76237results about "Transistor" patented technology

In a thin film transistor (1), a gate insulating layer (4) is formed on a gate electrode (3) formed on an insulating substrate (2). Formed on the gate insulating layer (4) is a semiconductor layer (5). Formed on the semiconductor layer (5) are a source electrode (6) and a drain electrode (7). A protective layer (8) covers them, so that the semiconductor layer (5) is blocked from an atmosphere. The semiconductor layer (5) (active layer) is made of, e.g., a semiconductor containing polycrystalline ZnO to which, e.g., a group V element is added. The protective layer (8) thus formed causes decrease of a surface level of the semiconductor layer (5). This eliminates a depletion layer spreading therewithin. Accordingly, the ZnO becomes an n-type semiconductor indicating an intrinsic resistance, with the result that too many free electrons are generated. However, the added element works on the ZnO as an accepter impurity, so that the free electrons are reduced. This decreases a gate voltage required for removal of the free electrons, so that the threshold voltage of the thin film transistor (1) becomes on the order of 0V. This allows practical use of a semiconductor device which has an active layer made of zinc oxide and which includes an protective layer for blocking the active layer from an atmosphere.

To provide a semiconductor device in which a defect or fault is not generated and a manufacturing method thereof even if a ZnO semiconductor film is used and a ZnO film to which an n-type or p-type impurity is added is used for a source electrode and a drain electrode. The semiconductor device includes a gate insulating film formed by using a silicon oxide film or a silicon oxynitride film over a gate electrode, an Al film or an Al alloy film over the gate insulating film, a ZnO film to which an n-type or p-type impurity is added over the Al film or the Al alloy film, and a ZnO semiconductor film over the ZnO film to which an n-type or p-type impurity is added and the gate insulating film.

This invention relates to novel, transparent oxide semiconductor thin film transistors (TFT's) and a process for making them.

A thin film transistor (TFT) includes a source electrode, a drain electrode, and a gate electrode. A gate insulator is coupled to the source electrode, drain electrode, and gate electrode. The gate insulator includes room temperature deposited high-K materials so as to allow said thin film transistor to operate at low operating voltage.

A thin film transistor comprises a zinc-oxide-containing semiconductor material. Such transistors can further comprise spaced apart first and second contact means or electrodes in contact with said material. Further disclosed is a process for fabricating a thin film transistor device, wherein the substrate temperature is no more than 300° C. during fabrication.

An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

A semiconductor device improves the electron mobility in the n-channel MOSFET and reduces the bend or warp of the semiconductor substrate or wafer. The fist nitride layer having a tensile stress is formed on the substrate to cover the n-channel MOSFET. The tensile stress of the first nitride layer serves to relax a compressive stress existing in the channel region. The second nitride layer having an actual compressive stress is formed on the substrate to cover the p-channel MOSFET. The first and second nitride layers serve to decrease bend or warp of the substrate. Preferably, the first nitride layer is a nitride layer of Si formed by a LPCVD process, and the second nitride layer is a nitride layer of Si formed by a PECVD process.