THE EFFECTS OF SPUTTERING POWER ON STRUCTURE AND ELECTRICAL PROPERTIES OF Cu FILMS

Cu films with thickness of about 500nm were deposited on glass substrateswithout heating by DC magnetron sputtering in pure Ar gas of 1.0Pa. The sputtering powers weremaintained at 390V X 0.27A, 430V X 0.70A and 450V X l.04A, and the corresponding deposition rates ofCu film reached 35nm/min, l04nm/min and 167nm/min. X-ray diffraction, scanning electron microscopyand atomic force microscopy were used to observe the structural characteristics of the films. Theresistance of the films was measured using four-point probe technique. The amount of larger grainsincreases and the resistivity of the films decreases evidently with an increase in sputtering power.It is considered that the increase in deposition rate with sputtering power mainly weakens theinfluence of residual gas atoms on the growing film, and increases substrate and gas temperatures,resulting in the increase in grain size and the decrease in resistivity of the Cu film.

Influence of Microwave Power on the Properties of Hydrogenated Diamond-Like Carbon Films Prepared by ECR Plasma Enhanced DC Magnetron Sputtering

Electron cyclotron resonance （ECR） plasma was applied to enhance the direct current magnetron sputtering to prepare hydrogenated diamond-like carbon （H-DLC） films. For different microwave powers, both argon and hydrogen gas are introduced separately as the ECR working gas to investigate the influence of microwave power on the microstructure and electrical property of the H-DLC films deposited on P-type silicon substrates. A series of characterization methods including the Raman spectrum and atomic force microscopy are used. Results show that, within a certain range, the increase in microwave power affects the properties of the thin films, namely the sp3 ratio, the hardness, the nanoparticle size and the resistivity all increase while the roughness decreases with the increase in microwave power. The maximum of resistivity amounts to 1.1×10^9 Ω.cm. At the same time it is found that the influence of microwave power on the properties of H-DLC films is more pronounced when argon gas is applied as the ECR working gas, compared to hydrogen gas.

Origin of Initial Current Peak in High Power Impulse Magnetron Sputtering and Verification by Non-Sputtering Discharge

A non-sputtering discharge is utilized to verify the effect of replacement of gas ions by metallic ions and consequent decrease in the secondary electron emission coefficient in the discharge current curves in high-power impulse magnetron sputtering （HiPIMS）. In the non-sputtering discharge involving hydrogen, replacement of ions is avoided while the rarefaction still contributes. The initial peak and ensuing decay disappear and all the discharge current curves show a similar feature as the HiPIMS discharge of materials with low sputtering yields such as carbon. The results demonstrate the key effect of ion replacement during sputtering.

Microstructure and Oxidation Resistance of V Thin Films Deposited by Magnetron Sputtering at Room Temperature

Vanadium films were deposited on Si(100)substrates at room temperature by direct current(DC)magnetron sputtering.The microstructure and surface morphology were studied using scanning electron microscopy(SEM)and atomic force microscope(AFM).The oxidation resistance of films in air was studied using X-ray photoelectron spectroscopy(XPS)and transmission electron microscopy(TEM).The results showed that the amorphous vanadium film with a flatter surface had higher oxidation resistance than the crystalline film when exposed to atmosphere.The rapid formation of the thin oxide layer of amorphous vanadium film could protect the film from sustained oxidation,and the relative reasons were discussed.

The influence of RF power on the electrical properties of sputtered amorphous InGa-Zn-O thin films and devices

The influence of radio frequency（RF） power on the properties of magnetron sputtered amorphous indium gallium zinc oxide（a-IGZO） thin films and the related thin-film transistor（TFT） devices is investigated comprehensively.A series of a-IGZO thin films prepared with magnetron sputtering at various RF powers are examined.The results prove that the deposition rate sensitively depends on RF power.In addition,the carrier concentration increases from 0.91 x 1019 to 2.15 x 1019 cm-3 with the RF power rising from 40 to 80 W,which may account for the corresponding decrease in the resistivity of the a-IGZO thin films.No evident impacts of RF power are observed on the surface roughness,crystalline nature and stoichiometry of the a-IGZO samples.On the other hand,optical transmittance is apparently influenced by RF power where the extracted optical band-gap value increases from 3.48 to 3.56 eV with RF power varying from 40 to 80 W,as is supposed to result from the carrierinduced band-filling effect.The rise in RF power can also affect the performance of a-IGZO TFTs,in particular by increasing the field-effect mobility clearly,which is assumed to be due to the alteration of the extended states in a-IGZO thin films.

Low-temperature deposition of transparent conducting Mn-W co-doped ZnO thin films

Mn-W co-doped ZnO（ZMWO） thin films with low resistivity and high transparency were successfully prepared on glass substrate by direct current（DC） magnetron sputtering at low temperature.The sputtering power was varied from 65 to 150 W.The crystallinity and resistivity of ZMWO films greatly depend on sputtering power while the optical transmittance and optical band gap are not sensitive to sputtering power.All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate.Considering the crystallinity and the electrical and optical properties,we suggest that the optimal sputtering power in this experiment is 90 W and,at this power,the ZMWO film has the lowest resistivity of 9.8×10^（-4）Ω.cm with a high transmittance of approximately 89%in the visible range.

Microstructure and corrosion resistance of vanadium films deposited at different target-substrate distance by HPPMS

High power pulsed magnetron sputtering（HPPMS）, a novel physical vapor deposition technology, was applied to prepare vanadium films on aluminum alloy substrate in this paper. The influence of target–substrate distance（Dt–s）（ranging from 8 to 20 cm） on phase structure, surface morphology, deposition rate, and corrosion resistance of vanadium films was investigated. The results show that the vanadium films are textured with a preferential orientation in the（111） direction except for that fabricated at 20 cm. With Dt–sincreasing, the intensity of（111） diffraction peak of the films decreases and there exists a proper distance leading to the minimum surface roughness of 0.65 nm. The deposition rate decreases with Dt–sincreasing. All the V-coated aluminum samples possess better corrosion resistance than the control sample. The sample fabricated at Dt–sof 12 cm demonstrates the best corrosion resistance with the corrosion potential increasing by 0.19 V and the corrosion current decreasing by an order of magnitude compared with that of the substrate. The samples gain further improvement in corrosion resistance after annealing, and if compared with that of annealed aluminum alloy, then the corrosion potential of the sample fabricated at 20 cm increases by 0.415 V and the corrosion current decreases by two orders of magnitude after annealed at 200 °C. If the annealing temperature further rises to 300 °C, then the corrosion resistance of samples increases less obviously than that of the control sample.