A method of fabricating a thin film transistor comprising an active layer having a channel region (cr), a source electrode contact region (scr), and a drain electrode contact region(dcr), comprising: forming a semiconductor material layer comprising M1O a N b on a base substrate; wherein M1 is a single metal or a combination of metals, a > 0, and b ≥ 0; forming a conductive metal material layer on a side of the semiconductor material layer distal to the base substrate; and doping a first portion of the semiconductor material layer in a region corresponding to the channel region with a dopant thereby forming the etch stop layer, the etch stop layer being substantially resistant to an etchant for etching a metal material in the semiconductor material layer and the conductive metal material layer, wherein subsequent to forming the semiconductor material layer and forming the conductive metal material layer, the method further comprises: forming a first photoresist layer on a side of the conductive metal material layer distal to the semiconductor material layer, the first photoresist layer being in a region outside that corresponding to the channel region, exposing a first portion of the conductive metal material layer in a region corresponding to the channel region (cr); removing the first portion of the conductive metal material layer in the region corresponding to the channel region (cr) to expose a first portion of the semiconductor material layer in the region corresponding to the channel region; and doping the first portion of the semiconductor material layer with a dopant thereby forming the etch stop layer, the etch stop layer being substantially resistant to an etchant for etching the metal material, forming a second photoresist layer by removing a portion of the first photoresist layer to expose a second portion of the conductive metal material layer in a region outside those corresponding to the channel region (cr), the source electrode contact region (scr), and the drain electrode contact region (dcr); removing the second portion of the conductive metal material layer; removing a second portion of the semiconductor material layer in the region outside those corresponding to the channel region, the source electrode contact region, and the drain electrode contact region thereby forming the active layer; and removing the second photoresist layer thereby forming the source electrode and the drain electrode, wherein the etchant is hydrogen peroxide. forming a semiconductor material layer comprising M1O a N b on a base substrate; wherein M1 is a single metal or a combination of metals, a > 0, and b ≥ 0; forming a conductive metal material layer on a side of the semiconductor material layer distal to the base substrate; and doping a first portion of the semiconductor material layer in a region corresponding to the channel region with a dopant thereby forming the etch stop layer, the etch stop layer being substantially resistant to an etchant for etching a metal material in the semiconductor material layer and the conductive metal material layer, wherein subsequent to forming the semiconductor material layer and forming the conductive metal material layer, the method further comprises: forming a first photoresist layer on a side of the conductive metal material layer distal to the semiconductor material layer, the first photoresist layer being in a region outside that corresponding to the channel region, exposing a first portion of the conductive metal material layer in a region corresponding to the channel region (cr); removing the first portion of the conductive metal material layer in the region corresponding to the channel region (cr) to expose a first portion of the semiconductor material layer in the region corresponding to the channel region; and doping the first portion of the semiconductor material layer with a dopant thereby forming the etch stop layer, the etch stop layer being substantially resistant to an etchant for etching the metal material, forming a first photoresist layer on a side of the conductive metal material layer distal to the semiconductor material layer, the first photoresist layer being in a region outside that corresponding to the channel region, exposing a first portion of the conductive metal material layer in a region corresponding to the channel region (cr); removing the first portion of the conductive metal material layer in the region corresponding to the channel region (cr) to expose a first portion of the semiconductor material layer in the region corresponding to the channel region; and doping the first portion of the semiconductor material layer with a dopant thereby forming the etch stop layer, the etch stop layer being substantially resistant to an etchant for etching the metal material, forming a second photoresist layer by removing a portion of the first photoresist layer to expose a second portion of the conductive metal material layer in a region outside those corresponding to the channel region (cr), the source electrode contact region (scr), and the drain electrode contact region (dcr); removing the second portion of the conductive metal material layer; removing a second portion of the semiconductor material layer in the region outside those corresponding to the channel region, the source electrode contact region, and the drain electrode contact region thereby forming the active layer; and removing the second photoresist layer thereby forming the source electrode and the drain electrode, wherein the etchant is hydrogen peroxide.