We examined the selective epitaxial growth of Ge on Si(001) substrates with 40, 65, and 90 nm width trench arrays by ultra-high vacuum chemical vapor deposition. Because SiO2 trench walls were present, no surface undulation in the direction parallel to the trenches was observed and compressive strain developed in the same direction. Based on reciprocal space mapping (RSM) measurements, this strain along the parallel direction increased from - 0.28 to - 0.72% as the width of the exposed Si substrate between the SiO2 walls decreased from 90 to 40 nm, which was due to a decrease in strain relaxation. We calculated the effect of the Si trench width on changes in strain after removing the SiO2 walls and compared the calculated values with the RSM results. No significant change in the strain relaxation was detected along the direction perpendicular to the trenches, and the strain changes were < 0.1%.
Bibliographical noteFunding Information:
B. Kim wishes to thank the Samsung Electronics Co., Ltd. (SEC) for support via the university–industry cooperation scholarship program. This work was financially supported by the IT R&D program of MKE/KEIT ( 10039174 , Technology Development of 22 nm level Foundry Device and PDK) and the Joint Program for SEC–Yonsei University . It was also supported by a grant from the R&D Program for Industrial Core Technology funded by the Ministry of Trade, Industry and Energy (MOTIE), Republic of Korea (Grant No. 10045216 ).
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry