Ultimate Top-down Etching Processes for Future Nanoscale Devices: Advanced Neutral-Beam Etching

Abstract

For the past 30 years, plasma etching technology has led in the efforts to shrink the pattern size of ultralarge-scale integrated (ULSI) devices. However, inherent problems in the plasma processes, such as charge buildup and UV photon radiation, limit the etching performance for nanoscale devices. To overcome these problems and fabricate sub-10-nm devices in practice, neutral-beam etching has been proposed. In this paper, I introduce the ultimate etching processes using neutral-beam sources and discuss the fusion of top-down and bottom-up processing for future nanoscale devices. Neutral beams can perform atomically damage-free etching and surface modification of inorganic and organic materials. This technique is a promising candidate for the practical fabrication technology for future nano-devices.

The 2017 Plasma Roadmap: Low temperature plasma science and technology

“…Neutral beam process technology has attracted attention as one method to address the challenges of atomic precision plasma processing [62]. Use of a neutral beam eliminates the incidence of charged particles and UV photons on the substrate, and so expose the substrate only to energycontrolled neutral beams.…”

“…These attributes enable precise nano-processing, which suppresses the formation of defects at the atomic layer level and controls the surface chemical reactions with high precision. Atomic layer defect-free and roughness-free Si (or Ge) channel etching for sub-22 nm Fin-FETs (figure 11) [61,62], ultra-thin gate dielectric film formation for sub-22 nm Fin-FETs, transition metal oxidation for ReRAM, atomic layer super-low dielectric film deposition for sub-22 nm FETs, atomic layer damage-free etching of magnetic materials [61] and low-damage surface modification of carbon materials (including nanotubes, grapheme, and organic molecules) for future nano-devices using neutral beam processing have been demonstrated.…”

Electron g-factor and spin decoherence in GaAs quantum nanodisks fabricated by fully top-down lithography

“…Quantum nanodisks (NDs) of GaAs with desirable optical qualities have recently been grown from quantum wells (QWs) by fully top-down lithography, using damage-free neutral-beam etching aided by bioengineering [1][2][3][4]. This fabrication method allows us to flexibly design the structural parameters of the NDs.…”

Comparison between AlGaN surfaces etched by carbon tetrafluoride and argon plasmas: Effect of the fluorine impurities incorporated in the surface

“…The photogenerated holes are considered to cause the surface dissolution and/or to weaken the bond strength at the surface through the oxidation reaction [39,40]. The vacuum ultraviolet (VUV) light irradiation is also considered to affect the morphological change in the surface, because the VUV light irradiation generates defects in the surface [41]. In general, VUV light of 105 and 107 nm in wavelength is reportedly emitted from Ar plasma generated using inductively-coupled RF plasma reactors [42,43], though the feature of these plasma reactors essentially differs from that of the plasma reactor used in the present study.…”