Growth of CNx/BN : C multilayer films by magnetron sputtering

Symmetric CNx/BN:C multilayer thin films, with nominal compositional modula tion periods of Lambda = 2.5, 5, and 9 nm were deposited by unbalanced dual cathode magnetron sputtering from C (graphite) and B4C targets in an Ar/N- 2 (60/40) discharge. The multilayers and singlelayer of the constituent CNx and BN:C compounds were grown to a total thickness of 0.5 mu m onto Si(001 ) substrates held at 225 degrees C and a negative floating potential of sim ilar to 30 V (E-i approximate to 24 eV). Layer characterizations were pet-f ormed by TEM, X-ray reflectivity? RES, and nanoindentation measurements. Re sults show that CN0.33 and BN:C (35, 50, and 15 at.% of B, N, and C, respec tively) layers were prepared at the above conditions. It is suggested that all films exhibit a three-dimensional interlocked structure with a cylindri cal texture in the film growth direction. The structure was continuous over relatively well defined and smooth CNx/BN:C interfaces. All coatings exhib it extreme elasticity with elastic recoveries as high as 85-90% (10 mN maxi mum load) attributed to the observed structure. However, the multilayers we re stiffer and more elastic compared to that of the single-layers and thus shows promise for improved protective properties. (C) 2000 Elsevier Science S.A All rights reserved.