Ge as a surfactant in metal-organic vapor phase epitaxy growth of a-plane GaN exceeding carrier concentrations of 1020 cm−3

Wieneke, Matthias; Witte, Hartmut; Lange, Karsten; Feneberg, Martin; Dadgar, A.; Bläsing, J.; Goldhahn, R.; Krost, A.

doi:10.1063/1.4812666

Cited by 20 publications

(14 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…15 On the other hand, it is reported that germanium acts as a surfactant in a-plane growth of wurtzite GaN at doping levels above 10 20 cm −3 . 16 Further investigation on the role of silicon and germanium in c-GaN growth kinetics is required at this point.…”

Section: B Structural Propertiesmentioning

confidence: 99%

Germanium doping of cubic GaN grown by molecular beam epitaxy

Deppe

Gerlach

Shvarkov

et al. 2019

Journal of Applied Physics

View full text Add to dashboard Cite

We present a study of germanium as an alternative to silicon for n-type doping of cubic GaN. We find that Ge is a well-suited donor impurity. Our layers were grown by plasma-assisted molecular beam epitaxy on 3C-SiC/Si (001) substrates. Germanium-doped layers were fabricated with donor concentrations ranging over several orders of magnitude up to 3.7 × 10 20 cm −3 . For comparison, silicon-doped layers with donor concentrations of up to 3.8 × 10 19 cm −3 were also grown. Incorporation of germanium into the cubic GaN layers was verified by time-of-flight secondary ion mass spectrometry. The crystalline quality of our layers was analyzed using high-resolution x-ray diffraction. Germanium-as well as silicon-doped layers with donor concentrations above 10 19 cm −3 exhibited an increase of the dislocation density with increasing dopant concentration. The surface topography of our layers was investigated by atomic force microscopy. Comparable values for the surface roughness were measured for germanium-as well as silicon-doped layers. Optical properties were investigated by photoluminescence spectroscopy at 13 K. Doping with silicon resulted in a spectrally slightly narrower luminescence than doping with germanium. Donor concentrations and carrier mobilities were determined by Hall effect measurements at room temperature and we observe 20% higher electron mobilities for Ge-doping compared to Si-doping in the case of high dopant concentrations.Published under license by AIP Publishing. https://doi.

show abstract

Section: B Structural Propertiesmentioning

confidence: 99%

Germanium doping of cubic GaN grown by molecular beam epitaxy

Deppe

Gerlach

Shvarkov

et al. 2019

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

without negatively affecting surface morphology [ 3 , 8 ] nor introducing mechanical strain in the epitaxial structure [ 3 , 9 ]. Such a high doping level is sufficient to bring about a decrease of the refractive index of the material, and opens up possibilities of using GaN layers as waveguide claddings in laser structures in place of strained AlGaN layers [ 2 , 10 ].…”

Section: Introductionmentioning

confidence: 99%

Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium

et al. 2021

View full text Add to dashboard Cite

The effect of growth temperature and precursor flow on the doping level and surface morphology of Ge-doped GaN layers was researched. The results show that germanium is more readily incorporated at low temperature, high growth rate and high V/III ratio, thus revealing a similar behavior to what was previously observed for indium. V-pit formation can be blocked at high temperature but also at low V/III ratio, the latter of which however causing step bunching.

show abstract

“…Recently, germanium has emerged as a better alternative to silicon as a donor dopant. While it has a similar activation energy [5,6] and provides similar carrier mobility at every doping level [7], germanium has proved capable of attaining doping levels beyond 10 20 cm −3 without negatively affecting the surface morphology [3,8]. Such a high doping level is sufficient to bring about a decrease of the refractive index of the material and opens up possibilities of using GaN layers as waveguide claddings in laser structures [2,9].…”

Section: Introductionmentioning

confidence: 99%

Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium

Schiavon¹,

Litwin‐Staszewska²,

Jakieła³

et al. 2020

Preprint

View full text Add to dashboard Cite

The effect of growth temperature and precursor flows on the doping level and surface morphology of Ge-doped GaN layers was researched. The results show that germanium is more readily incorporated at low temperature, high growth rate and high V/III ratio, thus revealing a similar behavior to what was previously observed for indium. V-pit formation can be blocked at high temperature but also at low V/III ratio, the latter of which however causing step bunching.

show abstract

Ge as a surfactant in metal-organic vapor phase epitaxy growth of a-plane GaN exceeding carrier concentrations of 1020 cm−3

Cited by 20 publications

References 29 publications

Germanium doping of cubic GaN grown by molecular beam epitaxy

Germanium doping of cubic GaN grown by molecular beam epitaxy

Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium

Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium

Contact Info

Product

Resources

About