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High performance a‐IGZO thin‐film transistors with mf‐PVD SiO 2 as an etch‐stop‐layer
Author(s) -
Nag Manoj,
Steudel Soeren,
Bhoolokam Ajay,
Chasin Adrian,
Rockele Maarten,
Myny Kris,
Maas Joris,
Fritz Thomas,
Trube Jutta,
Groeseneken Guido,
Heremans Paul
Publication year - 2014
Publication title -
journal of the society for information display
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.578
H-Index - 52
eISSN - 1938-3657
pISSN - 1071-0922
DOI - 10.1002/jsid.212
Subject(s) - materials science , thin film transistor , plasma enhanced chemical vapor deposition , amorphous solid , optoelectronics , threshold voltage , layer (electronics) , chemical vapor deposition , physical vapor deposition , atomic layer deposition , transistor , thin film , composite material , nanotechnology , voltage , electrical engineering , chemistry , crystallography , engineering
In this work, we report on high‐performance bottom‐gate top‐contact (BGTC) amorphous‐Indium‐Gallium‐Zinc‐Oxide (a‐IGZO) thin‐film transistor (TFT) with SiO 2 as an etch‐stop‐layer (ESL) deposited by medium frequency physical vapor deposition (mf‐PVD). The TFTs show field‐effect mobility (μ FE ) of 16.0 cm 2 /(V.s), sub‐threshold slope (SS −1 ) of 0.23 V/decade and off‐currents (I OFF ) < 1.0 pA. The TFTs with mf‐PVD SiO 2 ESL deposited at room temperature were compared with TFTs made with the conventional plasma‐enhanced chemical vapor deposition (PECVD) SiO 2 ESL deposited at 300 °C and at 200 °C. The TFTs with different ESLs showed a comparable performance regarding μ FE , SS −1 , and I OFF , however, significant differences were measured in gate bias‐stress stability when stressed under a gate field of +/−1 MV/cm for duration of 10 4 s. The TFTs with mf‐PVD SiO 2 ESL showed lower threshold‐voltage (V TH ) shifts compared with TFTs with 300 °C PECVD SiO 2 ESL and TFTs with 200 °C PECVD SiO 2 ESL. We associate the improved bias‐stress stability of the mf‐PVD SiO 2 ESL TFTs to the low hydrogen content of the mf‐PVD SiO 2 layer, which has been verified by Rutherford‐Back‐Scattering‐Elastic‐Recoil‐Detection technique.