Thin film transistor and method for manufacturing the same, array substrate, and display device

Embodiments of the present disclosure disclose a thin film transistor, a method for manufacturing a thin film transistor, an array substrate, and a display device. The thin film transistor includes a source electrode and a drain electrode, each of the source electrode and the drain electrode including a metal substrate and a conductive layer covering the metal substrate. An adhesion between the conductive layer and a photoresist material is larger than an adhesion between the metal substrate and the photoresist material. The metal substrate and the conductive layer are both formed on a base substrate, an orthographic projection of the conductive layer on the base substrate covers an orthographic projection of the metal substrate on the base substrate, and. an area of the orthographic projection of the conductive layer on the base substrate is larger than an area of the orthographic projection of the metal substrate on the base substrate.