Fabrication of Well-Organized and Densely Packed Si Nanopillars Containing SiGe Nanodots by Using Block Copolymer Templates

• Published in: Chemistry of materials 2008-10, Vol.20 (19), p.6183-6188
• Main Authors: Aissou, Karim, Baron, Thierry, Kogelschatz, Martin, Hertog, Martien Den, Rouvière, Jean Luc, Hartmann, Jean-Michel, Pélissier, Bernard
• Format: Article
• Language: English
• Subjects: Nanomaterials (Nanops, Nanotubes, etc.); Patterning of Materials (Micro- and Nanoscale); Self-Assembly and Self-Assembled Materials
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm800364t

We present a method to obtain a dense array of well-organized SiGe quantum dots in Si nanopillars on a large substrate area by using a PS-b-PMMA block copolymer template. First, the 2D order of the template is evaluated using a pair correlation function and a bond-orientational correlation function. It is shown that the holes contained in the polystyrene template form a structure presenting a hexatic order. This template is then used to fabricate the nanopillars using the following method: in a first step, the copolymer template serves as a deposition mask to fabricate a hexagonal array of Pt dots. In a second step, the Pt dot pattern is transferred to an alternation of Si and SiGe layers on a silicon substrate with an anisotropically etching using Cl2/O2 plasma.