Dislocation Energetics and Pop-Ins in AlN Thin Films by Berkovich Nanoindentation

Sheng-Rui Jian; Yu-Chin Tseng; I-Ju Teng; Jenh-Yih Juang

doi:10.3390/ma6094259

Dislocation Energetics and Pop-Ins in AlN Thin Films by Berkovich Nanoindentation

Materials (Basel). 2013 Sep 23;6(9):4259-4267. doi: 10.3390/ma6094259.

Authors

Sheng-Rui Jian¹, Yu-Chin Tseng², I-Ju Teng^{3

4}, Jenh-Yih Juang^{5

6}

Affiliations

¹ Department of Materials Science and Engineering, I-Shou University, Main Campus: No.1, Sec. 1, Syuecheng Rd., Dashu District, Kaohsiung City 84001, Taiwan. srjian@gmail.com.
² Department of Materials Science and Engineering, I-Shou University, Main Campus: No.1, Sec. 1, Syuecheng Rd., Dashu District, Kaohsiung City 84001, Taiwan. a0938188197@gmail.com.
³ Centre for Interdisciplinary Science, National Chiao Tung University, Hsinchu 30010, Taiwan. eru7023@gmail.com.
⁴ Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan. eru7023@gmail.com.
⁵ Centre for Interdisciplinary Science, National Chiao Tung University, Hsinchu 30010, Taiwan. jyjuang@g2.nctu.edu.tw.
⁶ Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan. jyjuang@g2.nctu.edu.tw.

Abstract

Nanoindentation-induced multiple pop-ins were observed in the load-displacement curves when the mechanical responses of AlN films grown on c-plane sapphire substrates were investigated by using Berkovich indenters. No evidence of phase transformation is revealed by cross-sectional transmission electron microscopy (XTEM) and selected area diffraction (SAD) analyses. Instead XTEM observations suggest that these "instabilities" resulted from the sudden nucleation of dislocations propagating along the slip systems lying on the {0001} basal planes and the pyramidal planes commonly observed in hexagonal compound semiconductors. Based on this scenario, an energetic estimation of dislocation nucleation is made.

Keywords: AlN thin films; nanoindentation; pop-ins; transmission electron microscopy.