Deposition of Ti1−xAlxN using bipolar pulsed dual magnetron sputtering

Bipolar Pulsed Dual Magnetron Sputtering (BPDMS) technique has opened a wide range of opportunities for the deposition of insulating layers. In BPDMS, two magnetrons alternately act as a cathode and an anode and hence preserve stable operation over long process times. Owing to the versatility and the numerous variables in a BPDMS process, also deposition of conducting coatings such as Ti1−xAlxN is of great interest. present work, Ti1−xAlxN coatings have been deposited in a full-scale pilot plant using BPDMS. Two DMS pairs each comprised of one Ti and one Al target have been used for the deposition. The influence of sputtering pulse times on the Ti and Al magnetrons, respectively, and the nitrogen partial pressure on the process characteristics as well as coating properties have been investigated. old substrate rotation has been used during the deposition and the deposition rate was about 1 μm/h. The use of single-metal targets of Ti and Al and threefold substrate rotation resulted in nanolayered coatings and it has been shown that the characteristics of the coating can be varied within a wide range. For example, the Al-content in Ti1−xAlxN has been varied as 0.16<x<0.84 by varying the sputtering pulse times and the N2 pressure. The coatings change from columnar [200]-textured to less columnar [111]-textured with increasing Al content. For the highest Al contents (x>0.58) the deposited coatings are XRD amorphous with a glassy morphology. Also the coating hardness and elastic modulus are sensitive to the variation of the metal ratio as demonstrated in the paper.