Enhancement of Ru–Si–O/In–Ga–Zn–O MESFET Performance by Reducing Depletion Region Trap Density

Author

Kaczmarski, Jakub ; Grochowski, Jakub ; Kaminska, Eliana ; Taube, Andrzej ; Borysiewicz, Michal A. ; Pagowska, Karolina ; Jung, Wojciech ; Piotrowska, Anna

Author_Institution

Inst. of Microlelectronics & Optoelectron., Warsaw Univ. of Technol., Warsaw, Poland

Volume

36

Issue

5

fYear

2015

fDate

42125

Firstpage

469

Lastpage

471

Abstract

In this letter, we investigated the effect of magnetron cathode current (I_c) during reactive sputtering of In-Ga-Zn-O (a-IGZO) channel layer on properties of metal-semiconductor field-effect transistors with Ru-Si-O Schottky gate electrode. One can observe that as I_c increased from 90 to 150 mA channel mobility (μ_ch) and subthreshold swing (S) improved from μch = 7.5 cm²/V·s and S = 580 V/dec to μch = 8.8 cm²/V ·s and S = 420 V/dec, respectively. This enhancement in transistors performance was attributed to the reduction of charge density in the depletion region of Ru-Si-O/In-Ga-Zn-O Schottky contacts, which we assigned to the densification of a-IGZO films fabricated at higher I_c.

Keywords

Schottky barriers; Schottky gate field effect transistors; gallium compounds; indium compounds; ruthenium compounds; silicon compounds; sputtering; zinc compounds; MESFET performance; Ru-Si-O-In-Ga-Zn-O; Schottky contacts; Schottky gate electrode; a-IGZO channel layer; channel mobility; charge density reduction; depletion region trap density reduction; magnetron cathode current; metal-semiconductor field-effect transistors; subthreshold swing; Cathodes; Films; Integrated circuits; Logic gates; MESFETs; Schottky barriers; MESFET; Ru-Si-O; Schottky barrier; TAOS; a-IGZO; transparent amorphous oxide semiconductors;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2015.2411749

Filename

7060684