High Performance Complementary Circuits Based on p-SnO and n-IGZO Thin-Film Transistors

Area of Science:

• Materials Science
• Electronics Engineering
• Semiconductor Physics

Background:

• Oxide semiconductors are key for developing large-area and flexible electronic devices.
• Complementary circuits require both n-type and p-type semiconductor materials for efficient operation.

Purpose of the Study:

• To develop and characterize a complementary ring oscillator using n-type indium-gallium-zinc-oxide (IGZO) and p-type tin monoxide (SnO).
• To evaluate the performance of IGZO and SnO thin-film transistors (TFTs) for complementary circuit applications.

Main Methods:

• Fabrication and characterization of IGZO and SnO TFTs.
• Design and testing of a complementary inverter and a three-stage ring oscillator circuit.
• Analysis of device performance metrics including mobility, threshold voltage, gain, oscillation frequency, and amplitude.

Main Results:

• IGZO TFTs exhibited a linear mobility of 11.9 cm²/(V·s) and a threshold voltage of 12.2 V.
• SnO TFTs showed a mobility of 0.51 cm²/(V·s) and a threshold voltage of 20.1 V, suitable for complementary circuits.
• The complementary inverter achieved a gain of 24, and the ring oscillator operated at 2.63 kHz with an amplitude of 36.1 V at 40 V supply voltage.

Conclusions:

• The developed oxide-based complementary circuits, utilizing IGZO and SnO, show promising performance for flexible electronics.
• Further optimization of operating voltage could enhance the applicability of these circuits in practical large-area flexible electronic systems.