It is an object to manufacture and provide a highly reliable display device including a thin film transistor with a high aperture ratio which has stable electric characteristics. In a manufacturing method of a semiconductor device having a thin film transistor in which a semiconductor layer including a channel formation region is formed using an oxide semiconductor film, a heat treatment for reducing moisture and the like which are impurities and for improving the purity of the oxide semiconductor film (a heat treatment for dehydration or dehydrogenation) is performed. Further, an aperture ratio is improved by forming a gate electrode layer, a source electrode layer, and a drain electrode layer using conductive films having light transmitting properties.

A semiconductor device having favorable electrical characteristics is provided. The semiconductor device is manufactured by a first step of forming a semiconductor layer containing a metal oxide, a second step of forming a first insulating layer, a third step of forming a first conductive film over the first insulating layer, a fourth step of etching part of the first conductive film to form a first conductive layer, thereby forming a first region over the semiconductor layer that overlaps with the first conductive layer and a second region over the semiconductor layer that does not overlap with the first conductive layer, and a fifth step of performing first treatment on the conductive layer. The first treatment is plasma treatment in an atmosphere including a mixed gas of a first gas containing an oxygen element but not containing a hydrogen element, and a second gas containing a hydrogen element but not containing an oxygen element.

A semiconductor device includes a first oxide insulating layer over a first insulating layer, an oxide semiconductor layer over the first oxide insulating layer, a source electrode layer and a drain electrode layer over the oxide semiconductor layer, a second insulating layer over the source electrode layer and the drain electrode layer, a second oxide insulating layer over the oxide semiconductor layer, a gate insulating layer over the second oxide insulating layer, a gate electrode layer over the gate insulating layer, and a third insulating layer over the second insulating layer, the second oxide insulating layer, the gate insulating layer, and the gate electrode layer. A side surface portion of the second insulating layer is in contact with the second oxide insulating layer. The gate electrode layer includes a first region and a second region. The first region has a width larger than that of the second region.

By using a conductive layer including Cu as a long lead wiring, increase in wiring resistance is suppressed. Further, the conductive layer including Cu is provided in such a manner that it does not overlap with the oxide semiconductor layer in which a channel region of a TFT is formed, and is surrounded by insulating layers including silicon nitride, whereby diffusion of Cu can be prevented; thus, a highly reliable semiconductor device can be manufactured. Specifically, a display device which is one embodiment of a semiconductor device can have high display quality and operate stably even when the size or definition thereof is increased.

A display device, includes: a first gate electrode; a lower insulating film; a lower gate insulating film including a metal oxide film; and an oxide semiconductor layer, all of which are provided on a substrate in a stated order; and a first transistor provided on the substrate and including the oxide semiconductor layer, the first transistor including one or more first transistors, the first transistor including: a first channel region; a first conductor region holding the first channel region; and the first gate electrode across the lower gate insulating film from the first channel region, and between the lower insulating film and the first gate electrode, a clearance being provided, and the clearance being filled with the lower gate insulating film.

In a semiconductor device including a transistor including a gate electrode formed over a substrate, a gate insulating film covering the gate electrode, a multilayer film overlapping with the gate electrode with the gate insulating film provided therebetween, and a pair of electrodes in contact with the multilayer film, a first oxide insulating film covering the transistor, and a second oxide insulating film formed over the first oxide insulating film, the multilayer film includes an oxide semiconductor film and an oxide film containing In or Ga, the oxide semiconductor film has an amorphous structure or a microcrystalline structure, the first oxide insulating film is an oxide insulating film through which oxygen is permeated, and the second oxide insulating film is an oxide insulating film containing more oxygen than that in the stoichiometric composition.

Exemplary methods of semiconductor processing may include providing a silicon-containing precursor and an oxygen-containing precursor to a processing region of a semiconductor processing chamber. A substrate may be disposed within the processing region of the semiconductor processing chamber. The methods may include providing a carbon-containing precursor to the processing region of the semiconductor processing chamber. The carbon-containing precursor may be characterized by a carbon-carbon double bond or a carbon-carbon triple bond. The methods may include thermally reacting the silicon-containing precursor, the oxygen-containing precursor, and the carbon-containing precursor at a temperature below about 650° C. The methods may include forming a silicon-and-oxygen-and-carbon-containing layer on the substrate.

A semiconductor device with little variation in transistor characteristics is provided. A first insulator to a third insulator are formed. A fourth insulator, a first oxide film, a second oxide film, a third oxide film, a first conductive film, a first insulating film, and a second conductive film are sequentially formed over the third insulator. Shaping them into island-like shapes to form a first oxide, a second oxide, a first oxide layer, a first conductive layer, a first insulating layer, and a second conductive layer. The second conductive layer is removed. A fifth insulator and a sixth insulator are formed over the fourth insulator, the first oxide, the second oxide, the first oxide layer, the first conductive layer, and the first insulating layer. An opening reaching the second oxide is formed to form a third oxide, a fourth oxide, a first conductor, a second conductor, a seventh insulator, and an eighth insulator. A fifth oxide, a ninth insulator, and a third conductor are formed in the opening. The fifth insulator is formed using a bias sputtering method.

A semiconductor device having favorable characteristics is provided. A semiconductor device having stable electrical characteristics is provided. An island-shaped insulating layer containing an oxide is provided in contact with a bottom surface of a semiconductor layer containing a metal oxide that exhibits semiconductor characteristics. The insulating layer containing an oxide is provided in contact with a portion of the semiconductor layer to be a channel formation region and is not provided under portions to be low-resistance regions.

A method may include forming a plasma of a fluorine-containing precursor and contacting a semiconductor substrate with plasma effluents. The semiconductor substrate may include a layer of a first silicon-containing material having a first germanium content formed over the semiconductor substrate, and alternating layers of a second silicon-containing material and a third silicon-containing material over the layer of the first silicon-containing material. The third silicon-containing material may have a second germanium content. The method may further include laterally recessing the third silicon-containing material relative to the first and second silicon-containing materials. The method may further include depositing a spacer material adjacent to the third silicon-containing material relative to the first and second silicon-containing materials. The method may also include etching the first silicon-containing material relative to the second silicon-containing material and the spacer material.