Demonstration of radio-frequency response of amorphous IGZO thin film transistors on the glass substrate

• Published in: Solid-state electronics 2015-02, Vol.104, p.122-125
• Main Authors: Su, Liang-Yu, Huang, JianJang
• Format: Article
• Language: English
• Subjects: Amorphous InGaZnO; Channels; Density; Devices; Gates; Glass; Radio frequencies; Radio frequency; Radio frequency identification; Semiconductor devices; Thin film transistors
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/j.sse.2014.10.007

•The radio frequency response of an In–Ga–Zn–O thin film transistor is demonstrated.•The device shows a current gain cutoff frequency fT of 384MHz and a maximum frequency of oscillation fmax of 1.06GHz.•A small signal circuit model for the radio frequency response is also shown. The relatively high-mobility metal-oxide thin-film transistors (TFTs) have the potential to realize radio-frequency (RF) circuits operating in the megahertz regime. Here, we investigate the RF performance of amorphous indium gallium zinc oxide (a-IGZO) TFTs on the glass substrate with the sputtered channel layer. The device exhibits a high current density of 22.6mA/mm by employing thin bi-layer Al2O3/SiO2 gate dielectrics. The 1.5μm gate length device achieves a current gain cutoff frequency fT of 384MHz and a maximum frequency of oscillation fmax of 1.06GHz. The record high RF response among the amorphous oxide channels makes it possible to explore new large-area electronics applications, such as low-cost radio frequency identification (RFID) tags. Furthermore, the corresponding small signal parameters were extracted and the voltage dependences of RF response were studied.