A micro-bolometric infrared (IR) staring array is described. The active element in each pixel within a two-dimensional array is a device having a selectively forward-biased p-n junction, e.g. a selectively biased diode. Each diode in the array serves as both an IR energy detecting element and a switching element. Each diode in a given row of the IR pixel array to be sensed, or read, is driven at a constant voltage, rendering its IR response highly controllable in the forward biased operating curve of the diodes in the addressed row. Diodes not being driven are, due to their reverse bias, in their off state producing minute leakage current and thus make no significant contribution to the sensed current representing a given pixel's IR exposure. The row-addressed driven or active diodes are sensed column by column by sample and hold techniques to produce a two-dimensional IR pixel image of a target. This simplifies the geometries as well as the cell structures while increasing the fill ratio to greater than approximately fifty percent. Moreover, manufacturing yields are greatly improved because of the topologic and process simplicities and compatibility with standard integrated circuit processes.

Micro-bolometric infrared staring array

A bonding apparatus (40) is provided for use in coupling a first substrate (20) with flip chip type interconnections (24) to a second substrate (22) having matching flip chip type interconnections (26). The bonding apparatus (40) includes a pedestal assembly (50) which may be used to align and couple the first substrate (20) with the second substrate (22) and transport the substrates (20 and 22) from the bonding apparatus (40) to a heater assembly (110). Magnetic force is used to maintain the alignment of the first substrate (20) with the second substrate (22) during temperature cycling within the heater assembly. The pedestal assembly (50) includes a magnet slidably disposed on the exterior of the pedestal assembly (50). For some applications, the magnet (60) may be formed from one or more permanent magnets. For other applications, magnet (60) may be formed from one or more electromagnets.

Apparatus and method for flip-chip bonding

An infrared radiation detector device comprises a dipole antenna mounted on a substrate and connected through blocking contacts to a bandgap detector element. The dipole antenna has a length which is approximately one half the wavelength of the incident infrared radiation. The bandgap detector element has linear dimensions which are each substantially smaller than the wavelength of the detected radiation. A group of detector devices are combined to form an array which can produce a pixel signal for an image. Unlike conventional infrared radiation detectors, the disclosed detector device is capable of producing a usable output signal without the need for cooling below ambient temperature.

Uncooled infrared detector

An infrared radiation detector is disclosed which is fabricated on a dielectric substrate. The detector utilizes photosensitive segments which are included within elongate members disposed on the surface of the substrate. The elongate members comprise photosensitive detector segments which are located between and contact non-photosensitive segments and the entirety of each strip is electrically conductive. The elongate members are preferably offset from each other by less than the wavelength of the radiation and the photosensitive segments within the elongate members are also preferably spaced apart by less than the wavelength of the radiation. A reflective plane, typically an aluminum layer, is offset from the plane of the detector segments by less than the wavelength of the radiation. Incident radiation is captured by the overall detector structure which includes the reflective plane and the elongate members which include both photosensitive and non-photosensitive segments. The radiation power is transferred to the photosensitive detector segments to produce a detection signal. The detection signals are combined along the length of the elongate members and conveyed through electrical conductors at the ends of the members to produce a composite radiation detection signal. A plurality of the detectors can be combined to produce an infrared imager.

Infrared radiation detector

An infrared radiation detector device has an array of detectors each of which comprises a pattern of parallel detector elements. Each detector produces a pixel signal for an image. The elements of the detector are photoconductive or photovoltaic bandgap materials and the elements are spaced apart at a dimension which is equal to or less than the wavelength of the radiation to be received. Additional layered structures above and/or below the detector elements provide impedance matching between free space radiation and the radiation impedance of the detector elements to increase the capture of radiation.

Bandgap radiation detector

An improved electromagnetic radiation-sensitive semiconductor device together with a method of making same is disclosed in which surface regions directly beneath the active portion of the electrical contacts are provided with a layer of semiconductor material having a higher bandgap than the radiation sensitive material which repels minority carriers but allows the passage of majority carriers. Because the rate of annihilation of minority carriers at the contact to which they are attracted is reduced, the responsivity of the detector is greatly enhanced.

Electromagnetic radiation detectors

The electromagnetic radiation sensitive detector comprises a substrate (10), a first layer (12) on the substrate of radiation sensitive semiconductor material of a given conductivity type and having a first energy bandgap, at least one ohmic contact (16) providing electrical communication with the first layer, and a second layer (14) of semiconductor material of the same conductivity type as the first layer but having an energy bandgap greater than that of the first layer, the second layer being located on the first layer (12) beneath the or each contact (16) to which minority carriers are attracted from the first layer to enhance the responsivity of the detector

Darryl Lyle Smith

Papers

Electromagnetic radiation detectors

Electromagnetic radiation detector