MEASUREMENT AND MODELING OF SELF-HEATING IN SOI NMOSFETS

Self-heating in SOI nMOSFET's is measured and modeled. Temperature ris es in excess of 100 K are observed for SOI devices under static operat ing conditions. The measured temperature rise agrees well with the pre dictions of an analytical model and is a function of the silicon thick ness, buried oxide thickness, and channel-metal contact separation. Un der dynamic circuit conditions, the channel temperatures are much lowe r than predicted from the static power dissipation. This work provides the foundation for the extraction of device modeling parameters for d ynamic operation (at constant temperature) from static device characte rization data (where temperature varies widely). Self-heating does not greatly reduce the electromigration reliability of SOI circuits, but might influence SOI device design, e.g., requiring a thinner buried ox ide layer for particular applications and scaled geometries.