THIN FILM TRANSISTOR STRUCTURE, AND THIN FILM TRANSISTOR AND DISPLAY DEVICE PROVIDED WITH SAID STRUCTURE

摘要

Provided is an oxide semiconductor layer which, in a display device such as an organic EL display or liquid crystal display, is capable of stabilizing the electrical characteristics of a thin film transistor without the need for an oxidatively treated layer during the formation of a protective film. This thin film transistor structure has at least an oxide semiconductor layer, source and drain electrodes, and a protective layer, provided on a substrate in that order from the substrate side. The oxide semiconductor layer is a laminate comprising a first oxide semiconductor layer, which is formed on the side of the source and drain electrodes and the protective layer and has a Zn content of 50 atomic percent or more relative to the total amount of metal elements, and a second oxide semiconductor layer, which is formed on the substrate side and contains Sn and at least one element selected from the group consisting of In, Ga and Zn. The first oxide semiconductor layer is in direct contact with the source and drain electrodes and the protective film.