X-ray scattering studies on InGaAs quantum dots

Authors :: Hsu, C.-H.
Lee, H.-Y.
Hsieh, Y.-W.
Stetsko, Y.P.
Tang, M.-T.
Liang, K.S.
Yeh, N.T.
Chyi, J.-I.
Noh, D.Y.
Source :: Physica B. Aug2003, Vol. 336 Issue 1/2, p98. 5p.
Publication Year :: 2003
Abstract: We present a structural investigation of self-assembled InGaAs quantum dots on GaAs(0 0 1) substrates grown by molecular-beam epitaxy. The grazing incidence X-ray scattering measurements were performed at BL17B of Taiwan Light Source and BL12B2 of SPring-8. The strain field, composition distribution, and shape of the dots are determined. We found that In concentration was less than the nominal composition, 50% near the dot/substrate interface and exceeded 50% near the top of the dots, indicating In surface segregation. In addition, the relation between the strain and the composition did not obey Vegard’s law. [Copyright &y& Elsevier]