Measurement of three dimensional stress and modeling of stress induced migration failure in aluminium interconnects

Abstract

Stress-induced migration failure in fine aluminium interconnects is explained by measurements of mechanical stress and a kinetic failure model. An advanced stress-measurement method using X-ray diffractometry revealed the actual three-dimensional mechanical stresses and open failure test results were well correlated in terms of the covering insulator, metal linewidth, test temperature, and time-dependent relaxation profile. A kinetic model, successfully reproduced the non-Arrhenius behavior of the failure rate under various parameters. An exponent of 4 and an activation energy of 1.0-1.4 eV were obtained. The microscopic mechanism of stress migration along with stress relaxation, and the practical advantage of the modeling are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>