Reduced Contact Resistance Between Metal and n-Ge by Insertion of ZnO with Argon Plasma Treatment

Nanoscale Research Letters

Hao Wu¹  Haihua Zheng¹  Chang Liu¹  Xue Chen¹  Xiao Wang²  Huan Liu²  Yan Liu²  Genquan Han²  Jincheng Zhang²  Yi Zhang²  Yue Hao² 

[1] Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University;State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University;

关键词: Germanium;    Fermi-level pinning;    Ohmic contact;    Argon plasma;    ZnO;   

DOI  :  10.1186/s11671-018-2650-y

来源: DOAJ

【 摘 要 】

Abstract We investigate the metal-insulator-semiconductor contacts on n-Ge utilizing a ZnO interfacial layer (IL) to overcome the Fermi-level pinning (FLP) effect at metal/Ge interface and reduce the barrier height for electrons. A small conduction band offset of 0.22 eV at the interface between ZnO and n-Ge is obtained, and the ZnO IL leads to the significant reduced contact resistance (R c) in metal/ZnO/n-Ge compared to the control device without ZnO, due to the elimination of FLP. It is observed that the argon (Ar) plasma treatment of ZnO can further improve the R c characteristics in Al/ZnO/n-Ge device, which is due to that Ar plasma treatment increases the concentration of oxygen vacancy V o, acting as n-type dopants in ZnO. The ohmic contact is demonstrated in the Al/ZnO/n-Ge with a dopant concentration of 3 × 1016 cm−3 in Ge. On the heavily doped n+-Ge with a phosphor ion (P+) implantation, a specific contact resistivity of 2.86 × 10− 5 Ω cm2 is achieved in Al/ZnO/n+-Ge with Ar plasma treatment.

【 授权许可】

Unknown