A Direct n+-Formation Process by Magnetron Sputtering an Inter-Layer Dielectric for Self-Aligned Coplanar Indium Gallium Zinc Oxide Thin-Film Transistors

Xinlv Duan; Congyan Lu; Xichen Chuai; Qian Chen; Guanhua Yang; Di Geng

doi:10.3390/mi13050652

A Direct n⁺-Formation Process by Magnetron Sputtering an Inter-Layer Dielectric for Self-Aligned Coplanar Indium Gallium Zinc Oxide Thin-Film Transistors

Micromachines (Basel). 2022 Apr 19;13(5):652. doi: 10.3390/mi13050652.

Authors

Xinlv Duan^{1

2}, Congyan Lu¹, Xichen Chuai^{1

2}, Qian Chen^{1

2}, Guanhua Yang¹, Di Geng¹

Affiliations

¹ Key Laboratory of Microelectronics Device and Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.

Abstract

An inter-layer dielectric (ILD) deposition process to simultaneously form the conductive regions of self-aligned (SA) coplanar In-Ga-Zn-O (IGZO) thin-film transistors (TFTs) is demonstrated. N⁺-IGZO regions and excellent ohmic contact can be obtained without additional steps by using a magnetron sputtering process to deposit a SiO_x ILD. The fabricated IGZO TFTs show a subthreshold swing (SS) of 94.16 mV/decade and a linear-region field-effect mobility (μ_FE) of 23.06 cm²/Vs. The channel-width-normalized source/drain series resistance (R_SDW) extracted using the transmission line method (TLM) is approximately as low as 9.4 Ω·cm. The fabricated ring oscillator (RO) with a maximum oscillation frequency of 1.75 MHz also verifies the applicability of the TFTs.

Keywords: IGZO TFT; S/D region; magnetron sputtering inter-layer dielectric; n+-formation; self-aligned coplanar.

Abstract

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