scholarly journals Deposition of Zinc Selenide by Atomic Layer Epitaxy for Multilayer X-Ray Optics

1989 ◽  
Vol 161 ◽  
Author(s):  
J.K. Shurtleff ◽  
D.D. Allred ◽  
R.T. Perkins ◽  
J.M. Thorne

ABSTRACTThin film deposition techniques currently being used to produce multilayer x-ray optics (MXOs) have difficulty producing smooth, uniform multilayers with d-spacings less than about twelve angstroms. We are investigating atomic layer epitaxy (ALE) as an alternative to these techniques.ALE is a chemical vapor deposition technique which deposits an atomic layer of material during each cycle of the deposition process. The thickness of a film deposited by ALE depends only on the number of cycles. Multilayers deposited by ALE should be smooth and uniform with precise d-spacings which makes ALE an excellent technique for producing multilayer x-ray optics.We have designed and built an ALE system and we have used this system to deposit ZnSe using diethyl zinc and hydrogen selenide.

2013 ◽  
Vol 1538 ◽  
pp. 275-280
Author(s):  
S.L. Rugen-Hankey ◽  
V. Barrioz ◽  
A. J. Clayton ◽  
G. Kartopu ◽  
S.J.C. Irvine ◽  
...  

ABSTRACTThin film deposition process and integrated scribing technologies are key to forming large area Cadmium Telluride (CdTe) modules. In this paper, baseline Cd1-xZnxS/CdTe solar cells were deposited by atmospheric-pressure metal organic chemical vapor deposition (AP-MOCVD) onto commercially available ITO coated boro-aluminosilicate glass substrates. Thermally evaporated gold contacts were compared with a screen printed stack of carbon/silver back contacts in order to move towards large area modules. P2 laser scribing parameters have been reported along with a comparison of mechanical and laser scribing process for the scribe lines, using a UV Nd:YAG laser at 355 nm and 532 nm fiber laser.


2012 ◽  
Vol 157-158 ◽  
pp. 1320-1323
Author(s):  
Branko Škorić ◽  
D. Kakaš ◽  
G. Favato ◽  
A. Miletić ◽  
M. Arsenovic

In this paper, we present the results of a study of TiN thin films which are deposited by a Physical Vapour Deposition (PVD) and Ion Beam Assisted Deposition (IBAD). In the present investigation the subsequent ion implantation was provided with N2+ ions. The ion implantation was applied to enhance the mechanical properties of surface. The thin film deposition process exerts a number of effects such as crystallographic orientation, morphology, topography, densification of the films.. A variety of analytic techniques were used for characterization, such as scratch test, calo test, Scanning electron microscopy (SEM), Atomic Force Microscope (AFM), X-ray diffraction (XRD) and Energy Dispersive X-ray analysis (EDAX).


2011 ◽  
Vol 189-193 ◽  
pp. 2032-2036 ◽  
Author(s):  
Zhi Jian Wang ◽  
Xiao Feng Shang

Taking Silicon tetrachloride (SiCl4) and hydrogen (H2) as the reaction gas, by the method of plasma-enhanced chemical vapor deposition (PECVD), this paper simulates the deposition process of polycrystalline silicon thin film on the glass substrates in the software FLUENT. Three dimensional physical model and mathematics model of the simulated area are established. The reaction mechanism including main reaction equation and several side equations is given during the simulation process. The simulation results predict the velocity field, temperature distribution, and concentration profiles in the PECVD reactor. The simulation results show that the deposition rate of silicon distribution is even along the circumference direction, and gradually reduced along the radius direction. The deposition rate is about 0.005kg/(m2•s) at the center. The simulated result is basically consistent with the practical one. It means that numerical simulation method to predict deposition process is feasible and the results are reliable in PECVD system.


2019 ◽  
Vol 891 ◽  
pp. 195-199
Author(s):  
Theerapol Thurakitseree ◽  
Chupong Pakpum

According to their wonderful properties, carbon nanotubes (CNTs) have been well known for decades. The synthesis process and catalyst deposition method have also drawn attention to control the nanotube structure and properties. Sputtering method is then one promising option to grow the nanotubes in mass production. This method is, however, still costly. Here, we have presented a simple low-cost custom-made DC magnetron sputtering for catalyst thin film deposition. Three different metal thin films (Fe, Ni, Cu) deposited on Si substrates have been employed to investigate nanotube production. Prior to deposition of the catalysts, Al was used as supporting layer. (Al/Fe, Al/Ni, Al/Cu). CNTs were grown by chemical vapor deposition process at 800°C. Ethanol was preliminary used as a carbon source. It was found that CNTs could be successfully grown from only Al/Ni catalysts in our system with the diameter of approximately 200 nm, where the rest of samples were not observed. In addition, vertical-aligned CNTs with the thickness of about 10 μm could be obtained when acetylene was replaced instead of ethanol with reducing partial pressure of the feedstock. A large D-band at 1338 cm-1 with broader G-band at 1582 cm-1 from Raman spectra give a rise to multi layers growth of sp2 carbon walls. Such dimension suggests that it is the characteristic of multi-walled carbon nanotubes.


2002 ◽  
Vol 716 ◽  
Author(s):  
J.F. Conley ◽  
Y. Ono ◽  
D.J. Tweet ◽  
W. Zhuang ◽  
R. Solanki

AbstractHfO2 films have been deposited using anhydrous hafnium nitrate (Hf(NO3)4) as a precursor for atomic layer chemical vapor deposition (ALCVD). These films have been characterized using x-ray diffraction, x-ray reflectivity, atomic force microscopy, current vs. voltage, and capacitance vs. voltage measurements. An advantage of this precursor is that it produces smooth and uniform initiation of film deposition on H-terminated silicon surfaces. As deposited films remained amorphous at temperatures below ∼700°C. The effective dielectric constant of the film (neglecting quantum effects) for films less than ∼15 nm thick, was in the range of kfilm ∼ 10-11, while the HfO2 layer value was estimated to be kHfO2 ∼ 12-14. The lower than expected dielectric constant of the film stack is due in part to the presence of an interfacial layer such as HfSiOx. Excess oxygen may play a role in the lower than expected dielectric constant of the HfO2 layer. Breakdown of HfO2 films occurred at ∼5-7 MV/cm. Leakage current was lower than that of SiO2 films of comparable equivalent thickness.


2006 ◽  
Vol 51 (21) ◽  
pp. 4347-4351 ◽  
Author(s):  
Venkatram Venkatasamy ◽  
Mkhulu K. Mathe ◽  
Stephen M. Cox ◽  
Uwe Happek ◽  
John L. Stickney

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