A semiconductor device includes thin film transistors each having an oxide semiconductor. The oxide semiconductor has a channel region, a drain region, a source region, and low concentration regions which are lower in impurity concentration than the drain region and the source region. The low concentration regions are located between the channel region and the drain region, and between the channel region and the source region. Each of the thin film transistors has a gate insulating film on the channel region and the low concentration regions, an aluminum oxide film on a first part of the gate insulating film, the first part being located on the channel region, and a gate electrode on the aluminum oxide film and a second part of the gate insulating film, the second part being located on the low concentration regions.

Even when a light shielding film is provided between a transistor and a substrate, a threshold voltage of the transistor can be prevented or suppressed from being shifted. A display device includes light shielding films provided between a substrate and a semiconductor layer of a transistor including a gate electrode and the semiconductor layer. The semiconductor layer includes a source region and a drain region. Both of the light shielding films overlap the semiconductor layer when seen in a plan view, and are spaced apart from each other in a direction.

A semiconductor device and the method of manufacturing the same are provided. The semiconductor device comprises a well region, a first doped region, a drain region, a source region and a gate electrode. The first doped region of a first conductivity type is located at a first side within the well region. The drain region of the first conductivity type is within the first doped region. The source region of the first conductivity type is at a second side within the well region, wherein the second side being opposite to the first side. The gate electrode is over the well region and between the source region and the drain region. A surface of the drain region and a surface of the source region define a channel and the surface of the source region directly contacts the well region.

A semiconductor device and the method of manufacturing the same are provided. The semiconductor device comprises a well region, a first doped region, a drain region, a source region and a gate electrode. The first doped region of a first conductivity type is located at a first side within the well region. The drain region of the first conductivity type is within the first doped region. The source region of the first conductivity type is at a second side within the well region, wherein the second side being opposite to the first side. The gate electrode is over the well region and between the source region and the drain region. A surface of the drain region and a surface of the source region define a channel and the surface of the source region directly contacts the well region.

A novel semiconductor device including an oxide semiconductor is provided. In particular, a planar semiconductor device including an oxide semiconductor is provided. A semiconductor device including an oxide semiconductor and having large on-state current is provided. The semiconductor device includes an oxide insulating film, an oxide semiconductor film over the oxide insulating film, a source electrode and a drain electrode in contact with the oxide semiconductor film, a gate insulating film between the source electrode and the drain electrode, and a gate electrode overlapping the oxide semiconductor film with the gate insulating film. The oxide semiconductor film includes a first region overlapped with the gate electrode and a second region not overlapped with the gate electrode, the source electrode, and the drain electrode. The first region and the second region have different impurity element concentrations. The gate electrode, the source electrode, and the drain electrode contain the same metal element.

The present invention provides an amorphous silicon semiconductor TFT backboard structure, which includes a semiconductor layer (4) that has a multi-layer structure including a bottom amorphous silicon layer (41) in contact with a gate insulation layer (3), an N-type heavily-doped amorphous silicon layer (42) in contact with a source electrode (6) and a drain electrode (7), at least two N-type lightly-doped amorphous silicon layers (43) sandwiched between the bottom amorphous silicon layer (41) and the N-type heavily-doped amorphous silicon layer (42), a first intermediate amorphous silicon layer (44) separating every two adjacent ones of the lightly-doped amorphous silicon layers (43), and a second intermediate amorphous silicon layer (45) separating the N-type heavily-doped amorphous silicon layer (42) from the one of the lightly-doped amorphous silicon layers (43) that is closest to the N-type heavily-doped amorphous silicon layer (42). Such a structure further reduces the energy barrier between the drain electrode and the semiconductor layer, making injection of electron easier and ensuring the ON-state current is not lowered down and also helping increase the barrier for transmission of holes, lowering down the leakage current and improving reliability and electrical stability of the TFT.

A novel semiconductor device including an oxide semiconductor is provided. In particular, a planar semiconductor device including an oxide semiconductor is provided. A semiconductor device including an oxide semiconductor and having large on-state current is provided. The semiconductor device includes an oxide insulating film, an oxide semiconductor film over the oxide insulating film, a source electrode and a drain electrode in contact with the oxide semiconductor film, a gate insulating film between the source electrode and the drain electrode, and a gate electrode overlapping the oxide semiconductor film with the gate insulating film. The oxide semiconductor film includes a first region overlapped with the gate electrode and a second region not overlapped with the gate electrode, the source electrode, and the drain electrode. The first region and the second region have different impurity element concentrations. The gate electrode, the source electrode, and the drain electrode contain the same metal element.

A highly reliable semiconductor device is provided. The semiconductor device includes a gate electrode, a gate insulating film over the gate electrode, a semiconductor film overlapping with the gate electrode with the gate insulating film positioned therebetween, a source electrode and a drain electrode that are in contact with the semiconductor film, and an oxide film over the semiconductor film, the source electrode, and the drain electrode. An end portion of the semiconductor film is spaced from an end portion of the source electrode or the drain electrode in a region overlapping with the semiconductor film in a channel width direction. The semiconductor film and the oxide film each include a metal oxide including In, Ga, and Zn. The oxide film has an atomic ratio where the atomic percent of In is lower than the atomic percent of In in the atomic ratio of the semiconductor film.

The present invention provides a low temperature polysilicon thin film transistor and a fabricating method thereof. According to the method, a laser annealing process is performed to a remained portion of a a-Si layer on a substrate to form a first lightly doped drain (LDD) terminal, a second LDD terminal, a first phosphor material structure and a second phosphor material structure. A gate metal layer is then formed on the remained portion of the a-Si layer. A source metal layer and a drain metal layer are formed on the first doped layer and the second doped layer located at opposite sides of the gate metal layer, respectively. The present invention use the high temperature of the laser annealing process to perform a heat diffusion of phosphor material to form the LDD terminal and the phosphor material structure, the times of photomasks are used is reduced, and the process is simplified.

The present invention provides a manufacture method of a TFT substrate structure and a TFT substrate structure. In the manufacture method of the TFT substrate structure according to the present invention, by adjusting the parameter of etching as manufacturing the gate, the angular surfaces are formed at the two sides of the gate, and the gate is used to be a mask to implement ion implantation to the polysilicon layer to form the n-type heavy doping area and the n-type light doping area are formed at the polysilicon layer at the same time. In the TFT structure according to the present invention, the polysilicon layer comprises n-type heavy doping areas at two sides and n-type light doping areas between the channel area of the polysilicon layer and the n-type heavy doping areas.