Patent ID: 8823126

Claim:
A backside-illuminated image sensor comprising: a semiconductor substrate having a first substrate surface and a second substrate surface, the first substrate surface being opposite to the second substrate surface; one or more light sensing elements in the semiconductor substrate, the light sensing elements being arranged for receiving image light from outside the semiconductor substrate; a cavity formed in the semiconductor substrate, the cavity having a base surface overlying the light sensing elements, and the cavity extending from the first substrate surface to the base surface; and at least one first electrical path formed between the first substrate surface and the base surface; wherein the first electrical path being formed on at least a portion of a sidewall of the cavity and residing on the cavity to facilitate electronic signal communication between the first substrate surface and the base surface; wherein the first substrate surface being an image sensor backside; and wherein the image light being allowed to reach the light sensing elements through the base surface such that a distance traveled by the image light, through the semiconductor substrate, towards the image sensor backside and to the light sensing elements is shorter than it is if the cavity is absent.