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AssigneeSharp Kabushiki Kaisha
InventorsYuichi Saito, Masao Moriguchi, Tokuo Yoshida, Yasuaki Iwase, Yohsuke Kanzaki, Mayuko Sakamoto
Estimating the term…
A diode 201 includes a gate electrode 2, a gate insulating layer 5 provided on the gate electrode 2, at least one semiconductor layer 6, 7 provided on the gate insulating layer 5 and which includes a first region 6a and a second region 7b, a first electrode 10 which is provided on the first region 6a and which is electrically coupled to the first region 6a and the gate electrode 2, and a second electrode 12 which is provided on the second region 7b and which is electrically coupled to the second region 7b. The at least one semiconductor layer 6, 7 includes a channel region 6c which extends above the gate electrode 2 with the intervention of the gate insulating layer 5 therebetween, and a resistor region 7d which does not extend above the gate electrode 2. When the diode 201 is in an ON state, an electric current path is formed between the first electrode 10 and the second electrode 12, the electric current path including the channel region 6c and the resistor region 7d.
A semiconductor device, comprising a substrate, and a thin film transistor and a diode which are provided on the substrate, wherein
Dependencies are inferred from the claim text.
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Integrated devices formed in or on insulating or conducting substrates
Active matrix addressed cells: arrangements to prevent high voltage or static electricity failures
Having a particular composition, shape or crystalline structure of the active layer: comprising semiconductor materials not belonging to the Group…
Characterised by multiple TFTs: integrated with passive devices, e.g. auxiliary capacitors
About 2 years 10 months of term left · ends 1 Sep 2029 (estimated)
The present invention relates to a semiconductor device which includes a thin film transistor and a diode on the same substrate.
An active matrix substrate for use in a liquid crystal display device, or the like, includes a switching element, such as a thin film transistor (hereinafter, “TFT”), in each pixel. Examples of such a switching element which have been conventionally used in various applications include a TFT which includes an amorphous silicon film as an active layer (hereinafter, “amorphous silicon TFT”) and a TFT which includes a polycrystalline silicon film as an active layer (hereinafter, “polycrystalline silicon TFT”).
Since the mobility of electrons and holes in the polycrystalline silicon film is higher than in the amorphous silicon film, the polycrystalline silicon TFT has a higher ON current, and is capable of operating at a higher speed, than the amorphous silicon TFT. Thus, when an active matrix substrate is fabricated using the polycrystalline silicon TFT, the polycrystalline silicon TFT can also be used for a peripheral circuit, such as a driver and the like, as well as the switching elements. Therefore, there is an advantage that part or entirety of the peripheral circuit, such as a driver and the like, and a display portion can be integrally formed on the same substrate. Also, there is another advantage that the pixel capacitor of a liquid crystal display device, or the like, can be charged within a shorter switching time.
FIGS. 1(a) and (b) schematically shows a semiconductor device of embodiment 1 of the present invention. (a) is a plan view of the semiconductor device. (b) is a cross-sectional view taken along line A-A′ and line B-B′ of (a).
FIG. 2 A flowchart for illustrating an example of the fabrication method of the semiconductor device of embodiment 1 of the present invention.
FIGS. 3(a) and (b) are diagrams for illustrating a fabrication step of the semiconductor device of embodiment 1 of the present invention. (a) is a plan view. (b) is a cross-sectional view taken along line A-A′ and line B-B′ of (a).
The present invention is characterized in that, in a TFT-type diode, an electric current path of at least one semiconductor layer includes a channel region that extends above a gate electrode and a portion which does not extend above the gate electrode.
According to the present invention, a portion of the semiconductor layer in the electric current path which does not extend above the gate electrode serves as a resistor, so that an electric current does not smoothly flows between the terminals of the diode. Thus, by modifying the size of such a resistor (hereinafter, “resistor region”), the magnitude of the electric current flowing between the terminals of the diode can be controlled to have a desired value, without increasing the size of the diode.
In the present specification, the “electric current path” of a diode refers to a region through which an ON-current flows when the diode is in an ON state. The electric current path includes, in the semiconductor layer, a first region which is electrically coupled to a first electrode (source electrode), a channel region, and a second region which is electrically coupled to a second electrode (drain electrode). However, the electric current path does not include part of the semiconductor layer which is electrically coupled to, for example, an intermediate electrode.