CMOS integrated method for fabrication of thermopile pixel on semiconductor substrate with buried insulation regions

摘要

A method for manufacturing an imaging device in a semiconductor substrate is disclosed. The substrate includes a first surface, a second surface substantially opposite the first surface, and a thickness defined by a distance between the first surface and the second surface. A trench is fabricated in the semiconductor substrate first surface. A passivation layer is applied over the substrate first surface and the trench, optionally filling the trench by depositing a conformal layer over the substrate first surface. The conformal layer and the passivation layer are planarized from the substrate first surface, and a membrane is fabricated on the substrate first surface. From the substrate second surface, a cavity is formed in the substrate abutting the membrane and at least a portion of the trench via the unmasked region.

主权项

1. A method for manufacturing an imaging device in a semiconductor wafer comprising a substrate with a first surface, a second surface substantially opposite the first surface, and a thickness defined by a distance between the first surface and the second surface, comprising the steps of:
fabricating a trench in the first surface; applying a passivation layer over the first surface and the trench; planarizing the passivation layer to remove a portion of the passivation layer from the first surface; fabricating a membrane upon the first surface; applying a first mask to the second surface, wherein an unmasked region of the second surface corresponds to a membrane central reion and wherein the first mask defines a cavity profile shape; and from the second surface, forming a cavity in the substrate abutting the membrane and at least a portion of the trench via the unmasked region of the second surface, wherein forming the cavity in the substrate further comprises etching the cavity having a shape substantially according to the cavity profile shape, and extending a portion of the cavity substantially adjacent to the membrane to abut at least a portion of the trench.