Electrical Noise and Charge Transport Studies of AlGaN/GaN High Electron Mobility Transistors

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Material Information

Title:
Electrical Noise and Charge Transport Studies of AlGaN/GaN High Electron Mobility Transistors
Physical Description:
1 online resource (116 p.)
Language:
english
Creator:
Xu, Weikai
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Electrical and Computer Engineering
Committee Chair:
BOSMAN,GIJSBERTUS
Committee Co-Chair:
LAW,MARK E
Committee Members:
NISHIDA,TOSHIKAZU
JONES,KEVIN S

Subjects

Subjects / Keywords:
gan -- hemt -- leakage-path -- lorentzian -- noise -- reliability -- space-charge-limited -- stress -- temperature -- thermionic-emission -- traps
Electrical and Computer Engineering -- Dissertations, Academic -- UF
Genre:
Electrical and Computer Engineering thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
AlGaN/GaN HEMTs have shown great performance in high frequency and high power applications. However, since the fabrication process of GaN devices is developed in recent years, it is not as mature as the silicon technology. Device reliability is one of the major issues that limit AlGaN/GaN HEMTs reaching their potential. In this work, unstressed and stressed AlGaN/GaN HEMTs are studied through I-V characteristics and low frequency noise measurements. Both the channel and the gate stack were examined to reveal the origins for device failure. Through noise measurement of channel, traps are found at AlGaN-GaN interface. A drain noise model is established to extract noise information of the gated part of the channel. For unstressed device the Hooge mobility fluctuation model dominates the noise mechanism, while the carrier number fluctuation model fits with the data of stressed devices. Hooge parameters and trap density are extracted for the channel part. For the gate stack, room temperature gate leakage current is measured and interpreted with a space charge limited current flow model. The gate leakage current is attributed to very small area conductive gate leakage paths. The effective area of the leakage paths and related trap densities are calculated from the measured gate I-V characteristics. The trap density has no obvious change after stress, and the significant increase of gate current after stress is due to an expansion of the gate leakage path towards the gate edge. High temperature gate leakage current is also measured and interpreted with two mechanisms, space charge limited current flow through small area leakage paths and thermionic emission current through the whole gate area. The Schottky barrier height is extracted through the analysis of gate current. Finally, the gate noise is measured and 1/f noise, RTS noise and Lorentzian generation recombination noise components are studied. The gate noise parameter is calculated. Single traps, which affect the space charge limited current flow, are identified through the analysis of Lorentzian components de-embedded from the noise spectra.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Weikai Xu.
Thesis:
Thesis (Ph.D.)--University of Florida, 2014.
Local:
Adviser: BOSMAN,GIJSBERTUS.
Local:
Co-adviser: LAW,MARK E.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-05-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2014
System ID:
UFE0046499:00001