Atmospheric pressure chemical vapor deposition of aluminum nitride thin films at 200–250 °C

1991 ◽  
Vol 6 (1) ◽  
pp. 5-7 ◽  
Author(s):  
Roy G. Gordon ◽  
David M. Hoffman ◽  
Umar Riaz

The atmospheric pressure chemical vapor deposition of aluminum nitride coatings using hexakis(dimethylamido)dialuminum, Al2(NMe2)6, and ammonia precursors is reported. The films were characterized by ellipsometry, transmission electron microscopy, x-ray photoelectron spectroscopy, and Rutherford backscattering spectrometry. The films were deposited at 200–250 °C with growth rates up to 1000 Å/min. They displayed good adhesion to silicon, vitreous carbon, and glass substrates and were chemically inert, except to concentrated hydrofluoric acid. Rutherford backscattering analysis showed that the N/Al ratio ranged from 1.1 to 1.2. Refractive indexes were 1.8–1.9. The films were smooth and amorphous by transmission electron microscopy.

1992 ◽  
Vol 7 (7) ◽  
pp. 1679-1684 ◽  
Author(s):  
Roy G. Gordon ◽  
Umar Riaz ◽  
David M. Hoffman

The atmospheric pressure chemical vapor deposition of aluminum nitride coatings from hexakis(dimethylamido)dialuminum, Al2(N(CH3)2)6, and ammonia precursors is reported. The films were characterized by ellipsometry, transmission electron microscopy, x-ray photoelectron spectroscopy, Rutherford backscattering, and forward recoil spectrometry. The films were deposited at 100–500 °C with growth rates up to 1500 Å/min. The films showed good adhesion to silicon, glass, and quartz substrates and were chemically inert. Rutherford backscattering analysis revealed that the N/Al ratio was 1.15 ± 0.05 for films deposited at 100–200 °C and 1.05 ± 0.05 for those deposited at 300–500 °C. Films deposited at 100–200 °C had refractive indexes in the range 1.65–1.80 whereas indexes for films deposited at 300–400 °C were 1.86–2.04. The films were transparent in the visible region. The optical bandgap varied from 5.0 eV for films deposited at 100 °C to 5.77 eV for those deposited at 500 °C. Films deposited at 100–200 °C were amorphous whereas those deposited at 300–500 °C were polycrystalline.


1990 ◽  
Vol 204 ◽  
Author(s):  
Roy G. Gordon ◽  
David M. Hoffman ◽  
Umar Riaz

ABSTRACTThe atmospheric-pressure chemical vapor deposition of gallium nitride films from hexakis(dimethylamido)digallium, Ga2(NMe2)6, and ammonia precursors at 200 °C with growth rates up to 1000 Å/min is described. The films were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and Rutherford backscattering spectrometry. Rutherford backscattering analysis showed that the N/Ga ratio was 1.12–1.17. The films were crystalline with ≃ 5–15 nm crystallites.


Author(s):  
K. Doong ◽  
J.-M. Fu ◽  
Y.-C. Huang

Abstract The specimen preparation technique using focused ion beam (FIB) to generate cross-sectional transmission electron microscopy (XTEM) samples of chemical vapor deposition (CVD) of Tungsten-plug (W-plug) and Tungsten Silicides (WSix) was studied. Using the combination method including two axes tilting[l], gas enhanced focused ion beam milling[2] and sacrificial metal coating on both sides of electron transmission membrane[3], it was possible to prepare a sample with minimal thickness (less than 1000 A) to get high spatial resolution in TEM observation. Based on this novel thinning technique, some applications such as XTEM observation of W-plug with different aspect ratio (I - 6), and the grain structure of CVD W-plug and CVD WSix were done. Also the problems and artifacts of XTEM sample preparation of high Z-factor material such as CVD W-plug and CVD WSix were given and the ways to avoid or minimize them were suggested.


2021 ◽  
Vol 21 (4) ◽  
pp. 2538-2544
Author(s):  
Nguyen Minh Hieu ◽  
Nguyen Hoang Hai ◽  
Mai Anh Tuan

Tin oxides nanowires were prepared by chemical vapor deposition using shadow mask. X-ray diffraction indicated that the products were tetragonal having crystalline structure with lattice constants a = 0.474 nm and c = 0.318 nm. The high-resolution transmission electron microscopy revealed that inter planar spacing is 0.25 nm. The results chemical mapping in scanning transmission electron microscopy so that the two elements of Oxygen and Tin are distributed very homogeneously in nanowires and exhibit no apparent elements separation. A bottom-up mechanism for SnO2 growth process has been proposed to explain the morphology of SnO2 nanowires.


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.


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