title: Enhanced device performance of germanium nanowire junctionless (GeNW-JL) MOSFETs by germanide contact formation with Ar plasma treatment.
abstract: In this study, germanium nanowire junctionless (GeNW-JL) metal-oxide-semiconductor-field-effect-transistors (MOSFETs) exhibited enhanced electrical performance with low source/drain (S/D) contact resistance under the influence of Ar plasma treatment on the contact regions. We found that the transformation of the surface oxide states by Ar plasma treatment affected the S/D contact resistance. With Ar plasma treatment, the germanium dioxide on the GeNW surface was effectively removed and increased oxygen vacancies were formed in the suboxide on the GeNW, whose germanium-enrichment surface was obtained to form a germanide contact at low temperature. After a rapid thermal annealing process, Ni-germanide contacts were formed on the Ar-plasma-treated GeNW surface. Ni-germanide contact resistance was improved by more than an order of magnitude compared to that of the other devices without Ni-germanide contact. Moreover, the peak field effect mobility value of the GeNW-JL MOSFETs was dramatically improved from 15 cm(2)/(V s) to 550 cm(2)/(V s), and the Ion/off ratio was enhanced from 1 × 10 to 3 × 10(3) due to Ar plasma treatment. The Ar plasma treatment process is essential for forming uniform Ni-germanide-contacts with reduced time and low temperature. It is also crucial for increasing mass productivity and lowering the thermal budget without sacrificing the performance of GeNW-JL MOSFETs.
authors.affiliation: Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Young Gwang
authors.initials: YG
authors.lastname: Yoon
authors.forename: Tae Kyun
authors.initials: TK
authors.lastname: Kim
authors.forename: In-Chan
authors.initials: IC
authors.lastname: Hwang
authors.forename: Hyun-Seung
authors.initials: HS
authors.lastname: Lee
authors.forename: Byeong-Woon
authors.initials: BW
authors.lastname: Hwang
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Moon
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Seo
authors.forename: Suk Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Moon-Ho
authors.initials: MH
authors.lastname: Jo
authors.forename: Seok-Hee
authors.initials: SH
authors.lastname: Lee