Structural and mechanical properties of (B0.5-xSix)N0.5films synthesized by dual-ion-beam deposition

Chung Wo Ong, X. A. Zhao, Y. M. Ng, K. F. Chan, T. C. Tsang, C. L. Choy, P. W. Chan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

6 Citations (Scopus)

Abstract

The structural and mechanical properties of ion-beam deposited (B0.5-xSix)N0.5films (0≤x ≤0.5) were characterized by x-ray photoelectron spectroscopy, infrared absorption experiments, and nanoindentation tests. A single-layer BN film (x = 0) has 70 vol. % in cubic phase (c-BN), and a hardness of 38 GPa. However, it peeled off very soon after deposition due to the high internal stress. If a buffer layer was deposited first, followed by a (B0.5-xSix)N0.5 film with x ≈ 0.013, the whole configuration adhered very firmly to both quartz and silicon substrates. This improvement in adhesion was probably due to the formation of Si-N bonds, which served to release partly the stress inside the (B0.5-xSixN0.5films. Since the Si content was low, the film structure remained highly cubic, and there was no observable drop in hardness. For higher x, the cubic structure in (B0.5-xSix)N0.5films disappeared rapidly and was replaced by a hexagonal structure. This structural change led to a rapid drop in hardness from 38 to 12 GPa. As x was further increased, more Si-N bonds were formed in the (B0.5-xSix)N0.5layers. As a result, the hardness increased from the minimum value to a value ≈24 GPa.
Original languageEnglish
Pages (from-to)3501-3503
Number of pages3
JournalApplied Physics Letters
Volume69
Issue number23
DOIs
Publication statusPublished - 2 Dec 1996

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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