Strain mapping in deep sub-micron Si devices by convergent beam electron diffraction in the STEM

¹ CNR-IMM Sezione di Bologna, Via P. Gobetti 101, 40129 Bologna, Italy
² INFM-National Research Centre-S3 and Dipartimento di Fisica, Universitá di Modena e Reggio Emilia, Via G. Campi 213/A, 41100 Modena, Italy

Corresponding author: balboni@lamel.bo.cnr.it

Received: 5 July 2003
Accepted: 9 December 2003
Published online: 15 July 2004

Abstract

The principles of the convergent beam electron diffraction technique, which is a point-to-point method for local strain analysis of thin crystals in the transmission electron microscope, are briefly outlined. The availability in modern instruments of scanning attachments coupled with high-angle annular dark-field detectors (STEM/HAADF) has recently enabled the automatic acquisition of diffraction patterns in a large number of points, selected by digitally rastering the probe in a two dimensional region of the sample. As the components of the strain tensor can be calculated at each point, 2D strain mapping has thus become possible. An example of application of the technique to deep sub-micron shallow-trench isolation structures in silicon is reported.