Berlin 2015 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 96: Poster III C (III-V Semiconductors incl. Nitrides)

HL 96.2: Poster

Donnerstag, 19. März 2015, 14:00–20:00, Poster B

Fabrication of nanopattern arrays of gold dots for nanowire arrays on GaP substrates by electron-beam lithography — •Emad H. Hussein^1,2, Vanesa Hortelano¹, M. P. Semtsiv¹, and W. T. Masselink¹ — ¹Institut für Physik, Humboldt Universtät zu Berlin, Newtonstrasse 15, 12489 Berlin, Germany — ²Department of Physics, college of Science, Al-Mustansiriyah University, Iraq

Fabrication of high-density and uniformly distributed gold dots on GaP (100) substrates using electron-beam lithography (EBL) was carried out. A positive EBL resist of PMMA (polymethyl methacrylate -600k) with a nominal thickness about 300 nm was spun onto the substrate and immediately baked on a hotplate at 160 ^∘C for 3 min. The pattern on the PMMA resist was written using a Raith nanolithography system connected to a JEOL JSM- 6360 scanning electron-microscopy. Arrays of 100 × 100 µ m² including holes patterns have been printed on the resist. We optimized the electron beam acceleration voltage to less than 15 kV and exposure doses between 150 and 220 µc/cm² that are needed to generate a high-contrast pattern. A gold layer with thickness of 35 nm was evaporated onto the produced pattern and lifted off. The resulting nanopattern of gold dots with diameter about 130 nm and density of 3 × 10⁷ cm⁻² has been fabricated on the substrates. These patterns are used either to directly etch nano-columns in the GaP substrate or as etch masks for initiating organized arrays of GaP nanowires grown by gas-source molecular-beam epitaxy. Results of the pattering and of resulting nanowires will be discussed.