Photodetector and method for forming the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorChan-Hong Chern
Life of this patent
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Abstract
A photodetector is provided. The photodetector includes a bottom electrode region in a semiconductor layer, a light absorption material in the semiconductor layer, and a first buffer layer sandwiched between a bottom surface of the light absorption material and the semiconductor layer. The first buffer layer includes, from bottom to top, a first Si layer, a first SiGe layer, a second Si layer, and a second SiGe layer. A first atomic percentage of Ge in the first SiGe layer is less than a second atomic percentage of Ge in the second SiGe layer. The photodetector further includes a top electrode region over the light absorption material.
Claims20
A photodetector, comprising:
- a bottom electrode region in a semiconductor layer;
- a light absorption material in the semiconductor layer;
- a first buffer layer sandwiched between a bottom surface of the light absorption material and the semiconductor layer, wherein the first buffer layer comprises, from bottom to top, a first Si layer, a first SiGe layer, a second Si layer, and a second SiGe layer, and a first atomic percentage of Ge in the first SiGe layer is less than a second atomic percentage of Ge in the second SiGe layer;
- and
- a top electrode region over the light absorption material.
A photodetector, comprising:
- bottom electrode regions above a buried oxide layer;
- a semiconductor layer between the bottom electrode regions;
- a light absorption material at least partially embedded within the semiconductor layer;
- a first buffer layer above the light absorption material, wherein the first buffer layer comprises alternatingly stacking Ge layers and first SiGe layers;
- and
- a top electrode region above the first buffer layer.
A method for forming a photodetector, comprising:
- forming a bottom electrode region in a semiconductor layer;
- etching a semiconductor layer to form a first cavity;
- forming a light absorption material in the first cavity;
- forming a buffer layer over the light absorption material, wherein the forming the buffer layer comprises repeating steps of:
- delivering a germanium-containing precursor to grow a Ge layer;
- and
- delivering a silicon-containing precursor and the germanium-containing precursor to grow a SiGe layer;
- and
- forming a top electrode region over the buffer layer.
Dependencies are inferred from the claim text.