A transistor and a method for manufacturing the same, a display substrate, and a display apparatus are provided. The transistor may include: a substrate; an active region on the substrate and including a polycrystalline silicon region; an etch stop layer at a side of the polycrystalline silicon region distal to the substrate; and a first heavily doped amorphous silicon region and a second heavily doped amorphous silicon region both at a side of the etch stop layer distal to the substrate; the polycrystalline silicon region having a first side surface corresponding to the first heavily doped amorphous silicon region and a second side surface corresponding to the second heavily doped amorphous silicon region; wherein an orthographic projection of the polycrystalline silicon region on a plane in which a lower surface of the etch stop layer lies does not go beyond the lower surface of the etch stop layer.