Effect Of N2 Flow Rate Research Articles

Effect of N2 flow rate on structure and property of ZrNbAlNx multilayer films deposited by magnetron sputtering

Deposition property and microstructure evolution of nano-scaled ZrNbAlNx multilayer films, which present a periodic modulation structure of ZrNx/AlNx/ZrNx/NbNx with different N atomic concentration, deposited using a reactive unbalanced magnetron sputtering system was investigated by varying N2 flow rate. Multilayer films were characterized using X-ray diffraction, Scanning electron microscope, Transmission electron microscope, Laser Raman spectrometer and nano-indentation tester. The experimental results show that the nano-scaled multilayer film displays a columnar growth at N2 flow rate of 4sccm and an un-columnar deposition at N2 flow rate of 33sccm. The increase in N2 flow rate leads to increase of N atomic concentration and decrease of Zr atomic concentration. Microstructure of multilayer films indicates a variation from close-packed hexagonal structure with (101) preferred orientation to faced cubic structure with (111) preferred orientation. The Raman spectrums position presents a shift corresponding to microstructure evolution of multilayer films. Maximum micro-hardness value of multilayer film is 22GPa at N2 flow rate of 27.5sccm.

Effect of N2 flow rate on the properties of CNx thin films prepared by radio frequency plasma enhanced chemical vapor deposition from ethane and nitrogen

Carbon nitride (CNx) thin films were deposited using radio frequency plasma enhanced chemical vapor deposition (rf PECVD) from a mixture of nitrogen (N2) gas and either methane (CH4) or ethane (C2H6) gases. The CH4 and C2H6 flow rates were kept constant, while the N2 flow rate was varied. The effects of nitrogen incorporation on the growth rate and structural properties of the films were studied. The use of these two hydrocarbon precursors was also compared. It was found that the effects of N incorporation are significant for films deposited from the CH4 mixture and it greatly affects the bonding and optical properties of the films. In contrast, the effects of N incorporation on the films produced from C2H6 are not as significant, though these films appear to be more uniform and show lower film porosity. Generally, the photoluminescence (PL) intensities increase with the increase in N incorporation for film deposited from both hydrocarbon mixtures. However, the PL properties of these CNx films are enhanced by the use of C2H6 as compared to CH4 since the films produced show lower defects.

Effect of N<sub>2</sub> Flow Rate on Structure and Morphology of (Ti,Cr)N Thin Films Deposited by Unbalanced Magnetron Co-Sputtering

The (Ti,Cr)N thin films were deposited with various N2 flow rates on silicon wafers by reactive unbalanced magnetron co-sputtering without heating and biasing substrates. The effects of N2 flow rate on the structure and morphologies of the films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM) and energy dispersive x-ray spectroscopy (EDS). The results revealed that the (Ti,Cr)N thin films formed solid solutions with the fcc structure. The crystallite sizes calculated from Scherrer formula are about 13 nm. The root-mean-square roughness (Rrms) and the thickness (Tth) of the films were slightly decreased with the increase in N2 flow rate. The cross-sectional morphology showed columnar structure corresponding to zone 2. In addition, the N atomic concentration was also increased with the increase in N2 flow rate.

Effects of nitrogen flow rate on titanium nitride films deposition by DC facing target sputtering method

TiN films were deposited onto a glass substrate by DC facing target sputtering, and the effects of N2 flow rate on the film properties were investigated. Prepared TiN films had a rock salt (NaCl-type) structure with a very low resistivity (∼30 μΩ·cm) and gold-like color. Increase in the N2 flow rate played an important role in controlling the properties of TiN films, such as Ti/N ratio and growth orientation. The growth orientation changed from a (111) phase to (200), with the ratio of N/Ti becoming near stoichiometric. The change in the growth orientation was caused by the increase in the N2 flow rate, which weakens the kinetic energy of the bombarding particles. The observed phenomenon is explained by an energy loss in the reactive plasma due to the difference in the inner degree of freedom of the molecular gas causing the reduction in the effective energy for radicals.

Effect Analysis of Ar-N<sub>2</sub> Flow Rates on ZrN<sub>X</sub> Film by Pulsed Magnetron Sputtering Using Design of Experimental Method

The various nitrogen gas (N2) flows for depositing zirconium-nitride (ZrN) films on the substrate of a p-type (100) silicon wafer are investigated through reactive magnetron sputtering by a pulsed-DC power. The results, based on the design of experimental (DOE) method, indicate that the deposition effect of the ZrNx film is obviously affected by various flow rates of nitrogen gas at the specific pulsing duty cycles. The crystal orientation of the zirconium-nitride film has a less order microstructure which is similar to an amorphous microstructure. Although the composition ratio of chemical elements is not identical in Zr and N, the surface roughness, grain size, and resistivity are the better feature. The deposition rate is inversely proportional to the nitrogen flow rate and the chamber pressure is also an important factor. The basic effect of N2 flow rate on the surface roughness is rougher when more nitrogen gas is supplied. The resistivity of ZrNx thin film has a positive relationship to N2 flow rates at the reactive vacuum chamber.

