Electric Field-aided Selective Activation for Indium-Gallium-Zinc-Oxide Thin Film Transistors

Abstract

A new technique is proposed for the activation of low temperature amorphous InGaZnO thin film transistor (a-IGZO TFT) backplanes through application of a bias voltage and annealing at 130 °C simultaneously. In this ‘electrical activation’, the effects of annealing under bias are selectively focused in the channel region. Therefore, electrical activation can be an effective method for lower backplane processing temperatures from 280 °C to 130 °C. Devices fabricated with this method exhibit equivalent electrical properties to those of conventionally-fabricated samples. These results are analyzed electrically and thermodynamically using infrared microthermography. Various bias voltages are applied to the gate, source, and drain electrodes while samples are annealed at 130 °C for 1 hour. Without conventional high temperature annealing or electrical activation, current-voltage curves do not show transfer characteristics. However, electrically activated a-IGZO TFTs show superior electrical characteristics, comparable to the reference TFTs annealed at 280 °C for 1 hour. This effect is a result of the lower activation energy, and efficient transfer of electrical and thermal energy to a-IGZO TFTs. With this approach, superior low-temperature a-IGZO TFTs are fabricated successfully.

Performance Enhancement and Bending Restoration for Flexible Amorphous Indium Gallium Zinc Oxide Thin-Film Transistors by Low-Temperature Supercritical Dehydration Treatment

“…Figure a illustrates the O 1s XPS analysis for the a-IGZO film. The two fitted peaks are located at 529.75 ± 0.15 and 530.95 ± 0.15 eV, corresponding to lattice oxygen and non-lattice oxygen, respectively . It is clear that after the treatment, the percentage of lattice oxygen increases from 50.8 to 70.1% and that of nonlattice oxygen drops from 49.2 to 29.9%.…”

Hydrogen Barriers Based on Chemical Trapping Using Chemically Modulated Al2O3 Grown by Atomic Layer Deposition for InGaZnO Thin-Film Transistors

“…In this process, the bottom gates of each device were all fabricated in an isolated state to avoid drift collection of carriers. Thereafter, the fabricated TFTs were thermally annealed at 300 °C for 1 h to improve and stabilize their performance . To incorporate hydrogen into the a-IGZO, hydrogen plasma treatment was performed using a commercial ALD chamber (Atomic Premium; CN1 Co.).…”

P‐12: Activation of IGZO Devices at 150°C via Reduction Process Using Hydrogen Gas During Sputtering

“…However, such thermal treatment at a high temperature is not suitable for the direct formation of IGZO devices on a cost-effective flexible polymer substrate including PET and PEN, which has a relatively low glasstransition temperature (< 200 °C). The oxygen vacancy is a typical defects in oxide semiconductors; thus, an oxidation acceleration process of IGZO films, such as O3 annealing, wet O2 annealing, high-pressure O2 annealing, and simultaneous additional external energy (ultraviolet, electric fields, and magnetic fields) and thermal treatments, have been proposed for low-temperature activation of the IGZO films (< 200 °C) [7][8][9][10][11][12][13].…”