Influence of sputter power and N2 gas flow ratio on crystalline quality of AlN layers deposited at 823 K by RF reactive sputtering

2011 ◽  
Vol 9 (3-4) ◽  
pp. 515-518 ◽  
Author(s):  
Tomoyuki Kumada ◽  
Makoto Ohtsuka ◽  
Kazuya Takada ◽  
Hiroyuki Fukuyama
2002 ◽  
Vol 16 (06n07) ◽  
pp. 876-880
Author(s):  
S. G. Wang ◽  
Q. Zhang ◽  
D. J. Yang ◽  
S. F. Yoon ◽  
J. Ahn ◽  
...  

In this paper, we studied the effects of hydrogen gas flow ratio of [H2]/[N2 + CH4 + H2] on the quality of nanometer diamond (nano-diamond) films prepared by microwave plasma enhanced chemical vapor deposition method. Nano-diamond films were deposited on the silicon substrates from a gaseous mixture of nitrogen, methane and hydrogen. The experimental results show that if only using a gaseous mixture of nitrogen and methane, although we can obtain nano-diamond films with a grain size of about 5nm, the diamond films contain much non-diamond components. With hydrogen addition, and with increasing the hydrogen gas flow ratio from 1 to 10%, the non-diamond components in the films are significantly reduced and the grain size of the films increases from 5nm to 60nm. However optical transmittance of the films increases with increasing hydrogen gas flow ratio from 1 to 7% because of an improvement of film quality, and then decreases with further increasing hydrogen gas flow ratio owing to the increase of film roughness.


Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 555 ◽  
Author(s):  
Luis E. Jardón-Pérez ◽  
Daniel R. González-Morales ◽  
Gerardo Trápaga ◽  
Carlos González-Rivera ◽  
Marco A. Ramírez-Argáez

In this work, the effects of equal (50%/50%) or differentiated (75%/25%) gas flow ratio, gas flow rate, and slag thickness on mixing time and open eye area were studied in a physical model of a gas stirred ladle with dual plugs separated by an angle of 180°. The effect of the variables under study was determined using a two-level factorial design. Particle image velocimetry (PIV) was used to establish, through the analysis of the flow patterns and turbulence kinetic energy contours, the effect of the studied variables on the hydrodynamics of the system. Results revealed that differentiated injection ratio significantly changes the flow structure and greatly influences the behavior of the system regarding mixing time and open eye area. The Pareto front of the optimized results on both mixing time and open eye area was obtained through a multi-objective optimization using a genetic algorithm (NSGA-II). The results are conclusive in that the ladle must be operated using differentiated flow ratio for optimal performance.


2018 ◽  
Vol 2018.56 (0) ◽  
pp. 512
Author(s):  
Muhammad Aminurul HELMY ◽  
Shinsuke KUNITSUGU ◽  
Tatsuyuki NAKATANI ◽  
Ichiro SHIMIZU ◽  
Koji HIRAI ◽  
...  

Vacuum ◽  
2000 ◽  
Vol 56 (1) ◽  
pp. 25-30 ◽  
Author(s):  
R Martins ◽  
V Silva ◽  
I Ferreira ◽  
A Domingues ◽  
E Fortunato

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