Time resolved measurement of film growth during reactive high power pulsed magnetron sputtering (HIPIMS) of titanium nitride

TL;DR

This study measures the film growth dynamics during reactive HIPIMS of titanium nitride with high temporal resolution, revealing growth mainly occurs during pulses and varies with HIPIMS phases.

Contribution

It introduces a rotating shutter method for time-resolved measurement of film growth during reactive HIPIMS, providing new insights into phase-dependent growth behavior.

Findings

Growth occurs mainly during HIPIMS pulses.

Titanium dominates early, nitrogen later in the pulse.

Growth rate follows HIPIMS phases: ignition to afterglow.

Abstract

The growth rate during reactive high power pulsed magnetron sputtering (HIPIMS) of titanium nitride is measured with a temporal resolution of up to 25 us using a rotating shutter concept. According to that concept a 200 um slit is rotated in front of the substrate synchronous with the HIPIMS pulses. Thereby, the growth flux is laterally distributed over the substrate. By measuring the resulting deposition profile with profilometry and with x-ray photoelectron spectroscopy, the temporal variation of the titanium and nitrogen growth flux per pulse is deduced. The analysis reveals that film growth occurs mainly during a HIPIMS pulse, with the growth rate following the HIPIMS phases ignition, current rise, gas rarefaction, plateau and afterglow. The growth fluxes of titanium and nitrogen follow slightly different behaviors with titanium dominating at the beginning of the HIPIMS pulse and nitrogen at the end of the pulse. This is explained by the gas rarefaction effect resulting in a dense initial metal plasma and metal films which are subsequently being nitrified.