Recently, scanning probe lithography by applying an electric field between the tip and the sample has been shown to be a promising technique for nanofabrication. In this paper, we present a novel method of nanofabrication, namely, nanolithography by tip-enhanced laser irradiation. Based on the operation of the laser-assisted scanning tunneling microscope (STM), we established a nanolithography system using tip-enhanced laser irradiation, which was developed from a commercial scanning probe microscope (SPM). In our investigation, the SPM was operated as an STM. During imagin and lithography, the STM is in a constant current mode. The tip is fixed and the sample moves via a tube scanner. Nanolithography software controls the scanner movement in the x and y direction. The SPM has an open architecture, allowing an external laser beam incident on the tip at an incident angle between 0 to 45 degrees. A vertical polarized Nd:YAG pulsed laser with a pulse duration of 7 ns was focused on the surfaces of the tip and the sample. An electrical shutter was introduced to switch the laser irradiation during lithography. Alignment of the laser to the tip-sample gap was performed under a high power charge coupled device microscope. Nanolithography was performed on hydrogen (H)-passivated Si (100) surfaces and H-passivated Ge (100) surface.s The Si samples and the Ge samples were passivated in HF solution. STM tips were homemade electrochemically form a 0.5-mm tungsten wire. Oxide features were created by tip-enhanced laser irradiation. The experimental result will be discussed.

Date Published: 4 November 1999
PDF: 8 pages
Proc. SPIE 3898, Photonic Systems and Applications in Defense and Manufacturing, (4 November 1999); doi: 10.1117/12.368476

Published in SPIE Proceedings Vol. 3898:
Photonic Systems and Applications in Defense and Manufacturing
Yee Loy Lam; Koji Ikuta; Metin S. Mangir, Editor(s)