Characterization of submicrometer thickness of copper film on silicon wafer by using pulsed eddy current method

Pulsed eddy current (PEC) method for thickness measurement of metal film has been widely investigated in recent years. In the previous researches, this method has been mainly used in metal thickness measurement in the range from millimeter to centimeter and nondestructive inspection. The effectiveness of the PEC method for measurement of submicrometer thick copper (Cu) film has not been reported. In this experimental study, a prototype transducer based on the PEC principle has been developed for detecting the thickness copper films sputtered on silicon wafer. It has been found that PEC method can be applied to the thickness measurement of copper film down to submicrometer scale.