Structure for implementation of back-illuminated CMOS or CCD imagers
AssigneeCalifornia Institute of Technology
InventorsBedabrata Pain, Thomas Cunningham
Life of this patent
Estimating the term…
Abstract
A structure for implementation of back-illuminated CMOS or CCD imagers. An epitaxial silicon layer is connected with a passivation layer, acting as a junction anode. The epitaxial silicon layer converts light passing through the passivation layer and collected by the imaging structure to photoelectrons. A semiconductor well is also provided, located opposite the passivation layer with respect to the epitaxial silicon layer, acting as a junction cathode. Prior to detection, light does not pass through a dielectric separating interconnection metal layers.
Claims29
A backside illuminated imaging structure comprising:
- a passivation layer;
- a silicon layer connected with the passivation layer, acting as a junction anode, the silicon layer adapted to convert light passing through the passivation layer and collected by the imaging structure to photoelectrons;
- a semiconductor well of a first conductivity type, located opposite the passivation layer with respect to the silicon layer, acting as a junction cathode;
- and
- a reflector layer adapted to receive photons passing through the silicon layer and to reflect the photons back to the silicon layer.
A backside illuminated imaging structure, comprising:
- a base layer;
- a silicon device layer connected with the base layer, wherein light is absorbed in the silicon device layer, through a surface of the silicon device layer not connected with the base layer, without passing through the base layer;
- and
- metal pads, facing an illumination side of the structure and connected with the surface of the silicon device layer not connected with the base layer.
A wafer comprising:
- a passivation layer;
- a silicon layer connected with the passivation layer, the silicon layer comprising a photodiode array, adapted to convert light passing through the passivation layer;
- inter-layer dielectric connected with the silicon layer;
- and
- a base connected with the inter-layer dielectric.
A light detection method comprising:
- providing a junction comprising a junction cathode and a silicon layer acting as a junction anode;
- connecting a passivation layer to the silicon layer on a side of the silicon layer opposite the junction cathode;
- inputting light to the silicon layer through the passivation layer, whereby light is detected in the silicon layer;
- and
- providing a reflector to receive photons passing through the silicon layer and to reflect the photons back to the silicon layer.
An illumination method comprising:
- providing a base layer;
- providing a silicon device layer having a first surface not connected with the base layer and a second surface connected with the base layer;
- connecting metal pads with the first surface of the silicon device layer;
- impinging light through the first surface of the silicon device layer;
- and
- absorbing light in the silicon device layer.
Dependencies are inferred from the claim text.