Characteristics of ZnO thin film transistor prepared by two different methods

We succeeded the fabrication of bottom gate ZnO-TFT on thermal oxidized n-type Si substrate with the high-resistivity ZnO active layer which was prepared by two different methods. The first preparation methods was LP-CVD using the fibrous bis(acetylacetonato)-zinc(II) (Zn(C(5)H(7)O(2))(2)) and ozone(O(3)). The second one was RF(13.56 MHz) sputtering using a ceramic oxide target ZnO with a purity of 99.99% and 2 in. diameter. For all the ZnO films prepared by different methods, the ZnO (0001) peak at 20 approximate to 34.4 degrees was mainly observed. The films are polycrystalline with a hexagonal structure and a preferred orientation with the c-axis perpendicular to the substrate. The ZnO-TFT prepared by LP-CVD shows electrical properties with a field effect mobility of 6 cm(2)/V s, an on to off ratio greater than 10(6), the off current of less than 10(-10)A. Zn, O, Si elerment in the interface of ZnO and SiO(2) gate insulator were analyzed by using X-ray photoelectron spectroscopy. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim