Electrical impedance tomography based sensors for semiconductor manufacturing

This paper explores the feasibility of a class of sensors for semiconductor manufacturing based on Electrical Impedance Tomography. We briefly summarize the role of sensors in semiconductor manufacturing and the essential principles of Electrical Impedance Tomography. We then discuss numerical aspects of the EIT problem that arise in the context of our specific application. We have built a prototype etch rate sensor based on these ideas. We discuss both experimental and simulation results from this sensor.