Sub-10-nm half-pitch electron-beam lithography by using poly(methyl methacrylate) as a negative resist

Abstract

Developing high-resolution resists and processes for electron-beam lithography is of great importance for high-density magnetic storage, integrated circuits, and nanoelectronic and nanophotonic devices. Until now, hydrogen silsesquioxane ͑HSQ͒ and calixarene were the only two reported negative resists that could approach sub-10-nm half-pitch resolution for electron-beam lithography. Here, the authors report that 10-nm half-pitch dense nanostructures can also be readily fabricated using the well known poly͑methyl methacrylate͒ ͑PMMA͒ resist operating in negative tone, even at exposure energies as low as 2 keV. In addition to scanning electron microscopy metrology, transmission electron microscopy metrology was done to confirm the high-resolution capability of negative-tone PMMA. This process was compared to HSQ with salty development and showed similar ultimate resolution, so it could be used as an alternative for applications incompatible with HSQ.

A simple PAN-based fabrication method for microstructured carbon electrodes for organic field-effect transistors

“…The normalized thickness of the PAN microstructures after development was increased with an increasing fluence up to 3 · 10 15 ions cm À2 , after which it levelled off. The contrast (c) is determined by c = [log 10 (D 100 /D 0 )] À1 , where D 100 and D 0 are the fluences at the normalized thickness of 100% and the onset of the complete development, respectively [29,30]. The calculated contrast and sensitivity of the PAN thin films were 3.3 and 1.9 · 10 15 ions cm À2 , respectively.…”

Light generation via quantum interaction of electrons with periodic nanostructures

“…The immediate reason, which also highlights a requirement important to our prediction, is the use of gratings of very small periodicities, that have been, until recently, outside the reach of our fabrication tools. However, recent years have shown significant advances in the resolution of nanofabrication techniques such as electron beam lithography and ion beam milling, that now reach features of a few nanometers and gratings with periodicities on the order of 10 nm (see e.g., [46,47]). …”

Fabrication of high-resolution nanostructures of complex geometry by the single-spot nanolithography method

“…PMMA's dual-tone resist capability opens up a simple and inexpensive route to produce a range of polymer nanostructures using direct overexposure of the electron beam [11,12,13,14,15].…”