Thin film transistor including composition graded gate dielectric and method of forming same

The invention provides a thin film transistor including a compositionally graded gate dielectric and a method of forming the same. The thin film transistor may be manufactured by: forming a gate electrode in an insulating layer over a substrate; forming a gate dielectric over the gate electrode and the insulating layer; forming an active layer over the gate electrode; and forming a source electrode and a drain electrode, the source electrode and the drain electrode being in contact with respective portions of the top surface of the active layer. Surface oxygen concentration in a respective one of the gate dielectric and the active layer may be increased by introducing oxygen atoms into a surface region of at least one of the gate dielectric and the active layer. 本申请提供了包括成分渐变栅极电介质的薄膜晶体管及其形成方法。薄膜晶体管可以通过以下步骤来制造：在衬底之上的绝缘层中形成栅极电极；在栅极电极和绝缘层之上形成栅极电介质；在栅极电极之上形成有源层；以及形成源极电极和漏极电极，源极电极和漏极电极与有源层的顶表面的相应部分接触。可以通过将氧原子引入到栅极电介质和有源层中的至少一者的表面区域中来增加栅极电介质和有源层中的相应一者中的表面氧浓度。