Cross-sectional transmission electron microscopy (XTEM) has been used to investigate the effects of variations in the low-energy ion irradiation flux during the growth of reactively sputter-deposited TiN. The films were deposited on steel substrates with a negative bias of 100 V at 350 °C in mixed Ar–N2 discharges at a pressure of 5 Pa (37 mTorr). The ion-to-Ti arrival rate ratio Jion /JTi at the substrate was varied between 0.3 and 7.1 through the use of a variable external magnetic field. Films grown with Jion /JTi ≲2 had a columnar morphology with a highly underdense microstructure. Increasing Jion /JTi ≳4 was sufficient to cause the growth of dense films with a more equiaxed grain structure due to renucleation. Further increases in Jion /JTi ≳7 resulted in increased TiN grain size and local heteroepitaxy between TiN and the martensitic phase of the substrate.
No takes yet. Share an insight, caveat, or question.
Hultman et al. (1991) studied this question.