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Diamond-shaped Ge and Ge0.9Si0.1 gate-all-around nanowire FETs with four {111} facets by dry etch technology

MetadataDetails
Publication Date2015-12-01
AuthorsYao‐Jen Lee, Fu-Ju Hou, Shang-Shiun Chuang, Fu-Kuo Hsueh, Kuo-Hsing Kao
InstitutionsNational Cheng Kung University, National Yang Ming Chiao Tung University
Citations22

We propose a feasible pathway to scale the Ge MOSFET technology by using a novel diamond-shaped Ge and Ge <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;09&lt;/sub> Si <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;01&lt;/sub> gate-all-around (GAA) nanowire (NW) FETs with four {111} facets. The device fabrication requires only simple top-down dry etching and blanket Ge epitaxy techniques readily available in mass production. The proposed dry etching process involves three isotropic/anisotropic etching steps with different Cl <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/sub> /HBr ratios for forming the suspended diamond-shaped channel. Taking advantages of the GAA configuration, favorable carrier mobility of the {111} surface, nearly defect-free suspended channel, and improved dopant activation by incorporating Si, nFET and pFET with excellent performance have been demonstrated, including an I <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;on&lt;/sub> /I <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;off&lt;/sub> ratio exceeding 10 <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;8&lt;/sup> , the highest ever reported for Ge-based pFETs.

  1. 2012 - Triangular-channel Ge NFETs on Si with (111) Sidewall-Enhanced Ion and Nearly Defect-free Channels
  2. 2011 - Nearly Defect-free Ge Gate-All-Around FETs on Si Substrates
  3. 2009 - CMOS Compatible Ge/Si Core/Shell Nanowire Gate-All-Around pMOSFET Integrated with HfO2/TaN Gate Stack