Ultraviolet laser damage mechanisms of amorphous InGaZnO4 thin films

• DOI: 10.1364/ome.9.002545
• Publication Date: 2019-05-10T19:08:51Z
• Authors: Jian Ke Yao; Fan Ye; Ping Fan
• Keywords: Ultraviolet; Pulsed Laser Deposition

Laser annealing is a usual step in the process to improve performance of amorphous InGaZnO4 (a-IGZO) thin film transistors (TFTs). However, high energy laser will induce damage a-IGZO films during annealing. Knowing induced thresholds (LIDT) and mechanisms helps use appropriate density avoid achieve best TFTs’ properties. In this article, ultraviolet with wavelength 355 nm pulse width 7.7 ns LIDT are reported. The morphologies characterized optical microscopy scanning electron microscope Raman spectra. electrical properties studied. have increased from 0.12 J/cm2, 0.16 0.23 J/cm2 0.24 absorbance decreased 22.4%, 18.1%, 17.3% 12.3%. concentrations oxygen free carrier (Ne) thermal conductivity band gap (Eg) effective mass (m*) important factors affecting films. influences surface temperature Eg m* Ne other reasons for LIDT. mainly induces intrinsic processes including avalanche ionization multi-photon absorption. No apparent phase transformation lattice expansion exists irradiation stable structures