In-situ real time sputtering source health monitoring using ultrasonics

This work describes the technique of monitoring functional health of sputtering source during sputter-deposition process using ultrasound time of flight (TOF) measurements. The TOF is measured between echoes reflecting from boundaries of dissimilar components inside the source. The technique described can be used for in-situ real time monitoring of target thickness, target bond integrity as well as for monitoring of cooling water temperature and target deformation.