Monolithic integration of III-V semiconductors with Si has been pursued for some time in the semiconductor industry. However, the mismatch of lattice constants and thermal expansion coefficients represents a large technological challenge for the heteroepitaxial growth. Nanowires, due to their small lateral dimension, can relieve strain and mitigate dislocation formation to allow single-crystal III-V materials to be grown on Si. Here, we report a facile five-step heteroepitaxial growth of GaAs nanowires on Si using selective area growth (SAG) in metalorganic chemical vapor deposition, and we further report an in-depth study on the twin formation mechanism. Rotational twin defects were observed in the nanowire structures and showed strong dependence on the growth condition and nanowire size. We adopt a model of faceted growth to demonstrate the formation of twins during growth, which is well supported by both a transmission electron microscopy study and simulation based on nucleation energetics. Our study has led to twin-free segments in the length up to 80 nm, a significant improvement compared to previous work using SAG. The achievements may open up opportunities for future functional III-V-on-Si heterostructure devices.
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http://dx.doi.org/10.1021/acsnano.5b07232 | DOI Listing |
ACS Appl Electron Mater
December 2024
Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria.
Germanium (Ge), the next-in-line group-IV material, bears great potential to add functionality and performance to next-generation nanoelectronics and solid-state quantum transport based on silicon (Si) technology. Here, we investigate the direct epitaxial growth of two-dimensional high-quality crystalline Ge layers on Si deposited at ultralow growth temperatures ( = 100-350 °C) and pristine growth pressures (≲10 mbar). First, we show that a decreasing does not degrade the crystal quality of homoepitaxial Ge/Ge(001) by comparing the point defect density using positron annihilation lifetime spectroscopy.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK.
Residual strain in an epilayer grown on a foreign wafer induces epiwafer's bow, that is often considered undesirable. Wafer bow however, can be advantageous because both the direction and magnitude of strain are vital for the fabrication of various Micro Electro Mechanical Systems (MEMS), such as resonators. Here strain control is reported for highly mismatched heteroepitaxy of cubic silicon carbide (3C-SiC) compound semiconductor on silicon (Si), a prized functional material, dependent solely on carbon to silicon ratio (C/Si) during growth.
View Article and Find Full Text PDFAdv Mater
December 2024
School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai, 200235, P. R. China.
The heteroepitaxy of 2D materials with engineered bandgaps are crucial to broaden the spectral response for their integrated optoelectronic devices. However, it is a challenge to achieve the high-oriented epitaxy and integration of multicomponent 2D materials with varying lattice constants on the same substrate due to the limitation of lattice matching. Here, in-plane adaptive heteroepitaxy of a series of high-oriented 2D cesium bismuth halide (CsBiX X = I, Br, Cl) single crystals with varying lattice constants from 8.
View Article and Find Full Text PDFNano Lett
November 2024
Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.
Van der Waals heteroepitaxy refers to the growth of strain- and misfit-dislocation-free epitaxial films on layered substrates or vice versa. Such heteroepitaxial technique can be utilized in developing flexible near-infrared transition metal nitride plasmonic materials to broaden their photonic and bioplasmonic applications, such as antifogging, smart windows, and bioimaging. Here, we show the first conclusive experimental demonstration of the van der Waals heteroepitaxy-enabled flexible semiconducting scandium nitride (ScN) thin films exhibiting near-infrared, low-loss epsilon-near-zero, and surface plasmon-polariton resonances.
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