Ion mixing of Ti and TiOy films on SiOx

Abstract

The influence of ion implantation on the interfacial chemistry, morphology, and adhesion of Ti and TiOy films on SiOx was examined. The Ti/SiOx and TiOy/SiOx specimens were implanted with 180‐keV 84Kr+ at various doses and substrate temperatures (2×1016 Kr cm−2 at 70 °C, 1×1017 Kr cm−2 at 70 °C, and 1×1017 Kr cm−2 at 350 °C). These 84Kr+ implanted specimens were compared to specimens vacuum annealed at 1000 °C for 3600 s. Ion implantation intermixed interfacial Ti, Si, and O in both the Ti/SiOx and TiOy/SiOx specimens, producing interfacial Ti–Si oxide layers. This interfacial mixing increased with both implantation dose and temperature. Despite similar interfacial mixing, the influence of ion implantation on film adhesion was very different for the Ti/SiOx and TiOy/SiOx specimens. Ion implantation resulted in a tenfold adhesion increase at the Ti/SiOx interface. In contrast, ion implantation did not produce adhesion increases at the TiOy/SiOx interface. The adhesion enhancement in the ion‐mixed Ti/SiOx specimens was attributed to increased Si–O–Ti bonding. The absence of adhesion enhancement in the TiOy/SiOx specimens was attributed to phase separation. The implanted 84Kr+ coalesced in both the Ti/SiOx and TiOy/SiOx specimens, resulting in bubble and crack formation. Film characterization was performed using Rutherford backscattering spectrometry, Auger electron spectroscopy, x‐ray photoelectron spectroscopy, scanning electron microscopy, and x‐ray diffraction. Film adhesion was examined using a scratch test.