Active matrix liquid crystal display
AssigneeHitachi, Ltd.
InventorsMasahiko Ando, Masatoshi Wakagi, Ritsuo Fukaya
Life of this patent
Estimating the term…
Abstract
A thin film transistor used as a switching element of an active matrix type liquid crystal display is an enhancement-mode thin film transistor including a silicon nitride film formed over a scanning electrode, an insulating layer formed on the silicon nitride film, and a semiconductor layer having a source region and a drain region formed on the insulating layer. The thin film transistor has a threshold voltage higher than the maximum value of the liquid crystal operating voltage. The insulating layer is a silicon oxide film having a thickness of 30 Å or more.
Claims18
An active matrix type liquid crystal display having a pair of substrates and a liquid crystal layer sandwiched by the substrates,
- wherein a plurality of scanning electrodes, a plurality of signal electrodes which intersect with said scanning electrodes in the form of a matrix, a plurality of semiconductor switching elements corresponding to respective intersections of said scanning electrodes and said signal electrodes, a plurality of pixel electrodes each connected to a respective one of said switching elements, and a plurality of opposed electrodes each connected to one of said scanning electrodes, are formed on one of said pair of substrates, and
- wherein each of said plural semiconductor switching elements is a thin film transistor of an enhancement type and comprises a semiconductor layer having a silicon nitride film formed on a corresponding scanning electrode, an insulating layer formed on the silicon nitride film, and source and drain areas formed on the insulating layer.
An active matrix type liquid crystal display having a pair of substrates and a liquid crystal layer sandwiched by the substrates,
- wherein a plurality of scanning electrodes, a plurality of signal electrodes which intersect with said scanning electrodes in the form of a matrix, and a plurality of semiconductor switching elements corresponding to respective intersections of said scanning electrodes and said signal electrodes, are formed on one of said pair of substrates,
- wherein at least one pixel is formed at each area founded by a scanning electrode and a signal electrode,
- wherein each pixel has a pixel electrode connected to a corresponding thin film transistor, and an opposed electrode formed in the same direction as the pixel electrode and connected to a corresponding one of the scanning electrodes, and
- wherein each of said plural thin film transistors is of an enhancement type and comprises a semiconductor layer having a silicon nitride film formed on a corresponding scanning electrode, an insulating layer formed on the silicon nitride film, and source and drain areas formed on the insulating layer.
Dependencies are inferred from the claim text.