Local Strain Measurement on Strained Si/SiGe Heterostructures Using Convergent Beam Electron Diffraction Analysis

Abstract

Local strain variations in microelectronic device structures have been investigated with convergent beam electron diffraction (CBED). The analysis has been improved with a series of tasks: high order Laue zone (HOLZ) line detection by the Hough transform, HOLZ line position simulation with the kinematic theory, lattice parameter refinement by the examination of least square fitting, and theoretical strain state calculation with finite element (FE) modeling. The goal of this paper is to demonstrate the procedure of this strain measurement analysis. The actual strain variation in a TEM foil of a CMOS device structure was shown, followed by the FE in a strain Si/SiGe heterostructure. The strain data will not be included in this paper, but will be added later.