TY - JOUR
T1 - Thermally induced transformations of amorphous carbon nanostructures fabricated by electron beam induced deposition
AU - Kulkarni, Dhaval D.
AU - Rykaczewski, Konrad
AU - Singamaneni, Srikanth
AU - Kim, Songkil
AU - Fedorov, Andrei G.
AU - Tsukruk, Vladimir V.
PY - 2011/3/23
Y1 - 2011/3/23
N2 - We studied the thermally induced phase transformations of electron-beam-induced deposited (EBID) amorphous carbon nanostructures by correlating the changes in its morphology with internal microstructure by using combined atomic force microscopy (AFM) and high resolution confocal Raman microscopy. These carbon deposits can be used to create heterogeneous junctions in electronic devices commonly known as carbon-metal interconnects. We compared two basic shapes of EBID deposits: dots/pillars with widths from 50 to 600 nm and heights from 50 to 500 nm and lines with variable heights from 10 to 150 nm but having a constant length of 6 μm. We observed that during thermal annealing, the nanoscale amorphous deposits go through multistage transformation including dehydration and stress-relaxation around 150 °C, dehydrogenation within 150-300 °C, followed by graphitization (>350 °C) and formation of nanocrystalline, highly densified graphitic deposits around 450 °C. The later stage of transformation occurs well below commonly observed graphitization for bulk carbon (600-800 °C). It was observed that the shape of the deposits contribute significantly to the phase transformations. We suggested that this difference is controlled by different contributions from interfacial footprints area. Moreover, the rate of graphitization was different for deposits of different shapes with the lines showing a much stronger dependence of its structure on the density than the dots.
AB - We studied the thermally induced phase transformations of electron-beam-induced deposited (EBID) amorphous carbon nanostructures by correlating the changes in its morphology with internal microstructure by using combined atomic force microscopy (AFM) and high resolution confocal Raman microscopy. These carbon deposits can be used to create heterogeneous junctions in electronic devices commonly known as carbon-metal interconnects. We compared two basic shapes of EBID deposits: dots/pillars with widths from 50 to 600 nm and heights from 50 to 500 nm and lines with variable heights from 10 to 150 nm but having a constant length of 6 μm. We observed that during thermal annealing, the nanoscale amorphous deposits go through multistage transformation including dehydration and stress-relaxation around 150 °C, dehydrogenation within 150-300 °C, followed by graphitization (>350 °C) and formation of nanocrystalline, highly densified graphitic deposits around 450 °C. The later stage of transformation occurs well below commonly observed graphitization for bulk carbon (600-800 °C). It was observed that the shape of the deposits contribute significantly to the phase transformations. We suggested that this difference is controlled by different contributions from interfacial footprints area. Moreover, the rate of graphitization was different for deposits of different shapes with the lines showing a much stronger dependence of its structure on the density than the dots.
KW - amorphous and nanocrystalline carbon
KW - electron-beam-induced deposition
KW - graphitization
UR - http://www.scopus.com/inward/record.url?scp=79955947210&partnerID=8YFLogxK
U2 - 10.1021/am1010173
DO - 10.1021/am1010173
M3 - Article
C2 - 21319745
AN - SCOPUS:79955947210
SN - 1944-8244
VL - 3
SP - 710
EP - 720
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 3
ER -