Low-frequency Noise in GaN HEMTs under UV Illumination

• Main Authors: LIN, HSIN-YI, 林欣儀
• Other Authors: HU, HSIN-HUI
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/cqtfdu

碩士 === 國立臺北科技大學 === 電子工程系 === 107 === Gallium Nitride (GaN) materials are suitable for high frequency and, high power, applications, such as 5G communication and, automotive electronics, because of its high electron mobility, high breakdown voltage, wide energy gap. One of the main problems of GaN-based devices is the charge trapping dispersion effect, which will reduce their reliability. To solve these problems, the location and property of traps in GaN high electron mobility transistors (HEMTs) have to be examined. Low-frequency noise measurement is a good diagnosis tool for device quality and reliability. Since the GaN material is very sensitive to the ultraviolet (UV) light, it is easier to detect the trap location and type using the low-frequency noise measurement, with when the GaN-based device is illuminated with the UV light. This thesis investigate the low-frequency noise characteristics of AlGaN/GaN HEMTs and Metal-Insulator-Semiconductor HEMTs (MIS-HEMTs) in the dark and under UV illumination. The physical mechanisms of the low-frequency noise variation with the UV light are discussed for these two devices. According to the experimental analysis, the noise properties of AlGaN/GaN HEMTs and MIS-HEMTs can be explained by the number fluctuation model. It is found that the noise source of HEMTs comes from the AlGaN barrier layer and the GaN buffer layer, and the MIS-HEMTs comes from the SiN gate dielectric.