Various embodiments of the present disclosure are directed towards an image sensor having a photodetector disposed in a semiconductor substrate. The photodetector comprises a first doped region comprising a dopant having a first doping type. A deep well region is disposed within the semiconductor substrate, where the deep well region extends from a back-side surface of the semiconductor substrate to a top surface of the first doped region. A second doped region is disposed within the semiconductor substrate and abuts the first doped region. The second doped region and the deep well region comprise a second dopant having a second doping type opposite the first doping type, where the second dopant comprises gallium.

A process for fabricating a hybrid optical detector, includes the steps of: assembling, via an assembly layer, on the one hand an absorbing structure and on the other hand a read-out circuit, locally etching, through the absorbing structure, the assembly layer and the read-out circuit up to the contacts, so as to form electrical via-holes, depositing a protective layer on the walls of the via-holes, producing a doped region of a second doping type different from the first doping type by diffusing a dopant into the absorbing structure through the protective layer, the region extending annularly around the via-holes so as to form a diode, depositing a metallization layer on the walls of the via-holes allowing the doped region to be electrically connected to the contact.

A mid-infrared detector that uses a heavily doped material (e.g., indium arsenide) as a backplane to the detector structure to improve detector performance and fabrication cost. The infrared detector includes a substrate and a backplane of heavily doped material consisting of two or more of the following materials: indium, gallium, arsenic and antimony. The backplane resides directly on the substrate. The infrared detector further includes a photodetector (e.g., type-I or type-II strained layer superlattice (SLS) nBn photodetector, type-I or type-II SLS pn junction photodetector, a quantum-dot infrared photodetector, a quantum well infrared photodetector, a homogeneous material pn junction photodetector) residing directly on the backplane. Additionally, the infrared detector may include a metal structure residing directly on the photodetector. In this manner, the absorption of electromagnetic energy in the photodetector is enhanced.

Systems and methods for thermal radiation detection utilizing a thermal radiation detection system are provided. The thermal radiation detection system includes one or more Indium Antimonide (InSb)-based photodiode infrared detectors and a temperature sensing circuit. The temperature sensing circuit is configured to generate signals correlated to the temperatures of one or more of the plurality of infrared sensor elements. The thermal radiation detection system also includes a signal processing circuit.

Diffusion-based and ion implantation-based methods are provided for fabricating planar photodetectors. The methods may be used to fabricate planar photodetectors comprising type II superlattice absorber layers but without mesa structures. The fabricated planar photodetectors exhibit high quantum efficiencies, low dark current densities, and high specific detectivities as compared to photodetectors having mesa structures.

Systems and methods for thermal radiation detection utilizing a thermal radiation detection system are provided. The thermal radiation detection system includes one or more mercury-cadmium-telluride (HgCdTe)-based photodiode infrared detectors or Indium Arsenide (InAs)-based photodiode infrared detectors and a temperature sensing circuit. The temperature sensing circuit is configured to generate signals correlated to the temperatures of one or more of the plurality of infrared sensor elements. The thermal radiation detection system also includes a signal processing circuit.

Provided is a semiconductor epitaxial wafer, including a substrate, a first epitaxial structure, a first ohmic contact layer and a second epitaxial stack structure. It is characterized in that the ohmic contact layer includes a compound with low nitrogen content, and the ohmic contact layer does not induce significant stress during the crystal growth process. Accordingly, the second epitaxial stack structure formed on the ohmic contact layer can have good epitaxial quality, thereby providing a high-quality semiconductor epitaxial wafer for fabricating a GaAs integrated circuit or a InP integrated circuit. At the same time, the ohmic contact properties of ohmic contact layers are not affected, and the reactants generated during each dry etching process are reduced.

Provided is a high-performance infrared optical device including a reflecting layer structure that can be widely used in the mid-infrared region. An infrared optical device that has a light emission/reception property of having a peak at a center wavelength λ comprises: a semiconductor substrate; and a thin film laminate portion including a first reflecting layer formed on the semiconductor substrate, a lower semiconductor layer of a first conductivity type, a light emitting/receiving layer, an upper semiconductor layer of a second conductivity type, and a second reflecting layer in the stated order, wherein the first reflecting layer has a constituent material made of AlGaInAsSb where 0≤Al+Ga≤0.5 and 0≤As≤1.0, and includes a plurality of layers that differ in impurity concentration, and the center wavelength λ is 2.5 μm or more at room temperature.

Various embodiments of the present disclosure are directed towards an image sensor having a photodetector disposed in a semiconductor substrate. The photodetector comprises a first doped region comprising a first dopant having a first doping type. A deep well region extends from a back-side surface of the semiconductor substrate to a top surface of the first doped region. A second doped region is disposed within the semiconductor substrate and abuts the first doped region. The second doped region and the deep well region comprise a second dopant having a second doping type opposite the first doping type. An isolation structure is disposed within the semiconductor substrate. The isolation structure extends from the back-side surface of the semiconductor substrate to a point below the back-side surface. A doped liner is disposed between the isolation structure and the second doped region. The doped liner comprises the second dopant.

A semiconductor light-receiving element, includes: a semiconductor substrate; a high-concentration layer of a first conductivity type formed on the semiconductor substrate; a low-concentration layer of the first conductivity type formed on the high-concentration layer of the first conductivity type and in contact with the high-concentration layer of the first conductivity type; a low-concentration layer of a second conductivity type configured to form a PN junction interface together with the low-concentration layer of the first conductivity type; and a high-concentration layer of the second conductivity type formed on the low-concentration layer of the second conductivity type and in contact with the low-concentration layer of the second conductivity type. The low-concentration layers have a carrier concentration of less than 1×10.sup.16/cm.sup.3. The high-concentration layers have a carrier concentration of 1×10.sup.17/cm.sup.3 or more. At least one of the low-concentration layers includes an absorption layer with a band gap that absorbs incident light.