Patent attributes
Light sensing devices are monolithically integrates with CMOS devices on Thin-Film Silicon-On-insulator (TF-SOI) or Thin-Film Germanium-On-Insulator (TF-GeOI) substrates. Photo-diode active layers are epitaxially grown on the front-side of the substrate and after full processing of the front-side of the substrate, the substrate material is removed under the buried insulator (buried oxide). Monolithically integrated structures are then fabricated on the back of the buried oxide. The back-side is then bonded to a new substrate that is transparent to the wavelengths of interest. For example, quartz, sapphire, glass, or plastic, are suitable for the visible range. Back-side illumination of the sensor matrix is thereby allowed, with light traveling through the structures fabricated on the back of the substrate, opposite to the side on which CMOS is made.
