SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

摘要

A semiconductor device having high electric characteristics and in which a capacitor is efficiently formed even if the semiconductor device has a miniaturized structure. In a top-gate (also referred to as staggered) transistor using an oxide semiconductor film as its active layer, a source electrode and a drain electrode has a two-layer structure (a first electrode film and a second electrode film). Then, a capacitor is formed using a film formed using a material and a step similar to those of the first electrode film, a gate insulating film, and a gate electrode. Accordingly, the transistor and the capacitor can be formed through the same process efficiently. Further, the second electrode is connected onto the oxide semiconductor film between a first electrode and a channel formation region of the transistor. Accordingly, resistance between source and drain electrodes can be reduced; therefore, electric characteristics of the semiconductor device can be improved.

主权项

1. A method for manufacturing a semiconductor device including a transistor and a capacitor, comprising the steps of:
forming an oxide semiconductor film over an insulating surface; forming a first electrode film covering an end portion of the oxide semiconductor film an lower electrode film of the capacitor through a same step; forming a gate insulating film over the oxide semiconductor film and an insulating film of the capacitor over the lower electrode film through a same step; forming a gate electrode over the gate insulating film and an upper electrode film of the capacitor over the insulating film through a same step; forming a second insulating film covering at least a side surface of the gate electrode, and forming a second electrode film electrically connected to the first electrode film and the oxide semiconductor film.