U.S. Philips Corporation

Jacobus G Bakker

Leonard J Esser

Marnix G Collet

In a method of manufacturing a raster transfer image sensor, the charge transport channels and the channel-bounding regions and the vertical anti-blooming channels are formed in a self-registering manner in that the channel-bounding regions are provided via a mask, and the intervening charge transport channels are provided in a maskless doping step. Since this doping is also carried out in the channel-bounding regions, a doping profile favorable for the photosensitivity is obtained in the channel-bounding regions with a maximum concentration at a distance from the surface.

Method of manufacturing a buried-channel charge-coupled image sensor

An image sensor device of the frame transfer type comprises a substrate having a first region (10) of a first n type, a second region (12) of the opposite p-type and charge transfer channels (15) as well as an arrangement of electrodes (1A . . . 1D) of charge transfer. A photosensitive layer (50) is arranged on the surface (19) of the substrate and has window regions (100, 200) in electrical contact with the channels (15) through windows (40) provided in the arrangement of electrodes, for example through electrodes (1B, 1D). Insulating strips (24) and conductive strips (30) serve to prevent the drift from one window region to the other of charges to be transferred and to evacuate the charges of a sign opposite to that of the charges to be transferred.

Image sensor device of the frame transfer type

In a CCD image sensor arrangement, during the transport through the CCD channels the distance between successive signal packets is enlarged and an empty potential well is induced between these packets, which is then transferred as a normal packet together with the signal charges. During the transport, in the said additional well charge is collected which is representative for the smear charge which is trapped during the transport by the corresponding signal packet. When during reading, the smear charge is subtracted from the signal charge, the accurate value of the smear-compensated signals can be determined.

CCD image sensor including smear suppression means

A charge-coupled device comprising two clock electrodes (4,5) on the two opposite sides of the charge transport channel (3) and which extend the entire length of the channel. Charge storage regions (6-9) are located zigzagwise on both sides of the channel, as a result of which during charge transport the charge is transferred from one side to the other. Due to the separation of the electrodes the parasitic capacitance between them is low, achieving low power dissipation. The electrodes are located in grooves at the sides of the channel, leaving the surface of the channel unobstructed. The device can therefore serve as an image sensor of high sensitivity.

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Eindhoven, Netherlands

Jacobus G Bakker