Scanning thermal microscopy for fast multiscale imaging and manipulation

Abstract

Multiscale resolution imaging and manipulation are essential for applications ranging from defect screening in circuits to nanoscale manipulation, patterning, and lithography. In this paper, we introduce a variant of scanning thermal microscopy to image surfaces at both the micro- and nanoscale. Electrothermal imaging at the microscale is performed in a completely out-of-contact, i.e., "noncontact" or "off-contact", mode with a microscale heater, followed by higher resolution nanoscale imaging in contact mode with a nanoscale probe tip. Using this methodology, the imaging and manipulation functions of a single probe can be decoupled completely. This off-contact imaging mode is useful for avoiding tip wear and can be performed safely at high velocities. We demonstrate imaging of microscale features at speeds of up to 2 mm/s. The lateral resolution is determined by the dimensions of the heater used for imaging. For the flying heights and heater dimensions used here, the 1σ lateral spatial resolution limit in the off-contact mode is less than 10 μm for 10-nm-tall features. A silicon nanowire attached to microscale electrodes is imaged to demonstrate the efficacy of this scheme. © 2010 IEEE.