The fabrication and study of zinc oxide nanowire transistor

• Main Authors: Wan-Zhen Jen, 任婉貞
• Other Authors: Chau-Nan Hong
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/27421382546309477020

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 95 === In our study, n-type ZnO (zinc oxide) nanowire transistor has been developed in five methods. In the method 1, AZO (aluminum doped zinc oxide) or IZO (indium doped zinc oxide) source and drain electrodes were defined by photolithography, ZnO nanowires were grown between two electrodes by hydrothermal method. For AZO experiment, the best parameter in our experiment is the concentration of HMTA and zinc acetate is 0.01M. In IZO experiment, on/off current ratio increased with decreased the thickness of IZO electrode. And on/off ratio is more distinct with depositing ZnO thin film in the side wall of IZO electrodes. In the method 2, nanowires were manipulated between source and drain using dielectrophoresis (DEP) and then both of nanowires and electrodes were transferred to another substrate. When the press force was 10kg during transferring, on/off current ratio was 200, carrier mobility was 6.15 cm2V-1s-1, VTH was about -3.34V and transconductance was 5.18μS. In the method 3, nanowires were manipulated between source and drain using DEP, and then the polymer layer was deposited by spin-coating. We discussed the characteristics of nanowire transistor by using different polymer and vacuuming or not after spin-coating. By using epoxy and then vacuuming, on/off current ratio was 625, carrier mobility was 814 cm2V-1s-1, VTH was about -7.21V and transconductance was 1.57mS. In the method 4, nanowires were manipulated between source and drain using DEP, and then nanowires were pressed in different force under high temperature (180oC) in order to reduce contact electric resistance between nanowire and electrode. When pressing force was too much, nanowires embed in metal. But there was leakage current between drain and gate. Method 5 was combining method 3 and method 4. Nanowires were manipulated between source and drain using DEP, and then nanowires were pressed in different force under high temperature. Finally, the polymer layer was deposited by spin-coating. When the electrodes was Al and pressing force was 100kg, there was ohmic contact between nanowire and electrode and drain current was saturated when drain voltage increased. The on/off current ratio was 100, carrier mobility was 1000 cm2V-1s-1, VTH was about -0.7V and transconductance was 0.164mS.