Reduced Trap-State Density of Ni-Silicide Seed-Induced Crystallized Poly-Si TFTs by Gettering

Author

Byun, Chang Woo ; Son, Se Wan ; Lee, Yong Woo ; Joo, Seung Ki

Author_Institution

Res. Inst. of Adv. Mater., Seoul Nat. Univ., Seoul, South Korea

Volume

33

Issue

8

fYear

2012

Firstpage

1141

Lastpage

1143

Abstract

Polycrystalline silicon thin-film transistors (TFTs) fabricated by seed-induced crystallization (SIC) have large leakage currents due to defects that consist of Ni impurities. Here, we describe a novel method of gettering to remove Ni impurities using a Si gettering layer that is separated from the active layer by a chemical SiO₂ etch stop interlayer formed by dipping into H₂SO₄. The leakage current, the on/off ratio, and a channel breakdown voltage were greatly improved. These results were explained by lowered trap-state density in the channel.

Keywords

etching; hydrogen compounds; leakage currents; nickel; silicon compounds; thin film transistors; H₂SO₄; Ni-SiO₂; SIC; channel breakdown voltage; etch stop interlayer; gettering layer; leakage currents; on off ratio; polycrystalline silicon thin film transistors; seed induced crystallization; trap state density; Crystallization; Gettering; Nickel; Silicon; Silicon carbide; Thin film transistors; Polycrystalline silicon (poly-Si); silicide seed-induced crystallization (SIC); silicides; thin-film transistors (TFTs);

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2012.2200093

Filename

6230602