Stress and Strain Measurements in Semiconductor Device Channel Areas by Convergent Beam Electron Diffraction

摘要

Convergent electron beam diffraction (CBED) has been successfully applied to measure strain/stress in the channel area in PMOS semiconductor device with embedded SiGe (eSiGe) for 65nm technology. Reliable results of strain/stress measurements in the channel area have been achieved by good fitting of experimental CBED patterns with theoretical calculations. Stress measurements from CBED are in good agreement with simulations. A compressive stress as high as 823.9 MPa was measured in the < 110 > direction in the channel area of a PMOS device with eSiGe with 15% Ge and a thickness of 80nm. Stress measurements from CBED also confirm that the depth of the eSiGe and defects such as dislocation loops within the eSiGe relax strain/stress within the film and reduce strain/stress in the channel area.