title: Damage-free top-down processes for fabricating two-dimensional arrays of 7 nm GaAs nanodiscs using bio-templates and neutral beam etching.
abstract: The first damage-free top-down fabrication processes for a two-dimensional array of 7 nm GaAs nanodiscs was developed by using ferritin (a protein which includes a 7 nm diameter iron core) bio-templates and neutral beam etching. The photoluminescence of GaAs etched with a neutral beam clearly revealed that the processes could accomplish defect-free etching for GaAs. In the bio-template process, to remove the ferritin protein shell without thermal damage to the GaAs, we firstly developed an oxygen-radical treatment method with a low temperature of 280 °C. Then, the neutral beam etched the defect-free nanodisc structure of the GaAs using the iron core as an etching mask. As a result, a two-dimensional array of GaAs quantum dots with a diameter of ∼ 7 nm, a height of ∼ 10 nm, a high taper angle of 88° and a quantum dot density of more than 7 × 10(11) cm(-2) was successfully fabricated without causing any damage to the GaAs.
authors.affiliation: Institute of Fluid Science, Tohoku University, Aoba-ku, Sendai, Japan.
authors.forename: Xuan-Yu
authors.initials: XY
authors.lastname: Wang
authors.forename: Chi-Hsien
authors.initials: CH
authors.lastname: Huang
authors.forename: Rikako
authors.initials: R
authors.lastname: Tsukamoto
authors.forename: Pierre-Andre
authors.initials: PA
authors.lastname: Mortemousque
authors.forename: Kohei M
authors.initials: KM
authors.lastname: Itoh
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Ohno
authors.forename: Seiji
authors.initials: S
authors.lastname: Samukawa
mesh_terms: D000818:Animals; D001152:Arsenicals / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry; D005293:Ferritins / Q000737:chemistry* / Q000648:ultrastructure; D005708:Gallium / Q000737:chemistry*; D006736:Horses; D006851:Hydrochloric Acid / Q000737:chemistry; D008163:Luminescent Measurements; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010100:Oxygen / Q000737:chemistry; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D045663:Quantum Dots; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D001152:Arsenicals; D005290:Ferric Compounds; D012996:Solutions; C000499:ferric oxide; C043055:gallium arsenide; D005293:Ferritins; D005708:Gallium; D006851:Hydrochloric Acid; D010100:Oxygen