Fabrication of Coaxial Si1−xGex Heterostructure Nanowires by O2 Flow-Induced Bifurcate Reactions
نویسندگان
چکیده
We report on bifurcate reactions on the surface of well-aligned Si(1-x)Ge(x) nanowires that enable fabrication of two different coaxial heterostructure nanowires. The Si(1-x)Ge(x) nanowires were grown in a chemical vapor transport process using SiCl(4) gas and Ge powder as a source. After the growth of nanowires, SiCl(4) flow was terminated while O(2) gas flow was introduced under vacuum. On the surface of nanowires was deposited Ge by the vapor from the Ge powder or oxidized into SiO(2) by the O(2) gas. The transition from deposition to oxidation occurred abruptly at 2 torr of O(2) pressure without any intermediate region and enables selectively fabricated Ge/Si(1-x)Ge(x) or SiO(2)/Si(1-x)Ge(x) coaxial heterostructure nanowires. The rate of deposition and oxidation was dominated by interfacial reaction and diffusion of oxygen through the oxide layer, respectively.
منابع مشابه
Fabrication of silicon nanowires
Pentagon-shaped silicon wires with linewidth around 300 nm are successfully fabricated by using the Si/SiGe epitaxy technique, reactive ion etching, and subsequent selective chemical etching. The nanowires are oxidized in wet O2 at 750 ◦C and 850 ◦C. The oxide and interface morphology are characterized by cross-sectional scanning electron microscope images. It is found that the oxidized nanowir...
متن کاملFabrication of vertical GaN/InGaN heterostructure nanowires using Ni-Au bi-metal catalysts
We have fabricated the vertically aligned coaxial or longitudinal heterostructure GaN/InGaN nanowires. The GaN nanowires are first vertically grown by vapor-liquid-solid mechanism using Au/Ni bi-metal catalysts. The GaN nanowires are single crystal grown in the [0001] direction, with a length and diameter of 1 to 10 μm and 100 nm, respectively. The vertical GaN/InGaN coaxial heterostructure nan...
متن کاملControlling the Composition and Morphology of Si1-xGex Nanowires
Silicon (Si) and germanium (Ge) semiconductor nanowires can be utilized in next generation electronic, photonic, and energy conversion devices. Si, Ge, and Si1-xGex materials are also well studied and currently used in industry. Optoelectronic properties, such as the band gap, can be tuned by modulating the alloy composition, thus allowing for a wider range of uses. The focus of this project wa...
متن کاملFabrication of Si1−xGex Alloy on Silicon by Ge-Ion-Implantation and Short-Time-Annealing
In our contribution we present the fabrication of Si1−xGex alloy by ion-implantation and millisecond ash lamp annealing. The 100 keV Ge ions at the uence of 10 × 10, 5 × 10, and 3 × 10 cm−2 were implanted into monocrystalline (100)-oriented Si wafers covered by 50 nm thermal oxide. In the consequence, the 50 nm amorphous Ge rich Si layers were obtained. The recrystallization of the implanted la...
متن کاملEnhanced electrical properties of nominally undoped Si/SiGe heterostructure nanowires grown by molecular beam epitaxy
Electrical properties of epitaxial single-crystalline Si/SiGe axial heterostructure nanowires (NWs) on Si/111S substrate were measured by contacting individual NWs with a micro-manipulator inside an scanning electron microscope. The NWs were grown by incorporating compositionally graded Si1 xGex segments of a few nm thicknesses in the Si NWs by molecular beam epitaxy. The I–V characteristics of...
متن کامل