Epitaxial Gold in Au/Si Eutectic Reaction and Epitaxial Aluminum Spikes in Al-1%Si/Ti-W/Si System

Abstract

AbstractEpitaxial regrowth of gold film on Si as a result of Au/Si eutectic reaction and epitaxial aluminum spikes forming at IC contacts during sintering have been investigated by transmission electron microscopy (TEM). For gold film on Si, three types of epitaxy were observed: (1) the crystal structures of the two lattices are exactly the same, (2) the two structures have the orientation relationship of Au(111)//Si(111) and Au[132]//Si[231] and (3) 20° misorientation from the relationship in (2). Two orientation relationships were observed in the case of Al spike in Si: (1) Al[011]//Si[123] and Al(200)//Si(11), (2) Al[001]//Si[112] and 2° misorientation between Al(200) and Si(111). Possible mechanisms are proposed to explained the observed epitaxial growth.