Abstract: A radiation imaging device includes an image cell array having an array of detector cells and an array of image cell circuits. Each image cell circuit is associated with a respective detector cell and includes counting. The image cell circuits may include threshold circuitry configured to receive signals generated in the respective detector cell and having values dependent on the incident radiation energy. The counting circuitry may be coupled to the threshold circuitry.

Abstract: A method, suitable for forming metal contacts on a semiconductor substrate at positions for defining radiation detector cells, includes the steps of forming one or more layers of material on a surface of the substrate with openings to the substrate surface at the contact positions; forming a layer of metal over the layer(s) of material and the openings; and removing metal overlying the layer(s) of material to separate individual contacts. Optionally, a passivation layer to be left between individual contacts on the substrate surface may be applied. Etchants used for removing unwanted gold (or other contact matter) are preferably prevented from coming into contact with the surface of the substrate, thereby avoiding degradation of the resistive properties of the substrate.

Abstract: A semiconductor imaging device includes a semiconductor radiation detector substrate, for example of cadmium zinc telluride, with at least two faces. A first face has at least one charge output contact formed from electrically conductive material or materials and a second face having a contact formed from electrically conductive material or materials. The second face contact is for applying a bias voltage to provide an electric field between the first and second faces. The second face contact, or a third face of the semiconductor imaging device, or an edge between the second and third faces has deposited thereon at least a partial covering of a further material different from the electrically conductive material or materials of the second face contact. The deposited material can be a semiconductor, insulating or passivation material, for example aluminium nitride. Such a radiation detector can provide linear detector behaviour for all possible combinations of exposure and X-ray tube voltage.

Abstract: An imaging support for supporting a plurality of imaging device tiles at respective tile mounting locations to define a tiled imaging surface is provided. Each of the imaging device tiles has a semiconductor detector with a plurality of pixel cells coupled to a semiconductor substrate with a corresponding plurality of pixel circuits. The semiconductor detector and the semiconductor substrate are carried on a mount having an imaging device tile contact. The imaging support is configured for mounting each of the imaging device tiles on the imaging support in a non-destructive, removable manner at respective tile mounting locations, each of which includes an imaging support contact at a contact position.

Abstract: A method, suitable for forming metal contacts on a semiconductor substrate at positions for defining radiation detector cells, includes the steps of forming one or more layers of material on a surface of the substrate with openings to the substrate surface at the contact positions; forming a layer of metal over the layer(s) of material and the openings; and removing metal overlying the layer(s) of material to separate individual contacts. Optionally, a passivation layer to be left between individual contacts on the substrate surface may be applied. Etchants used for removing unwanted gold (or other contact matter) are preferably prevented from coming into contact with the surface of the substrate, thereby avoiding degradation of the resistive properties of the substrate.

Abstract: An imaging support for supporting imaging devices in respective positions to define an imaging surface is arranged to permit the imaging devices to be removably mounted on the support in a non-destructive, removable manner. In one embodiment the removable mounting is achieved by providing a source of reduced air pressure behind the imaging devices on the imaging support to suck the imaging devices onto the imaging support so that the imaging devices are accurately located on the support in a removable, non-destructive manner. The imaging devices are removable without damage to the device to be removed, the surrounding devices or the support. Defective devices can readily and quickly be replaced. Correctly functioning imaging devices can easily be removed and re-used on the same or a different imaging support.

Abstract: A semiconductor imaging device, for use, for example, in medical diagnosis and non-destructive testing, includes a radiation detector semiconductor substrate and a readout substrate connected to the detector by means of low temperature solder bumps A low temperature solder is preferably a lead-tin based solder having a melting point below that of eutectic lead-tin solder. Preferred embodiments of such low temperature solder include bismuth based alloys such as, for example, the eutectic (52 wt-%Bi, 32 wt-%Pb, 16 wt-%Sn) alloy which has a melting point under 100.degree. C.

Abstract: A semiconductor high-energy radiation imaging device having an array of pixel cells includes a semiconductor detector substrate and a semiconductor readout substrate. The semiconductor detector substrate includes an array of pixel detector cells, each of which directly generates charge in response to incident high-energy radiation. The semiconductor readout substrate includes an array of individually addressable pixel circuits, each of which is connected to a corresponding pixel detector cell to form a pixel cell. Each pixel circuit includes charge accumulation circuitry for accumulating charge directly resulting from high-energy radiation incident on a corresponding pixel detector cell, readout circuitry for reading the accumulated charge, and reset circuitry for resetting the charge accumulation circuitry. The charge accumulation circuitry has a charge storage capacity sufficient to store at least 1.