This publication is a compilation of papers presented at the Semiconductor Device Reliabi lity Workshop sponsored by the NATO International Scientific Exchange Program. The Workshop was held in Crete, Greece from June 4 to June 9, 1989. The objective of the Workshop was to review and to further explore advances in the field of semiconductor reliability through invited paper presentations and discussions. The technical emphasis was on quality assurance and reliability of optoelectronic and high speed semiconductor devices. The primary support for the meeting was provided by the Scientific Affairs Division of NATO. We are indebted to NATO for their support and to Dr. Craig Sinclair, who admin isters this program. The chapters of this book follow the format and order of the sessions of the meeting. Thirty-six papers were presented and discussed during the five-day Workshop. In addi tion, two panel sessions were held, with audience participation, where the particularly controversial topics of bum-in and reliability modeling and prediction methods were dis cussed. A brief review of these sessions is presented in this book.