Reversibility of silicidation of Ta filaments in HWCVD of thin film silicon

THIN SOLID FILMS

卷:517

Article; Proceedings Paper

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

[1] Univ Utrecht, Debye Inst Nanomat Sci, NL-3584 CC 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;    Tantalum silicide;    Filament lifetime;    Silicon diffusion;   

DOI  :  10.1016/j.tsf.2009.01.049

来源: Elsevier

【 摘 要 】

If tantalum filaments are used for the hot wire chemical vapour deposition (HWCVD) of thin film silicon, various types of tantalum silicides are formed, depending on the filament temperature. Under deposition conditions employed for device quality amorphous and microcrystalline silicon (T(wire)approximate to 1750 degrees C) a Ta(5)Si(3) (as determined by XRD) shell is formed around the Ta core. After 8 h of accumulated deposition time this shell has a thickness of around 20 mu m. Upon annealing of the filament in vacuum at 2100-2200 degrees C the tantalum silicide shell becomes thinner, while a Ta layer is reappearing at the surface of the wire. After 4 h of annealing the silicide is completely removed, whereas the total diameter of the wire has not significantly changed. The resistance of the filament has been monitored and after the annealing procedure, it completely recovered to that of a fresh wire. This regeneration procedure greatly helps to avoid frequent replacement of the filaments. (C) 2009 Elsevier B.V. All rights reserved.

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