Fabrication of Graphene/Zinc Oxide Junction Field Effect Transistor with High On-off Ratio and High Mobility

• Main Authors: Tseng, Po Yuan, 曾柏元
• Other Authors: Tai, Nyan-Hwa
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/90919428678831289348

碩士 === 國立清華大學 === 材料科學工程學系 === 103 === Graphene possesses excellent chemical stability, high carrier mobility, and unique optoelectrical properties at atomic level, which was considered as a promising material to replace Si in semiconductor industry. In this study, the chemical vapor deposition method was adopted to grow monolayer graphene on the electropolished Cu foil, followed by transferring the as-synthesized graphene to zinc oxide film, which was prepared by atomic layer deposition, forming graphene/zinc oxide junction field effect transistor. Graphene growth and transferring were characterized using Raman spectrum, optical microscopy; thickness and absorbance were measured using atomic force microscopy and UV-visable spectrometer, respectively. In other side, zinc oxide deposited at different temperature were also characterized using X-ray diffractometer and photoluminescence spectroscopy, investigating the effect of different growth temperature on zinc oxide. Electrical properties of the fabricated FETs were examined by a multi-probe system and the influences of irradiation of UV on electrical properties were also analyzed. The results indicate that the thickness, absorbance, and hole(electron) mobility of the graphene were 0.4-0.7 nm, 3.35%, and 4638(5470) cm2/V∙s, respectively. The current on-off ratio of hole and electron was 2.91 and 2.12, respectively. Graphene/zinc oxide junction field effect transistor was formed combining with graphene and zinc oxide film, showed high electron mobility of 670 cm2/V∙s and high current on-off ratio of 2.87 × 105.