Conductivity and Hall effect measurements on intentionally undoped and doped AlGaN/GaN heterostructures before and after passivation

Bernát, J.; Javorka, P.; Marso, Michel; Kordoš, P.

doi:10.1063/1.1637154

Cited by 35 publications

(24 citation statements)

References 14 publications

(19 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hall effect measurements on van der Pauw patterns have shown an increase of the sheet carrier density and slight decrease of the carrier mobility in all passivated samples. The passivation induced sheet density [7] increased from 0.62×10 12 cm -2 to 1.37×10 12 cm -2 with increased stress from compressive (−150MPa) to tensile (50 MPa), as it is shown in Fig.1. The lowering in the passivation effectiveness of SiO 2 compared with that of Si 3 N 4 can be explained not only by more compressive stress but also by the higher density of SiO 2 /GaN interface states [8].…”

Section: Resultsmentioning

confidence: 62%

Influence of passivation induced stress on the performance of AlGaN/GaN HEMTs

Gregušová

Bernát

Držík

et al. 2005

phys. stat. sol. (c)

Self Cite

View full text Add to dashboard Cite

PACS 81.65.Rv, 85.30.De, 85.30.Tv This paper reports on properties of intentionally undoped AlGaN/GaN/sapphire-based high electron mobility transistors (HEMTs) before and after passivation with SiO 2 and Si 3 N 4 . Our results indicate that the DC performance of the AlGaN/GaN HEMTs improved significantly as the stress in the passivation layer increased from compressive to tensile. It corresponded to changes in the sheet carrier concentration. Unlike the DC properties, RF properties of the HEMTs were less sensitive to the stress.

show abstract

Section: Resultsmentioning

confidence: 62%

Influence of passivation induced stress on the performance of AlGaN/GaN HEMTs

Gregušová

Bernát

Držík

et al. 2005

phys. stat. sol. (c)

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is assumed that the surface trap density is reduced or an additional stress-induced polarization charge is created because of passivation. 12 The electron mobility in all unpassivated samples is nearly the same (µ H Х 1,200 cm 2 /Vs) and decreases after passivation only slightly (<10%). The passivation-induced sheet charge, n s,pas , decreases with increased doping level from 2 ϫ 10 12 cm Ϫ2 on undoped samples to 0.7 ϫ 10 12 cm Ϫ2 on 1 ϫ 10 19 cm Ϫ3 doped samples (Fig.…”

Section: Resultsmentioning

confidence: 96%

Influence of layer structure on performance of AlGaN/GaN high electron mobility transistors before and after passivation

Bernát

Javorka

Fox

et al. 2004

Journal of Elec Materi

Self Cite

View full text Add to dashboard Cite

Intentionally undoped and three different, doped layer structures are used to investigate properties of AlGaN/GaN high electron mobility transistors (HEMTs) before and after SiN passivation. For unpassivated devices, the drain current, transconductance, cutoff frequency, and microwave output-power increase with increased doping level, in spite of an increase in the gate-leakage current. After passivation, an overall performance improvement of all devices occurs. The passivation-induced sheet charge decreases from 2 ϫ 10 12 cm Ϫ2 in undoped structures to ~0.7 ϫ 10 12 cm Ϫ2 in higher doped structures and performance improvement with passivation is less pronounced for higher doped devices. However, the output power of unpassivated and passivated devices on higher doped structures is much higher than that on the undoped-passivated counterpart. These results underline an advantage of the doped layer structure for the preparation of high-performance AlGaN/GaN HEMTs.

show abstract

“…Due to piezoelectric and spontaneous polarization, AlGaN/AlN/GaN heterostructures have twodimensional electron gas (2DEG) densities in the order of 10 13 cm -2 [1,2]. However, by increasing the AlN content in the barrier, the sheet carrier density can be enhanced, but only at the cost of strain relaxation with the known detrimental side effects [3].…”

mentioning

confidence: 98%

Epitaxy and characterisation of AlInGaN heterostructures for HEMT application

Khoshroo

Mauder

Behmenburg

et al. 2009

Phys. Status Solidi (c)

View full text Add to dashboard Cite

In this paper we report on the growth and charcterization of quaternary AlInGaN/AlN/GaN heterostructures, spanning a range from 26% to 82% AlN, 4% to 18% InN and 0% to 70% GaN in the barrier layer. All samples were grown in AIXTRON metal organic vapor phase epitaxy (MOVPE) reactors on 2″ sapphire substrates. Sample characterisation was performed using high resolution X‐ray diffraction (HRXRD), X‐ray reflection (XRR), photoluminescence spectroscopy (PL), atomic force microscopy (AFM) and Rutherford backscattering (RBS). Inductive sheet resistance measurements and Hall measurements in van der Pauw geometry provided electrical characterization. AFM measurements show closed layers, in HRXRD measurements pendellösung oscillations are visible even in asymmetric reciprocal space maps. Mobility and sheet carrier concentration reach state of the art values currently achieved for ternary structures showing the high degree of tunability in the quaternary nitride system. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

Conductivity and Hall effect measurements on intentionally undoped and doped AlGaN/GaN heterostructures before and after passivation

Cited by 35 publications

References 14 publications

Influence of passivation induced stress on the performance of AlGaN/GaN HEMTs

Influence of passivation induced stress on the performance of AlGaN/GaN HEMTs

Influence of layer structure on performance of AlGaN/GaN high electron mobility transistors before and after passivation

Epitaxy and characterisation of AlInGaN heterostructures for HEMT application

Contact Info

Product

Resources

About