SIMULATION OF ZINCBLENDE GALLIUM NITRIDE HIGH ELECTRON MOBILITY TRANSISTORS FOR NORMALLY-OFF OPERATION

Grady, Ryan

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https://hdl.handle.net/2142/97855 Copy

Description

Title

SIMULATION OF ZINCBLENDE GALLIUM NITRIDE HIGH ELECTRON MOBILITY TRANSISTORS FOR NORMALLY-OFF OPERATION

Author(s)

Grady, Ryan

Contributor(s)

Bayram, Can

Issue Date

2017-05

Keyword(s)

• cubic
• zincblende
• AlGaN, high electron mobility transitor
• technology computer aided design
• breakdown voltage
• on-state resistance

Abstract

For high-power, high-frequency applications, silicon is being pushed to its physical limits. In order to meet demand for devices in this area, new material systems need to be considered. Gallium nitride (GaN) and related alloys including aluminum gallium nitride (AlGaN) are highly suited to these applications, but are yet to mature. The leading issue in the design of GaN high electron mobility transistors (HEMTs) is ensuring normally-off behavior. Here we present a new method for creating normally-off GaN HEMTs: the use of polarization-free zincblende (ZB-) GaN. In order to create the conductive two-dimension electron gas (2DEG) channel, carriers are introduced through δ –doping of the AlGaN layer. With the use of Sentaurus Technology Computer Aided Design (TCAD), we are able to show a working design for ZB-GaN HEMTs and give guidelines to ensure normally-off behavior. This includes tuning the aluminum mole fraction, gate metal work function, δ-doping density, and AlGaN layer thicknesses. It is found that aluminum content less than 35% and δ-doping below 4 x 1012 cm-2 result in normally-off behavior. We are able to demonstrate turn-on voltages (VT) greater than 1 V, and 2DEG sheet density exceeding 1013 cm-2. Additionally, the breakdown voltage (VBR) and on-state resistance is provided to characterize an optimized device.

Type of Resource

text

Language

en

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http://hdl.handle.net/2142/97855

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