Damage-free top-down processes for fabricating two-dimensional arrays of 7 nm GaAs nanodiscs using bio-templates and neutral beam etching

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 × 1011 cm − 2 was successfully fabricated without causing any damage to the GaAs.

[1]  Y. Okada,et al.  Optical absorption characteristic of highly ordered and dense two-dimensional array of silicon nanodiscs , 2011, Nanotechnology.

[2]  A. Luque,et al.  Photovoltaics: Towards the intermediate band , 2011 .

[3]  Y. Ohno,et al.  Defect-free etching process for GaAs/AlGaAs hetero-nanostructure using chlorine/argon mixed neutral beam , 2010 .

[4]  P. Smowton,et al.  Many-body effects in InAs/GaAs quantum dot laser structures , 2010 .

[5]  J. Morante,et al.  InAs quantum dot arrays decorating the facets of GaAs nanowires. , 2010, ACS nano.

[6]  Y. Okada,et al.  InAs/GaNAs strain-compensated quantum dots stacked up to 50 layers for use in high-efficiency solar cell , 2010 .

[7]  Antonio Luque,et al.  The Intermediate Band Solar Cell: Progress Toward the Realization of an Attractive Concept , 2010, Advanced materials.

[8]  T. Fuyuki,et al.  Two-Dimensional Si-Nanodisk Array Fabricated Using Bio-Nano-Process and Neutral Beam Etching for Realistic Quantum Effect Devices , 2009 .

[9]  G. Salamo,et al.  Mechanisms of interdot coupling in (In,Ga)As/GaAs quantum dot arrays , 2009 .

[10]  Y. Okada,et al.  Optical studies on InAs/InGaAs/GaNAs strain-compensated quantum dots grown on GaAs (0 0 1) by molecular beam epitaxy , 2009 .

[11]  Stanko Tomić,et al.  Absorption characteristics of a quantum dot array induced intermediate band: Implications for solar cell design , 2008 .

[12]  I. Yamashita,et al.  Improvement of Co3O4 Nanoparticle Synthesis in Apoferritin Cavity by Outer Surface PEGylation , 2008 .

[13]  Y. T. Lee,et al.  Influence of dot size distribution and interlayer thickness on the optical property of closely stacked InAs/GaAs quantum dots with growth interruption , 2008 .

[14]  I. Walmsley.  Looking to the Future of Quantum Optics , 2008, Science.

[15]  I. Yamashita,et al.  Direct Production of a Two-Dimensional Ordered Array of Ferritin-Nanoparticles on a Silicon Substrate , 2007 .

[16]  T. Fuyuki,et al.  Low-damage fabrication of high aspect nanocolumns by using neutral beams and ferritin-iron-core mask , 2007 .

[17]  I. Yamashita,et al.  Realizing a two-dimensional ordered array of ferritin molecules directly on a solid surface utilizing carbonaceous material affinity peptides. , 2007, Langmuir : the ACS journal of surfaces and colloids.

[18]  S. Samukawa.  Ultimate Top-down Etching Processes for Future Nanoscale Devices: Advanced Neutral-Beam Etching , 2006, 2006 8th International Conference on Solid-State and Integrated Circuit Technology Proceedings.

[19]  T. Fuyuki,et al.  Novel Method for Making Nanodot Arrays Using a Cage-like Protein , 2003 .

[20]  Yoshitaka Okada,et al.  Fabrication of ultra-high density InAs-stacked quantum dots by strain-controlled growth on InP(3 1 1)B substrate , 2002 .

[21]  Ichiro Yamashita,et al.  Fabrication of a two-dimensional array of nano-particles using ferritin molecule , 2001 .

[22]  K. Asakawa,et al.  Dry etching and consequent burring regrowth of nanosize quantum wells stripes using an in situ ultrahigh vacuum multichamber system , 1998 .

[23]  Z. Lu,et al.  Ultraviolet‐ozone oxidation of GaAs(100) and InP(100) , 1993 .

[24]  A. Forchel,et al.  Transport and optical properties of semiconductor quantum wires , 1991 .

[25]  A. Forchel,et al.  Time-resolved investigations of sidewall recombination in dry-etched GaAs wires , 1990 .

[26]  I. Yamashita,et al.  Direct Fabrication of Uniform and High Density Sub-10-nm Etching Mask Using Ferritin Molecules on Si and GaAs Surface for Actual Quantum-Dot Superlattice , 2010 .