Thin film transistors with wurtzite ZnO channels grown on Si3N4/SiO2/Si (111) substrates by pulsed laser deposition

Thin Film Transistors (TFT) were made by growing ZnO on Si3N4/SiO2/Si (111) substrates by pulsed laser deposition. X-ray diffraction and scanning electron microscope studies revealed the ZnO to have a polycrystalline wurtzite structure with a smooth surface, good crystallographic quality and a strong preferential c-axis orientation. Transmission studies in similar ZnO layers on glass substrates showed high transmission over the whole visible spectrum. Electrical measurements of a back gate geometry FET showed an enhancement-mode response with hard saturation, mA range Id and a V-ON similar to 0V. When scaled down, such TFTs may be of interest for high frequency applications.