Wafer-Scale Synthesis of WS2 Films with In Situ Controllable p-Type Doping by Atomic Layer Deposition

Date
2021-12-06
Authors
Yang, Hanjie
Wang, Yang
Zou, Xingli
Bai, Rongxu
Wu, Zecheng
Han, Sheng
Chen, Tao
Hu, Shen
Zhu, Hao
Chen, Lin
Journal Title
Journal ISSN
Volume Title
Publisher
American Association for the Advancement of Science
Abstract

Wafer-scale synthesis of p-type TMD films is critical for its commercialization in next-generation electro/optoelectronics. In this work, wafer-scale intrinsic n-type WS2 films and in situ Nb-doped p-type WS2 films were synthesized through atomic layer deposition (ALD) on 8-inch α-Al2O3/Si wafers, 2-inch sapphire, and 1 cm2 GaN substrate pieces. The Nb doping concentration was precisely controlled by altering cycle number of Nb precursor and activated by postannealing. WS2 n-FETs and Nb-doped p-FETs with different Nb concentrations have been fabricated using CMOS-compatible processes. X-ray photoelectron spectroscopy, Raman spectroscopy, and Hall measurements confirmed the effective substitutional doping with Nb. The on/off ratio and electron mobility of WS2 n-FET are as high as 105 and 6.85 cm2 V-1 s-1, respectively. In WS2 p-FET with 15-cycle Nb doping, the on/off ratio and hole mobility are 10 and 0.016 cm2 V-1 s-1, respectively. The p-n structure based on n- and p- type WS2 films was proved with a 104 rectifying ratio. The realization of controllable in situ Nb-doped WS2 films paved a way for fabricating wafer-scale complementary WS2 FETs.

Description
Citation
Hanjie Yang, Yang Wang, Xingli Zou, Rongxu Bai, Zecheng Wu, Sheng Han, Tao Chen, Shen Hu, Hao Zhu, Lin Chen, et al. Wafer-Scale Synthesis of WS2 Films with In Situ Controllable p-Type Doping by Atomic Layer Deposition. Research. 2021;2021:DOI:10.34133/2021/9862483