Gate-bias dependent phonon softening observed in Ge MOSFETs

Shoichi Kabuyanagi, Tomonori Nishimura, Takeaki Yajima, Akira Toriumi

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We investigate impacts of free carriers on phonon frequency of zone-center optical phonon in Germanium (Ge). By taking advantage of Ge-on-insulator structure, Raman measurement with applying the back-gate bias was performed. The phonon softening was clearly observed by increasing hole density. It is also pointed out that the phonon softening in heavily-doped Ge is mainly attributed to the free carrier effect rather than dopant atom one. Furthermore, we show that the free carrier effect on phonon softening can be simply and reasonably interpreted from the view point of modification of the covalent bonding by free carriers.

Original languageEnglish
Title of host publicationULSI Process Integration 9
EditorsC. Claeys, J. Murota, M. Tao, H. Iwai, S. Deleonibus
PublisherElectrochemical Society Inc.
Number of pages6
ISBN (Electronic)9781607685395
Publication statusPublished - 2015
Externally publishedYes
EventSymposium on ULSI Process Integration 9 - 228th ECS Meeting - Phoenix, United States
Duration: Oct 11 2015Oct 15 2015

Publication series

NameECS Transactions
ISSN (Print)1938-6737
ISSN (Electronic)1938-5862


OtherSymposium on ULSI Process Integration 9 - 228th ECS Meeting
Country/TerritoryUnited States

All Science Journal Classification (ASJC) codes

  • Engineering(all)


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