Substitution of Paraelectric for Conventional Dielectric in AlGaN/GaN MISFETs

Author

Kong, Yuechan ; Xue, Fangshi ; Zhou, Jianjun ; Li, Liang ; Chen, Chen ; Li, Yanrong

Author_Institution

Nat. Key Lab. of Sci. & Technol. on Monolithic Integrated Circuits & Modules, Nanjing Electron. Devices Inst., Nanjing, China

Volume

31

Issue

2

fYear

2010

Firstpage

93

Lastpage

95

Abstract

A ferroelectric material of paraelectric state is proposed as a substitute for the conventional dielectric in AlGaN/GaN metal-insulator-semiconductor field-effect transistors (MISFETs). Owing to its switchable polarization, the maximum transconductance of a barium strontium titanate (BST)/AlGaN/GaN metal-paraelectric-semiconductor FET (MPSFET) is significantly improved by 44% as compared to a conventional SiN/AlGaN/GaN MISFET. The pinchoff voltage is greatly reduced from -10.7 V for the MISFET to -4.7 V for the MPSFET, accompanied with a distinct improvement in the pinchoff characteristics and suppression of soft pinchoff. Small-signal measurements result a comparable frequency performance of the FETs with BST and SiN gate dielectrics. Based on a self-consistent calculation, the switchable polar nature of the paraelectric is revealed to be essential for improving the device transconductance.

Keywords

MISFET; aluminium compounds; barium compounds; ferroelectric materials; silicon compounds; strontium compounds; wide band gap semiconductors; AlGaN-GaN; BST; MISFET; SiN-AlGaN-GaN; device transconductance; ferroelectric material; gate dielectrics; metal-insulator-semiconductor field-effect transistors; metal-paraelectric-semiconductor FET; pinchoff voltage; small-signal measurements; voltage -10.7 V; voltage -4.7 V; Dielectric materials; metal–insulator–semiconductor (MIS) devices; paraelectrics; switchable polarization;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2009.2036136

Filename

5352223