A model of trap-assisted tunneling in GaN/AlGaN/GaN heterostructure based on exchange times

Racko, J.; Benko, P.; Hotovy, I.; Harmatha, L.; Mikolášek, Miroslav; Granzner, Ralf; Kittler, M.; Schwierz, Frank; Breza, Juraj

doi:10.1016/j.apsusc.2014.05.065

Cited by 8 publications

(3 citation statements)

References 14 publications

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“…not thermionic) field emission component to conduction in such samples, where carriers are able to tunnel between adjacent trap states . Pure field emission is independent of temperature , which when combined with the well defined temperature profile of thermionic field emission is presumed to cause the unusual behaviour of contact resistivity with temperature in the fissured samples, HA and NA.…”

Section: Results and Analysismentioning

confidence: 99%

Nanoscale fissure formation in Al_xGa_1–xN/GaN heterostructures and their influence on Ohmic contact formation

Smith¹,

Thomson

Zubialevich³

et al. 2016

Physica Status Solidi (a)

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Nanoscale surface fissures on AlxGa1–xN/GaN (15 nm/1 µm) heterostructures grown by metalorganic vapour phase epitaxy (MOVPE) were imaged using tapping‐mode atomic force microscopy (AFM) and electron channelling contrast imaging (ECCI). Fissure formation was linked to threading dislocations, and was only observed in samples cooled under H2 and NH3, developing with increasing barrier layer Al content. No strain relaxation was detected regardless of fissure formation up to barrier layer Al composition fractions of x = 0.37. A reduction of measured channel carrier density was found in fissured samples at low temperature. This instability is attributed to shallow trap formation associated with fissure boundaries. For Ti/Al/Ni/Au Ohmic contact formation to high Al content barrier layers, fissures were found to offer conduction routes to the 2DEG that allow for low resistance contacts, with fissure‐free samples requiring additional optimisation of the metal stack and anneal conditions to achieve contact resistivity of order those measured in fissured samples. In addition, the effects of fissures were found to be detrimental to thermal stability of sheet and contact resistance, suggesting that fissure formation compromises the integrity of the 2DEG.

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Section: Results and Analysismentioning

confidence: 99%

Nanoscale fissure formation in Al_xGa_1–xN/GaN heterostructures and their influence on Ohmic contact formation

Smith¹,

Thomson

Zubialevich³

et al. 2016

Physica Status Solidi (a)

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“…Our TAT model was first published in [15,16], however, without presenting in detail how the tunnelling and thermal exchange times had been derived. The model considers a metal/semiconductor heterostructure that may contain numerous deep trapping levels in the forbidden band of the semiconductor.…”

Section: Band Diagram and Exchange Processesmentioning

confidence: 99%

Deriving the exchange times for a model of trap-assisted tunnelling

Racko

Mikolášek

Kadlečíková

et al. 2020

Journal of Electrical Engineering

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The work presents a physical model of trap-assisted tunnelling that allows assessing the impact of traps upon the total current through metal/semiconductor heterostructures. The model is based on expressing the occupation probability of the trapping centres by electrons in terms of thermal and tunnelling capture and emission times, commonly referred to as exchange times. The occupation probabilities calculated in this way are then used to evaluate the generation-recombination rates occurring in the continuity equations.

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“…So far, high performance AlGaN‐based heterojunction p–i–n PDs have been reported . However, it should be noted that some issues are also introduced during epitaxial growth, such as numerous trapping levels which existed in the forbidden band because of the lattice mismatch between the different AlGaN films, and these levels may capture and emit free carriers to the conduction or valence bands because of thermal exchange processes or tunneling . In addition, the fixed interface polarization charges are also introduced at nitride hetero‐interfaces due to the piezoelectric and spontaneous polarization, which leads to potential barriers, band bending, and internal electric field .…”

Section: Introductionmentioning

confidence: 99%

Dependence of dark current and photoresponse on polarization charges for AlGaN‐based heterojunction p–i–n photodetectors

Chen

Song

et al. 2017

Physica Status Solidi (a)

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The influence of the polarization charges on the properties of AlGaN‐based heterojunction p–i–n ultraviolet photodetectors was investigated. It is found that the polarization charges at the hetero‐interface can enhance the electric field intensity and result in an increased dark current. On the contrary, the polarization charges can lower the photoresponse because the direction of polarization electric field is opposite to the applied electric field in the light absorption layer.

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A model of trap-assisted tunneling in GaN/AlGaN/GaN heterostructure based on exchange times

Cited by 8 publications

References 14 publications

Nanoscale fissure formation in Al_xGa_1–xN/GaN heterostructures and their influence on Ohmic contact formation

Nanoscale fissure formation in Al_xGa_1–xN/GaN heterostructures and their influence on Ohmic contact formation

Deriving the exchange times for a model of trap-assisted tunnelling

Dependence of dark current and photoresponse on polarization charges for AlGaN‐based heterojunction p–i–n photodetectors

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A model of trap-assisted tunneling in GaN/AlGaN/GaN heterostructure based on exchange times

Cited by 8 publications

References 14 publications

Nanoscale fissure formation in AlxGa1–xN/GaN heterostructures and their influence on Ohmic contact formation

Nanoscale fissure formation in AlxGa1–xN/GaN heterostructures and their influence on Ohmic contact formation

Deriving the exchange times for a model of trap-assisted tunnelling

Dependence of dark current and photoresponse on polarization charges for AlGaN‐based heterojunction p–i–n photodetectors

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Product

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Nanoscale fissure formation in Al_xGa_1–xN/GaN heterostructures and their influence on Ohmic contact formation

Nanoscale fissure formation in Al_xGa_1–xN/GaN heterostructures and their influence on Ohmic contact formation