Raman scattering in ion-implanted GaN

Limmer, W.; Ritter, W.; Sauer, R.; Mensching, B.; Liu, C.; Rauschenbach, B.

doi:10.1063/1.121426

Cited by 219 publications

(148 citation statements)

References 10 publications

Supporting

Mentioning

115

Contrasting

Unclassified

Order By: Relevance

“…In the previous work on Raman spectroscopy for ionimplanted GaN films, the modes at 290 and 670 cm Ϫ1 appeared in samples implanted with Ar, Mg, P, C, and Ca ions. 19 This means that such modes are independent of the local vibrations of Mn impurities. Therefore, it is believed that these modes at 290 and 670 cm Ϫ1 originated from the macroscopic disorder or vacancy-related defects due to the Mn implantation.…”

Section: Optical Propertiesmentioning

confidence: 99%

“…19 Thus, it is suggested that annealing the implanted GaN at temperatures higher than 800°C resulted in the reduction of implantation-induced disorders in Mn-implanted GaN films, improving magnetic properties of the films. Consequently, it is suggested that optimum annealing temperature ͑Ͻ900°C͒ could be an important parameter in enhancing the ferromagnetism in the Mn-implanted and annealed GaN by suppressing the production of N vacancies…”

Section: B Correlation Between Magnetic Properties and Mn-induced Dementioning

confidence: 99%

See 1 more Smart Citation

Microstructural, optical, and magnetic properties of Mn-implanted p-type GaN

Baik

Lee

Shon

et al. 2003

Journal of Applied Physics

View full text Add to dashboard Cite

The effect of microstructural change on both magnetic and optical properties of Mn-implanted p-type GaN was studied. A dilute magnetic semiconductor was achieved by implanting Mn ions into p-type GaN and subsequently annealing. The magnetization measurement showed that the Curie temperature was the highest in the 800°C annealed sample due to the formation of Ga-Mn magnetic phases. The annealing at a higher temperature of 900°C produced antiferromagnetic Mn-N compounds such as Mn 6 N 2.58 and Mn 3 N 2 , leaving N vacancies. This provides evidence that N vacancies played a critical role in weakening the ferromagnetic property in the Mn-implanted GaN. The photoluminescence peak at 2.92 eV became strong after annealing at 800°C, indicating an increase in hole concentration due to an enhanced activation of Mn impurities in p-type GaN. The intensity of Raman modes at 290 and 670 cm Ϫ1 decreased drastically as annealing temperature increased ͑Ͼ800°C͒, due to the reduction in Mn-implantation-induced lattice imperfections. From this, it is proposed that the increase in magnetic properties of Mn-implanted GaN originated from the enhancement in the crystallinity as well as the production of Ga-Mn magnetic phases.

show abstract

Section: Optical Propertiesmentioning

confidence: 99%

Section: B Correlation Between Magnetic Properties and Mn-induced Dementioning

confidence: 99%

Microstructural, optical, and magnetic properties of Mn-implanted p-type GaN

Baik

Lee

Shon

et al. 2003

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…These extra modes have been attributed to vacancy and vacancy cluster related modes. 22,23 However, after annealing, these peaks are no longer detected and thus the annealing is able to remove most of the implantation damage. It should also be noted that the sapphire substrate is barely detectable in the Raman spectra, indicating that the method is surface sensitive and thus is suitable for characterizing the implanted portion of the GaN.…”

Section: Resultsmentioning

confidence: 99%

Symmetric Multicycle Rapid Thermal Annealing: Enhanced Activation of Implanted Dopants in GaN

Greenlee

Feigelson

Anderson

et al. 2015

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

Selectively activated p-type regions are necessary for many electronic devices that require planar processing. The standard process of implanting p-type dopants, such as Mg, in GaN is notoriously more difficult than in other material systems, as the extremely high temperatures required to activate the implanted Mg also damage the GaN surface. In this research, a novel annealing technique is introduced for this purpose -symmetric multicycle rapid thermal annealing (SMRTA). It is shown that SMRTA is superior to the earlier developed multicycle rapid thermal annealing (MRTA) in terms of improvement of the crystalline quality of implanted GaN. The SMRTA technique was applied to Mg-implanted GaN to realize a rectifying junction. The annealing process detailed in this research will be a key enabling step for future GaN-based GaN and other III-nitride based semiconductors have received a great deal of attention from the research community due to favorable material properties which include a tunable direct bandgap, radiation hardness, and a favorable Baliga figure of merit compared to Si and SiC.1,2 The doping of p-type GaN during growth is challenging and has been the focus of numerous studies because it has many potential transformative applications in power electronics and optoelectronics.3 P-type dopant implantation and activation adds additional complexity to the synthesis of p-type GaN. The ability to implant and activate p-type species in GaN is a key enabling process for devices that require selective area doping. Device structures that benefit from the ability to selectively implant and activate p-type dopants in GaN include implanted guard rings for electric field spreading, implanted current blocking layers for current aperture vertical electron transistors, and implanted regions below contacts to lower contact resistance. 4,5 Unfortunately, the implantation and activation of Mg in GaN is difficult because of the high temperatures required (over 1300• C) for the activation anneal, 6 which are significantly higher than the decomposition temperature of GaN at atmospheric pressures (845 • C). 7 The decomposition of GaN occurs due to a loss of nitrogen and results in surface damage and the formation of N vacancies, which are compensating donors. 8To avoid GaN decomposition at the elevated annealing temperatures required for Mg activation, high pressure environments and non-equilibrium annealing conditions combined with capping layers have been investigated. 9,10 GaN can be successfully annealed at about 1500• C, but a 1.5 GPa overpressure of N 2 is necessary to avoid surface degradation.11 Such high gas pressures also require a complicated experimental setup and are not easily industrial scalable. 12A second, more scalable, alternative to the high pressure annealing of GaN relies on using non-equilibrium annealing conditions. For this type of annealing, a capping layer is used to prevent nitrogen loss from the GaN surface. Depending on the material, structure, and thickness of the capping layer, higher annealin...

show abstract

“…These modes can be observed when long-range lattice ordering of the host lattice is lost. A relatively strong peak "a" is assigned to a LVM of GaN related to a N vacancy [31]. The peak "b" is assigned to the LVM of Mn occupying the Ga site.…”

Section: Resultsmentioning

confidence: 99%

Mn clusterisation in

Wang

Zhang

Wang

et al. 2009

Solid State Communications

View full text Add to dashboard Cite

Local structure of Mn atoms in Ga1-xMnxN has been investigated by the Mn L3 edge x-ray absorption spectrum (XAS) at total electron yield mode, which preferentially looks at atoms near the surface. A modeling defects configuration, the Mn5 micro-clusters complexed with substitutional MnGa and interstitial MnI is found for the higher Mn doping concentration.This new configuration is also confirmed by the total energy calculations.

show abstract

Raman scattering in ion-implanted GaN

Cited by 219 publications

References 10 publications

Microstructural, optical, and magnetic properties of Mn-implanted p-type GaN

Microstructural, optical, and magnetic properties of Mn-implanted p-type GaN

Symmetric Multicycle Rapid Thermal Annealing: Enhanced Activation of Implanted Dopants in GaN

Mn clusterisation in

Contact Info

Product

Resources

About