Thin film transistor and manufacturing method therefor, and display apparatus

A thin film transistor, comprising:

• a substrate;
• an active layer disposed on the substrate, the active layer having a channel region, the active layer including a first active pattern, at least one second active pattern, and at least one third active pattern, at least part of the first active pattern being located in the channel region;
• an etch stop pattern disposed on the top surface of the first active pattern, wherein an orthogonal projection of the first active pattern on the substrate is located within an orthogonal projection of the etch stop pattern on the substrate, and the orthogonal projection of the etch stop pattern on the substrate is non-overlapping with an orthogonal projection of the at least one second active pattern on the substrate;
• wherein
• the first active pattern includes a bottom surface, a top surface and at least one side surface, the bottom surface and the top surface are arranged opposite to each other in a thickness direction of the substrate, and the bottom surface is further close to the substrate;
• the at least one side surface connects the bottom surface and the top surface, and is in contact with the at least one second active pattern, and a length direction of each side surface of the at least one side surface is approximately perpendicular to a length direction of the channel region;
• a material of at least the top surface of the first active pattern includes a first polysilicon material, a material of the at least one second active pattern includes a second polysilicon material;
• in the length direction of the channel region, an average grain size of the first polysilicon material is greater than an average grain size of the second polysilicon material;
• a material of the at least one third active pattern is amorphous silicon;
• the at least one third active pattern is disposed on at least one side of an active pattern group in the length direction of the channel region;
• wherein the active pattern group includes the first active pattern and the at least one second active pattern.