a change in its local electrical configuration as a function of Ga/N flux ratio. Indeed, by means of the investigation of its trapping kinetics, this level has been previously assigned to a linear arrangement of point defects likely found along the TDs, 10 which, taken together with its change in electrical configuration, correlates with reported variations of the local electrical activity for screw-type TDs with Ga/N flux ratio. 2 The deep levels found closer to the midgap, at E c Ϫ1.35 and 2.40 eV, do not show any significant variations in trap concentration with Ga/N flux ratio.…”

mentioning

confidence: 89%

See 1 more Smart Citation

Impact of Ga/N flux ratio on trap states in n-GaN grown by plasma-assisted molecular-beam epitaxy

Hierro

Arehart

Heying

et al. 2002

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

Deep level transient spectroscopy in plasma-assisted molecular beam epitaxy grown Al 0.2 Ga 0.8 N / GaN interface and the rapid thermal annealing effect Appl. Phys. Lett. 97, 112110 (2010); 10.1063/1.3491798Effect of N to Ga flux ratio on the GaN surface morphologies grown at high temperature by plasma-assisted molecular-beam epitaxyThe effect of growth regime on the deep level spectrum of n-GaN using molecular-beam epitaxy ͑MBE͒ was investigated. As the Ga/N flux ratio was decreased towards Ga-lean conditions, the concentration of two acceptor-like levels, at E c Ϫ3.04 and 3.28 eV, increased from 10 15 to 10 16 cm Ϫ3 causing carrier compensation in these films. Thus, these two traps behaved as the dominant compensating centers in MBE n-GaN. Furthermore, the increase in trap concentration also strongly correlated with the degradation of both surface morphology and bulk electron mobility towards Ga-lean conditions, where higher pit densities and lower mobility were observed. These results show that the growth regime directly impacts all morphology, bulk transport, and trap states in n-GaN.

show abstract

supporting

confidence: 85%

mentioning

confidence: 89%

Impact of Ga/N flux ratio on trap states in n-GaN grown by plasma-assisted molecular-beam epitaxy

Hierro

Arehart

Heying

et al. 2002

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

show abstract

“…Concentration (cm -3 ) of the deep levels found in the as-grown and hydrogenated n-GaN films [9]. The TDD obtained from plan-view TEM and EBIC analysis is also shown for both films [16]. We focus here on the trapping kinetics of the E c --2.64/E v + 0.87 eV level, which were studied on a p + -n GaN sample grown immediately after that previously discussed.…”

Section: Dlos and Dlts Resultsmentioning

confidence: 93%

Carrier Trapping and Recombination at Point Defects and Dislocations in MOCVD n-GaN

Hierro

Hansen

Zhao

et al. 2001

phys. stat. sol. (b)

Self Cite

View full text Add to dashboard Cite

We present the results of an approach that allows the analysis of grown-in defects in n-GaN grown by metal organic vapor phase epitaxy by relating the presence of various structural defects to the concentration and properties of distinct deep levels. Transmission electron microscopy and electron beam induced current (EBIC) microscopy together with post-growth hydrogenation are used to determine the threading dislocation density (TDD) and observe their local electrical activity. In conjunction, deep level optical and transient spectroscopies (DLOS and DLTS, respectively) are used to detect deep levels, determine their concentration and analyze their carrier trapping kinetics for these films. The comparison of EBIC analysis with trap spectra prior and after hydrogenation establishes a strong correlation between two specific levels, at E c --E t = 0.58 and 1.35 eV, and recombination centers distributed in the field of the GaN films. Further, EBIC analysis shows that, independent of hydrogenation, TDs behave as strong recombination centers, and indicates that there must be a deep level associated with these regions. A level observed at E c --2.64/E v + 0.87 eV is a good candidate to account for the electrical activity of the TDs because it captures both electrons and holes, which is characteristic of recombination centers. This is supported by DLTS analysis of the trapping kinetics for this level that reveals a behavior characteristic of a linear arrangement of point defects likely found along the TDs.

show abstract

“…Compared to the widely studied field of deep levels in n-type GaN, [3][4][5][6][7] understanding of deep levels within p-type GaN is lacking because the deep Mg acceptor complicates many electrically sensitive defect spectroscopy techniques. The difficultly of transient capacitance measurements for p-type GaN arises from the inability of the thermal emission rate of the Mg dopant to follow a high frequency ac signal, which leads to frequency dispersion of the depletion capacitance.…”

Section: Introductionmentioning

confidence: 99%

Deep level investigation of p-type GaN using a simple photocurrent technique

Armstrong

Thaler

Koleske

2009

Journal of Applied Physics

View full text Add to dashboard Cite

Effects of interface states and temperature on the C -V behavior of metal/insulator/AlGaN/GaN heterostructure capacitorsThe deep level spectrum of p-type GaN was investigated using time-resolved photocurrent spectroscopy. The spectral dependence of the optical cross section for hole photoemission from a deep level was determined from the initial value of the photocurrent transient. Unlike other implementations of photocurrent, the present method does not require multiple excitation sources or determination of the optical emission rate. A deep level was observed at E v + 1.84 eV, where E v is the valence band maximum, with a Franck-Condon shift of 0.25 eV. A bias-dependent component of the photocurrent, possibly due to metal-semiconductor interface states, complicated the steady-state response but did not affect the measured spectrum for the E v + 1.84 eV deep level. This photocurrent method is expected to be readily extended to materials with very deep dopants, such as p-type AlGaN, for which many other deep level spectroscopy techniques are unsuited.

show abstract

Capture Kinetics of Electron Traps in MBE-Grown n-GaN

Cited by 57 publications

References 11 publications

Impact of Ga/N flux ratio on trap states in n-GaN grown by plasma-assisted molecular-beam epitaxy

Impact of Ga/N flux ratio on trap states in n-GaN grown by plasma-assisted molecular-beam epitaxy

Carrier Trapping and Recombination at Point Defects and Dislocations in MOCVD n-GaN

Deep level investigation of p-type GaN using a simple photocurrent technique

Contact Info

Product

Resources

About