Strain mapping in a nanoscale-triangular SiGe pattern by dark-field electron holography with medium magnification mode.
Recent years have seen a great deal of progress in the development of transmission electron microscopy-based techniques for strain measurement. Dark-field electron holography (DFEH) is a new technique offering configuration of the off-axis principle. Using this technique with medium magnification (Holo-M), we carried out strain measurements in nanoscale-triangular SiGe/(001) Si with (004), (2-20) and (-111) diffraction spots. The reconstruction of holograms and interpretation of strain maps in term of strain precision were discussed and the strain distributions in the SiGe/(001) Si patterns were visualized. Based on linear anisotropic elastic theory for strain simulation, the simulated results obtained by the finite element method compared with the experimental results acquired by DFEH. The strain values were found to be 0.9-1.0%, 1.1-1.2% and 1.0-1.1%, for the (004), (2-20) and (-111) diffracted beams, respectively, and the strain precisions were determined to be ~2.1 × 10-3, 3.2 × 10-3and 9.1 × 10-3for the corresponding diffraction spots. As a result, DFEH is highlighted as a powerful technique for strain measurement, offering high-strain precision, high-spatial resolution and a large field of view.
Department of Measurement and Analysis, National Nanofab Center, Daejeon 34141.|Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134.
Van Vuong
VV
Hoang
Department of Measurement and Analysis, National Nanofab Center, Daejeon 34141.
Youngji
Y
Cho
Department of Measurement and Analysis, National Nanofab Center, Daejeon 34141.
Jung Ho
JH
Yoo
Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134.
Soon-Ku
SK
Hong
Department of Aero-Materials Engineering, Jungwon University, Chungbuk, Goesan 28024.
Yong Ho
YH
Choi
FC R&D Team, Eugene Technology, Co., Ltd, Gyeonggi, Yongin 17156.
Sungha
S
Choi
FC R&D Team, Eugene Technology, Co., Ltd, Gyeonggi, Yongin 17156.
Wooduck
W
Jung
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141.|KAIST Institute for the NanoCentury (KINC), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
Chang Kyu
CK
Jeong
Department of Measurement and Analysis, National Nanofab Center, Daejeon 34141 jmyang@nnfc.re.kr.
Jun-Mo
JM
Yang
SiGe; dark-field electron holography (DFEH); finite element method (FEM); simulation; strain mapping