Performance Improvement of N-Type TiOx Active-Channel TFTs Grown by Low-Temperature Plasma-Enhanced ALD

Abstract

We report on performance improvement of n-type oxide-semiconductor thin-film transistors (TFTs) based on TiOx active channels grown at 250 degrees C by plasma-enhanced atomic layer deposition. TFTs with as-grown TiOx films exhibited the saturation mobility (mu(sat)) as high as 3.2 cm(2)/V . s but suffered from the low on-off ratio (I-ON/I-OFF) of 2.0 x 10(2). N2O plasma treatment was then attempted to improve I-ON/I-OFF. Upon treatment, the TiOx TFTs exhibited I-ON/I-OFF of 4.7 x 10(5) and mu(sat) of 1.64 cm(2) /V . s, showing a much improved performance balance and, thus, demonstrating their potentials for a wide variety of applications such as backplane technology in active-matrix displays and radio-frequency identification tags.