Optical sensor
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsHongyong Zhang, Masayuki Sakakura
Life of this patent
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Abstract
Disposing the light absorption layer formed in contact with a polycrystal silicon layer of a bottom gate type polycrystal silicon TFT allows a depletion layer formed between drain and channel forming regions to extend further into the inside of the light absorption layer, resulting in collection of photo carriers produced in the depletion layer into the channel forming region. The photo carriers collected into the channel forming region are subsequently collected into the source region to be output as large photocurrents by high mobility of the polycrystal silicon.
Claims24
An image sensor comprising:
- an optical sensor comprising a gate electrode over a substrate, a polycrystal semiconductor layer formed over said gate electrode with a gate insulating film interposed therebetween, and an amorphous semiconductor layer formed on said polycrystal semiconductor layer;
- a thin film transistor electrically connected to said optical sensor in series;
- and
- a capacitor having a first electrode and a second electrode, wherein said first electrode of said capacitor is electrically connected to said optical sensor and said thin film transistor.
An image sensor comprising:
- an optical sensor comprising a gate electrode over a substrate, a polycrystal semiconductor layer formed over said gate electrode with a gate insulating film interposed therebetween, and an amorphous semiconductor layer formed on said polycrystal semiconductor layer;
- a thin film transistor electrically connected to said optical sensor in series;
- a capacitor having a first electrode and a first electrode, wherein said first electrode of said capacitor is electrically connected to said optical sensor and said thin film transistor;
- and
- an amplifier electrically connected to said thin film transistor in series.
An image sensor comprising:
- an optical sensor comprising a gate electrode over a substrate, a polycrystal semiconductor layer formed over said gate electrode with a gate insulating film interposed therebetween, and an amorphous semiconductor layer formed on said polycrystal semiconductor layer;
- a thin film transistor electrically connected to said optical sensor;
- and
- a capacitor having a first electrode and a second electrode, wherein said first electrode of said capacitor is electrically connected to said optical sensor and said thin film transistor.
An image sensor comprising:
- an optical sensor comprising a gate electrode over a substrate, a polycrystal semiconductor layer formed over said gate electrode with a gate insulating film interposed therebetween, and an amorphous semiconductor layer formed on said polycrystal semiconductor layer;
- a thin film transistor electrically connected to said optical sensor;
- a capacitor having a first electrode and a first electrode, wherein said first electrode of said capacitor is electrically connected to said optical sensor and said thin film transistor;
- and
- an amplifier electrically connected to said thin film transistor in series.
An image sensor comprising:
- an optical sensor comprising a gate electrode over a substrate, a polycrystal semiconductor layer formed over said gate electrode with a gate insulating film interposed therebetween, and an amorphous semiconductor layer formed on said polycrystal semiconductor layer;
- and
- a thin film transistor electrically connected to said optical sensor.
An image sensor comprising:
- an optical sensor comprising a gate electrode over a substrate, a polycrystal semiconductor layer formed over said gate electrode with a gate insulating film interposed therebetween, and an amorphous semiconductor layer formed on said polycrystal semiconductor layer;
- a thin film transistor electrically connected to said optical sensor;
- and
- an amplifier electrically connected to said thin film transistor in series.
Dependencies are inferred from the claim text.