The present disclosure relates to semiconductor structures and, more particularly, to a photodiode with an integrated, light focusing elements and methods of manufacture. The structure includes: a trench photodiode comprising a domed structure; and a doped material on the domed structure, the doped material having a concave underside surface.

There is to provide a semiconductor device including a light receiving element capable of reducing the manufacturing cost and improving the optical performance of the light receiving element. For example, a p type germanium layer, an intrinsic germanium layer, and an n type germanium layer forming the structure body of a Ge photodiode are formed according to a continuous selective epitaxial growth. An insulating film having an opening portion is formed on the silicon layer of a SOI substrate, and an intrinsic germanium layer is formed bulging from the opening portion to above the insulating film. In short, by using the insulating film having the opening portion, the cross section of the intrinsic germanium layer is formed into a mushroom shape.

A light absorption apparatus includes a substrate, a light absorption layer above the substrate on a first selected area, a silicon layer above the light absorption layer, a spacer surrounding at least part of the sidewall of the light absorption layer, an isolation layer surrounding at least part of the spacer, wherein the light absorption apparatus can achieve high bandwidth and low dark current.

A germanium metal-semiconductor-metal (MSM) photodetector is fabricated by growing crystalline germanium from an amorphous silicon seed, supported by an amorphous substrate, at a temperature of about 450° C. In this fabrication, crystalline Ge is grown via selective deposition in geometrically confined channels, where amorphous silicon is disposed as the growth seed. Ge growth extends from the growth seed along the channels to a lithographically defined trench. The Ge emerging out of the channels includes crystalline grains that coalesce to fill the trench, forming a Ge strip that can be used as the active area of a photodetector. One or more Schottky contacts can be formed by a thin tunneling layer (e.g., Al.sub.2O.sub.3) deposited on the Ge strip and metal contracts formed on the tunneling layer.

Disclosed is an active photonic device having a Darlington configuration with a substrate and a collector layer that is over the substrate. The collector layer includes an inner collector region. An outer collector region substantially surrounds the inner collector region and is spaced apart from the inner collector region. A base layer is over the collector layer. A first outer base region and a second outer base region substantially surround the inner base region and are spaced apart from the inner base region and each other. An emitter layer is over the base layer. The emitter layer includes an inner emitter region that is ring-shaped and resides over and extends substantially around an outer periphery of the inner base region. A first outer emitter region and a second outer emitter region substantially surround the inner emitter region and are spaced apart from the inner emitter region and each other.

Radiation detectors are disclosed. The radiation detectors comprise a substrate and at least one radiation sensitive region on the substrate, the at least one radiation sensitive region comprising an array of elongate nanostructures projecting from the substrate. Methods of manufacture of such radiation detectors are also disclosed.

A light absorption apparatus includes a substrate, a light absorption layer above the substrate on a first selected area, a silicon layer above the light absorption layer, a spacer surrounding at least part of the sidewall of the light absorption layer, an isolation layer surrounding at least part of the spacer, wherein the light absorption apparatus can achieve high bandwidth and low dark current.

A photodetector structure includes a substrate including a semiconductor film, a light absorption layer which is in contact with the semiconductor film and includes germanium (Ge), on the substrate, a first coating layer which wraps at least a part of a side surface of the light absorption layer, on the substrate, and an optical waveguide which is in contact with the light absorption layer and includes silicon nitride (SiN), on the first coating layer, wherein a lower surface of the optical waveguide is higher than a lower surface of the light absorption layer.

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 and structure providing an optical sensor having an optimized Ge—Si interface includes providing a substrate having a pixel region and a logic region. In some embodiments, the method further includes forming a trench within the pixel region. In various examples, and after forming the trench, the method further includes forming a doped semiconductor layer along sidewalls and along a bottom surface of the trench. In some embodiments, the method further includes forming a germanium layer within the trench and over the doped semiconductor layer. In some examples, and after forming the germanium layer, the method further includes forming an optical sensor within the germanium layer.