Low frequency noise in polysilicon thin film transistors: effect of the laser annealing of the active layer

Laurent Pichon (1) , Christophe Cordier (2) , Abdelmalek Boukhenoufa (3)

1 IETR - Institut d'Electronique et de Télécommunications de Rennes
2 Equipe Electronique - Laboratoire GREYC - UMR6072
3 GREYC - Groupe de Recherche en Informatique, Image et Instrumentation de Caen

Low-frequency noise is studied in N-channel polysilicon TFTs issued from two (low temperature '600°C) technologies: fur-nace solid phase crystallized (FSPC) and laser solid phase crystallized (LSPC) TFTs. The distribution of the trap states (DOS) into the polysilicon bandgap determined for devices biased in the weak inversion is one decade lower for LSPC devices. The high range values 'Α' of the measured macroscopic noise parameter, defined according to the Hooge empirical re-lationship, are explained by the drain current crowding due to structural defects within the active layer. The higher values of Α for the LSPC TFTs are attributed to a better structural quality of the active layer.

Domaines: Micro et nanotechnologies/Microélectronique

Laurent Pichon, Christophe Cordier, Abdelmalek Boukhenoufa. Low frequency noise in polysilicon thin film transistors: effect of the laser annealing of the active layer. physica status solidi (c), 2008, 5 (10), pp.3271. ⟨10.1002/pssc.200779510⟩. ⟨hal-00307198⟩