Low‐Voltage Heterojunction Metal Oxide Transistors via Rapid Photonic Processing
Emre Yarali, Hendrik Faber, Emre Yengel, Akmaral Seitkhan, Kalaivanan Loganathan, George T. Harrison, Begimai Adilbekova, Yuanbao Lin, Chun Ma, Yuliar Firdaus, Thomas D. Anthopoulos
Abstract
Abstract Solution‐processed metal oxide thin‐film transistors (TFTs) represent a promising technology for applications in existing but also emerging large‐area electronics. However, high process temperatures and lengthy annealing times represent two remaining technical challenges. Different approaches aiming to address these challenges have been proposed but progress remains modest. Here, the development of high electron mobility metal oxide TFTs based on photonically converted Al 2 O 3 /ZrO 2 and In 2 O 3 /ZnO bilayers acting as the high‐ k dielectric and electron‐transporting channel, respectively is described. Sequential solution‐phase deposition and photonic processing lead to low substrate temperature (<200 °C) while minimizing the overall process time to less than 60 s without compromising the quality of the formed layers. The bilayer Al 2 O 3 /ZrO 2 dielectric exhibits low leakage current density (10 −6 A cm −2 at 1 MV cm −1 ), high geometric capacitance (≈120 nF cm −2 ) and breakdown electric field of ≈1 MV cm −1 . Combining Al 2 O 3 /ZrO 2 with a photonically converted In 2 O 3 /ZnO heterojunction channels, results in TFTs with high electron mobility (19 cm 2 V −1 s− 1 ), low operation voltage (≤2 V), high current on/off ratio (>10 6 ), and low subthreshold swing (108 mV dec −1 ), that can be manufactured even onto thermally sensitive polymer substrates. The work is a significant step toward all‐photonic processed metal oxide electronics.