Semiconductor device

摘要

An object of the present invention is to provide a semiconductor device in which stored data can be held even when power is not supplied for a certain time. Another object is to increase the degree of integration of a semiconductor device and to increase the storage capacity per unit area. A semiconductor device is formed with a material capable of sufficiently reducing off-state current of a transistor, such as an oxide semiconductor material that is a wide-bandgap semiconductor. With the use of a semiconductor material capable of sufficiently reducing off-state current of a transistor, the semiconductor device can hold data for a long time. Furthermore, a wiring layer provided under a transistor, a high-resistance region in an oxide semiconductor film, and a source electrode are used to form a capacitor, thereby reducing the area occupied by the transistor and the capacitor.

主权项

1. A semiconductor device comprising:
a transistor; and a capacitor, wherein the transistor comprises:
an oxide semiconductor film comprising:
a channel formation region;a pair of first regions; anda pair of second regions over the pair of first regions,a source electrode layer and a drain electrode layer over the pair of second regions;a gate electrode layer over the oxide semiconductor film; anda gate insulating film between the oxide semiconductor film and the gate electrode layer, wherein the capacitor comprises:
a wiring layer;one of the pair of first regions over the wiring layer;one of the pair of second regions over the one of the pair of first regions; andthe source electrode layer over the one of the pair of second regions, wherein a resistance value of the pair of first regions is higher than a resistance value of the pair of second regions, and wherein the pair of second regions comprises at least one of aluminum, titanium, molybdenum, tungsten, hafnium, tantalum, lanthanum, barium, magnesium, zirconium, and nickel.