In this thesis, we use the novel film-profile engineered (FPE) TFTs structure to fabricate and demonstrate high-performance ZnO unipolar inverters. The ZnO FPE inverters with submicron channel lengths only need four masks and show a high voltage gain of 120 at VDD=15V. Besides, we also explore the root causes of hysteresis mechanism which is related to the use of gate dielectrics. We also explore the AC characteristics of FPE inverters. Based on the measurement result, trade-off between DC and AC characteristics is identified a crucial factor for circuit application. Through analysis and experiment, we proposed a solution which is able to enhance both AC and DC characteristics.