Sharp Kabushiki Kaisha Corporation

Matsushita Electric Industrial Co., Ltd.

Narihiro Morosawa

Hiroshi Iwata

Yasushi Kubota

Masahiro Adachi

Hiromi Sakamoto

A thin film transistor having a source region and a drain region having a low melting point region composed of a semiconductor with a melting point lower than that of the semiconductor of the channel region is provided. In the thin film transistor, the dopant concentrations of the low melting point region of the source region adjacent to the channel region and the low melting point region of the drain region adjacent to the channel region are precisely controlled. Using the thin film transistor, a high performance thin film transistor array substrate is also provided, as well as a high display speed liquid crystal display device and a high display speed electroluminescent display device having a high aperture ratio or a high pixel resolution.

Thin film transistor, thin film transistor array substrate, liquid crystal display device, and electroluminescent display device

An insulated gate transistor in which nitride oxide film having a nitrogen concentration of 1&times;10 (/cm ) or more and containing a halogen element is used as a gate insulator. Because the gate insulator has a nitrogen concentration of 1&times;10 (/cm ) or more, boron contained in the gate electrode of the p-type transistor is never diffused into the channel. Further because a halogen element is contained in the gate insulator, transistor conductance is increased and reliability in hot carrier injection is improved. Thus, an insulated gate transistor which has a sufficiently large conductance and which is superior in reliability can be fabricated.

Insulated gate transistor having a gate insulator containing nitrogen atoms and fluorine atoms

A semiconductor device includes an insulating gate field effect transistor including a gate electrode, wherein the gate electrode includes a polycrystalline semiconductor film having a crystal defect density of about 1&times;10 cm or less. In certain embodiments, the polycrystalline semiconductor film may be oxidation thermally annealed by subjecting the polycrystalline semiconductor film to thermal treatment in an oxidation atmosphere to carry out oxidization of the polycrystalline semiconductor film and activation of impurities simultaneously.

Semiconductor device

An insulating gate field effect semiconductor device having a gate insulating film of high resistance to moisture adsorption, wherein trap densities in the gate insulator film and at the interface between a channel semiconductor film and the gate insulator film are lowered, and causing no degradation of device characteristics and no lowering of reliability are caused. A SiO.sub.2 film including fluorine atoms is used as the gate insulator film to compensate defects in the gate insulator film and at the interface between the channel semiconductor film and the gate insulator film.

Insulating gate field effect semiconductor device and method of

A thin-film transistor circuit, which is used as a driving circuit for driving pixels in an image display, is constituted of a plurality of thin-film transistors that are formed on an insulating substrate. In each thin-film transistor, a conductive electrode is placed so as to face a gate electrode with a channel region of a polycrystal silicon thin-film that forms an active layer located in between. Here, a constant voltage is applied to the conductive electrode. When threshold voltage is shifted by applying a voltage to the conductive electrode, it is possible to allow the absolute value of the threshold voltage of n-channel-type transistors and the absolute value of the threshold voltage of p-channel-type transistors to become virtually equal to each other. Moreover, it is possible to properly set the threshold voltage in accordance with factors such as the channel length of the thin-film transistors, the types of circuits that are constituted of the thin-film transistors and voltages to be applied to the thin-film transistors. Thus, it becomes possible to remarkably improve the characteristics of thin-film transistor circuits, such as operation speeds and holding characteristics.

Growing community of inventors

Nara, Japan

Narihiro Morosawa