Modifications of ion beam sputtered tantala thin films by secondary argon and oxygen bombardment

Amorphous tantala ($Ta2O5$) thin films were deposited by reactive ion beam sputtering with simultaneous low energy assist$Ar+$or$Ar+/O2+$bombardment. Under the conditions of the experiment, the as-deposited thin films are amorphous and stoichiometric. The refractive index and optical band gap of thin films remain unchanged by ion bombardment. Around 20% improvement in room temperature mechanical loss and 60% decrease in absorption loss are found in samples bombarded with 100-eV$Ar+$. A detrimental influence from low energy$O2+$bombardment on absorption loss and mechanical loss is observed. Low energy$Ar+$bombardment removes excess oxygen point defects, while$O2+$bombardment introduces defects into the tantala films.

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Publication Date:
NSF-PAR ID:
10130458
Journal Name:
Applied Optics
Volume:
59
Issue:
5
Page Range or eLocation-ID:
Article No. A150
ISSN:
1559-128X; APOPAI
Publisher:
Optical Society of America
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