The effects of substrate bias, substrate temperature, and pulse frequency on the microstructures of chromium nitride coatings deposited by pulsed direct current reactive magnetron sputtering

Abstract

Recently, great attention has been devoted to the pulsed direct current (DC) reactive magnetron sputtering technique, due to its ability to reduce arcing and target poisoning, and its capability of producing insulating thin films. In this study, chromium nitride (CrN) coatings were deposited by the bipolar symmetric pulsed DC magnetron reactive sputtering process at different pulse frequency, substrate bias voltage, and the substrate temperature. It was observed that the texture of CrN changed from (111) to (200) as substrate temperature increased to 300°C as deposited at 2 kHz without substrate bias. With increasing pulsing bias and pulse frequency of target, predominated (200) orientation of CrN film was shown due to the ion bombardment/ channeling effect to preferentially sputter those unaligned planes. For the CrN coatings deposited with pulsed biasing, the grain size decreased with increasing pulse frequency and substrate bias, whereas the surface roughness showed a reverse trend. The deposition rate of the CrN films decreased with increasing pulse frequency. It was concluded that the pulse frequency, substrate bias, and substrate temperature played important role in the texture, microstructure, and surface roughness of the CrN coatings deposited by the pulsed DC magnetron sputtering process.

A Fluid Model of Pulsed Direct Current Planar Magnetron Discharge

“…7c. This results in the decreasing of deposition rate as rising of pulsed frequency which is consistent to the conclusion in literature 10,11 .…”

“…Glocker 4 compared direct current (DC) magnetron and 35 kHz alternating current (AC) magnetron at the same power and reported electron energies, ion densities and deposition rates of 3.2 eV, 6.4 × 10 16 m -3 , 0.70 nm/s for AC, and 2.4 eV, 1.63 × 10 16 m -3 , 0.82 nm/s for DC, respectively. Lee et al 10 reported decreasing deposition rate at pulse frequencies less than 20 kHz, supported by similar results for vanadium oxide sputtering at frequencies up to 350 kHz 11 . Deposition rates were generally found to increase with duty cycles 12,13 .…”

“…The effect of pulsed frequency on deposition rate, time-averaged electron density (𝑛 ̅ 𝑒 ) and time-averaged electron temperature (𝑇 ̅ 𝑒 ) near the substrate are experimentally studied by several researchers 4,[8][9][10][11] .…”

Effect of bias voltage on microstructure and phase evolution of Cr–Mo–N coatings by an arc bonded sputter system

“…The columnar grain structure is more homogeneous with the higher bias induced condition. This might be due to grain refinement related to the increased surface energy by highly induced bias power [24,27,28].…”

The Effect of Interfacial Ge and RF-Bias on the Microstructure and Stress Evolution upon Annealing of Ag/AlN Multilayers

“…As demonstrated in the present study and in e.g., Refs. [17][18][19][20][21], the ion bombardment induced by the substrate bias voltage can greatly affect e.g., the crystallinity, preferential growth direction, stress state and density of deposited thin films and NMLs. Therefore, in this work, Ag[Ge]/AlN NMLs were fabricated with and without RF bias.…”