Morphology and Dielectric Properties of Reactively Sputtered Aluminum Nitride Thin Films

1996 ◽  
Vol 449 ◽  
Author(s):  
A. G. Randolph ◽  
S.K. Kurinec

ABSTRACTAluminum nitride thin films (∼ 100 mn) have been deposited on silicon substrate by reactive sputtering using Al target in 1:1 Ar:N2 environment. The atomic force microscopy examination revealed continuous microcrystalline film structure. The Auger electron spectroscopic analysis show the presence of oxygen in the films. The annealing at 850 C in nitrogen is found to cause recrystallization and further oxidation of the films. The films can be characterized as lossy dielectrics with relative permittivity ∼ 10, higher than the bulk value of 8.9. Annealing the films is found to reduce anion vacancies and improve the dielectric strength within a range of a few MV/cm in these thin films.

2001 ◽  
Vol 672 ◽  
Author(s):  
G. Wei ◽  
J. Du ◽  
A. Rar ◽  
J. A. Barnard

ABSTRACTThe nanoindentation behavior of DC magnetron sputtered 10 nm Cu and 10 nm Cu/2 nm Cr thin films deposited on Si (100) has been studied using a Hysitron nanomechanical system. X- ray diffraction and X-ray reflectivity were used to measure the film structure and film thickness, respectively. The grain size and orientation of Cu and Cu/Cr thin films were measured by TEM. Atomic force microscopy (AFM) was used to evaluate the surface morphology and roughness. At the same load, the nanoindentaion displacement of Cu/Cr is smaller than that for Cu, i.e., the 2nm thick Cr underlayer enhances the hardness of Cu. X-ray, TEM, and AFM results show that the grain size of Cu/Cr (< 15 nm) is actually larger than Cu (∼ 3 nm) indicating that the inverse Hall-Petch relationship may be operative.


2010 ◽  
Vol 654-656 ◽  
pp. 1708-1711
Author(s):  
Zong Xin Mu ◽  
Xiao Dong Mu ◽  
Chun Wang ◽  
Chuang Dong

Aluminum nitride (AlN) thin films were deposited on (100) oriented silicon wafers substrates by Hollow Cathode Electron Beam Vapor Deposition system (HCEBVD) under various Ar/N2 mass flow ratio. The films were characterized by Atomic Force Microscopy (AFM), Glancing Incident X-ray Diffraction (GIXRD) techniques and Ultraviolet/Visible Spectrophotometer (UV/VIS). It was found that the thin films are polycrystalline and have a hexagonal wurtzite structure with (002) preferred orientation, as revealed by GIXRD. AFM analysis indicates that the surface of the thin films is smooth, with average RMS (Root Mean Square) roughness Ra of 0.7nm, which is suitable for application in surface acoustic wave devices. The film thickness and optical refractory properties of the AlN thin films were investigated.


2013 ◽  
Vol 341-342 ◽  
pp. 149-152
Author(s):  
Guo Hua Wang ◽  
Niu Yi Sun ◽  
Juan Qin ◽  
Wei Min Shi ◽  
Lin Jun Wang

Half-Heusler compound YNiBi thin films have been prepared by direct current (DC) magnetron sputtering from an YNiBi target. The film structure and surface morphology of YNiBi thin films were analyzed with X-ray diffraction (XRD) and atomic force microscopy (AFM). The electrical properties of the films were studied by Hall measurements. XRD patterns show that the films prepared at lower sputtering pressure and higher growth temperature exhibit minimum full width at half maximum (FWHM) and maximum diffraction peaks which belong to the same family of crystal planes. Results of AFM reveal that the surface of a variety of fabricated YNiBi films is smooth and keeps good adhesion to the substrate. The increasing of substrate temperature and slightly lowering of sputtering pressure are in favor of reducing the root mean square roughness during magnetron sputtering process. The film with high crystallinity has an electrical conductivity of 938 S/cm and carrier concentration of 2.15×1021cm-3.


NANO ◽  
2008 ◽  
Vol 03 (03) ◽  
pp. 155-160 ◽  
Author(s):  
V. N. POPOK ◽  
A. V. GROMOV ◽  
M. JÖNSSON ◽  
A. TANINAKA ◽  
H. SHINOHARA ◽  
...  

La @ C 82 and Li @ C 60 thin films obtained by sublimation in vacuum are studied using four-probe current–voltage measurements and atomic force microscopy. In situ electrical measurements show semiconducting behavior of both films with room-temperature resistivity of 21 ± 8 and 1230 ± 50 Ω · cm for the La @ C 82 and Li @ C 60, respectively. A variable range hopping mechanism of conductance is suggested from the temperature dependences of resistance. The activation energies for electron transport are calculated for both metallofullerenes. Irreversible changes to the Li @ C 60 film structure increasing the film resistivity to values typical for C 60 are found at elevated temperatures. The effect of exposure to ambient atmosphere on the conductance of the films is discussed.


1999 ◽  
Vol 353 (1-2) ◽  
pp. 194-200 ◽  
Author(s):  
C. Coupeau ◽  
J.F. Naud ◽  
F. Cleymand ◽  
P. Goudeau ◽  
J. Grilhé

2018 ◽  
Vol 5 (2) ◽  
pp. 171179 ◽  
Author(s):  
Bramaramba Gnapareddy ◽  
Sreekantha Reddy Dugasani ◽  
Junyoung Son ◽  
Sung Ha Park

DNA is considered as a useful building bio-material, and it serves as an efficient template to align functionalized nanomaterials. Riboflavin (RF)-doped synthetic double-crossover DNA (DX-DNA) lattices and natural salmon DNA (SDNA) thin films were constructed using substrate-assisted growth and drop-casting methods, respectively, and their topological, chemical and electro-optical characteristics were evaluated. The critical doping concentrations of RF ([RF] C , approx. 5 mM) at given concentrations of DX-DNA and SDNA were obtained by observing the phase transition (from crystalline to amorphous structures) of DX-DNA and precipitation of SDNA in solution above [RF] C . [RF] C are verified by analysing the atomic force microscopy images for DX-DNA and current, absorbance and photoluminescence (PL) for SDNA. We study the physical characteristics of RF-embedded SDNA thin films, using the Fourier transform infrared spectrum to understand the interaction between the RF and DNA molecules, current to evaluate the conductance, absorption to understand the RF binding to the DNA and PL to analyse the energy transfer between the RF and DNA. The current and UV absorption band of SDNA thin films decrease up to [RF] C followed by an increase above [RF] C . By contrast, the PL intensity illustrates the reverse trend, as compared to the current and UV absorption behaviour as a function of the varying [RF]. Owing to the intense PL characteristic of RF, the DNA lattices and thin films with RF might offer immense potential to develop efficient bio-sensors and useful bio-photonic devices.


1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.


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