transport in two-dimensional GaN electron systems
Date Issued
2007
Date
2007
Author(s)
Huang, Jian-Zhe
DOI
en-US
Abstract
Abstract
This thesis describes the measurements on the low-temperature electron transport properties in a two-dimensional GaN electron system. This thesis consists of the following two parts:
1. Electron-electron interaction in a perpendicular magnetic field:
We report on experimental studies of Al0.15Ga0.85N/GaN high electron mobility transistor (HEMT) structures grown on p-type Si (111) substrates. By introducing an ultra thin SiN layer during the crystal growth, the Hall mobility of the HEMT structure can be greatly enhanced (>3 times). This SiN treatment technique also allows the observation of Shubnikov-de Haas oscillations which is not possible in the untreated HEMT structure. Our experimental results pave way to integration of AlxGa1-xN/GaN HEMT structures with the mature Si technology in industry.
2. Weak localization effect in a perpendicular magnetic field:
We can illustrate weak localization by the constructive interference of wave functions which back to the origin after transmitting along time-reversed paths. Electrons will be localized by weal localization. The dephasing time , which determines the time scale kept the constructive interference of wave functions, limits the length of the time-reversed paths. It is known that weak localization causes a negative magnetoresistivity.
This thesis describes the measurements on the low-temperature electron transport properties in a two-dimensional GaN electron system. This thesis consists of the following two parts:
1. Electron-electron interaction in a perpendicular magnetic field:
We report on experimental studies of Al0.15Ga0.85N/GaN high electron mobility transistor (HEMT) structures grown on p-type Si (111) substrates. By introducing an ultra thin SiN layer during the crystal growth, the Hall mobility of the HEMT structure can be greatly enhanced (>3 times). This SiN treatment technique also allows the observation of Shubnikov-de Haas oscillations which is not possible in the untreated HEMT structure. Our experimental results pave way to integration of AlxGa1-xN/GaN HEMT structures with the mature Si technology in industry.
2. Weak localization effect in a perpendicular magnetic field:
We can illustrate weak localization by the constructive interference of wave functions which back to the origin after transmitting along time-reversed paths. Electrons will be localized by weal localization. The dephasing time , which determines the time scale kept the constructive interference of wave functions, limits the length of the time-reversed paths. It is known that weak localization causes a negative magnetoresistivity.
Subjects
二維電子
氮化鎵
2DES
GaN
Type
thesis