Nanolithography on thin layers of PMMA using atomic force microscopy

Abstract

A new technique for producing nanometre scale patterns on thin layers (<30 nm thick) of PMMA on silicon is described. The method consists of inducing the local modification of the PMMA by applying a positive voltage between the silicon and an atomic force microscope (AFM) tip. At voltages larger than 28 V, it is observed that a hole is directly produced on the PMMA. The silicon surface is simultaneously oxidized even in the case where a hole has not been created. Monitoring of the electrical current through the AFM tip during the application of the voltage allows elucidating the mechanism of the PMMA removal. The process is used to define nanometre scale electrodes by combining the AFM lithography with electron beam lithography, metal deposition and lift-off processes.

Phase shifting-based debris effect detection in USV-assisted AFM nanomachining

“…Atomic force microscopy (AFM) tip-based nanomechanical machining, due to its advantages of high resolution, low cost, and simplicity [20][21][22][23], has been employed to pattern polymer resist films [24][25][26] for fabricating and transferring substrate materials through the lift-off process [21][22][23]27,28]. However, the debris formation in the nanomachining process leads to the instability and inaccuracy of machining results, which limits the further application of AFM-based machining.…”

Reproducible nanostructure fabrication using atomic force microscopy indentation with minimal tip damage

“…14,15 If the indentation is made on a single polymer layer, the tip applies vertical force directly to the substrate. [16][17][18] Although this single-layer indentation method could make nanostructures, the AFM tip could be easily damaged because the tip applies the force to the hard substrate directly while making indentations. The ploughing method, which also uses an AFM, is another way to simply fabricate nanowires, but the AFM tip can be easily damaged because of the lateral force applied to it.…”

Nanolithography Study Using Scanning Probe Microscope

“…Recently, the interest to design useful nanostructures in science and technology has rapidly increased and these technologies will be superior for the fabrication of nanostructures (Iwanaga & Darling, 2005;Martin et al, 2005;Sadegh Hassani et al, 2010). The patterning of material in this scale is one of the great importances for future lithography in order to attain higher integration density for semiconductor devices (Sadegh Hassani & Sobat, 2011).…”

“…This method is not restricted to conductive materials (Fonseca Filho et al, 2004). The advantages of this technique are high resolution and alignment accuracy, which could not be achieved by conventional lithographic techniques (Sheehan & Whitman, 2002;Martin et al, 2005). Moreover, the AFM nanolithography technique takes advantages of the ability to move a probe over the sample in a controllable way (Samori, 2005).…”