Membrane Stacking: Periodic Superlattice Patterning

The ability to stack and bond SiNM’s provides an interesting platform to study the effects of interacting surfaces and interfaces.  It is well known from wafer bonding experiments that bonding of two Si wafers at a misfit angle produces a periodic network of dislocations. Using membranes, we can vary the thickness of the bonded layer (membrane), and hence the degree of strain propagation to the surface. We are investigating Ge dot decoration of the modulated strain field that results when a Si(001) membrane is bonded at a misfit angle to a Si(001) host.

Figure 1. Ge grown on a 13nm thick Si(001) membrane bonded to a Si(001) host, note that the morphology is dramatically different from the typical dots observed on bulk Si (shown in the right image for comparison, under identical deposition conditions) Figure 2. Ge grown on Si(001)

 

Author: Shelley Scott

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