Poly-silicon thin film transistor and manufacturing method thereof, array substrate and manufacturing method thereof, and display device

A method for manufacturing a poly-silicon thin film transistor comprising:

• forming an active layer on a base substrate, and a gate insulation layer and a gate electrode above the active layer, the active layer including a first poly-silicon area, lightly doped areas located at both sides of the first poly-silicon area, and heavily doped areas located at a side of the lightly doped areas away from the first poly-silicon area,
• wherein forming of the lightly doped areas of the active layer includes:
• forming a poly-silicon layer on the base substrate, the poly-silicon layer including the first poly-silicon area, second poly-silicon areas located at both sides of the first poly-silicon area, and third poly-silicon areas located at a side of the second poly-silicon areas away from the first poly-silicon area;
• forming a barrier layer between the gate electrode and the gate insulation layer by a dry etching method so that the barrier layer corresponds to the first poly-silicon area;
• and
• with the barrier layer covering the first poly-silicon area as a mask, doping the second poly-silicon areas to form the lightly doped areas.