ABSTRACT
This chapter presents two complementary transmission electron microscopy methods which are based on plan-view large angle convergent beam electron diffraction (LACBED) observations and used to determine the chemical composition of epitaxial strained layers. The first one concerns the quantitative analysis of the splitting of the kinematical rocking curves induced by a tetragonally strained buried layer. The second one deals with the effect on the dynamical rocking curves of a thin strained layer lying near or at the surface of a substrate. The precise determination of the chemical composition of compound semiconductor strained layers is of strong technological and fundamental interest, particularly for applications using III-Nitride compounds, whose compositions are difficult to control. The samples for LACBED observations were mechanically thinned to transparency using a South Bay Technology tripod polisher. LACBED patterns were taken with a Philips CM30 microscope and directly captured with a cooled slow-scan charge-coupled device Gatan camera.
