Performance improvement in p-Type WS2field-effect transistors with 1T phase contacts

Yafen Yang; Han Li; Zhenghao Gu; Lin Chen; Hao Zhu; Li Ji; Qingqing Sun

doi:10.1088/1361-6528/ac037d

Performance improvement in p-Type WS₂field-effect transistors with 1T phase contacts

Nanotechnology. 2021 Jun 4;32(34). doi: 10.1088/1361-6528/ac037d.

Authors

Yafen Yang¹, Han Li¹, Zhenghao Gu¹, Lin Chen¹, Hao Zhu¹, Li Ji¹, Qingqing Sun¹

Affiliation

¹ State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, People's Republic of China.

PMID: 34015782
DOI: 10.1088/1361-6528/ac037d

Abstract

The non-ideal contact between the metal electrode and semiconducting channel has become one of the major bottlenecks degrading the performance of field-effect transistors (FETs) based on two-dimensional (2D) materials. The formation of the Schottky barrier prohibiting the carrier injection as well as the Fermi level pinning effect have a strong impact on the device performance. In this work, we fabricated a 2D WS₂FET device with engineered metallic 1T phase at the source/drain region by using Li intercalation method. As compared to the device with conventional 2H-WS₂channel, the engineered FET with a 2H-WS₂/1T-WS₂junction has exhibited greatly improved performance such as over 10 times higher carrier mobility and steeper subthreshold slope. Such results have demonstrated the boosted carrier injection into the channel over the engineered metal contact as well as the reduced tunnel barrier width between the 2H/1T-WS₂junction. This can be attractive for the large-scale integration of the 2D devices towards high-performance and high-reproducibility nanoelectronics applications.

Keywords: Li intercalation; Schottky barrier; WS2; hole mobility; n-butyllithium solution.