Scanning probe microscopes (SPMs) have some ability to image sub-surface structures. This paper describes the theoretical and practical basis for imaging metal lines buried beneath insulating layers and for imaging insulating regions or voids within metal with SPMs. Three techniques are discussed: scanning Kelvin force microscopy (SKFM) to image the potential of buried metal lines, scanning microwave microscopy (SMM) to image the capacitance of buried metal lines, and SMM to image voids in metals through the frequency dependence of the skin depth. A test chip, designed at NIST, and that contains buried structures to precisely produce electric potential and magnetic field variations at the surface to test the presumptions is described, along with some preliminary results.
Proceedings Title: Electrochemical Society Transactions,Proceedings of the Symposium on Dielectrics for Nanosystems 6: Materials Science, Processing, Reliability, and Manufacturing
Conference Dates: May 11-15, 2014
Conference Location: Orlando, FL
Conference Title: 225th Electrochemical Society Meeting
Pub Type: Conferences
Metrology, scanning Kelvin force microscopy, scanning microwave microscopy, semiconductor-insulator interfaces, semiconductor-metal interfaces, three-dimensional integrated circuits, through silicon vias