Manufacturing method of semiconductor device

摘要

In an embodiment, an insulating film is formed over a flat surface; a mask is formed over the insulating film; a slimming process is performed on the mask; an etching process is performed on the insulating film using the mask; a conductive film covering the insulating film is formed; a polishing process is performed on the conductive film and the insulating film, so that the conductive film and the insulating film have equal thicknesses; the conductive film is etched, so that a source electrode and a drain electrode which are thinner than the conductive film are formed; an oxide semiconductor film is formed in contact with the insulating film, the source electrode, and the drain electrode; a gate insulating film covering the oxide semiconductor film is formed; and a gate electrode is formed in a region which is over the gate insulating film and overlaps with the insulating film.

主权项

1. A semiconductor device comprising:
a source electrode on an insulating surface; a drain electrode on the insulating surface; an insulating film on the insulating surface, wherein at least a portion of the insulating film is between the source electrode and the drain electrode; an oxide semiconductor film over the insulating film, the source electrode, and the drain electrode, wherein the oxide semiconductor film comprises indium and zinc; a gate insulating film over the oxide semiconductor film; and a gate electrode over the oxide semiconductor film with the gate insulating film interposed therebetween, wherein the insulating film comprises gallium oxide, wherein the oxide semiconductor film comprises a first region overlapping with the insulating film and a second region overlapping with one of the source electrode and the drain electrode, wherein a transistor comprises the oxide semiconductor film and the gate electrode, wherein a channel length of the transistor is less than 2000 nm, and wherein a height of a top surface of the first region from the insulating surface is different from a height of a top surface of the second region from the insulating surface.