Nonlinear Alternating Current Tunneling Microscopy.
01 January 1989
A new method of scanning tunneling microscopy is proposed that should allow atomic resolution on insulators. A nonlinear AC technique is used that is shown to allow stable tunneling on insulating aluminum oxide and liquid-crystal films where DC tunneling is not possible. Images of the layered semiconductor WSe sub 2 were obtained with this technique. Nanometer features have been repeatably observed.