Effect of ammonia on Ta filaments in the hot wire CVD process

THIN SOLID FILMS

卷:517

Article; Proceedings Paper

Verlaan, V.¹  van der Werf, C. H. M.¹  Oliphant, C. J.^2,3  Bakker, R.¹  Houweling, Z. S.¹  Schropp, R. E. I.¹ 

[1] Univ Utrecht, Fac Sci, Dept Phys & Astron, NL-3508 TA Utrecht, Netherlands

[2] CSIR, Natl Ctr Nanostructured Mat, ZA-0001 Pretoria, South Africa

[3] Univ Western Cape, Dept Phys, ZA-7535 Bellville, South Africa

关键词: Hot wire CVD;    Ta alloys;    Filament aging;   

DOI  :  10.1016/j.tsf.2009.01.064

来源: Elsevier

【 摘 要 】

The exposure of Ta filaments to a pure NH3 ambient in a hot wire chemical vapour deposition (HWCVD) reactor affects the resistance of the wires. For filament temperatures below 1950 degrees C the resistance increases over time, which is probably caused by in-diffusion of N atoms. Using the filaments in a mixed SiH4 and NH3 atmosphere (under SiNx deposition conditions) the filaments are hardly affected. Only at the cold parts near the electrical contact SiNx deposition on the Ta filaments is observed. X-ray diffraction patterns and cross-section microscope images reveal that in a CH4, H-2 and NH3 ambient the TaC0.275N0.218 phase is formed on the surface of the filament. Annealing of these filaments at 2000 degrees C causes the TaC0.275N0.218 structure to separate into Ta and Ta2C phases. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

Free