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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

a A schematic illustration of the aluminization process. Al flux reacts with β-Si3N4 to form AlN islands as nuclei for AlN NW growth. AFM images of the substrates aluminized at (b) 850 °C and (c) 950 °C
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Fig1: a A schematic illustration of the aluminization process. Al flux reacts with β-Si3N4 to form AlN islands as nuclei for AlN NW growth. AFM images of the substrates aluminized at (b) 850 °C and (c) 950 °C

Mentions: A schematic illustration of the aluminization process is shown in Fig. 1a. After the nitridation process, an Al flux was irradiated for a long enough time, reacting with β-Si3N4 at high temperature to form AlN islands as nuclei for AlN NW growth. Samples right after the aluminization process were taken out of the MBE chamber and examined by AFM. Figure 1b, c shows the AFM images of the samples aluminized at 850 and 950 °C, respectively. It can be seen that the sample aluminized at higher temperature presents more uniform crystal islands with higher density and smaller average diameter. The densities of the islands formed at 850 and 950 °C are 2.4 × 108 and 1.6 × 109 cm−2, respectively.Fig. 1


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)

a A schematic illustration of the aluminization process. Al flux reacts with β-Si3N4 to form AlN islands as nuclei for AlN NW growth. AFM images of the substrates aluminized at (b) 850 °C and (c) 950 °C
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4593981&req=5

Fig1: a A schematic illustration of the aluminization process. Al flux reacts with β-Si3N4 to form AlN islands as nuclei for AlN NW growth. AFM images of the substrates aluminized at (b) 850 °C and (c) 950 °C
Mentions: A schematic illustration of the aluminization process is shown in Fig. 1a. After the nitridation process, an Al flux was irradiated for a long enough time, reacting with β-Si3N4 at high temperature to form AlN islands as nuclei for AlN NW growth. Samples right after the aluminization process were taken out of the MBE chamber and examined by AFM. Figure 1b, c shows the AFM images of the samples aluminized at 850 and 950 °C, respectively. It can be seen that the sample aluminized at higher temperature presents more uniform crystal islands with higher density and smaller average diameter. The densities of the islands formed at 850 and 950 °C are 2.4 × 108 and 1.6 × 109 cm−2, respectively.Fig. 1

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