Manufacturing method of display substrate, display substrate and display device

A manufacturing method of a display substrate, comprising manufacturing a top-gate type thin film transistor on a side of a base substrate, wherein the manufacturing the top-gate type thin film transistor on the side of the base substrate comprises following steps of:

• forming an active layer, a gate insulation film layer, a gate film layer and a photoresist film layer sequentially on the base substrate;
• exposing the photoresist film layer to a light using a mask as a protection mask, and developing the exposed photoresist film layer;
• over-etching the gate film layer to form a gate electrode using the developed photoresist film layer as a protection mask;
• over-etching the gate insulation film layer by a gaseous corrosion method to form a gate insulation layer using the developed photoresist film layer as a protection mask, wherein a gas atmosphere of the gaseous corrosion comprises carbon tetrafluoride (CF4) at a flow rate of 2000 to 2500 SCCM and oxygen (O2) at a flow rate of 200 to 650 SCCM;
• peeling off the photoresist film layer remaining on a surface of the gate electrode;
• and
• performing a conductive treatment to the active layer using the gate insulation layer as a protection mask.