Magnetron sputtering of epitaxial ZrB₂ thin films on 4H‐SiC(0001) and Si(111)

Abstract

Epitaxial ZrB2 thin films were deposited at a temperature of 900 °C on 4H-SiC(0001) and Si (111) substrates by magnetron sputtering from a ZrB2 source at high rate ~80 nm/min. The films were analyzed by thin film X-ray diffraction including pole figure measurements and reciprocal space mapping as well as high resolution electron microscopy.

Stoichiometric, epitaxial ZrB2 thin films with low oxygen-content deposited by magnetron sputtering from a compound target: Effects of deposition temperature and sputtering power

“…When the deposition temperature is increased up to 550 °C the films exhibit a more random growth behavior with an increasing contribution from 101 ̅ 1-oriented grains [14]. Following those experiences, we demonstrated that it is possible to grow epitaxial films of ZrB2 on 4H-SiC(0001) substrates, with the epitaxial relationship of ZrB2(0001)║4H-SiC(0001) and ZrB2[1 1 ̅ 00]║4H-SiC[1 1 ̅ 00], in a laboratory scale ultra-high vacuum (UHV) system at 900 °C [15]. However, the growth behavior on 4H-SiC(0001) at temperatures between 550 °C and 900 °C remains to be investigated.…”

“…The ZrB2 thin film growth was conducted in an UHV system with the same set-up and conditions as described elsewhere [15]. The substrates were outgassed in the growth chamber at 900 °C for 1 h. The temperature was then changed to a deposition temperature of either 500 °C, 600 °C, 700 °C, 820 °C or left at 900 °C.…”

“…As mention above, we note that all studies reporting on crystalline, and not amorphous, growth at low deposition temperatures, have applied high sputtering powers [9,10,14,18]. Given the issues discussed above, the aim of our work is to grow stoichiometric, dense, highly ordered crystalline ZrB2 thin films with low oxygen-content, preferably at lower deposition temperature than we have demonstrated previously [15].…”

“…ZrB2 thin films can be synthesized by sputtering from a compound or composite target [7][8][9][10][11][12][13][14][15]. This is the predominant synthesis route, given the lack of a suitable boron precursor for reactive sputtering.…”

“…Given some substrate materials' tendencies to react with the film at high temperatures [15], such as for Si and GaN, it is desirable to find a synthesis route to increase the crystal ordering in the film without increasing temperature. One parameter that is likely to affect the structure of the film is the amount of power applied to the cathode, where a higher sputtering power results in a denser flux of precursors arriving at the substrate.…”