A combinatorial device analysis method of oxide thin-film transistors

Defects at the interface as well as in the bulk of semiconductor of oxide thin film transistor are the major concern for the successful development of oxide thin-film devices since it governs initial transistor performance and reliability characteristics such as hysteresis and stress induced Vth shift. Once the oxide semiconductor is integrated in the device structures, the quality of oxide semiconductor and surrounding media could only be characterized by seeming information such as drive current, mobility, sub-threshold slope and hysteresis. Here we present a combinatorial device analysis method using pulsed I-V, transient I-V and low frequency noise measurement methods to assess the quality of oxide device. In this presentation, we will deal with various oxide thin-film transistors such as HfInZnO (HIZO) device with metal cation contents, HIZO-IZO bi-layer device and HIZO device with gate insulator quality. Via pulsed I-V measurement method, we found that conventional DC measurement method significantly underestimate the performance of oxide devices. Using a short pulse I-V analysis, the trapping time constants were identified. The charge trapping phenomena were verified by low frequency noise measurements. This combinatorial method can be an effective way to improve reliability characteristics of oxide devices as it provides an accurate and quantitative way to assess the quality of device.