Author(s): Huang, A (Huang, An); Ma, YX (Ma, Yuan Xiao); Li, JC (Li, Jia Cheng); Dai, D (Dai, De); Yang, HX (Yang, Hui Xia); Liu, ZC (Liu, Zi Chun); Zhang, DC (Zhang, De Cheng); Yang, H (Yang, Han); Huang, Y (Huang, Yuan); Zhang, YY (Zhang, Yi Yun); Li, XR (Li, Xiao Ran); Wang, YL (Wang, Ye Liang); Lai, PT (Lai, Pui To)

Source: SEMICONDUCTOR SCIENCE AND TECHNOLOGY Volume: 38  Issue: 11 Article Number: 115003  DOI: 10.1088/1361-6641/acf784  Published: NOV 1 2023 

Abstract: In this work, room-temperature-processed amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) have been fabricated with high-k HfLaO as gate dielectric for synaptic devices. By raising the indium content in the a-IGZO film via co-sputtering and treating the HfLaO gate dielectric in an Ar plasma, the TFT with In1.0Ga3.0Zn0.4O2.1 presents excellent electrical characteristics: a high intrinsic carrier mobility of 45.8 cm(2) V-1<middle dot>s(-1), a small threshold voltage of 1.93 V, a small hysteresis of -0.015 V, and a small subthreshold swing (SS) of 0.21 V dec(-1). Although the oxygen vacancies in the In1.0Ga3.0Zn0.4O2.1 TFT are increased to produce a high carrier mobility, memristive behaviors are hardly observed under zero gate bias due to their occupied states. Various conductance modulations and synaptic plasticities are achieved under a 2-V drain spiking voltage and a small gate bias of 1 V due to migration of oxygen ions and emptying/detrapping of oxygen vacancies in the In1.0Ga3.0Zn0.4O2.1 film, resulting in a concurrent emulation of neurotransmitter and neuromodulator through exploiting the native three-terminal structure of the TFT.

Accession Number: WOS:001144997500001

ISSN: 0268-1242

eISSN: 1361-6641