Image sensor with a high absorption layer
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChien-Chang Huang, Chien Nan Tu, Ming-Chi Wu, Yu-Lung Yeh, Ji Heng Jiang
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Abstract
An image sensor with high quantum efficiency is provided. In some embodiments, a semiconductor substrate includes a non-porous semiconductor layer along a front side of the semiconductor substrate. A periodic structure is along a back side of the semiconductor substrate. A high absorption layer lines the periodic structure on the back side of the semiconductor substrate. The high absorption layer is a semiconductor material with an energy bandgap less than that of the non-porous semiconductor layer. A photodetector is in the semiconductor substrate and the high absorption layer. A method for manufacturing the image sensor is also provided.
Claims20
An image sensor, comprising:
- a substrate comprising a porous semiconductor layer along a bottom of the substrate;
- a photodetector in the substrate;
- and
- a semiconductor layer that lines and conforms to an uneven surface of the porous semiconductor layer at the bottom of the substrate.
An image sensor, comprising:
- a semiconductor substrate comprising a plurality of semiconductor protrusions on a bottom surface of the semiconductor substrate;
- a semiconductor layer lining the plurality of semiconductor protrusions, wherein the semiconductor layer has a direct bandgap;
- a photodetector in the semiconductor substrate;
- and
- a transistor overlying the semiconductor substrate adjacent to the photodetector.
An image sensor, comprising:
- a semiconductor substrate;
- a photodetector in the semiconductor substrate;
- and
- a semiconductor layer underlying the semiconductor substrate, and further having a surface with a periodic profile from a first side of the photodetector to a second side of the photodetector opposite the first side;
- wherein an energy bandgap of the semiconductor layer is less than about 1 electron volt (eV), and wherein an energy bandgap of the semiconductor substrate is greater than about 1 eV.
Dependencies are inferred from the claim text.