Abstract: A semiconductor layer with a threshold voltage for n-channel is formed and patterned to TFT island areas. A gate insulating film is deposited. The first gate electrode layer is formed and pattered to form an opening. Phosphorous ions are implanted into a p-channel TFT in the opening to set threshold voltage for p-channel TFT. A second gate electrode layer is formed and patterned to form second gate electrodes. By using the first gate electrode layer as a mask, boron ions are implanted at a high concentration to form source/drain regions of the p-channel TFT. By using the second gate electrodes as a mask, the first gate electrode layer is etched to form gate electrodes. Phosphorous ions are implanted at a low concentration to form LDD regions. By using a fourth mask, P ions are implanted at a high concentration to form source/drain regions of n-channel TFTs.

Abstract: LDD regions can be properly formed even when a gate insulation film is thin, and an impurity can be properly activated. After forming a gate electrode, an n-type impurity is implanted in a high density using a resist mask for etching the gate insulation film as a mask. A SiO2 film is formed as a first interlayer insulation film, and activation is thereafter performed using a laser. By implanting the impurity with the resist mask for etching left in place, the problem of excessive implantation of the n-type impurity in the LDD regions can be avoided without adding a photolithographic process even when the gate insulation film is thin.

Abstract: The invention relates to a TFT device, a method of manufacturing the same, and a TFT substrate and a display having the same and provides a TFT device having good characteristics and high reliability, a method of manufacturing the same, and a TFT substrate and a display having the same. A metal thin film is formed on a gate insulation film. Patterning is performed to remove the metal thin film on a semiconductor layer to become source and drain regions of an n-type TFT. Phosphorous ions are implanted using the patterned metal thin film as a mask to form the source and drain regions. The patterned metal thin film is further patterned to form a gate electrode of the n-type TFT. Phosphorous ions are implanted using the gate electrode as a mask to form LDD regions between the source and drain regions and a channel region.

Abstract: A polysilicon film is formed in a predetermined region on a glass substrate, and then a gate insulating film and a gate electrode, whose width is narrower than the gate insulating film, are formed thereon. Then, an interlayer insulating film and an ITO film are formed on an overall surface. Then, n-type source/drain regions having an LDD structure are formed by implanting the n-type impurity into the polysilicon film. Then, an n-type TFT forming region and a pixel-electrode forming region are covered with a resist film, and then p-type source/drain regions are formed by implanting the p-type impurity into the polysilicon film in a p-type TFT forming region. Then, the resist film is left only in the pixel-electrode forming region and the resist film is removed from other regions. A pixel electrode is formed by etching the ITO film while using the remaining resist film as a mask.

Abstract: A thin film transistor substrate including a semiconductor layer having a source region and a drain region, an insulating film and a gate electrode which are formed on the semiconductor layer, an interlayer insulating film which is a film stack with mutually different dielectric constants and which covers the gate electrode, a source region contact hole and a drain region contact hole which are formed on the interlayer insulating film, a pixel electrode connected to the source region through the source region contact hole, a first conductive film connected to the drain region through the drain region contact hole and formed of the same film as that of the pixel electrode, and a second conductive film connected to the drain region through the first conductive film.

Abstract: The present invention relates to a thin film transistor device formed on an insulating substrate of a liquid crystal display device and others, a method of manufacturing the same, and a liquid crystal display device. In structure, there are provided the steps of forming a negative photoresist film on a first insulating film for covering a first island-like semiconductor film, forming a resist mask that has an opening portion in an inner region with respect to a periphery of the first island-like semiconductor film by exposing/developing the negative photoresist film from a back surface side of a transparent substrate, etching the first insulating film in the opening portion of the resist mask, forming a second insulating film for covering the first insulating film and a conductive film thereon, and forming a first gate electrode and a second gate electrode by patterning the conductive film.

Abstract: In a case of a liquid crystal display apparatus, a gate insulating film of a TFT driven at a low voltage (3.3 V or 5 V) is constituted by one insulating film, and a thickness thereof is set to, for example, 30 nm. This TFT has a structure in which LDD regions (low concentration impurity regions) are not provided. A TFT having a CMOS structure, which is driven at a high voltage (18 V), has a gate insulating film constituted by two insulating films having a thickness of, for example, 130 nm in total. In an n-type TFT, a low concentration impurity region is provided on a drain side. A p-type TFT has a structure having no LDD region. A pixel TFT has a gate insulating film constituted by two insulating films, and LDD regions provided in both of its source/drain.