Strain Measurements from Single Grains in Passivated Aluminum Conductor Lines by X-Ray Microdiffraction During Electromigration

Abstract

AbstractWe describe a method for determining the local strain state of passivated aluminum metal lines from single grains within 2.6 µm × 7.0 µm × 0.75 µm sized regions along the line. X-ray microbeam diffraction is used to obtain localized measurements of thermal and electromigration-induced strain during 37 hours of electromigration in a passivated 2.6 µm-wide, 300 µm-long pure Al conductor line at a current density of 4.2×105 A/cm2 and temperature of 270°C. Diffraction from single grains is used to measure both the in-plane and normal components of strain and their evolution during electromigration at several positions along the line.