Method of making silicon-insulator-polysilicon infrared imaging device

Abstract

A layer of epitaxial silicon is grown on an epi-silicon growth substrate, a thin silicon dioxide layer is grown on the epitaxial layer, and thick layer of polysilicon is grown on the dioxide layer. The epi-silicon layer is then removed, and the epitaxial layer is masked and doped to produce both a region capable of CCD action and an infrared sensitive region. The doped epitaxial layer is orientially etched through a mask to produce isolated infrared sensitive areas to serve as detectors and an isolated area capable of CCD action. Coupling regions are also doped on the CCD ares. The detectors and the CCD area are each in the shape of a frustum of a right rectangular pyramid, with its base on the silicon dioxide layer. Electrical pads are grown to form CCDs. Electrical leads are grown, some to connect respective CCDs to respective coupling regions, some to serve as drive lines for the CCDs, some as common lines for the detectors, and some as connecting lines between respective detectors and coupling regions. A perforated opaque mask is placed on the opposite side of the polysilicon from the silicon dioxide layer, with the perforations aligned with respective ends of the detectors.