Improved TEM Sample Preparation by Low Energy FIB for Strain Analysis by Convergent Beam Electron Diffraction

Abstract

The application of the focused ion beam (FIB) to the preparation of thin lamellae of Si-based samples for strain analysis by means of convergent beam electron diffraction (CBED) was investigated. The crystal damage induced by the ion beam at the sample surface is expected to influence the pattern quality strain analysis too. Repeatable results in the strain measurements were obtained only if a low energy (5 KeV) finishing step was used in the sample preparation. The strain measurement results obtained in patterned structures with different strain amount were also compared with the ones calculated using a commercial process simulator and with electrical measurements performed on the final devices.

Analysis by HR-STEM of the Strain Generation in InP after SiNx Deposition and ICP Etching

“…The quantitative strain analysis in HR-STEM images is acquired at the [110] zone axis by using geometrical phase analysis (GPA) [16][17][18][19][20][21][22][23]. The lasts steps of the FIB procedure lamella thinning were carried out at 1kV ion beam accelerated voltage to avoid a possible generation of Ga implantation strain artefacts [24], that can occur above 5kV beam voltage.…”