Al-Ta2O5-GaN Semiconductor Device Structure
| dc.contributor.author | Yeoh, Lai Seng | |
| dc.date.accessioned | 2016-11-21T07:55:40Z | |
| dc.date.available | 2016-11-21T07:55:40Z | |
| dc.date.issued | 2014-08 | |
| dc.description.abstract | GaN-based semiconductor devices have been extensively investigated for used in high power and high temperature device applications in order to replace Si which is no longer capable to fulfill these ever-increasing demands. The characteristics of low leakage current, low oxide charge density, and high oxide capacitance would be necessary for device-quality GaN-based MOS devices. Along this, there is a great interest in development of GaN-based MOS transistors. The foremost work in early 2000s used a thermally oxidized GaN film as the gate dielectric in MOS structure. In late 2000s, GaN-based MOS with other dielectrics such as Al2O3, MgO, Sc2O3, Si3N4, SiO2, and Ta2O5 were developed. In the present work, commercial GaN-on-sapphire wafer was used as the semiconductor. The gate insulator was obtained by depositing selected oxide materials of SiO2, Al2O3, and Ta2O5 onto GaN using RF-sputtering technique. The gate metal was built by evaporating aluminium onto the insulator. The deposited insulators were characterized using AFM, XRD, XRF, SEM, and EDX. On the other hand, C-V, I-V, and Dit measurements were carried out to determine the electrical characteristics of the MOS structures. The fundamental properties of MOS structures with SiO2, Al2O3, and Ta2O5 gate dielectrics were studied and compared. Then, case studies of post-deposition annealing, post-metallization annealing, substrate temperature stress, constant voltage stress, and light radiation stress were investigated on the Al/Ta2O5/GaN MOS structure. The research results revealed that MOS structure with high-k dielectric of Ta2O5 possessed the best performance in term of lower oxide charge density, lower interface trap density, higher storage capacitance, higher dynamic conductivity, stability in high temperature operation, and durability in constant voltage stress. These characteristics were even better than the ones reported in some existing literatures. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/3137 | |
| dc.language.iso | en | en_US |
| dc.publisher | Universiti Sains Malaysia | en_US |
| dc.subject | GaN-based semiconductor devices structure | en_US |
| dc.title | Al-Ta2O5-GaN Semiconductor Device Structure | en_US |
| dc.type | Thesis | en_US |
Files
License bundle
1 - 1 of 1
Loading...
- Name:
- license.txt
- Size:
- 1.71 KB
- Format:
- Item-specific license agreed upon to submission
- Description: