Laser-Scanning Probe Microscope Based Nanoprocessing of Electronics Materials

Recently, scanning probe microscope (SPM) has become a promising technique for nanofabrication. In this paper, we present a novel method of nano-fabrication, namely, nano-fabrication by atomic force microscope (AFM) tips under laser irradiation. The SPM was operated as an AFM. During imaging and nano-fabrication, the AFM is in constant force mode. The tip is fixed with the sample moving via a tube scanner. Nano-lithography software controls the scanner motion in x and y directions. The SPM has an open architecture allowing an external laser beam incident on the tip at an incident angle between 0 to 45°. A vertically-polarized Nd:YAG pulsed laser with a pulse duration of 7 ns was focused on the tip. An electrical shutter was introduced to switch the laser irradiation. Alignment between the laser beam and the tip was performed under a high-power charge coupled device (CCD) microscope. The kinetics of the nanostructure fabrication has been studied. Craters were created in air ambient under different laser pulse numbers, pulse energies and tip force. The feature size of the craters, which are in the nanometer scale, increases with the pulse number, pulse energy and the tip force. This technique has potential applications in nano-lithography and high-density data storage.