A high-voltage switching device that can be fabricated in a standard low-voltage process, such as CMOS, and more specifically SOI CMOS. Embodiments include integrated circuits that combine, in a unitary structure, a FET device and an integrated, co-fabricated modulated resistance region (MRR) controlled by one or more Voltage-Drop Modulation Gates (VDMGs). The VDMGs are generally biased independently of the gate of the FET device, and in such a way as to protect each VDMG from excessive and potentially destructive voltages. In a first embodiment, an integrated circuit high voltage switching device includes a transistor structure including a source, a gate, and an internal drain; an MRR connected to the internal drain of the transistor structure; at least one VDMG that controls the resistance of the MRR; and a drain electrically connected to the MRR. Each VDMG at least partially depletes the MRR upon application of a bias voltage.

A transistor with stable electrical characteristics. A semiconductor device includes a first insulator over a substrate, a second insulator over the first insulator, an oxide semiconductor in contact with at least part of a top surface of the second insulator, a third insulator in contact with at least part of a top surface of the oxide semiconductor, a first conductor and a second conductor electrically connected to the oxide semiconductor, a fourth insulator over the third insulator, a third conductor which is over the fourth insulator and at least part of which is between the first conductor and the second conductor, and a fifth insulator over the third conductor. The first insulator contains a halogen element.

A semiconductor device according to an embodiment may include a substrate, an adhesive layer, and a semiconductor layer. The semiconductor layer includes a 2D material having a layered structure. The adhesive layer is interposed between the substrate and the semiconductor layer, and has adhesiveness to a 2D material.

The impurity concentration in the oxide semiconductor film is reduced, and a highly reliability can be obtained.

A semiconductor device includes a metal oxide layer over an insulating surface, an oxide semiconductor layer over the metal oxide layer, and an insulating layer over the oxide semiconductor. The insulating layer includes a first region overlapping the oxide semiconductor layer. A first aluminum concentration of the first region is greater than or equal to 110.sup.17 atoms/cm.sup.3.

In a thin film transistor, an increase in off current or negative shift of the threshold voltage is prevented. In the thin film transistor, a buffer layer is provided between an oxide semiconductor layer and each of a source electrode layer and a drain electrode layer. The buffer layer includes a metal oxide layer which is an insulator or a semiconductor over a middle portion of the oxide semiconductor layer. The metal oxide layer functions as a protective layer for suppressing incorporation of impurities into the oxide semiconductor layer. Therefore, in the thin film transistor, an increase in off current or negative shift of the threshold voltage can be prevented.

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, as manufacturing the gate, a plurality of metal sections distributed in spaces are formed at two sides of the gate, and the gate and the plurality of metal sections are employed to be a mask to implement ion implantation to the polysilicon layer. In the TFT substrate structure according to the present invention, the undoped areas are formed among the n-type heavy doping areas while forming the n-type heavy doping areas at the polysilicon layer.

Provided are liquid crystal display and the method for manufacturing the same. According to an aspect of the present invention, there is provided a liquid crystal display device, including a first substrate; a gate electrode disposed on the first substrate; a semiconductor pattern layer disposed on the gate electrode; and a source electrode and a drain electrode disposed on the semiconductor pattern layer and facing each other, wherein a diffusion prevention pattern is disposed on the semiconductor pattern layer to prevent diffusion into the semiconductor pattern layer or to maintain uniform thickness of the semiconductor pattern layer.

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.

An object is to provide a semiconductor device using an oxide semiconductor having stable electric characteristics and high reliability. A transistor including the oxide semiconductor film in which a top surface portion of the oxide semiconductor film is provided with a metal oxide film containing a constituent similar to that of the oxide semiconductor film and functioning as a channel protective film is provided. In addition, the oxide semiconductor film used for an active layer of the transistor is an oxide semiconductor film highly purified to be electrically i-type (intrinsic) by heat treatment in which impurities such as hydrogen, moisture, a hydroxyl group, or a hydride are removed from the oxide semiconductor and oxygen which is a major constituent of the oxide semiconductor and is reduced concurrently with a step of removing impurities is supplied.