Effect of the degree of high power impulse magnetron sputtering utilisation on the structure and properties of TiN films

• Published in: Thin solid films Vol. 562; pp. 132 - 139
• Main Authors: Hovsepian, Papken Eh, Sugumaran, Arunprabhu A., Purandare, Yashodhan, Loch, Daniel A.L., Ehiasarian, Arutiun P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2014; Elsevier
• Subjects: Cathodes; Coating; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Exact sciences and technology; High power impulse magnetron sputtering; Magnetron sputtering; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Microstructure; Optical emission spectroscopy; Physical radiation effects, radiation damage; Physics; Residual stress; Structure and morphology; thickness; Structure of solids and liquids; crystallography; Surface layer; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Texture; Theory and models of film growth; Thin film structure and morphology; Titanium nitride; Titanium nitride; High power impulse magnetron sputtering; Optical emission spectroscopy; Microstructure; Texture; Residual stress; Radiation effects; Scanning electron microscopy; Stoichiometry; Control systems; Residual stresses; XRD; Coatings; Under bump metallization; Operating conditions; Deposition process; Thin films; Cathode sputtering; Optical emission spectra; Bias voltage; Growth mechanism; Physical vapor deposition; Sputter deposition; Crystal structure
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2014.04.002

TiN films were deposited using high power impulse magnetron sputtering (HIPIMS) enabled four cathode industrial size coating system equipped with HIPIMS power supplies. The standard version of this system allows control over the ion bombardment during coating growth by varying the strength of the electromagnetic field of the unbalancing coils and bias voltage applied to the substrate. The coatings were produced in different coating growth conditions achieved in combined HIPIMS — direct current (dc) unbalanced magnetron sputtering (HIPIMS/UBM) processes where HIPIMS was used as an additional tool to manipulate the ionisation degree in the plasma. Four cathode combinations were explored with increasing contribution of HIPIMS namely 4UBM (pure UBM), 1HIPIMS+3UBM, 2HIPIMS+2UBM and 2HIPIMS (pure HIPIMS) to deposit TiN coatings. Optical emission spectroscopy (OES) measurements were carried out to examine the plasma generated by the various combinations of HIPIMS and UBM cathodes. The micro-structural study was done by scanning electron microscopy (SEM). X-ray diffraction (XRD) technique was used to calculate the residual stress and texture parameter. It has been revealed that the residual stress can be controlled in a wide range from −0.22GPa to −11.67GPa by intelligent selection of the degree of HIPIMS utilisation, strength of the electromagnetic field of the unbalancing coils and the bias voltage applied to the substrate while maintaining the stoichiometry of the coatings. The effect of the degree of HIPIMS utilisation on the microstructure, texture and residual stress is discussed. Combining HIPIMS with dc-UBM sputtering is also seen as an effective tool for improving the productivity of the deposition process. •High {Ti1+} in the plasma with increasing number of HIPIMS sources•Residual stress can be manipulated in a wide range.•Texture can be altered.•The 2HIPIMS+2UBM combination appears to be the most advantageous.