We report on a transmission electron microscopy (TEM) technique that can be used to measure strain due to individual nanometer-scale coherent heterostructures such as quantum dots or inclusions. The measurement relies on two-beam imaging and on an approximation that employs a universal model for lattice plane bending. We demonstrate that analysis is simple and accurate. Using this method, we measured the average strain in dome-shaped Ge islands grown on Si (001). We found that the method of specimen preparation can significantly affect the observed strain in these islands.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics