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 $25\mathrm{nm}$ below the gate in a $65\mathrm{nm}$ 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 $1.1\mathrm{GPa}$ along this direction. These findings demonstrate that CBED can serve as a strain metrology technique for the development of strained silicon device technology.