A High Voltage Gain Inverter Integrated With Enhancement- and Depletion-Mode a-InGaZnO Thin-Film Transistors

In this article, amorphous indium-galliumzinc oxide (a-IGZO) inverter integrated with enhancementmode (E-mode) and depletion-mode (D-mode) thin-film transistors (TFTs) with the record high voltage gain of 372 V/V is demonstrated. The D-mode a-IGZO TFTs are realized by local hydrogen plasma treatment, which induces hydrogen doping in the a-IGZO film. The X-ray photoelectron spectroscopy (XPS) measurements prove that the hydrogen doping process increases the oxygen vacancies and free electron concentration in the a-IGZO. Therefore, the doped-hydrogen causes a negative shift in threshold voltage (V-th) and improves the field effect mobility (mu(FE)). After carefully optimizing the process of hydrogen plasma treatment, the inverter with a D-mode load is fabricated. The proposed inverter shows excellent performance, including a wide output swing range of almost 100%, a narrow transition region of 0.05 V, and a remarkable voltage gain of 372 V/V.

Automated summary

In this article, an amorphous indium-gallium zinc oxide (a-IGZO) inverter integrated with enhancement-mode (E-mode) and depletion-mode (D-mode) thin-film transistors (TFTs) is demonstrated, achieving a record high voltage gain of 372 V/V. The D-mode a-IGZO TFTs are realized through local hydrogen plasma treatment, which introduces hydrogen doping in the a-IGZO film. X-ray photoelectron spectroscopy (XPS) measurements confirm that the hydrogen doping process increases oxygen vacancies and free electron concentration in the a-IGZO, resulting in a negative shift in threshold voltage (V-th) and an improvement in the field effect mobility (mu(FE)). A D-mode load inverter is fabricated by carefully optimizing the process of hydrogen plasma treatment, and it exhibits excellent performance, including a wide output swing range, a narrow transition region, and a remarkable voltage gain of 372 V/V.