Dual photodiode image pixels with preferential blooming path

摘要

An image sensor with an array of image sensor pixels is provided. Each image sensor pixel may include a set of photodiodes formed in a semiconductor substrate, a color filter structure formed over the set of photodiodes, a microlens formed over the color filter structure, and associated pixel circuitry coupled to the set of photodiodes. The set of photodiodes may include at least two photodiodes linked together via a preferential blooming channel that provides a reduced potential barrier between the two photodiodes. This allows excess charge to spill over from one photodiode to another when more charge is concentrated in a particular photodiode. Configured in this way, the pixel can provide depth sensing capabilities without suffering from reduced pixel capacity.

主权项

1. An image sensor pixel, comprising:
a substrate; a first photodiode that is formed in the substrate and that generates charge in response to incident light; a second photodiode formed in the substrate, wherein the first and second photodiodes are formed laterally with respect to each other along a surface of the substrate; and a preferential blooming channel interposed between the first and second photodiodes in the substrate that reduces a potential barrier between the first and second photodiodes, wherein some of the charge flows directly into the second photodiode via the preferential blooming channel.