Patent ID: 7784346

Claim:
A method of monitoring an electrochemical deposition process, comprising: configuring an electroplating bath comprising electroplating solution, a positive anode disposed in the solution, a negative cathode comprising a sample to be plated disposed in the solution, a current supply interconnected between the anode and the cathode; disposing a loudspeaker adjacent the electroplating bath; disposing an acoustic sensor opposite the loudspeaker adjacent the electroplating bath, which sensor comprises a deformable silicon membrane, an encapsulated piezoelectric layer formed on the silicon membrane, and two or more surface electrodes formed on the encapsulated piezoelectric layer; transmitting an acoustic signal through the electroplating bath for reception by the acoustic sensor while electroplating the sample; monitoring the acoustic response of the sensor with respect to plating thickness during electroplating of the sample to generate a predictive model defining the plating thickness versus time; and using the predictive model to monitor the plating thickness of samples in real time.