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Title: Chains of quantum dot molecules grown on Si surface pre-patterned by ion-assisted nanoimprint lithography

An original approach based on the combination of nanoimprint lithography and ion irradiation through mask has been developed for fabrication of large-area periodical pattern on Si(100). Using the selective etching of regions amorphized by ion irradiation ordered structures with grooves and ridges were obtained. The shape and depth of the relief were governed by ion energy and by the number of etching stages as well. Laterally ordered chains of Ge quantum dots were fabricated by molecular beam epitaxy of Ge on the pre-patterned Si substrates. For small amount of Ge deposited chains contain separate quantum dot molecules. The increase of deposition amount leads to overlapping of quantum dot molecules with formation of dense homogeneous chains of quantum dots. It was shown that the residual irradiation-induced bulk defects underneath the grooves suppress nucleation of Ge islands at the bottom of grooves. On pre-patterned substrates with whole defect regions, etched quantum dots grow at the bottom of grooves. The observed location of Ge quantum dots is interpreted in terms of local strain-mediated surface chemical potential which controls the sites of islands nucleation. The local chemical potential is affected by additional strain formed by the residual defects. It was shown by molecular dynamicsmore » calculations that these defects form the compressive strain at the bottom of grooves.« less
Authors:
; ; ;  [1] ; ;  [1] ;  [2]
  1. Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, Lavrenteva 13, 630090 Novosibirsk (Russian Federation)
  2. (Russian Federation)
Publication Date:
OSTI Identifier:
22350915
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 15; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AMORPHOUS STATE; CHAINS; CRYSTAL DEFECTS; DEPOSITION; ETCHING; FABRICATION; GERMANIUM; ION BEAMS; IRRADIATION; MOLECULAR BEAM EPITAXY; MOLECULAR DYNAMICS METHOD; MOLECULES; PERIODICITY; QUANTUM DOTS; SILICON; STRAINS; SUBSTRATES; SURFACES