Nanocrystalline ZrO2thin films on silicon fabricated by pulsed-pressure metalorganic chemical vapor deposition (PP-MOCVD)

2008 ◽  
Vol 23 (8) ◽  
pp. 2202-2211 ◽  
Author(s):  
L. Ramirez ◽  
M.L. Mecartney ◽  
S.P. Krumdieck

ZrO2films deposited on silicon (100) substrates using pulsed-pressure metalorganic chemical vapor deposition (PP-MOCVD) with zirconium n-propoxide (ZnP) Zr(OC3H7)4were dense and fully crystalline for substrate temperatures of 500 to 700 °C. Film thicknesses were 40 to 815 nm thick, measured after growth using ellipsometry and scanning electron microscopy (SEM). The growth rate was between 0.1 μm/h at 500 °C and 1 μm/h at 700 °C. Transmission electron microscopy (TEM) and x-ray diffraction (XRD) indicated an average grain size of 10 to 20 nm. There was a random orientation of cubic/tetragonal zirconia at the highest experimental temperature of 700 °C. SEM and atomic force microscopy (AFM) was used to characterize island height of discontinuous films in the initial stages of growth where defects in the substrate caused preferred nucleation of isolated particles. At later stages of growth, the average surface roughness of continuous films was 30 nm, which revealed a more uniform growth had developed. A growth model is proposed, and optimal growth conditions are suggested for targeted microstructures of ZrO2films.

1997 ◽  
Vol 468 ◽  
Author(s):  
Jing-Hong Li ◽  
Olga M. Kryliouk ◽  
Paul H. Holloway ◽  
Timothy J. Anderson ◽  
Kevin S. Jones

ABSTRACTMicrostructures of GaN films grown on the LiGaO2 by metalorganic chemical vapor deposition (MOCVD) have been characterized by transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). TEM and HRTEM results show that high quality single-crystal wurtzite GaN films have been deposited on the LiGaO2 and that the GaN film and the LiGaO2 have the following orientation relationship: (2110)(0002)GaN ̂ (002)LiGaO2 ^ 5–8°. A higher density of threading dislocations and stacking faults have been observed near the GáN/LiGaO2 interface, even though the lattice mismatch of GaN to LiGaO2 is only ∼1%. Threading dislocations with burgers vector b=<0001> and b=a/3<1120> are predominant in the GaN films. Also the GaN films contain some columnar inversion domain boundaries (IDBs). Both TEM and HRTEM results reveal that there is an unexpected amorphous or nano-crystalline inter-layer between the GaN and the LiGaO2 with a thickness of 50–100 nm.


2010 ◽  
Vol 25 (9) ◽  
pp. 1778-1783 ◽  
Author(s):  
Seok-Hyo Yun ◽  
Suthan Kissinger ◽  
Don Wook Kim ◽  
Jun-Ho Cha ◽  
Yong-Ho Ra ◽  
...  

We demonstrated the growth of indium nitride (InN) nanowires on Si(111) substrates by metalorganic chemical vapor deposition without the use of any intermediate GaN or AlN buffer layer. The InN nanowires were grown by forming the Au + In droplets and In droplets on the Au- and In-coated Si substrate. The growth conditions such as chamber pressure, chamber temperature, reaction gas flow rate, and carrier gas flow rate were optimized to yield nanowires free from contamination. Depending on the growth parameters different growth regimes for the InN nanowires were identified. The strength of self-catalytic route has been highlighted. The morphology and microstructures of samples were characterized by x-ray diffraction and scanning electron microscopy (SEM). The transmission electron microscopy and SEM investigations showed that the InN nanowires are single crystals with diameters ranging from 40 to 400 nm, and lengths up to 3 µm. Photoluminescence spectra of the InN nanowires showed a strong broad emission peak at 0.77 eV.


1999 ◽  
Vol 14 (6) ◽  
pp. 2662-2667 ◽  
Author(s):  
S. Y. Lee ◽  
R. S. Feigelson

Textured c-axis oriented LiNbO3 films have been grown for waveguiding applications on silicon substrates by the solid-source metalorganic chemical vapor deposition (MOCVD) method using tetramethylheptanedionate sources. Thermally grown SiO2 layers were used as cladding layers to provide optical confinement in the LiNbO3 films. The texture direction could be varied from the [006] to the [012] direction by either increasing the growth temperature and/or decreasing the growth rate. Under optimal growth conditions, 100% [006] texturing could be achieved without the aid of an electric field or by using a SiNx buffer layer. The crystallinity and surface rms roughness of c-axis oriented films were found to be strongly dependent on the growth rate. Rocking curve full-width half-maximum (FWHM) values of (006) peaks could be decreased to less than 2° by increasing the growth rate. The surface roughness also decreased with growth rate, and rms values as low as 1.5 nm were achieved. On the other hand, too high a growth rate leads to increased roughness due to gas phase nucleation. The optical losses were closely correlated with surface roughness, and the best films had optical losses near 4.5 dB/cm at a wavelength of 632.8 nm.


2003 ◽  
Vol 18 (8) ◽  
pp. 1868-1876 ◽  
Author(s):  
Spyridon Skordas ◽  
Filippos Papadatos ◽  
Guillermo Nuesca ◽  
John J. Sullivan ◽  
Eric T. Eisenbraun ◽  
...  

A low-temperature metalorganic chemical vapor deposition process was developed and optimized, using a design of experiments approach, for the growth of ultrathin aluminum oxide (Al2O3) as a potential gate dielectric in emerging semiconductor device applications. The process used the aluminum β-diketonate metalorganic precursor [aluminum(III) 2,4-pentanedionate] and water as, respectively, the metal and oxygen source reactants to grow Al2O3 films over a temperature range from 250 to 450 °C. The resulting films were analyzed by x-ray photoelectron spectroscopy, x-ray diffraction measurements, Rutherford backscattering spectrometry, nuclear-reaction analysis for hydrogen profiling, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The as-deposited Al2O3 phase was amorphous and dense and exhibited carbon and hydrogen incorporation of, respectively, 1 and 10 at.%. Postannealing at 600 °C led to a reduction in hydrogen concentration to 1 at.%, while maintaining an amorphous Al2O3 matrix.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Caroline E. Reilly ◽  
Stacia Keller ◽  
Shuji Nakamura ◽  
Steven P. DenBaars

AbstractUsing one material system from the near infrared into the ultraviolet is an attractive goal, and may be achieved with (In,Al,Ga)N. This III-N material system, famous for enabling blue and white solid-state lighting, has been pushing towards longer wavelengths in more recent years. With a bandgap of about 0.7 eV, InN can emit light in the near infrared, potentially overlapping with the part of the electromagnetic spectrum currently dominated by III-As and III-P technology. As has been the case in these other III–V material systems, nanostructures such as quantum dots and quantum dashes provide additional benefits towards optoelectronic devices. In the case of InN, these nanostructures have been in the development stage for some time, with more recent developments allowing for InN quantum dots and dashes to be incorporated into larger device structures. This review will detail the current state of metalorganic chemical vapor deposition of InN nanostructures, focusing on how precursor choices, crystallographic orientation, and other growth parameters affect the deposition. The optical properties of InN nanostructures will also be assessed, with an eye towards the fabrication of optoelectronic devices such as light-emitting diodes, laser diodes, and photodetectors.


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