Effect of Bulk-Accumulation on Switching Speed of Dual-Gate a-IGZO TFT-Based Circuits

The effect of bulk accumulation on switching speed of dual-gate amorphous indium-gallium-zinc-oxide thin-film transistor (TFT)-based circuits is investigated. Given that bulk accumulation is achieved by synchronized driving of the top gate (TG) and bottom gate, it can be modulated by varying the len...

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Bibliographic Details
Published inIEEE electron device letters Vol. 35; no. 12; pp. 1242 - 1244
Main Authors Xiuling Li, Di Geng, Mativenga, Mallory, Yuanfeng Chen, Jin Jang
Format Journal Article
LanguageEnglish
Published IEEE 01.12.2014
Subjects
a-IGZO TFTs
Capacitance
dual-gate
Electrodes
Indium gallium zinc oxide
Ring oscillators
ring-oscillator
Switching circuits
Thin film transistors
a-IGZO TFTs
ring-oscillator
dual-gate
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Summary:The effect of bulk accumulation on switching speed of dual-gate amorphous indium-gallium-zinc-oxide thin-film transistor (TFT)-based circuits is investigated. Given that bulk accumulation is achieved by synchronized driving of the top gate (TG) and bottom gate, it can be modulated by varying the length of the TG (L TG ) for fixed source-drain distance (L). It is confirmed from fabricated ring oscillators that switching speed increases with increasing L TG for fixed L, verifying that bulk accumulation improves switching speed. However, switching speed drops dramatically when the TG overlaps the source/drain electrodes due to additional parasitic capacitance. TFT-circuits with the longest, but nonoverlapping TGs are demonstrated to exhibit the fastest switching speed; operation frequency exceeding 2.63 MHz for input voltage V DD of 20 V, which is also the fastest among all inverted staggered amorphous-oxide-semiconductor TFT-based circuits.
ISSN:0741-3106
1558-0563
DOI:10.1109/LED.2014.2362992