The Effect of the Active Layer Thickness on the Negative Bias Stress-Induced Instability in Amorphous InGaZnO Thin-Film Transistors

Author

Dongsik Kong ; Hyun-Kwang Jung ; Yongsik Kim ; Minkyung Bae ; Yong Woo Jeon ; Sungchul Kim ; Dong Myong Kim ; Dae Hwan Kim

Author_Institution

Sch. of Electr. Eng., Kookmin Univ., Seoul, South Korea

Volume

32

Issue

10

fYear

2011

Firstpage

1388

Lastpage

1390

Abstract

The effect of the active layer thickness (T_IGZO) on the negative bias stress (NBS)-induced threshold voltage shift (ΔVT) in amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) is investigated and explained by using a subgap density-of-states (DOS) model. The NBS-induced negative ΔVT in a-IGZO TFT with a thinner T_IGZO is larger than that with a thicker T_IGZO. Based on the simulation result with the subgap DOS model, it is concluded that the T_IGZO-dependent ΔVT is originated from the accelerated creation of shallow donor states due to a higher surface electric field in a-IGZO TFTs with a thinner T_IGZO.

Keywords

III-V semiconductors; gallium compounds; indium compounds; thin film transistors; wide band gap semiconductors; zinc compounds; InGaZnO; active layer thickness; amorphous thin-film transistors; induced threshold voltage shift; negative bias stress-induced instability; shallow donor states; subgap density-of-states model; surface electric field; Hysteresis; Lighting; Logic gates; NIST; Stress; Thin film transistors; Active layer thickness; amorphous InGaZnO (a-IGZO) TFTs; density-of-states (DOS); negative bias stress (NBS)-induced instability;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2011.2161746

Filename

6012505