Abstract
We have grown the high quality and compressively strained Ge epilayers on a Si substrate with 40-nm width SiO 2 trench patterns at a growth temperature of 600 °C. Based on (224) reciprocal space mapping measurements of Ge samples with a different thickness, the residual in-plane strain value along the trench direction decreased from -0.74% to -0.42% with increasing thickness of the Ge layer from 150 nm to 180 nm. In addition, the compressive strain along the trench direction (ε1 ¯10 ) was larger than that in the direction perpendicular to the trench (ε 110 ) regardless of the thickness. For example, when Ge was overgrown on a SiO 2 trench, the ε1 ¯10 and ε 110 values were -0.42% and ~0%, respectively. We conclude that the asymmetric strain relaxation behavior of Ge is related to the SiO 2 trench patterns, which prevent the dislocations from gliding. Defects such as a microtwin and/or stacking fault were generated during the coalescence of Ge films having different lattice constants in each Ge layer arising from the different relaxation values. A local strain in Ge, with a high spatial resolution of 2.5 nm, was measured along the two directions by means of a nanobeam electron diffraction method, thus confirming asymmetric strain relaxation and the results are in good agreement with reciprocal space mapping results.
| Original language | English |
|---|---|
| Pages (from-to) | 308-313 |
| Number of pages | 6 |
| Journal | Journal of Crystal Growth |
| Volume | 401 |
| DOIs | |
| Publication status | Published - 2014 Sep 1 |
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All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry
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Strain evolution during the growth of epitaxial Ge layers between narrow oxide trenches. / Kim, Byongju; Kim, Sun Wook; Jang, Hyunchul; Kim, Jeong Hoon; Koo, Sangmo; Kim, Dae Hyun; Min, Byoung Gi; Park, Se Jeong; Song, Jason S.; Ko, Dae Hong.
In: Journal of Crystal Growth, Vol. 401, 01.09.2014, p. 308-313.Research output: Contribution to journal › Article
TY - JOUR
T1 - Strain evolution during the growth of epitaxial Ge layers between narrow oxide trenches
AU - Kim, Byongju
AU - Kim, Sun Wook
AU - Jang, Hyunchul
AU - Kim, Jeong Hoon
AU - Koo, Sangmo
AU - Kim, Dae Hyun
AU - Min, Byoung Gi
AU - Park, Se Jeong
AU - Song, Jason S.
AU - Ko, Dae Hong
PY - 2014/9/1
Y1 - 2014/9/1
N2 - We have grown the high quality and compressively strained Ge epilayers on a Si substrate with 40-nm width SiO 2 trench patterns at a growth temperature of 600 °C. Based on (224) reciprocal space mapping measurements of Ge samples with a different thickness, the residual in-plane strain value along the trench direction decreased from -0.74% to -0.42% with increasing thickness of the Ge layer from 150 nm to 180 nm. In addition, the compressive strain along the trench direction (ε1 ¯10 ) was larger than that in the direction perpendicular to the trench (ε 110 ) regardless of the thickness. For example, when Ge was overgrown on a SiO 2 trench, the ε1 ¯10 and ε 110 values were -0.42% and ~0%, respectively. We conclude that the asymmetric strain relaxation behavior of Ge is related to the SiO 2 trench patterns, which prevent the dislocations from gliding. Defects such as a microtwin and/or stacking fault were generated during the coalescence of Ge films having different lattice constants in each Ge layer arising from the different relaxation values. A local strain in Ge, with a high spatial resolution of 2.5 nm, was measured along the two directions by means of a nanobeam electron diffraction method, thus confirming asymmetric strain relaxation and the results are in good agreement with reciprocal space mapping results.
AB - We have grown the high quality and compressively strained Ge epilayers on a Si substrate with 40-nm width SiO 2 trench patterns at a growth temperature of 600 °C. Based on (224) reciprocal space mapping measurements of Ge samples with a different thickness, the residual in-plane strain value along the trench direction decreased from -0.74% to -0.42% with increasing thickness of the Ge layer from 150 nm to 180 nm. In addition, the compressive strain along the trench direction (ε1 ¯10 ) was larger than that in the direction perpendicular to the trench (ε 110 ) regardless of the thickness. For example, when Ge was overgrown on a SiO 2 trench, the ε1 ¯10 and ε 110 values were -0.42% and ~0%, respectively. We conclude that the asymmetric strain relaxation behavior of Ge is related to the SiO 2 trench patterns, which prevent the dislocations from gliding. Defects such as a microtwin and/or stacking fault were generated during the coalescence of Ge films having different lattice constants in each Ge layer arising from the different relaxation values. A local strain in Ge, with a high spatial resolution of 2.5 nm, was measured along the two directions by means of a nanobeam electron diffraction method, thus confirming asymmetric strain relaxation and the results are in good agreement with reciprocal space mapping results.
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U2 - 10.1016/j.jcrysgro.2013.12.057
DO - 10.1016/j.jcrysgro.2013.12.057
M3 - Article
AN - SCOPUS:84906967570
VL - 401
SP - 308
EP - 313
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
ER -