Direct strain measurement in a 65nm node strained silicon transistor by convergent-beam electron diffraction

Abstract

Using the energy-filtered convergent-beam electron diffraction (CBED) technique in a transmission electron microscope, the authors report here a direct measurement of the lattice parameters of uniaxially strained silicon as close as 25nm below the gate in a 65nm node p-type metal-oxide-semiconductor field-effect transistor with SiGe source and drain. It is found that the dominant strain component (0.58%) is compressive along the source-drain direction. The compressive stress is 1.1GPa along this direction. These findings demonstrate that CBED can serve as a strain metrology technique for the development of strained silicon device technology.