Ti doping enhanced alumina dielectrics for low-voltage thin-film transistors via low-temperature lightwave irradiation

Abstract

Herein, we report a high- k Al 1\u2009−\u2009 x Ti x O dielectric films and device applications via a facile low-temperature lightwave irradiation process. The Al 1\u2009−\u2009 x Ti x O films possess the smooth surface with subnanometer roughness. The successful doping of Ti in Al 2 O 3 films was confirmed via several characterizations. The properties of Al 1\u2009−\u2009 x Ti x O films are highly dependent on the ratio of Ti. With the introduction of 20% Ti, Al 1\u2009−\u2009 x Ti x O films obtain much better properties than single TiO 2 and Al 2 O 3 . The leakage current density reached 6.4\u2009×\u200910 −\u20098 A/cm 2 , and its capacitance is as high as 168 nF/cm 2 (at 1000 Hz). For the device applications, InZnO/Al 1\u2009−\u2009 x Ti x O TFTs show enhanced performance, such as a great field-effect mobility of 12.5 cm 2 /Vs, while InZnO/Al 2 O 3 TFTs have a mobility of 5.7 cm 2 /Vs. Moreover, the operating voltage is as low as 3 V. The low-temperature lightwave irradiated Al 1\u2009−\u2009 x Ti x O films, without high temperature or vacuum process, reveal great potential for the low-cost- but high-performance electronics.