Suspended Diamond-Shaped Nanowire with Four {111} Facets for High-Performance Ge Gate-All-Around FETs

Fu Ju Hou, Po Jung Sung, Fu Kuo Hsueh, Chien Ting Wu, Yao Jen Lee*, Yi-Ming Li, Seiji Samukawa, Tuo-Hung Hou

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


A feasible pathway to scale germanium (Ge) FETs in future technology nodes has been proposed using the tunable diamond-shaped Ge nanowire (NW). The Ge NW was obtained through a simple top-down dry etching and blanket Ge epitaxy techniques readily available in mass production. The different etching selectivity of surface orientations for Cl2 and HBr was employed for the three-step isotropic/anisotropic/isotropic dry etching. The ratio of Cl2 and HBr, mask width, and Ge recess depth were crucial for forming the nearly defect-free suspended Ge channel through effective removal of dislocations near the Si/Ge interface. This technique could also be applied for forming diamond-shaped Si NWs. The suspended diamond-shaped NW gate-all-around NWFETs feature excellent electrostatics, the favorable {111} surfaces along the {110} direction with high carrier mobility, and the nearly defect-free Ge channel. The pFET with a high ION/IOFF ratio of 6 × 107 and promising nFET performance have been demonstrated successfully.

Original languageEnglish
Article number7542120
Pages (from-to)3837-3843
Number of pages7
JournalIEEE Transactions on Electron Devices
Issue number10
StatePublished - 1 Oct 2016


  • gate-all-around (GAA)
  • germanium (Ge)
  • isotropic/anisotropic etching
  • nanowire (NW)
  • {111}


Dive into the research topics of 'Suspended Diamond-Shaped Nanowire with Four {111} Facets for High-Performance Ge Gate-All-Around FETs'. Together they form a unique fingerprint.

Cite this