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US 2024/0429332 A1Published application
Microstructure enhanced absorption photosensitive devices
AssigneeW&W Sens Devices, Inc.
InventorsShih-Yuan WANG, Shih-Ping WANG
Life of this patent
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Abstract
Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.
Claims15
An integrated structure comprising:
- an array of pillars comprising SI, Ge, and/or SiGe alloy semiconductor material, wherein at least some of the pillars are configured as photodetectors that have respective light-receiving surfaces and respective sides;
- wherein at least some of the photodetectors comprise P-doped and N-doped regions and are configured to respond to illumination with light in selected visible and infrared wavelengths by generating electrical charge carriers;
- one or more holes that are deliberately formed at the light-receiving surface of each of at least some of the photodetectors, have elongated or other shapes at the light-receiving surfaces, extend into the photodetectors to a depth of 100 to 10000 nm, and are filled at least partly with solid dielectric material;
- side-isolation comprising solid material between at least portions of the sides of at least some of the photodetectors;
- a solid dielectric material forming a base dielectric region for the array;
- electrical contacts configured to provide electrical pathways coupled electrically to at least some of the photodetectors, including for selected reverse-biasing thereof;
- wherein the presence of said one or more holes increases by a factor of at least 1.1 the absorption of the light by at least some of the photodetectors relative to like photodetectors lacking said holes.
4 more elements
An integrated structure comprising:
- an array of pillars comprising SI, Ge, and/or alloyed SiGe semiconductor material, wherein at least some of the pillars are configured as photodetectors that have respective sides and light-receiving surfaces with selected widths;
- wherein at least some of the photodetectors comprise P-doped and N-doped regions and are configured to respond to illumination with light in selected visible and infrared wavelengths by generating electrical charge carriers;
- one or more holes that are deliberately formed at the light-receiving surface of each of at least some of the photodetectors,
- wherein each of the holes (i) has an elongated shape extending in length over less than the width of the light-receiving surface in which the hole is formed, (ii) has at least one closed contour at the light-receiving surface in which the hole is formed, (ii) extends into the photodetector in which the hole is formed to a depth of 100 to 10000 nm, and (iv) is filled at least partly with solid dielectric material;
- side-isolation comprising solid material between at least portions of the sides of at least some of the photodetectors;
- a solid dielectric material forming a base dielectric region for the array;
- electrical contacts configured to provide electrical pathways coupled electrically to at least some of the photodetectors, including for selected reverse-biasing thereof;
- wherein the presence of the one or more holes increases, by a factor of at least 1.1, absorption of the light by at least some of the photodetectors relative to like photodetectors lacking the holes;
- and
- wherein the array of photodetectors is monolithically integrated with SI electronic devices for signal processing and transmission.
7 more elements
Dependencies are inferred from the claim text.