High-density Ge dots grown on Si substrate by modified S-K Method

In this work, we have performed epitaxy of Ge dots over Si nanometer-scale columns on Si (100) substrate. A two-step fabrication process has been developed. First, Si buffer layer is deposited on Si substrate by LPCVD and then Ge dots grow on the Si layer. The Ge dots on Si with the packing density as high as 1.6x 10/sup 12/cm/sup -2/ and the average size is 8nm. SEM, XRD, and HRTEM measurements indicate that Ge dots were formed on each nanometer Si column separately. This growth obeys the Stranski-Krastanov (S-K) mode in local area.