scholarly journals Single-Crystalline Si1−xGex (x = 0.5~1) Thin Films on Si (001) with Low Threading Dislocation Density Prepared by Low Temperature Molecular Beam Epitaxy

2019 ◽  
Vol 9 (9) ◽  
pp. 1772
Author(s):  
Gu ◽  
Zhao ◽  
Ye ◽  
Deng ◽  
Lu

Single-crystalline Si1−xGex thin films on Si (100) with low threading dislocation density (TDD) are highly desired for semiconductor industrials. It is challenging to suppress the TDD since there is a large mismatch (4.2%) between Ge and Si—it typically needs 106–107/cm2 TDD for strain relaxation, which could, however, cause device leakage under high voltage. Here, we grew Si1−xGex (x = 0.5–1) films on Si (001) by low temperature molecular beam epitaxy (LT-MBE) at 200 °C, which is much lower than the typical temperature of 450–600 °C. Encouragingly, the Si1−xGex thin films grown by LT-MBE have shown a dramatically reduced TDD down to the 103–104/cm2 level. Using transmission electron microscopy (TEM) with atomic resolution, we discovered a non-typical strain relaxation mechanism for epitaxial films grown by LT-MBE. There are multiple-layered structures being introduced along out-of-plane-direction during film growth, effectively relaxing the large strain through local shearing and subsequently leading to an order of magnitude lower TDD. We presented a model for the non-typical strain relaxation mechanism for Si1−xGex films grown on Si (001) by LT-MBE.

2004 ◽  
Vol 809 ◽  
Author(s):  
J. Cai ◽  
P. M. Mooney ◽  
S. H. Christiansen ◽  
H. Chen ◽  
J. O. Chu ◽  
...  

ABSTRACTThe strain relaxation and threading dislocation density of He-implanted and annealed SiGe/Si heterostructures have been studied. For He doses above a threshold of 8×1015 cm−2, the degree of strain relaxation depends primarily on the SiGe layer thickness; a similar degree of strain relaxation is obtained when the He dose and energy are varied over a relatively wide range. In contrast, the threading dislocation density is strongly influenced by the implantation depth. There is a strong correlation between the parameter He(SiGe), the He dose in the SiGe layer calculated from He profiles simulated using the program Stopping and Range of Ions in Matter (SRIM), and the threading dislocation density. We find that to achieve a low threading dislocation density, <5×107 cm−2, He(SiGe) must be less than 1015 cm−2. The strain relaxation mechanism is also discussed.


2017 ◽  
Vol 470 ◽  
pp. 135-142 ◽  
Author(s):  
Krista R. Khiangte ◽  
Jaswant S. Rathore ◽  
Vaibhav Sharma ◽  
Swagata Bhunia ◽  
Sudipta Das ◽  
...  

1989 ◽  
Vol 160 ◽  
Author(s):  
Y.H. Lee ◽  
R.P. Burns ◽  
J.B. Posthill ◽  
K.J. Bachmann

AbstractThe growth of Mo overtayers and Mo-Ni multilayers on single crystal Ni(001) substrates is described. The nucleation and growth processes of these thin films were analyzed by LEED, XPS, AES and SEM and High Resolution AES investigations without breaking vacuum. Growth of Mo-Ni multilayer heterostructures on Ni(001) with ≈20Å periodicity is possible at low temperature (≈200 °C). At high temperature (≈550 °C) the growth proceeds by the Volmer-Weber mechanism preventing the deposition of small period multilayers. Annealing experiments on ultra-thin (<20Å) Mo overiayers deposited at 200 °C show an onset of interdiffusion at ≈ 550°C coupled to the generation of a new surface periodicity.


2020 ◽  
Vol 116 (19) ◽  
pp. 192105 ◽  
Author(s):  
S. Inagaki ◽  
M. Nakamura ◽  
N. Aizawa ◽  
L. C. Peng ◽  
X. Z. Yu ◽  
...  

2004 ◽  
Vol 96 (12) ◽  
pp. 7665-7674 ◽  
Author(s):  
Yu. B. Bolkhovityanov ◽  
A. S. Deryabin ◽  
A. K. Gutakovskii ◽  
M. A. Revenko ◽  
L. V. Sokolov

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