Fabrication of HfO₂patterns by laser interference nanolithography and selective dry etching for III-V CMOS application

• Main Authors: Molina-Aldareguia Jon, Monaghan Scott, Hurley Paul, Cherkaoui Karim, Benedicto Marcos, Galiana Beatriz, Vazquez Luis, Tejedor Paloma
• Format: Article
• Language: English
• Published: SpringerOpen 2011-01-01
• Series: Nanoscale Research Letters
• Online Access: http://www.nanoscalereslett.com/content/6/1/400
• ISSN: 1931-7573; 1556-276X

<p>Abstract</p> <p>Nanostructuring of ultrathin HfO₂films deposited on GaAs (001) substrates by high-resolution Lloyd's mirror laser interference nanolithography is described. Pattern transfer to the HfO₂film was carried out by reactive ion beam etching using CF₄and O₂plasmas. A combination of atomic force microscopy, high-resolution scanning electron microscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray spectroscopy microanalysis was used to characterise the various etching steps of the process and the resulting HfO₂/GaAs pattern morphology, structure, and chemical composition. We show that the patterning process can be applied to fabricate uniform arrays of HfO₂mesa stripes with tapered sidewalls and linewidths of 100 nm. The exposed GaAs trenches were found to be residue-free and atomically smooth with a root-mean-square line roughness of 0.18 nm after plasma etching.</p> <p>PACS: Dielectric oxides 77.84.Bw, Nanoscale pattern formation 81.16.Rf, Plasma etching 52.77.Bn, Fabrication of III-V semiconductors 81.05.Ea</p>