Composition Dependence of Hardness and Moduli in GeSi/Si-Heterostructures Measured by Nanoindentation
- PDF / 366,947 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 29 Downloads / 216 Views
In the last four decades several investigations on the hardness of germanium-silicon bulk (poly)crystalline samples were performed [2-5]. However, the resulting curves of hardness as a function of composition show large discrepancies. Both linear dependence and alloy hardening as well as alloy softening have been reported. Thus, one goal was to reinvestigate hardness of GeSi using homogeneous heteroepitaxial layers. For binary alloys like germanium-silicon, which show complete solid solubility, the elastic moduli are generally assumed to vary linearly with composition. However, to our knowledge no investigation of Ge-Si using mechanical testing was performed up to now. Nanoindentation technique, or continuous depth recording, has recently become available for measuring film elastic properties, assuming the films are suffiently thick. Here we report on nanoindentation experiments that provide for the first time simultaneously hardness and elastic moduli data of GeSi15x for the whole range of compositions, 0 : x < 1. EXPERIMENTAL Sample Preparation For our investigations three series of GeSilx layers were manufactured. The first one, grown by APCVD (atmospheric pressure CVD) [61 on Si(100) at a temperature of 720 'C, covers the 277 Mat. Res. Soc. Symp. Proc. Vol. 356 01995 Materials Research Society
composition range 0.03 < x _
Data Loading...
