USING THE HREM TO STUDY MORPHOLOGY AND STRUCTURE

OF NANOMATERIAL Ta AND TaN_x

Vo Vong,^a Luu tien Hung,^b Steffen Schulze,^c and Michael Hietschold^c

^aLaboratory of Electron Microscopy - National Centre for Natural Science and Technology, 18 Hoangquocviet Str., Caugiay Hanoi, Vietnam; ^bDepartment of Physics, Vinh University, Vinh City, Nghean, Vietnam; ^cInstitute of Physics, Chemnitz University of Technology, D-09107 Germany (vvemlab@ncst.ac.vn)

The grain sizes, phases, structures and morphology of Ta and TaN_x thin films on Si and SiO₂ substrates, which belong to the most promising barrier materials for copper in interconnect systems of semiconductor devices were determined by using high resolution electron microscopy (HREM).

In this work, we present the sample preparation of these films for TEM plan-view investigations. Special efforts had to be made in order to reach electron transparency despite of the high internal stress in the thin films. In detail, we discuss the grain sizes, phases and structures of the films and alloys as deduced from bright-field and dark-field images and selected area electron diffraction patterns.

Keywords : Size, structure , dark-field , SAD