Negative transconductance effect in p-GaN gate AlGaN/GaN HEMTs by traps in unintentionally doped GaN buffer layer

ABSTRACTThe influence of growth temperature on oxygen incorporation into GaN epitaxial layers was studied. GaN layers deposited at low temperatures were characterized by much higher oxygen concentration than those deposited at high temperature typically used for epitaxial growth. GaN buffer layers (HT GaN) about 1 μm thick were deposited on GaN nucleation layers (NL) with various thicknesses. The influence of NL thickness on crystalline quality and oxygen concentration of HT GaN layers were studied using RBS and SIMS. With increasing thickness of NL the crystalline quality of GaN buffer layers deteriorates and the oxygen concentration increases. It was observed that oxygen atoms incorporated at low temperature in NL diffuse into GaN buffer layer during high temperature growth as a consequence GaN NL is the source for unintentional oxygen doping.

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Effect of N/Ga Flux Ratio in GaN Buffer Layer Growth by MBE on (0001) Sapphire on Defect Formation in the GaN Main Layer

MRS Proceedings ◽

10.1557/proc-572-295 ◽

1999 ◽

Vol 572 ◽

Cited By ~ 2

Author(s):

S. Ruvimov ◽

Z. Liliental-Weber ◽

J. Washburn ◽

Y. Kim ◽

G. S. Sudhir ◽

...

Keyword(s):

Dislocation Density ◽

Buffer Layer ◽

Defect Formation ◽

Flux Ratio ◽

Growth Conditions ◽

Buffer Layers ◽

Simultaneous Increase ◽

Growth Stages ◽

Dislocation Generation ◽

Gan Buffer Layer

ABSTRACTTransmission electron microscopy was employed to study the effect of N/Ga flux ratio in the growth of GaN buffer layers on the structure of GaN epitaxial layers grown by molecular-beamepitaxy (MBE) on sapphire. The dislocation density in GaN layers was found to increase from 1×1010 to 6×1010 cm−2 with increase of the nitrogen flux from 5 to 35 sccm during the growth of the GaN buffer layer with otherwise the same growth conditions. All GaN layers were found to contain inversion domain boundaries (IDBs) originated at the interface with sapphire and propagated up to the layer surface. Formation of IDBs was often associated with specific defects at the interface with the substrate. Dislocation generation and annihilation were shown to be mainly growth-related processes and, hence, can be controlled by the growth conditions, especially during the first growth stages. The decrease of electron Hall mobility and the simultaneous increase of the intensity of “green” luminescence with increasing dislocation density suggest that dislocation-related deep levels are created in the bandgap.

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High quality GaN buffer layer by isoelectronic doping and its application to 365 nm InGaN/AlGaN ultraviolet light-emitting diodes

Applied Surface Science ◽

10.1016/j.apsusc.2018.12.011 ◽

2019 ◽

Vol 471 ◽

pp. 231-238 ◽

Cited By ~ 43

Author(s):

Shengjun Zhou ◽

Haohao Xu ◽

Hongpo Hu ◽

Chengqun Gui ◽

Sheng Liu

Keyword(s):

Buffer Layer ◽

Ultraviolet Light ◽

Light Emitting Diodes ◽

High Quality ◽

Light Emitting ◽

Isoelectronic Doping ◽

Ultraviolet Light Emitting Diodes ◽

Gan Buffer Layer

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Negative transconductance effect in p-GaN gate AlGaN/GaN HEMTs by traps in unintentionally doped GaN buffer layer

Effect of multiple carbon-doped/undoped GaN buffer layer on current collapse in AlGaN/GaN HEMTs

Effects of the Trap Level in the Unintentionally Doped GaN Buffer Layer on Optimized p-GaN Gate AlGaN/GaN HEMTs

Measuring the thermal conductivity of the GaN buffer layer in AlGaN/GaN HEMTs

Improved breakdown voltage of AlGaN/GaN HEMTs grown on Si substrates using partially Mg-doped GaN buffer layer by MOCVD

Influence of pit defects on AlGaN surface and dislocation defects in GaN buffer layer on current collapse of AlGaN/GaN HEMTs

1/f noise characteristics of AlGaN/GaN HEMTs with periodically carbon-doped GaN buffer layer

Effect of low-temperature GaN buffer layer on the crystalline quality of subsequent GaN layers grown by MOVPE

The Influence of Growth Temperature on Oxygen Concentration in GaN Buffer Layer

Effect of N/Ga Flux Ratio in GaN Buffer Layer Growth by MBE on (0001) Sapphire on Defect Formation in the GaN Main Layer

High quality GaN buffer layer by isoelectronic doping and its application to 365 nm InGaN/AlGaN ultraviolet light-emitting diodes

High quality GaN buffer layer by isoelectronic doping and its application to 365 nm InGaN/AlGaN ultraviolet light-emitting diodes