Elucidation of the Growth Mechanism of Sputtered 2D Hexagonal Boron Nitride Nanowalls
详细信息 查看全文
- 作者：Duc-Quang Hoang ; Paulius Pobedinskas ; Shannon S. Nicley ; Stuart Turner ; Stoffel D. Janssens ; Marlies K. Van Bael ; Jan D’Haen ; Ken Haenen
- 刊名：Crystal Growth & Design
- 出版年：2016
- 出版时间：July 6, 2016
- 年：2016
- 卷：16
- 期：7
- 页码：3699-3708
- 全文大小：820K
- 年卷期：0
- ISSN：1528-7505
文摘
Hexagonal boron nitride nanowall thin films were deposited on Si(100) substrates using a Ar(51%)/N2(44%)/H2(5%) gas mixture by unbalanced radio frequency sputtering. The effects of various target-to-substrate distances, substrate temperatures, and substrate tilting angles were investigated. When the substrate is close to the target, hydrogen etching plays a significant role in the film growth, while the effect is negligible for films deposited at a farther distance. The relative quantity of defects was measured by a non-destructive infrared spectroscopy technique that characterized the hydrogen incorporation at dangling nitrogen bonds at defect sites in the deposited films. Despite the films deposited at different substrate tilting angles, the nanowalls of those films were found to consistently grow vertical to the substrate surface, independent of the tilting angle. This implies that chemical processes, rather than physical ones, govern the growth of the nanowalls. The results also reveal that the degree of nanowall crystallization is tunable by varying the growth parameters. Finally, evidence of hydrogen desorption during vacuum annealing is given based on measurements of infrared stretching (E1u) and bending (A2u) modes of the optical phonons, and the H–N vibration mode.