Effects of High Nitrogen Pressure and Thermal Treatment on Adhesion to Amorphous Silicon/Silicon Nitride/Polyethersulfone Substrate during Excimer Laser Annealing

Abstract

  The effects of high nitrogen (N₂) pressure and thermal treatment on the adhesion between a silicon film and a polyethersulfone (PES) substrate during crystallization by excimer laser annealing (ELA) were investigated using silicon nitride (SiN_x) as the barrier film for the fabrication of polycrystalline silicon (poly-Si) thin-film transistors on a plastic substrate. As the thickness of the SiN_x film increased from 50 to 150 nm at a gas pressure of 0.2 MPa, film exfoliation was suppressed. A poly-Si film with a crystalline fraction of 76% was obtained at an energy density of 200 mJ/cm² and a high pressure in N₂ atmosphere. In addition, thermal treatment before ELA was useful for improving the adhesion between the inorganic film and the PES substrate.