AVS 45th International Symposium
    Vacuum Metallurgy Division Monday Sessions
       Session VM-MoP

Paper VM-MoP3
Graded TiAlN Layers Deposited by ECR Assisted Reactive Sputtering

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Vacuum Metallurgy Division Poster Session
Presenter: M. Weiss, Nuclear Research Center-Negev, Israel
Authors: A. Raveh, Nuclear Research Center-Negev, Israel
M. Weiss, Nuclear Research Center-Negev, Israel
Correspondent: Click to Email
Graded layers have been reported to reduce property discontinuities at the interface. TiAlN layers were deposited by plasma reactive sputtering employing dual cathode radio-frequency sputtering targets, Ti and Al, assisted by electron cyclotron resonance (ECR). The layers were deposited using various combination of parameters such as power input, bias substrate voltage and gas feed composition. The deposition process was monitored by optical emission spectroscopy (OES). The OES results indicate that microwave excitation added to radio-frequency plasma has contrasting effects on Ti and Al concentration in the gas phase, enhancing titanium and quenching aluminium species reaching to the deposited substrate. Thus, by the regulation of the ECR power and the ratio of nitrogen flow to nitrogen plus argon flow, the formation of graded layers is allowed. Hence, this approach was found appropriate for controlling and tailoring the interface between a metallic substrate and hard coating. The layers formed in this way were characterized with regard to structure, composition, and mechanical properties using X-ray diffractometer, Auger electron spectroscopy microscope, and Vickers microhardness and scratch tester (adhesion). It was observed that layers deposited at a low ECR power (@<=@100 W) yielded oriented (111) crystalline structure with good adhesion (failure load >70 N). These layers displayed a higher microhardness (~25 GPa) at bias substrate voltage (-50 VDC) than that of grounded substrate (10-15 GPa). However, layers deposited at an ECR power higher than 100W showed a random or amorphous structure with an intermediate adhesion range (failure load 30-50 N). The relationship between the processing parameters, the structure, and the properties of the layers formed will be presented and discussed.