A method of forming an image sensor includes forming a first image sensor element within a substrate. The first image sensor element and the substrate respectively comprise a first material. A second image sensor element is formed within the substrate. Forming the second image sensor element includes forming an isolation layer over the first image sensor element. Further, a buffer layer is formed over the isolation layer and an active layer is formed over the buffer layer. The active layer comprises a second material different from the first material.

A direct bonding method for infrared focal plane arrays, includes steps of depositing a thin adhesion layer on infrared radiation detecting material, removing a portion of the thin adhesion layer with a chemical-mechanical polishing process, forming a bonding layer at a bonding interface, and bonding the infrared radiation detecting material to a silicon wafer with the thin adhesion layer as a bonding layer. The thin adhesion layer may include SiO.sub.x, where x ranges between 1.0 and 2.0. The thickness of the thin adhesion layer to form the bonding layer is 500 angstrom or less.

A hybrid multispectral imaging sensor, characterized in that it comprises a photosensitive backside-illumination detector (DET) that is made on a substrate (100) made of InP, and that is formed of a matrix of pixels (105, P1, P2, P3) that are themselves made in a structure based on InGaAs (103), and a filter module (MF) that is formed of a matrix of elementary filters (1, 2, 3) reproducing said matrix of pixels, and that is mounted into contact with said substrate (100), said substrate (100) made of InP having a thickness less than 50 m, and preferably less than 30 m.

An array sensor includes a sensor element array that includes a plurality of sensor elements, a signal processing circuit array that includes a plurality of signal processing circuits coupled to the corresponding sensor elements, and a resistor network that supplies bias voltages to the corresponding signal processing circuits, wherein different voltages are applied to at least two voltage application nodes in the resistor network.

An imaging sensor array comprises an epitaxial germanium layer disposed on a silicon layer, and an electrically biased photoelectron collector arranged on the silicon layer, on a side opposite the germanium layer.

An infrared detector includes a pixel separation wall. The infrared detector includes a semiconductor crystal substrate; a first contact layer formed on the semiconductor crystal substrate, a pixel separation wall formed on the first contact layer and configured to separate pixels; a buffer layer formed on the first contact layer and on a side surface of the pixel separation wall in a region surrounded by the pixel separation wall, an infrared-absorbing layer formed on the buffer layer, a second contact layer formed on the infrared-absorbing layer, an upper electrode formed on the second contact layer, and a lower electrode formed on the first contact layer. The buffer layer and the first contact layer are formed of a compound semiconductor of a first conductivity type. The pixel separation wall and the second contact layer are formed of a compound semiconductor of a second conductivity type.

An infrared detector includes: a first light receiving layer having a first cutoff wavelength; a second light receiving layer having a second cutoff wavelength longer than the first cutoff wavelength; an intermediate filter layer having a third cutoff wavelength that is the same as or longer than the first cutoff wavelength and the same as or shorter than the second cutoff wavelength, the intermediate filter layer being disposed between the first light receiving layer and the second light receiving layer; a first barrier layer disposed between the first light receiving layer and the intermediate filter layer; and a second barrier layer disposed between the second light receiving layer and the intermediate filter layer.

Imaging systems and methods for imaging using the same color or monochromatic image sensor, wherein imaging can be switched between at least two imaging modes, for example between a visible imaging mode and an IR imaging mode, without moving any system component from a given position in an optical path between an imaged object and the image sensor. In an example, a system includes an image sensor, a tunable spectral filter and a multi-bandpass filter, the tunable spectral filter and the multi-bandpass filter arranged in a common optical path between an object and the image sensor, and a controller configured and operable to position the tunable spectral filter in a plurality of operation states related to a plurality of imaging modes.

The invention relates to short-wave infrared (SWIR) detector arrays, and methods for forming such arrays, comprising a light conversion layer (10) having a germanium-tin alloy composition. The shortwave infrared (SWIR) detector array comprises an absorber wafer (II) and a readout wafer (I). The absorber wafer (II) comprises a SWIR conversion layer (10) which has a Gei-xSn.sub.xalloy composition. The SWIR conversion layer (10) may have an internal structure comprising an array of rods (12) extending between a patterned support layer (40) and a doped silicon layer (10c). The detector comprises also a readout wafer (I) including an array of charge collecting areas and a readout electric circuit. The readout wafer (I) and the absorber wafer (II) are bonded by a low temperature bonding technique. The invention also relates to methods of fabrication of the SWIR detector array and to SWIR detector array applications such as a multi/hyperspectral LIDAR imaging systems.

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.