High strain embedded-SiGe via low temperature reduced pressure chemical vapor deposition. He, H., Brabant, P., Chung, K., Shinriki, M., Adam, T., Reznicek, A., Sadana, D., Hasaka, S., & Francis, T. THIN SOLID FILMS, 520(8):3175-3178, FEB 1, 2012. ICSI-7 Conference, Leuven, BELGIUM, AUG 29-SEP 01, 2011
doi  abstract   bibtex   
Performance improvement of strained p-type metal oxide semiconductor field effect transistors (p-MOSFETs) via embedded SiGe (e-SiGe) is well established. Strain scaling of p-MOSFETs since 90 nm complementary metal oxide semiconductor node has been accomplished by increasing Ge content in e-SiGe from nominally <20% in 90 nm p-MOSFETs to > 35% Ge in 32 nm p-MOSFETs. Further strain enhancement for 22 nm and beyond p-MOSFETs is required due to disproportionate reduction in device area per generation caused by non-scaled gate length. Relaxation of SiGe with > 35% Ge during epitaxial growth and subsequent processing is a major concern. Specifically low temperature growth is required to achieve meta-stable pseudomorphic SiGe film with high Ge%. Currently, selective SiGe epitaxial film in reduced pressure chemical vapor deposition (RPCVD) epitaxy is grown with conventional Si gas precursors and co-flow etch using HCl at temperatures higher than 625 degrees C. At temperatures lower than 625 degrees C in RPCVD epitaxy, however, HCl has negligible etch capability making selectivity difficult to achieve during epitaxial growth. Hence, cyclic deposit and etch epitaxial growth in conjunction with a low temperature etching chemistry is desirable to achieve selectivity at temperatures lower than 625 degrees C. In this paper, we apply the above concept to achieve selective growth of high strain SiGe (> 35%) at 500 degrees C on test patterns corresponding to 65 nm node. SiGe is grown non-selectively first at 500 degrees C with high order of silane as Si source, and Germane as Ge source followed by an etching chemistry also at 500 degrees C to achieve selectivity. In addition, the growth rate of SiGe epitaxial film and the Ge concentration in the deposited epitaxial film were studied as a function of Si precursor flow; the effect of HCl introduction on Ge concentration and film growth rate was discussed. (C) 2011 Elsevier B.V. All rights reserved.
@article{ ISI:000301710800010,
Author = {He, Hong and Brabant, Paul and Chung, Keith and Shinriki, Manabu and
   Adam, Thomas and Reznicek, Alexander and Sadana, Devendra and Hasaka,
   Satoshi and Francis, Terry},
Title = {{High strain embedded-SiGe via low temperature reduced pressure chemical
   vapor deposition}},
Journal = {{THIN SOLID FILMS}},
Year = {{2012}},
Volume = {{520}},
Number = {{8}},
Pages = {{3175-3178}},
Month = {{FEB 1}},
Note = {{ICSI-7 Conference, Leuven, BELGIUM, AUG 29-SEP 01, 2011}},
Abstract = {{Performance improvement of strained p-type metal oxide semiconductor
   field effect transistors (p-MOSFETs) via embedded SiGe (e-SiGe) is well
   established. Strain scaling of p-MOSFETs since 90 nm complementary metal
   oxide semiconductor node has been accomplished by increasing Ge content
   in e-SiGe from nominally <20\% in 90 nm p-MOSFETs to > 35\% Ge in 32 nm
   p-MOSFETs. Further strain enhancement for 22 nm and beyond p-MOSFETs is
   required due to disproportionate reduction in device area per generation
   caused by non-scaled gate length. Relaxation of SiGe with > 35\% Ge
   during epitaxial growth and subsequent processing is a major concern.
   Specifically low temperature growth is required to achieve meta-stable
   pseudomorphic SiGe film with high Ge\%. Currently, selective SiGe
   epitaxial film in reduced pressure chemical vapor deposition (RPCVD)
   epitaxy is grown with conventional Si gas precursors and co-flow etch
   using HCl at temperatures higher than 625 degrees C. At temperatures
   lower than 625 degrees C in RPCVD epitaxy, however, HCl has negligible
   etch capability making selectivity difficult to achieve during epitaxial
   growth. Hence, cyclic deposit and etch epitaxial growth in conjunction
   with a low temperature etching chemistry is desirable to achieve
   selectivity at temperatures lower than 625 degrees C. In this paper, we
   apply the above concept to achieve selective growth of high strain SiGe
   (> 35\%) at 500 degrees C on test patterns corresponding to 65 nm node.
   SiGe is grown non-selectively first at 500 degrees C with high order of
   silane as Si source, and Germane as Ge source followed by an etching
   chemistry also at 500 degrees C to achieve selectivity. In addition, the
   growth rate of SiGe epitaxial film and the Ge concentration in the
   deposited epitaxial film were studied as a function of Si precursor
   flow; the effect of HCl introduction on Ge concentration and film growth
   rate was discussed. (C) 2011 Elsevier B.V. All rights reserved.}},
DOI = {{10.1016/j.tsf.2011.10.082}},
ISSN = {{0040-6090}},
Unique-ID = {{ISI:000301710800010}},
}

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