Journal
JOURNAL OF APPLIED CRYSTALLOGRAPHY
Volume 51, Issue -, Pages 1013-1020Publisher
INT UNION CRYSTALLOGRAPHY
DOI: 10.1107/S1600576718007367
Keywords
sputter deposition; nitrides; X-ray optics; extreme UV
Categories
Funding
- Industrial Focus Group XUV Optics at the MESA+ Institute at the University of Twente
- ASML
- Carl Zeiss SMT
- Malvern Panalytical
- NWO
- Province of Overijssel
Ask authors/readers for more resources
Lanthanum and lanthanum nitride thin films were deposited by magnetron sputtering onto silicon wafers covered by natural oxide. In situ and real-time synchrotron radiation experiments during deposition reveal that lanthanum crystallizes in the face-centred cubic bulk phase. Lanthanum nitride, however, does not form the expected NaCl structure but crystallizes in the theoretically predicted metastable wurtzite and zincblende phases, whereas post-growth nitridation results in zincblende LaN. During deposition of the initial 2-3 nm, amorphous or disordered films with very small crystallites form, while the surface becomes smoother. At larger thicknesses, the La and LaN crystallites are preferentially oriented with the close-packed lattice planes parallel to the substrate surface. For LaN, the onset of texture formation coincides with a sudden increase in roughness. For La, the smoothing process continues even during crystal formation, up to a thickness of about 6 nm. This different growth behaviour is probably related to the lower mobility of the nitride compared with the metal. It is likely that the characteristic void structure of nitride thin films, and the similarity between the crystal structures of wurtzite LaN and La2O3, evoke the different degradation behaviours of La/B and LaN/B multilayer mirrors for off-normal incidence at 6x nm wavelength.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available