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24.5: Back‐Channel‐Etched a‐IGZO TFTs with TiO 2 :Nb Protective Layer
Author(s) -
Zhang Letao,
Zhou Xiaoliang,
Shao Yang,
Zhang Shengdong
Publication year - 2018
Publication title -
sid symposium digest of technical papers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.351
H-Index - 44
eISSN - 2168-0159
pISSN - 0097-966X
DOI - 10.1002/sdtp.12697
Subject(s) - passivation , materials science , optoelectronics , layer (electronics) , annealing (glass) , fabrication , x ray photoelectron spectroscopy , electrical conductor , electrode , insulator (electricity) , nanotechnology , composite material , chemical engineering , chemistry , medicine , alternative medicine , pathology , engineering
A back‐channel‐etched (BCE) process for the fabrication of a‐IGZO TFTs is demonstrated, in which conductive TiO 2 :Nb (TNO) thin film is used to serve as protective layer for the a‐IGZO active layer. TNO film could excellently protect a‐IGZO due to its ultra‐small surface roughness. With treatment by N 2 O plasma + 200°C annealing, the conductive TNO can be converted into an insulator to serve as an in situ passivation layer. Besides, the TNO in the source—drain (S‐D) region remain conductive due to the protection of S‐D electrodes, which could be proved by the XPS results. Compare with the conventional device without TNO protective layer, the S‐D parasitic resistance (R SD ) of devices with 1 nm and 5 nm TNO is significantly reduced. The positive bias stress stability is improved as well for the devices with TNO in situ passivation layer.