Intermittent-Contact Scanning Capacitance Microscope for Lithographic Overlay Measurement
Joseph Kopanski, Santos D. Mayo
A new scanning capacitance microscope (SCM) mode was implemented by using an atomic force microscope (AFM) operated in intermittent contact and by measuring the tip-to-sample capacitance change at the tip vibration frequency. The intermittent-contact-mode SCM was able to image and determine the overlay separation of metal lines buried under an 1 [mu]m thick, planarized dielectric layer. Modeling of the intermittent-contact SCM signal across buried metal lines was consistent with the experimental results. This hybrid intermittent-contact AFM and SCM has the potential to measure the lithographic overlay between metal lines located at consecutive levels beneath dielectric layers in an integrated circuit.
Applied Physics Letters
atomic force microscopy, buried line imaging, overlay metrology
and Mayo, S.
Intermittent-Contact Scanning Capacitance Microscope for Lithographic Overlay Measurement, Applied Physics Letters
(Accessed September 22, 2023)