The transmission electron microscopic study of thin metal film interconnections on electronic integrated circuits requires a sophisticated in-situ capability. Electromigration, particularly, cannot be investigated solely by viewing static heat-treated or electrically stressed specimens ex-situ. The key to the early electromigration studies by Blech, and others, was the in-situ observation of material movement in anelectrical-powering-stage equipped TEM. Blech's approach was insensitive to structure effects because of an absence of heating capability; he therefore relied on joule heating and temperature gradient effects.