*3.5.3. Scanning Probe Lithography (SPL)*

SPL is an emerging area of research in which the scanning tunneling microscope (STM) or the atomic force microscope (AFM) is used to pattern nanometer-scale features. The patterning methods include mechanical pattering such as scratching or nano-indentation, or local heating with sharp tip (Dagata, 1995). When a voltage bias is applied between a sharp probe tip and a sample, an intense electric field is generated in the vicinity of the tip (Ref. Fig. 11).

**Figure 11.** Schematic diagram of the Scanning probe lithography. Electrical bias between a conducting tip and a sub‐ strate induces a highly localized enhanced oxidation [Courtesy Source: Dagata et al, *Science*, Vol.270, pp.1625-1626, 1995]

Advantages:


SPL method is a recognized as a lithographic tool in the deep sub-micron regime, as it is compatible with standard semiconductor processing. There are four main factors which dictate the viability of SPL as a known patterning method for the semiconductor industry. They are

