Single-fabrication-step Ge nanosphere/SiO2/SiGe heterostructures: A key enabler for realizing Ge MOS devices

P. H. Liao, K. P. Peng, Horng-Chih Lin, T. George, Pei-Wen Li

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


We report channel and strain engineering of self-organized, gate-stacking heterostructures comprising Ge-nanosphere gate/SiO2/SiGe-channels. An exquisitely-controlled dynamic balance between the concentrations of oxygen, Si, and Ge interstitials was effectively exploited to simultaneously create these heterostructures in a single oxidation step. Process-controlled tunability of the channel length (5-95 nm diameters for the Ge-nanospheres), gate oxide thickness (2.5-4.8 nm), as well as crystal orientation, chemical composition and strain engineering of the SiGe-channel was achieved. Single-crystalline (100) Si1-xGex shells with Ge content as high as ×= 0.85 and with a compressive strain of 3%, as well as (110) Si1-xGex shells with Ge content of x = 0.35 and corresponding compressive strain of 1.5% were achieved. For each crystal orientation, our high Ge-content, highly-stressed SiGe shells feature a high degree of crystallinity and thus, provide a core 'building block' required for the fabrication of Ge-based MOS devices.

Original languageEnglish
Article number205601
Issue number20
StatePublished - 19 Mar 2018


  • MOS
  • SiGe
  • channel engineering
  • germanium quantum dot
  • self-organization
  • strain engineering


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