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MBE Growth of AlN Nanowires on Si Substrates by Aluminizing Nucleation.

E Y, Hao Z, Yu J, Wu C, Liu R, Wang L, Xiong B, Wang J, Han Y, Sun C, Luo Y - Nanoscale Res Lett (2015)

Bottom Line: The influence of growth conditions on the morphologies of AlN NWs is carefully investigated.Island-like films are found to grow between the NWs due to poor migration ability of Al adatoms.Increasing the V/III ratio can efficiently suppress the growth of Al-polar AlN films.

View Article: PubMed Central - PubMed

Affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China. eyx11@mails.tsinghua.edu.cn.

ABSTRACT
By introducing an aluminization process to achieve nucleation of nanowires (NWs), spontaneous growth of AlN NWs on Si substrates has been realized by plasma-assisted molecular beam epitaxy. The AlN NWs are grown from the nuclei formed by the aluminization process, and the NW density and diameter can be controlled by the aluminization parameters. The influence of growth conditions on the morphologies of AlN NWs is carefully investigated. Island-like films are found to grow between the NWs due to poor migration ability of Al adatoms. The films are proved to be Al-polar different from the N-polar AlN NWs, which can explain the absence of newly formed NWs. Increasing the V/III ratio can efficiently suppress the growth of Al-polar AlN films.

No MeSH data available.


Related in: MedlinePlus

Cross-section HRTEM images of AlN NWs. a Interface area between an AlN NW and the Si (111) substrate. b Image of an NW and the film connecting to it. c Magnified image of the area in the white circle in (b). The white arrows indicate the boundary between the AlN NW and the film, and the nearby distorted lattice in the AlN NW can also be clearly observed. The red circles highlight the dislocations in the films
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Fig7: Cross-section HRTEM images of AlN NWs. a Interface area between an AlN NW and the Si (111) substrate. b Image of an NW and the film connecting to it. c Magnified image of the area in the white circle in (b). The white arrows indicate the boundary between the AlN NW and the film, and the nearby distorted lattice in the AlN NW can also be clearly observed. The red circles highlight the dislocations in the films

Mentions: The typical cross-section HRTEM images of AlN NWs are shown in Fig. 7. Fig. 7a shows the interface area between an AlN NW and the Si (111) substrate. The upper part of the AlN NW presents good crystalline quality, and there are quite a few crystal defects around the interface, where the domain coincidence matching between AlN and Si is absent. The defects at the bottom of AlN NWs arise to relax the elastic strain. Therefore, the AlN NWs are directly grown on Si instead of Si3N4, contrary to the situation of GaN NW growth [16]. This is also an evidence for the aluminizing nucleation during which the β-Si3N4 layer has completely reacted with the Al adatoms.Fig. 7


MBE Growth of AlN Nanowires on Si Substrates by Aluminizing Nucleation.

E Y, Hao Z, Yu J, Wu C, Liu R, Wang L, Xiong B, Wang J, Han Y, Sun C, Luo Y - Nanoscale Res Lett (2015)

Cross-section HRTEM images of AlN NWs. a Interface area between an AlN NW and the Si (111) substrate. b Image of an NW and the film connecting to it. c Magnified image of the area in the white circle in (b). The white arrows indicate the boundary between the AlN NW and the film, and the nearby distorted lattice in the AlN NW can also be clearly observed. The red circles highlight the dislocations in the films
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4593981&req=5

Fig7: Cross-section HRTEM images of AlN NWs. a Interface area between an AlN NW and the Si (111) substrate. b Image of an NW and the film connecting to it. c Magnified image of the area in the white circle in (b). The white arrows indicate the boundary between the AlN NW and the film, and the nearby distorted lattice in the AlN NW can also be clearly observed. The red circles highlight the dislocations in the films
Mentions: The typical cross-section HRTEM images of AlN NWs are shown in Fig. 7. Fig. 7a shows the interface area between an AlN NW and the Si (111) substrate. The upper part of the AlN NW presents good crystalline quality, and there are quite a few crystal defects around the interface, where the domain coincidence matching between AlN and Si is absent. The defects at the bottom of AlN NWs arise to relax the elastic strain. Therefore, the AlN NWs are directly grown on Si instead of Si3N4, contrary to the situation of GaN NW growth [16]. This is also an evidence for the aluminizing nucleation during which the β-Si3N4 layer has completely reacted with the Al adatoms.Fig. 7

Bottom Line: The influence of growth conditions on the morphologies of AlN NWs is carefully investigated.Island-like films are found to grow between the NWs due to poor migration ability of Al adatoms.Increasing the V/III ratio can efficiently suppress the growth of Al-polar AlN films.

View Article: PubMed Central - PubMed

Affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China. eyx11@mails.tsinghua.edu.cn.

ABSTRACT
By introducing an aluminization process to achieve nucleation of nanowires (NWs), spontaneous growth of AlN NWs on Si substrates has been realized by plasma-assisted molecular beam epitaxy. The AlN NWs are grown from the nuclei formed by the aluminization process, and the NW density and diameter can be controlled by the aluminization parameters. The influence of growth conditions on the morphologies of AlN NWs is carefully investigated. Island-like films are found to grow between the NWs due to poor migration ability of Al adatoms. The films are proved to be Al-polar different from the N-polar AlN NWs, which can explain the absence of newly formed NWs. Increasing the V/III ratio can efficiently suppress the growth of Al-polar AlN films.

No MeSH data available.


Related in: MedlinePlus