Patent ID: 9735196
Date: 2017-08-15
CPC Classifications: H01L

Claim:
1. A method of fabricating a pixel array for an image sensor, the method comprising: forming a transistor network in a semiconductor substrate layer along a frontside of the semiconductor substrate; forming a contact element for every pixel in the pixel array, wherein each contact element is electrically coupled to a transistor within the transistor network; forming an interconnect layer upon the frontside of the semiconductor substrate layer, wherein the interconnect layer is for facilitating control of the transistor network, and wherein the interconnect layer includes a dielectric that covers the contact element; forming a cavity in the interconnect layer, wherein the cavity is formed over the contact element; forming a conductive layer along cavity walls of the cavity; forming a dielectric layer over the conductive layer within the cavity; depositing a photosensitive semiconductor material within the cavity and over the dielectric layer; forming an electrode cavity over the contact element, wherein the electrode cavity extends to the contact element; filling, at least partially, the electrode cavity with a conductive material to form an electrode, wherein the electrode, the conductive layer, and the photosensitive semiconductor material form a photosensitive capacitor configured to vary an image signal received by the contact element in response to image light.