Nano Lithography

Chapter 3

Lithography Techniques Using Scanning Probe Microscopy ¹

3.1. Introduction

About 20 years ago, a new category within the field of nano-lithography techniques was created by the introduction of local-probe microscopes [SAL 99, WIE 94], which take advantage of the local interaction that exist between a probe and the surface to be patterned. There is a whole family of such microscopes, the best known being scanning tunneling microscopes (STMs) [BIN 82], and atomic force microscopes (AFMs) [BIN 86] (Figure 3.1). Their fame is such that they are sometimes considered to be the workhorses of nanotechnology. We are going to show in this chapter that these microscopes, thanks to their ultimate resolution, can be viewed as the "end of the roadmap" of top-down techniques for nano-lithography. Indeed, their resolution makes it possible to not only resolve but also to provide precise imaging of the elementary constituents of matter (atoms, molecules), and they were soon recognized as valuable tools for patterning with atomic resolution.

Since their advent in the late 80s, their importance has grown rapidly, notably when used in combination with complementary techniques involving bottom-up approaches, such as self-assembly, guided growth, chemical reactions etc. They are at the crossroads of the two "top-down" and "bottom-up" approaches and are also compatible with a great number of analytical tools (optical, electrochemical etc.). Scanning probe techniques are therefore bound to play ...