Atomic layer germanium etching for 3D Fin-FET using chlorine neutral beam

Daisuke Ohori, Takuya Fujii, Shuichi Noda, Wataru Mizubayashi, Kazuhiko Endo, En Tzu Lee, Yiming Li, Yao Jen Lee, Takuya Ozaki, Seiji Samukawa

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


In case of using pure chlorine chemistry, Ge etching reactivity is three times higher than Si etching reactivity because of the larger lattice spacing in Ge. As a result, during the chlorine plasma etching of a Ge Fin structure, there are serious problems such as a large side-etching and large surface roughness on the Ge sidewall. Conversely, the authors found that several-ten nanometer-width Ge Fin structures with defect-free, vertical, and smooth sidewalls were successively delineated by chlorine neutral beam etching. Based on these results, the problems caused by chlorine plasma etching are considered to be due to the enhancement of chemical reactivity caused by defect on the sidewall with the irradiation of ultraviolet/vacuum ultra violet (UV/VUV) photons. Namely, it is clarified that the neutral beam etching could achieve real atomic layer etching by controlling the defect without any UV/VUV photons on the sidewall surface for future nanoscale Ge Fin structures.

Original languageEnglish
Article number021003
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Issue number2
Publication statusPublished - 2019 Mar 1

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films


Dive into the research topics of 'Atomic layer germanium etching for 3D Fin-FET using chlorine neutral beam'. Together they form a unique fingerprint.

Cite this