Combinatorial study of zinc tin oxide thin-film transistors

Groups of thin-film transistors using a zinc tin oxide semiconductor layer have been fabricated via a combinatorial rf sputtering technique. The ZnO:SnO(2) ratio of the film varies as a function of position on the sample, from pure ZnO to SnO(2), allowing for a study of zinc tin oxide transistor performance as a function of channel stoichiometry. The devices were found to have mobilities ranging from 2 to 12 cm(2)/V s, with two peaks in mobility in devices at ZnO fractions of 0.80 +/- 0.03 and 0.25 +/- 0.05, and on/off ratios as high as 10(7). Transistors composed predominantly of SnO(2) were found to exhibit light sensitivity which affected both the on/off ratios and threshold voltages of these devices. (c) 2008 American Institute of Physics.