Investigation and Fabrication of Bottom Gate ZnO: Al TTFTs with Various Thicknesses of ZnO Buffer Layers

摘要

An Al doped ZnO (ZnO:Al) transparent thin film transistors (TTFTs) with various thickness of ZnO buffer layer sandwiched between gate insulator and channel layer were deposited by a magnetron radio frequency co-sputter system. When the thickness of the buffer layer was 80 nm, the field-effect carrier mobility of the TTFTs was as high as 122.0 cm~2/V-s. Furthermore, the associated gate voltage swing was 0.24 V/decade, and the maximum state density was 2.69×10~(11) eV~(-1)cm~(-2). The on-to-off current ratio of the TTFTs with 80 nm-thick ZnO buffer layer was up to 5×10~7.