Journal of Vacuum Science & Technology A, Vol.24, No.4, 1100-1106, 2006
Integrated active transient thermography for rapid nondestructive analysis of sputtering target bond integrity
Integrated active transient thermography is described and used to evaluate bond integrity of sputtering targets. In integrated active transient thermography one surface of a bonded target-backing plate assembly is rapidly heated while an infrared camera captures the time dependence of the surface temperature distribution on the opposite side. Bond defects inhibit heat transfer between the backing plate and the target, causing a slower rate of surface temperature rise in areas with poor bond integrity. Finite element models of the heat flow in the target assembly are used to establish the expected temperature rise for a perfectly bonded target assembly. A bond integrity map that is independent of the target assembly geometry, analysis time, applied power, and material is obtained by dividing the difference between the integrated finite element model generated map and the integrated experimental bond integrity map by the integrated finite element map. Measurement time for a commercial sized sputtering target assembly is only 50 s. (c) 2006 American Vacuum Society.