Hamburg 2001 – scientific programme

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DS: Dünne Schichten

DS 26: c-BN

DS 26.1: Talk

Friday, March 30, 2001, 10:15–10:30, S 5.1

Young’s modulus and density of nanocrystalline cubic boron nitride films determined by surface acoustic wave spectroscopy — •Gottfried Lehmann¹, Steffen Weissmantel², Günter Reiße², and Peter Hess¹ — ¹Phys.-Chem. Inst., Im Neuenheimer Feld 253, 69120 Heidelberg — ²Hochsch. f. Techn. und Wissensch., Technikumplatz, 09648 Mittweida

Cubic boron nitride (cBN) films of 200 to 415 nm thickness and high phase purity were prepared by pulsed laser deposition from a boron nitride or boron target using a KrF-excimer laser. A hexagonal boron nitride (hBN) film with 40 nm thickness was deposited as buffer layer with the same technique on the silicon(100) substrate. The density and Young’s modulus of the cBN films were obtained by surface acoustic wave spectroscopy (SAWS). In data analysis a two-layer model was applied in order to take the influence of the hBN layer into consideration. The values for the density vary from 3.0 g/cm³ to 3.4 g/cm³ and for the Young’s modulus from 432 GPa to 500 GPa. The results are compared with literature values reported for nanocrystalline films, polycrystalline disks, and single crystal cBN.