It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer including a channel formation region using an oxide semiconductor layer, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer.

The technical disclosure relates to a thin film transistor and a manufacturing method thereof, an array substrate and a display device. The thin film transistor comprises a base substrate, a gate electrode, an active layer, source/drain electrodes, a pixel electrode and one or more insulating layers, wherein at least one of the insulating layers comprises a bottom insulating sub-layer and a top insulating sub-layer, the top insulating sub-layer having a hydrogen content higher than that of the bottom insulating sub-layer.

The present invention provides an amorphous silicon thin film transistor and a manufacturing method of the amorphous silicon thin film transistor, which comprise: a substrate, a gate electrode layer, a gate insulating layer, an active layer, a source/drain electrode layer, an N+-doped layer, a protective insulating layer, and a passivation layer. The N+-doped layer is disposed between the active layer and the source/drain electrode layer. The protective insulating layer is disposed on the source/drain electrode layer. A channel is formed in the source/drain electrode layer and penetrates the N+-doped layer and the protective insulating layer. The passivation layer covers the channel and the protective insulating layer. The protective insulating layer and the source/drain electrode layer are flush with each other in the channel.

One object is to have stable electrical characteristics and high reliability and to manufacture a semiconductor device including a semi-conductive oxide film. Film formation is performed by a sputtering method using a target in which gallium oxide is added to a material that is easy to volatilize compared to gallium when the material is heated at 400° C. to 700° C. like zinc, and a formed film is heated at 400° C. to 700° C., whereby the added material is segregated in the vicinity of a surface of the film and the oxide is crystallized. Further, a semi-conductive oxide film is deposited thereover, whereby a semi-conductive oxide having a crystal which succeeds a crystal structure of the oxide that is crystallized by heat treatment is formed.

To improve the electrical characteristics of a semiconductor device including an oxide semiconductor, and to provide a highly reliable semiconductor device with a small variation in electrical characteristics. The semiconductor device includes a first insulating film, a first barrier film over the first insulating film, a second insulating film over the first barrier film, and a first transistor including a first oxide semiconductor film over the second insulating film. The amount of hydrogen molecules released from the first insulating film at a given temperature higher than or equal to 400° C., which is measured by thermal desorption spectroscopy, is less than or equal to 130% of the amount of released hydrogen molecules at 300° C. The second insulating film includes a region containing oxygen at a higher proportion than oxygen in the stoichiometric composition.

Provided is a transistor with small parasitic capacitance or high frequency characteristics or a semiconductor device including the transistor. An oxide semiconductor film includes a first region in contact with a first conductive film, a second region in contact with a first insulating film, a third region in contact with a third insulating film, a fourth region in contact with a second insulating film, and a fifth region in contact with a second conductive film. The first insulating film is positioned over the first conductive film and the oxide semiconductor film. The second insulating film is positioned over the second conductive film and the oxide semiconductor film. The third insulating film is positioned over the first insulating film, the second insulating film, and the oxide semiconductor film. The third conductive film and the oxide semiconductor film partly overlap with each other with the third insulating film provided therebetween.

A method of manufacturing a TFT substrate includes the steps of forming an oxide semiconductor layer above a substrate, forming a first oxide film on the oxide semiconductor layer, performing oxidation processing on the oxide semiconductor layer after formation of the first oxide film, and forming a second oxide film on the first oxide film after the oxidation processing.

Embodiments of the present invention provide for the application of strain inducing layers to enhance the mobility of transistors formed on semiconductor-on-insulator (SOI) structures. In one embodiment, a method for fabricating an integrated circuit is disclosed. In a first step, active circuitry is formed in an active layer of a SOI wafer. In a second step, substrate material is removed from a substrate layer disposed on a back side of the SOI wafer. In a third step, insulator material is removed from the back side of the SOI wafer to form an excavated insulator region. In a fourth step, a strain inducing material is deposited on the excavated insulator region. The strain inducing material interacts with the pattern of excavated insulator such that a single layer provides both tensile and compressive stress to p-channel and n-channel transistors, respectively. In alternative embodiments, the entire substrate is removed before forming the strain inducing material.

A display panel and a display device are provided to better protect a metal connecting line area in a peripheral wiring region, improve the protection degree and prevent the wire breakage. The display panel includes a gate insulating layer (102) disposed on a gate metal layer (101); and a protective layer (103), a passivation layer (105) and an indium tin oxide (ITO) coating layer (107) disposed on the gate insulating layer in sequence. The display panel and the display device can increase the film thickness in the peripheral wiring region, and hence can protect the entire peripheral wiring region and particularly the metal connecting line area exposed outside a color filter panel and improve the protection degree.

An array substrate and a display device are provided. A gate insulating layer and a gate electrode are formed on a semiconductor layer in sequence, the gate insulating layer and the gate electrode are located in a middle position of the semiconductor layer and have a uniform shape and size. In a region on the semiconductor layer that is not covered by the gate insulating layer, there is further provided a metal diffusion layer. A barrier layer includes a portion covering the gate insulating layer and the gate electrode and a portion located around the semiconductor layer. A passivation layer covers the semiconductor layer, the gate insulating layer, the gate electrode and the barrier layer. Source and drain electrodes are connected to the metal diffusion layer respectively, and a pixel electrode contacts with the drain electrode.