Various embodiments of the present disclosure are directed towards a semiconductor device. The semiconductor device includes a first doped region having a first doping type disposed in a semiconductor substrate. A second doped region having a second doping type different than the first doping type is disposed in the semiconductor substrate and laterally spaced from the first doped region. A waveguide structure is disposed in the semiconductor substrate and laterally between the first doped region and the second doped region. A photodetector is disposed at least partially in the semiconductor substrate and laterally between the first doped region and the second doped region. The waveguide structure is configured to guide one or more photons into the photodetector. The photodetector has an upper surface that continuously arcs between opposite sidewalls of the photodetector. The photodetector has a lower surface that continuously arcs between the opposite sidewalls of the photodetector.

A substrate is formed to include a substrate base and a substrate extension. A photodiode contacts the substrate base. The substrate extension is adjacent the photodiode. An additional device contacts the substrate extension. A sidewall spacer contacts the photodiode and the substrate extension. The additional device includes conductive elements within the substrate extension adjacent the sidewall spacer.

Some embodiments relate to an integrated circuit (IC) disposed on a silicon substrate, which includes a well region having a first conductivity type. An epitaxial pillar of SiGe or Ge extends upward from the well region. The epitaxial pillar includes a lower epitaxial region having the first conductivity type and an upper epitaxial region having a second conductivity type, which is opposite the first conductivity type. A dielectric layer is arranged over an upper surface of the substrate and is disposed around the lower epitaxial region to extend over outer edges of the well region. The dielectric layer has inner sidewalls that contact outer sidewalls of the epitaxial pillar. A dielectric sidewall structure has a bottom surface that rests on an upper surface of the dielectric layer and has inner sidewalls that extend continuously from the upper surface of the dielectric layer to a top surface of the epitaxial pillar.

Various embodiments of the present disclosure are directed towards a semiconductor device. The semiconductor device includes a first doped region having a first doping type disposed in a semiconductor substrate. A second doped region having a second doping type different than the first doping type is disposed in the semiconductor substrate and laterally spaced from the first doped region. A waveguide structure is disposed in the semiconductor substrate and laterally between the first doped region and the second doped region. A photodetector is disposed at least partially in the semiconductor substrate and laterally between the first doped region and the second doped region. The waveguide structure is configured to guide one or more photons into the photodetector. The photodetector has an upper surface that continuously arcs between opposite sidewalls of the photodetector. The photodetector has a lower surface that continuously arcs between the opposite sidewalls of the photodetector.

In some embodiments, the present disclosure relates to a semiconductor device, including a substrate including a first semiconductor material and a semiconductor layer extending into an upper surface of the substrate and including a second semiconductor material with a different band gap than the first semiconductor material. The semiconductor device also includes a passive cap including a first dielectric material and disposed along the upper surface of the substrate and on opposite sides of the semiconductor layer, and a photodetector in the semiconductor layer. The first dielectric material includes silicon nitride.

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.

Some embodiments relate to an integrated circuit (IC) disposed on a silicon substrate, which includes a well region having a first conductivity type. An epitaxial pillar of SiGe or Ge extends upward from the well region. The epitaxial pillar includes a lower epitaxial region having the first conductivity type and an upper epitaxial region having a second conductivity type, which is opposite the first conductivity type. A dielectric layer is arranged over an upper surface of the substrate and is disposed around the lower epitaxial region to extend over outer edges of the well region. The dielectric layer has inner sidewalls that contact outer sidewalls of the epitaxial pillar. A dielectric sidewall structure has a bottom surface that rests on an upper surface of the dielectric layer and has inner sidewalls that extend continuously from the upper surface of the dielectric layer to a top surface of the epitaxial pillar.

A photovoltaic cell includes a germanium-containing well embedded in a single crystalline silicon substrate and extending to a proximal horizontal surface of the single crystalline silicon substrate, wherein germanium-containing well includes germanium at an atomic percentage greater than 50%. A silicon-containing capping structure is located on a top surface of the germanium-containing well and includes silicon at an atomic percentage greater than 42%. The silicon-containing capping structure prevents oxidation of the germanium-containing well. A photovoltaic junction may be formed within, or across, the trench by implanting dopants of a first conductivity type and dopants of a second conductivity type.

A photodetector disclosed herein includes an N-doped waveguide structure defined in a semiconductor material, wherein the N-doped waveguide structure comprises a plurality of first fins. Each adjacent pair of the plurality of first fins is separated by a trench formed in the semiconductor material. The photodetector also includes a detector structure positioned on the N-doped waveguide structure, wherein a portion of the detector structure is positioned laterally between the plurality of first fins. The detector structure comprises a single crystal semiconductor material. The photodetector also includes a first diffusion region that extends from the bottom surface of the trench into the semiconductor material, wherein the first diffusion region comprises atoms of the single crystal semiconductor material of the detector structure.

A method for structuring an insulating layer on a semiconductor wafer, at least comprising the steps of: Provision of a semiconductor wafer with a top, a bottom and comprising multiple solar cell stacks, wherein each solar cell stack is a Ge substrate, which forms the bottom of the semiconductor wafer, a Ge subcell and at least two III-V subcells, in the above order, and at least one passage opening, which extends from the top to the bottom of the semiconductor wafer and has a connected side wall, an insulating layer two-dimensionally deposited on the top of the semiconductor wafer, on the side wall of the passage opening and/or on the bottom of the semiconductor wafer, and the deposition of an etch-resistant filling material by means of a printing process on an area of the top which comprises the passage opening, and into the passage opening.