The effect of N2 flow rate on discharge characteristics of microwave electron cyclotron resonance plasma

The properties of plasma in Ar/N2 microwave electron cyclotron resonance discharge with a percentage of N2 flow rate ranging from 5% to 50% have been studied in order to understand the effect of N2 flow rate on the mechanical properties of silicon nitride films. N2+ radicals as well as N2, N+ are found by optical emission spectroscopy analysis. The evolution of plasma density, electron kinetic energy, N2+, N2, and N+ emission lines from mixed Ar/N2 plasma on changing mixture ratio has been studied. The mechanisms of their variations have been discussed. Moreover, an Ar/N2 flow ratio of 2/20 is considered to be the best condition for synthesizing a-Si3N4, which has been confirmed in the as-deposited silicon nitride films with quite good mechanical properties by nanoindentation analyses.

The influence of N2 flow rate and substrate temperature on Ti1‐xAlxN thin films

AbstractTitanium aluminium nitride (Ti1‐xAlxN) films have been deposited on silicon (111) substrate at a N2 flow rate of 2 sccm and 20 sccm and at a substrate temperature of 773 K and at a N2 flow rate of 2 sccm and at a substrate temperature of 873 K by reactive DC magnetron sputtering technique. The effect of N2 flow rate and substrate temperature on the grain size and surface roughness of the deposited films have been investigated. The films have been analysed by X‐ray diffraction (XRD) and atomic force microscopy (AFM). The films were found to be nanocrystalline. While the grain size of the films decreases with increasing N2 flow rate and decreases with increasing substrate temperature, the surface roughness of the films decreases with increasing N2 flow rate and increases with increasing temperature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Another method of using dynamic tribo-electrification mechanisms for measuring gas flowrate

Another method of applying the dynamic tribo-electrification mechanisms in a gas flow sensor was studied experimentally in this paper. The gas used was nitrogen (N2) and the tribo-electrification mechanisms were from the incompatible pair (Pb/Fe) and the partially compatible pair (Cu/Fe) in dry severe wear condition. Generally, flow sensors using the dynamic tribo-electrification mechanisms will be sensitive for material pairs with high thermal eletromotive force, low specific heat, and thermal conductivity. For the incompatible pairs, results from this study revealed that the method was adequate for measuring small flowrate and only a small amount of masses was transferred from the soft metals to the iron, forming a very thin layer with a friction coefficient of less than 0.3. Moreover, variations of the tribo-electrification and friction coefficient with sliding time appeared to be very stable, indicate that the effect of N2 flowrate on tribo-electrification was significant. This effect of N2 flowrate and the average interface temperature rise were particularly pronounced at a N2 flowrate of less than 1001/min. Finally, a model to represent the tribo-electrification mechanisms of various soft metals sliding on iron in N2 gas flow was proposed.

Effect of N2 flow rate on morphology and structure of ZnO nanocrystals synthesized via vapor deposition

ZnO nanotetrapods, ZnO nanowires and Zn nanowires were fabricated by the vapor deposition process at the different flow rates of the carrier gas (N-2) Further oxidation of the Zn nanowires led to the formation of ultra-fine ZnO nanoneedles. Photoluminescence (PL) spectra of ZnO nanocrystals exhibited a deep-level emission in the visible region and a near-band-edge emission in the ultraviolet (UV) region. The PL spectra reflected the variation of the stoichiometry and the structure of ZnO nanocrystals. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Growth and doping of SiC-thin films on low-stress, amorphous Si3N4/Si substrates for robust microelectromechanical systems applications

The N2-doped 3C-SiC thin films have been grown by low-pressure, chemical vapor deposition (LPCVD) on amorphous Si3N4/p-Si (111) substrates using the single, organosilane-precursor trimethylsilane [(CH3)3SiH]. The effects of N2 flow rate and growth temperature on the electrical properties of SiC films were investigated by Hall-effect measurements. The electron-carrier concentration is between 1017-1018/cm3. The lowest resistivities at 400 K and 300 K are 1.12 × 10-2 and 1.18 × 10-1 cm, respectively. The corresponding sheet resistances are 75.02 Ω/□ and 790.36 Ω/□. The SiC film structure was studied by x-ray diffraction. The 3C-SiC films oriented in the 〈111〉 direction with a 2θ peak at 35.5° and line widths between 0.18-0.25° were obtained. The SiC/Si3N4 interface is very smooth and free of voids. The fabrication of microelectromechanical (MEMS) structures incorporating the SiC films is discussed.

Composition and Properties of PECVD Silicon Nitride Films Deposited from SiH4, N2, He Gases

ABSTRACTAmorphous silicon nitride films deposited from a gas mixture of SiH4 and N2 with a large flow of He have shown many interesting characteristics. The films show a wide variety of electrical, optical, and mechanical properties with varying amounts of SiH4 and N2. The effect of N2 flow rate on film composition in N2-SiH4 processes is quite different from that of NH3 flow in NH3-SiH4 processes. The films were characterized by measurements of (1) Si-H and N-H bond density and bonded hydrogen content, both from infrared absorption, (2) Si/N ratio, (3) refractive index, (4) film stress, and (5) wet chemical etch rate and (6) electrical properties including current-voltage (I-V) and capacitance-voltage (C-V). We find that adding helium to the PECVD process enhances the incorporation of nitrogen in the film and an optimized flow of SiH4 improves the electrical properties. Films with optimum electrical properties with minimum charge trapping are obtained with N/Si ratio close to 1.33. These films have a small amount of Si-H and N-H bonds, and a low etch rate (> 100 A/min) in aqueous HF solution. The properties of these low temperature (250°C) PECVD nitrides have many similarities with LPCVD nitrides. Compared with films deposited from SiH4, NH3 mixture, these films exhibit very low wet etch rates and much lower H contents, but greater hysteresis in C-V characteristics.