Authors: M.A. Rabie, S. Gou, Y.M. Haddara, A.P. Knights, J. Wojcik, P. Mascher
Affilation: McMaster University, Canada
Pages: 580 - 582
Keywords: sige, silicon germanium, oxidation, strain, relaxed sige
We report on a series of experiments in which a strained Si0.95Ge0.05 layer 600Å thick was oxidized along with relaxed SiGe layers and Si samples. In this work, we observed that the oxidation rate of the strained SiGe layer is always much higher than the relaxed model expectations. We also observed that the rate is higher than that of relaxed SiGe layers with higher Ge concentration oxidized at similar temperatures. We attributed this increase in the rate of oxidation to the effect of strain in the SiGe layer. To confirm our hypothesis, we oxidized strained SiGe layers together with relaxed SiGe layers of higher concentration (5% Ge for the strained samples, 9.5% Ge for the relaxed sample). We observed that the strained SiGe layer compared with relaxed sample has a thicker oxide despite the lower Ge concentration. We conclude that the strain in the SiGe layer causes a further increase in the oxidation rate. The faster oxidation rate can be attributed to a weaker Si-Ge bond in the case of strained SiGe. Our conclusion confirms that the weaker Si-Ge bond is one of the causes of the enhancement in the oxidation rate of SiGe compared to that of pure Si.
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