Role of in-situ hydrogen plasma treatment on gate bias stability and performance of a-IGZO thin-film transistors. (9th July 2021)

• Record Type: Journal Article
• Authors: Prasad, Om Kumar; Mohanty, Srikant Kumar; Wu, Chien Hung; Yu, Tsung Ying; Chang, Kow Ming
• Is Part Of: Nanotechnology. Volume 32:Number 39(2021)
• Publication Date: 2021-07-09
• Subjects: a-IGZO channel TFTs -- in-situ hydrogen plasma treatment -- positive bias stress; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ac0cb0
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: This work investigates the effect of an in situ hydrogen plasma treatment on gate bias stability and performance of amorphous InGaZnO thin-film transistors (TFTs) deposited by using atmospheric-pressure PECVD. The H2 plasma-treated a -IGZO channel has shown significant improvement in bias stress induced instability with a minuscule threshold voltage shift (Δ V th ) of 0.31 and −0.17 V under positive gate bias stress (PBS) and negative gate bias stress (NBS), respectively. With the aid of the energy band diagram, the proposed work demonstrates the formation of negative species O2 − and positive species H2 O + in the backchannel under PBS and NBS in addition to ionized oxygen vacancy (Vo ) defects at a -IGZO/ZrO2 interfaces are the reason for gate bias instability which could be effectively suppressed with in situ H2 plasma treatment. From the experimental result, it is observed that the electrical performance such as field-effect mobility ( μ FE ), on-off current ratio ( I on / I off ), and subthreshold swing improved significantly by in situ H2 plasma treatment with passivation of interface trap density and bulk trap defects.