Semiconductor device and manufacturing method thereof
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsKengo Akimoto, Satoshi Murakami
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Abstract
According to the present invention, wirings, electrodes or the like formed from two films (an ITO film and an aluminum film) which are incompatible with each other are connected, and low power consumption is realized even if a display screen size is increased in an active matrix display device. A three-layer structure or a two-layer structure is employed to obtain a favorable ohmic contact with ITO. The structure of a wiring or an electrode includes a layer having an aluminum carbon alloy which does not react with ITO. The wiring or an electrode is contacted with ITO.
Claims31
A semiconductor device comprising a wiring, said wiring including at least a first layer of aluminum and a second layer of an aluminum carbon alloy in contact with said first layer.
A semiconductor device comprising:
- a thin film transistor including a semiconductor film over a substrate having an insulating surface;
- an electrode or a wiring having at least a first conductive layer including titanium or molybdenum, a second conductive layer including aluminum, and a third conductive layer including an aluminum carbon alloy;
- and
- a transparent conductive layer which is formed on the third conductive layer,
- wherein the first conductive layer is formed on the semiconductor film,
- wherein the second conductive layer is formed on the first conductive layer,
- wherein the third conductive layer is formed on the second conductive layer.
A semiconductor device comprising:
- a thin film transistor including a semiconductor film over a substrate having an insulating surface;
- an electrode or a wiring having at least a first conductive layer including titanium or molybdenum, a second conductive layer including aluminum, and a third conductive layer including an aluminum carbon alloy;
- and
- a transparent conductive layer which is formed on the third conductive layer,
- wherein the first conductive layer is formed on the semiconductor film,
- wherein the second conductive layer is formed on the first conductive layer,
- wherein the third conductive layer is formed on the second conductive layer,
- wherein a content of the titanium included in the third conductive layer is 1 atoms % to 20 atoms %.
A semiconductor device comprising:
- a thin film transistor including a semiconductor film over a substrate having an insulating surface;
- an electrode or a wiring having at least a first conductive layer including titanium or molybdenum, a second conductive layer including aluminum, and a third conductive layer including an aluminum carbon alloy;
- and
- a transparent conductive layer which is formed on the third conductive layer,
- wherein the first conductive layer is formed on the semiconductor film,
- wherein the second conductive layer is formed on the first conductive layer,
- wherein the third conductive layer is formed on the second conductive layer
- wherein a content of the nickel included in the third conductive layer is 0.5 atoms % to 7 atoms %.
A semiconductor device comprising:
- a thin film transistor including a semiconductor film over a substrate having an insulating surface;
- an electrode or a wiring having at least a first conductive layer including titanium or molybdenum, a second conductive layer including aluminum, and a third conductive layer including an aluminum carbon alloy including molybdenum;
- and
- a transparent conductive layer which is formed on the third conductive layer,
- wherein the first conductive layer is formed on the semiconductor film,
- wherein the second conductive layer is formed on the first conductive layer,
- wherein the third conductive layer is formed on the second conductive layer,
A method for manufacturing a semiconductor device, comprising the steps of:
- forming a plurality of thin film transistors having a semiconductor film over a substrate having an insulating surface;
- and
- forming a transparent conductive film to be connected to the thin film transistors,
- wherein an electrode which is in contact with the transparent conductive film and the semiconductor film,
- wherein the electrode has at least a molybdenum film and an aluminum film,
- wherein the electrode is patterned through a step of dry etching of the aluminum film and a step of wet etching of the molybdenum film using a same mask, and by the wet etching, the molybdenum film is selectively etched and a surface of the transparent conductive film is cleaned simultaneously.
Dependencies are inferred from the claim text.